We were interested in the paper by Mutoh et al.[1], showing the development of epithelial intestinal metaplasia and mesenchymal proliferation in human stomach resections and Cdx2 transgenic mice. The authors used alpha-smooth muscle actin (alpha-SMA) staining to mark peri-glandular fibroblasts and failed to show any alpha-SMA positive cells surrounding the en-face glands of normal mouse and human stomach m...
We were interested in the paper by Mutoh et al.[1], showing the development of epithelial intestinal metaplasia and mesenchymal proliferation in human stomach resections and Cdx2 transgenic mice. The authors used alpha-smooth muscle actin (alpha-SMA) staining to mark peri-glandular fibroblasts and failed to show any alpha-SMA positive cells surrounding the en-face glands of normal mouse and human stomach mucosa. In metaplastic tissue however, the peri-glandular fibroblast sheath was easily discernible, and the authors concluded that the fibroblast sheath was generated from the
intestinal submucosa, possibly through expression of Cdx2.
Mesenchymal cells such as intestinal sub-epithelial myofibroblasts (ISEMF) are widely distributed. They are important coordinating cells that possess significant influence on their environment by virtue of their receptor profile and the signals they produce. Characteristically ISEMF’s form a protective fenestrated sheath around the stem cell compartment, creating the stem cell niche - the optimal microenvironment for stem cells to give rise to differentiated progeny.[2] The stem cell niche is situated in the
isthmus/neck region of the gastric gland. ISEMF’s regulate stem cell behaviour via paracrine secretion of growth factors and cytokines, and perform vital functions in
the growth, differentiation and development of the embryological stomach.
They
participate in mucosal wound healing and the response to inflammatory
stimuli in the adult gastro-intestinal tract.[3] As these are vital
homeostatic
roles it seems unlikely that the peri-glandular fibroblast sheath is only
generated in abnormal, metaplastic tissue.
We immunostained for ISEMF’s in paraffin embedded normal mouse and human stomach specimens. To identify
ISEMF’s we stained for alpha-SMA in 3 different mouse gastric specimens
and
alpha-
SMA and vimentin in 6 different sets of human gastric biopsies. Sections
for
vimentin
staining underwent 10 minutes microwave treatment in citrate buffer for
antigen retrieval. Immunostaining was completed using the same antibodies
and methods described in detail by Direkze et al.[5] Antibody binding was
detected by 1,3-diaminobenzidine (DAB; Sigma). ISEMF’s were identified on
the basis of their morphology and positive immunoreactivity for alpha-SMA
in
mouse tissue, and alpha-SMA and vimentin in human tissue. They were
clearly and consistently seen surrounding the stomach glands in normal
mouse and human stomach sections, both in the en-face and cross-sectional
plane (see figure 1). There was little variation in staining intensity
from
sample to sample in the 3 mouse and 6 human subjects studied.
Figure 1. The normal stomach periglandular fibroblast sheath (PGFS).
A: Human alpha-SMA control.
B: alpha-SMA immunostaining.
C: Human vimentin control. Normal human gastric glands counterstained with haematoxylin. (40x magnification).
D: Vimentin immunostaining. Normal human gastric glands with surrounding PGFS (brown stain) embracing the epithelial cells of the gastric glands. (40x magnification).
E: Mouse alpha-SMA control. Normal mouse gastric glands counterstained with haematoxylin (40x magnification).
F, G: alpha-SMA immunostaining. Normal mouse gastric glands in en-face
(F) and cross sectional (G) orientation showing the close association of the PGFS (brown stain) surrounding and enveloping the normal stomach glands. (60x magnification).
ISEMF’s are involved in the response to damage or disease in the
stomach.
After epithelial injury, ISEMF contraction limits the exposed area of the
wound
whilst secreted growth factors such as transforming growth factors alpha
and
beta (TGF-alpha, TGF-beta) epidermal growth factor (EGF) and fibroblast
growth factor (FGF), promote epithelial cell migration and proliferation.[3] In
intestinal type gastric cancer myofibroblasts appear not only at the edge
of
the tumour, contributing to a desmoplastic reaction, but also within the
tumour stroma.[4] The presence of increased inter-tubular reticulin, the
histological hallmark of increased extra-cellular matrix deposition, is
regarded among the first signs of chronic atrophic gastritis, and likely
to be
caused by elevated numbers or activity of the ISEMFs. The source of these
cells is very interesting:- it is more likely that these cells are
recruited from
circulating precursor cells than being generated by metaplastic mucosa.
Direkze et al have shown a large contribution of bone marrow donor-derived
myofibroblasts, making up to 64% of the peri-glandular fibroblast sheath
in
mouse stomach after total body irradiation and bone marrow transplant[5],
and Nakayama et al hypothesise that engraftment is responsible for
myofibroblast presence in tumours.[4] The mechanisms initiating this
engraftment unclear, however it may relate to the release of growth
factors
such as TGF-beta[6] released from inflammatory cells and the existing
peri-
glandular fibroblast sheath in response to gastritis induced damage.
We conclude that the peri-glandular myofibroblast sheath in normal
stomach
is very much a reality and likely to be pivotal in modulating epithelial
cell
behaviour.
No competing interests declared.
Grant Support – Medical Research Council Clinical Research Fellowship.
References
1. Mutoh H, Sakurai S, Satoh K, Osawa H, Tomiyama T, Kita H, et al.
Pericryptal fibroblast sheath in intestinal metaplasia and gastric
carcinoma.
Gut 2005;54(1):33-9.
2. Spradling A, Drummond-Barbosa D, Kai T. Stem cells find their niche.
Nature 2001;414(6859):98-104.
3. Powell DW, Mifflin RC, Valentich JD, Crowe SE, Saada JI, West AB.
Myofibroblasts. I. Paracrine cells important in health and disease. Am J
Physiol
1999;277(1 Pt 1):C1-9.
4. Nakayama H, Enzan H, Miyazaki E, Toi M. Alpha smooth muscle actin
positive stromal cells in gastric carcinoma. J Clin Pathol 2002;55(10):741
-4.
5. Direkze NC, Forbes SJ, Brittan M, Hunt T, Jeffery R, Preston SL, et al.
Multiple organ engraftment by bone-marrow-derived myofibroblasts and
fibroblasts in bone-marrow-transplanted mice. Stem Cells 2003;21(5):514
-20.
Surgery (resection or transplantation) is the first treatment choice for early HCC, but unfortunately it is feasible only in a minority of patients.[1] Local percutaneous ablation has therefore dramatically increase in importance and radio-frequency thermal ablation (RFTA) has showed in recent reports global or disease-free survivals better than those reported for percutaneous ethanol injection (PEI).[2] The...
Surgery (resection or transplantation) is the first treatment choice for early HCC, but unfortunately it is feasible only in a minority of patients.[1] Local percutaneous ablation has therefore dramatically increase in importance and radio-frequency thermal ablation (RFTA) has showed in recent reports global or disease-free survivals better than those reported for percutaneous ethanol injection (PEI).[2] The recent reports in GUT apparently also supports a superiority, albeit small, of RFTA on PEI or acetic acid injection in a randomised prospective controlled study.[3] Nevertheless, not all agree on RFTA efficacy [4], major complications are described [5], with an incidence rate of major complications significantly higher than in the ethanol or acetic acid injection procedures.[3]
We are carrying out a multicentre prospective study on efficiency and complications of RFTA in HCC in North-East Italy with 399 HCC patients having being recruited and a centralized radiological assessment.
Overall, 133 patients (33%) experienced some complication, 5 of which were severe (1.3%), with 2 casualties (0.5%) one being procedure-related, in relation to an intestinal perforation and the second being a cerebral infarction.
Last, but definitely not least, some author has reported rapid intra-hepatic progression after RFTA [6,7], a fact that in our minds, deserve special attention. We therefore would like to document 9 cases of rapid, unexpected spread of HCC after RFTA observed in our multicentric study, The nine cases (2.3% of the series) are hereby reported: 8 males and 1 female, etiology was HCV in 6 and HBV in 3, 6 had complete response at the CT scanning performed after 1 month, 2 90% and 1 70%, 1 nodule was treated in 7 cases and 2 in 2, the size ranging from 1,8 to 4,6 cm (all patients had CT scanning prior to the procedure). Grading was G1 in all instances and AFP values were normal in 4 cases.
New lesions were:
1. satellites + controlateral HCC at 1 month;
2. three x 3 cm nodes at 3 months;
3. multifocality at 4 months;
4. 3 nodes at 1 month;
5. multiple, up to 6 cm at 3 months;
6. multiple at 1 month;
7. thirteen nodes at 5 months;
8. 1 8 cm node at 6 months
9. multifocality at 5 months.
This rapid unexplained and biologically unclear progression of HCC following RFTA treatment is most unusual considering the natural history of the disease. It could be prompted by increased intra-tumoural pressure with intravascular spread, seeding due to artero-venus fistula or to the expandable hooks needles. Suggested risk factors have been high AFP levels, location near major portal branches and poor tumour differentiation.[5,6] Also, increased liver concentrations of growth factors (TGF-ALFA and BETA-FGF) have been documented in rat liver after thermal coagulation, with increased HCC growth.[8]
Our data show that side effects are relatively frequent following RFTA, with a mortality rate lower than 1% but still present. Our series additionally confirm that “explosive HCC spread” may occur after RFTA, in our experience with no correlation with AFP, differentiation and location of the tumour, and frequently even after total ablation.
Why do these patients develop this severe, (dramatic if observed in patients in the waiting list for OLTx!)[9] and unexpected complication, what is its prevalence, whether we can identify patients at risk is open to a discussion that we think should be exhaustive before abandoning PEI as obsolete and considering RFTA as the treatment of early disease not eligible for surgery. Let’s wait for the end of the honey-moon effect of this new procedure!
References
1. Christians K K, Pitt H A, Rilling WS , Franco J, Quiroz FA, Adams MB, Wallace JR, Quebbeman EJ. Hepatocellular carcinoma: Multi-modality management. Surgery 2001; 130 (4): 554-560
3. Lin SM, Lin CJ, Lin CC, HSU CW, Chen YC. Randomised controlled trial comparing percutaneous radiofrequency thermal ablation, percutaneous ethanol injection, and percutaneous acetic acid injection to treat hepatocellular carcinoma of 3 cm or less. Gut 2005; 54: 1151-6.
4. Mazzaferro V, Battiston C, Perrone S, Pulvirenti A, Regalia E, Romito R, Sarli D, Schiavo M, Garbagnati F, Marchiano A, Spreafico C, Camerini T, Mariani L, Miceli R, Andreola S.. Radiofrequency ablation of small hepatocellular carcinoma in cirrhotic patients awaiting liver transplantation: a prospective study. Ann Surg. 2004;240:900-9.
5. De Baère T, Risse O, Kuoch V, Domain C, Sengel C, Smayra T, Gamal El Din M, Letoublon C, Elias D. Adverse Event During Radiofrequency Treatment of 582 Hepatic Tumours. AJR 2003; 181: 695-700
6. Ruzzante A, De Manzoni G, Molfetta M, Pachera S, Genco B, Donataccio M, Guglielmi A. Rapid progression of hepatocellular carcinoma after Radiofrequency Ablation. World J Gastroenterol 2004; 10(8) 1137-1140
7. Nicoli N, Casaril A, Hilal MA, Mangiante G, Marchiori L, Ciola M, Invernizzi L, Campagnaro T, Mansueto G. A case of rapid intrahepatic dissemination of hepatocellular carcinoma after radiofrequency thermal ablation. Am J Surg. 2004 Aug;188(2):165-7.
8. Ohno T, Kawano K, Yokoyama H, Tahara K, Sasaki A, Aramaky M, Kitano S. Microwave coagulation therapy accelerates growth of cancer in rat liver. Journal of Hepatology 2002; 36: 774-779
9. Cillo U, Vitale A, Bassanello M, Boccagni P, Brolese A, Zanus G, Burra P, Fagiuoli S, Farinati F, Rugge M, D'Amico DF. Liver transplantation for the treatment of moderately or well-differentiated hepatocellular carcinoma. Ann Surg. 2004 Feb;239(2):150-9.
I would like to respond to the commentary written by Dr. R. Balfour
Sartor entitled, "Does Mycobacterium avium subspecies paratuberculosis
cause Crohn's disease?” The answer to this rhetorical question is yes,
and I would like to explain why we now have sufficient information to
conclude that Mycobacterium avium paratuberculosis (Map) is a major cause
of Crohn's disease.
I would like to respond to the commentary written by Dr. R. Balfour
Sartor entitled, "Does Mycobacterium avium subspecies paratuberculosis
cause Crohn's disease?” The answer to this rhetorical question is yes,
and I would like to explain why we now have sufficient information to
conclude that Mycobacterium avium paratuberculosis (Map) is a major cause
of Crohn's disease.
First, I will address the cons Dr. Sartor includes in table 1 of his
commentary which lists arguments for and against a Map causation of
Crohn's disease.
1) Differences in clinical and pathological responses in
Johne's and Crohn's diseases. This argument is not logical. Map causes a
different clinical and pathologic state in sheep and cattle.[1] A related
mycobacterium, mycobacterium tuberculosis, causes disease with a differing
clinical and pathologic presentation in mice, rabbits, monkeys and
humans.[2] Yet this variety of interspecies disease presentations is not an
argument against a common pathogen for these diseases.
2) Lack of
epidemiological support of transmissible infection. Studies have shown
that the incidence and prevalence of Crohn's disease has steadily
increased in the past 50 years.[3-5] This increase mirrors the corresponding
increasing prevalence of Map induced Johne's disease in dairy cattle. Most
observers accept that this alarming increase is not likely genetic but
rather environmental in origin.
3) No evidence of transmission to humans
in contact with animals infected with Map. Map is not efficiently
transmitted by proximity to infected animals. It is most efficiently
transmitted by consumption of contaminated food or water.
4) Genotypes of
Crohn’s disease and bovine Map isolates not similar. The evidence in this
area is conflicting. However, at least two studies show that the isolates
are similar.[6-7]
5) Variability in detection of Map by PCR and serological
testing. There has certainly been variability in the reported rates of
detection of Map in Crohn's disease. These differences are largely due to
significant methodological differences among studies. For example, some
negative studies have used formalin fixed paraffin embedded tissue.[8-9]
There is evidence in the literature that formalin fixation causes
fragmentation of DNA with resultant poor amplification of PCR primers.10
Ryan and others showed that when studying the same formalin fixed paraffin
embedded samples of tissue, use of PCR systems which amplified small
sequences of the IS900 gene detected Map much more reliably than PCR
systems which amplified large sequences of this gene.[11]
6) No evidence
of mycobacterial cell wall by histochemical staining. I agree with this
point, but it is not evidence against a Map causation of the disease.
Using in situ hybridization, Sechi and others demonstrated the DNA of the
Map organism in human tissue but could not demonstrate a cell wall. The
organism most likely exists in a cell wall deficient or spheroplast form
in human tissue.[12]
7) No worsening of Crohn's disease with
immunosuppressive agents or HIV infection. This argument does not hold
for a related mycobacterial infection and therefore cannot be used as
evidence against a Map causation in Crohn’s disease. Leprosy is
universally understood to be caused by another slow growing mycobacterium
and it does not worsen with steroid therapy. In fact, steroids are used
therapeutically in some cases of leprosy.[13-14]
8) No documented cell
mediated responses to Map in patients with Crohn's disease. The studies
which have been performed in this area could not rule out the possibility
of anergy.[15]
9) No therapeutic response to traditional
antimycobacterial antibiotics. This argument is nonsensical. Most of the
studies reported to date have used antibiotics which are not effective
against Map in vitro.[16-17] Why then would we expect the antibiotics which
were used in these studies to be effective in vivo?
Many of us are exposed to low levels of viable Mycobacterium avium
paratuberculosis on a regular basis. Map survives pasteurization [18] and
three studies have shown that it may be cultured from retail supplies of
pasteurized milk.[19-21] Thus Map joins a long list of pathogens which may
be transmitted through milk and the diseases which have been transmitted
by milk include tuberculosis, bovine tuberculosis, salmonellosis,
brucellosis, Q fever, listeriosis, yersiniosis and toxigenic e.coli.
The most challenging evidence for skeptics that this bacterium is
pathogenic is the fact that many patients with Crohn's disease are
bacteremic with Map.[22] In medicine we are taught that persistent
septicemia is a pathologic state that causes disease. The leaky bowel
theory has been proposed as the explanation for the growth of Map in the
blood of Crohn's disease. If this explanation is tenable, why are e.coli
and candida which are more prevalent in the fecal stream not cultured from
the blood of these patients? These patients can clear e.coli and candida
but they cannot clear Map, i.e., Map is pathogenic in these patients.
Colonization of diseased bowel is also an unlikely explanation considering
the fact that there are patients who are bacteremic with Map who have very
little gross endoscopic evidence of Crohn’s disease (personal
communication from Dr. Saleh Naser). The bacteria were cultured from the
Buffy coat in Naser's study and Map thus joins other pathogenic
mycobacteria which are intracellular within macrophages. The others
include mycobacterium tuberculosis and mycobacterium leprae.[23] A blood-
borne mycobacterial infection nicely explains the extraintestinal
manifestations of this disease[24] and the presence of granulomas (which are
not satisfactorily explained by other theories).[25] The skeptics are no
longer refuting the evidence that Map is in the tissue and/or blood of
Crohn's patients. However, now they posit some unlikely role for Map
rather than understanding that it is a pathogen in a susceptible host.
I agree with Dr. Sartor that clearance of Map infection with
resolution of the patient's Crohn's disease would be excellent evidence
that Map is causative of the disease. However, to obtain this evidence
under current conditions will be a nearly impossible task. Unless
patients carefully avoid dairy products, drink only Map free water and
consume Map free beef, they are at continual risk of contracting the
infection. Until Map is removed from the food chain and water supplies,
attempts to clear the bacterium with antibiotics will be difficult and in
many cases futile. Future antibiotic trials should include the recently
developed diarylquinoline compound which has been found to have activity
against most mycobacteria.[26]
I agree with Dr. Sartor that additional Map related studies are
necessary to further elucidate the role of this bacterium in Crohn’s
disease. Such studies should include a Map feeding and inoculation study
in primates to see whether we can induce Crohn's disease in primates who
are infected with the organism. Additional studies could include in vitro
studies of the differences in various subjects’ macrophages or neutrophils
to kill Map.
I disagree with Dr. Sartor that additional studies will resolve this
classic scientific revolution. The only study which could resolve this
controversy would be a Map feeding study in a human population. Of
course, this study could never be performed.
Because this controversy can not be resolved in short order, we must
use the available information to carry out proper public health measures.
We need government mandated programs for the testing and culling of Map
infected animals from the beef and dairy cattle herds, improved methods of
pasteurization, and we should eliminate Map from drinking water (Map is
resistant to chlorination). This task is daunting but a similar task has
been carried out effectively in the control and elimination of
tuberculosis from dairy herds. The cost will be high but will be offset
by the economic benefits for the agricultural industry which annually
faces large losses due to Johne's disease. In the United States alone,
losses to the cattle industry have been estimated at $1.5 billion per
year.[27] More importantly, we will save potential future Map infected
Crohn's patients from contracting what we now know is a preventable
disease.
References
1. Chiodini, R.J., Van Kruiningen, H.J., and Merkal, R.S. Ruminant
paratuberculosis (Johne’s disease): the current status and future
prospects. Cornell Vet. 1984; 74: 218-62.
2. Capuano, S.V., Croix, D.A., Pawar, S., et al. Experimental
Mycobacterium tuberculosis infection of cynomolgus macaques closely
resembles the various manifestations of human m. tuberculosis infection.
Infect Immun 2003; 71: 5831-44.
3. Loftus, E.V., Silverstein, M.D., Sandborn, W.J., et al. Crohn’s
disease in Olmsted County, Minnesota, 1940-1993: incidence, prevalence and
survival. Gastroenterology 1998; 114: 1161—8.
4. Tsironi, E., Feakins, R.M., Roberts, C.S.J., et al. Incidence of
inflammatory bowel disease is rising and abdominal tuberculosis is falling
in Bangladeshis in East London, United Kingdom. American Journal of
Gastroenterology 2004; 99: 1749-55.
5. Desai, H.G. and Gupte, P.A. Increasing incidence of Crohn’s
disease in India: is it related to improved sanitation? Indian Journal of
Gastroenterology 2005;24: 23-4.
6. Overduin, P., Schouls, L., Roholl, P. et al. Use of multilocus
variable-number tandem-repeat analysis for typing mycobacterium avium
subsp. Paratuberculosis. J Clin Microbiol 2004; 42: 5022-28.
7. Ghadiali, A.H., Strother, M., Naser S.A., et al. Mycobacterium
avium subsp. Paratuberculosis strains isolated from Crohn’s disease
patients and animal species exhibit similar polymorphic locus patterns. J
Clinical Microbiol 2004; 42: 5345-5348.
8. Fujita, H., Yoshinobu, E., Ishige, I., et al. Quantitative
analysis of bacterial DNA from mycobacteria spp., bacteroides vulgatus,
and escheria coli in tissue samples from patients with inflammatory bowel
disease. J Gastroenterol 2002; 37: 509-16.
9. Baksh, F.K., Finkelstein, S.D., Ariyanayagam-Baksh, S.M., et al.
Mod Pathol 2004; 17, 1289-94.
10. Goelz,S.E., Hamilton S.R. and Vogelstein, B. Purification of DNA
from a formalin fixed and paraffin embedded human tissue. Biochem Biophys
Res Commun 1985; 130: 118-26.
11. Ryan, P., Bennett, M.W., Aarons, S., et al. PCR detection of
mycobacterium paratuberculosis in Crohn’s disease granulomas isolated by
laser capture microdissection. Gut 2002; 51: 665-70.
12. Sechi, L.A., Manuela, M., Francesco, T. et al. Identification of
mycobacterium avium subsp. Paratuberculosis in biopsy specimens from
patients with Crohn’s disease identified by in situ hybridization. J Clin
Microbiol 2001; 39: 4514-17.
13. Marlowe, S.N., Hawksworth, R.A., Butlin, C.R., et al. Clinical
outcomes in a randomized controlled study comparing azathioprine and
prednisolone versus prednisolone alone in the treatment of severe leprosy
type 1 reactions in Nepal. Trans R Soc Trop Med Hyg 2004; 98: 602-9.
14. Richardus, J.H., Withigton, S.G., Anderson, A.M. et al. Adverse
events of standardized regimens of corticosteroids for prophylaxis and
treatment of nerve function impairment in leprosy: results from the
‘TRIPOD’ trials. Leprosy Review 2003; 74: 319-27.
15. Ibbotson, J.P., Lowes, J.R., Chahal, H. et al. Mucosal cell-
mediated immunity to mycobacterial, enterobacterial and other microbial
antigens in inflammatory bowel disease. Clin Exp Immunol 1992; 87: 224-
30.
16. Hermon-Taylor, J. The causation of Crohn’s disease and treatment
with antimicrobial drugs. It J. Gastroenterol Hepatol 1998; 30: 607-10.
17. Rastogi, Nalin, Goh, K.S. and Labrousse, V. Activity of
clarithromycin compared with those of other drugs against mycobacterium
paratuberculosis and further enhancement of its extracellular and
intracellular activities by ethambutol. Antimicrobl Agents Chemother
1992; 36: 2843-46.
18. Grant, I.R., Ball, H.J. and Rowe, M.T. Effect of higher
pasteurization temperatures, and longer holding times at 72 C, on the
inactivation of mycobacterium paratuberculosis in milk. Lett Applied
Microbiol 1999; 28: 461-65.
19. Grant, I.R., Ball, H.J. and Rowe, M.T. Incidence of mycobacterium
paratuberculosis in bulk raw and commercially pasteurized cow’s milk from
approved dairy processing establishments in the United Kingdom. Appl
Environ Microbiol 2002; 68: 2428-35.
20. Ellingson, J.L.E., Anderson, J.L., Koziczkowski, J.J., et al.
Detection of viable mycobacterium avium subsp. Paratuberculosis in retail
pasteurized whole milk by two culture methods and PCR. J Food Prot 2005;
68: 966-72.
21. Ayele, W.Y., Svastova, P., Roubal, P. et al. Mycobacterium avium
subspecies paratuberculosis cultured from locally and commercially
pasteurized cow’s milk in the Czech Republic. Appl Environ Microbiol 2005;
71: 1210-14.
22. Naser S.A., Ghobrial, G., Romero, C., et al. Culture of
mycobacterium avium subspecies paratuberculosis from the blood of patients
with Crohn’s disease. Lancet 2004; 364: 1039-44.
23. Harrison’s Principles of Internal Medicine, 15th Edition, McGraw-
Hill 2001; 1024 and1035.
24. Greenstein, A.J. et al. The extraintestinal manifestations of
Crohn’s disease and ulcerative colitis: a study of 700 patients. Medicine
1976; 55:401.
26. Andries, K., Verhasselt, P., Guillemont, J., et al. A
diarylquinoline drug active on the ATP synthase of mycobacterium
tuberculosis. Science 2005; 307: 223-7.
We read with great interest the paper by Israeli et al. assessing the
presence of anti-Saccharomyces cerevisiae antibodies (ASCA) and
perinuclear antineutrophil cytoplasmic antibodies (pANCA) before the
occurrence of overt clinical manifestations in patients with Crohn’s
disease (CD) and ulcerative colitis (UC).[1] They found that ASCA were
present in 31% CD patients before clinical diagnosis (but no...
We read with great interest the paper by Israeli et al. assessing the
presence of anti-Saccharomyces cerevisiae antibodies (ASCA) and
perinuclear antineutrophil cytoplasmic antibodies (pANCA) before the
occurrence of overt clinical manifestations in patients with Crohn’s
disease (CD) and ulcerative colitis (UC).[1] They found that ASCA were
present in 31% CD patients before clinical diagnosis (but not in UC
patients and controls), and that pANCA were detectable in 2 (25%) of 8 UC
patients before clinical manifestations, but not in 24 matched controls.
This observation led the Authors to conclude that ASCA and pANCA may
predict the development of inflammatory bowel disease long before its
clinical onset.
We have recently published our experience on the prevalence and behaviour
of ASCA and pANCA in adult and paediatric coeliac disease patients.[2] Sixty-two (59%) of 105 coeliac patients had IgA and/or IgG ASCA (Quanta
Lite ASCA IgG and IgA assay, Inova Diagnostics, San Diego, CA, USA) at
diagnosis, while only one patient (0.9%) had pANCA. No significant
correlation was found between ASCA positivity and severity of small
intestinal mucosal damage. Moreover, after gluten free diet (mean 14.4
months 2.7) 93% of the revaluated coeliac patients lost IgA ASCA, whereas
83% maintained the IgG ASCA reactivity.
Interestingly, 7 coeliac patients (6 woman, median age 26, range 18-33) of
the 62 with IgA and/or IgG ASCA were diagnosed before developing any
clinical symptom, since they were screened as first degree relatives of
coeliac patients. All of them had anti-tissue transglutaminase antibodies
(tTG), anti-endomysial antibodies (EmA), the HLA DQ2/DQ8 haplotype, and a
histological picture on small intestinal biopsy showing an increased
number of intraepithelial lymphocytes in 5, and mild villous flattening in
2 (grade 1 and grade 3a respectively, according to Marsh’s classification
modified by Oberhuber).
In this type of patients, known as having respectively a “potential” and
“silent” coeliac disease, the positivity of serological markers (EmA and
tTG) together with typical HLA predisposing genotype (DQ2 or DQ8), allows
to make accidentally a diagnosis of gluten enteropathy also when clinical
manifestation is still lacking.[3,4]
Our observation indicates that in asymptomatic patients ASCA positivity
not only is predictive of CD, but also may be associated to
“potential/silent” coeliac disease. The increased permeability in the
small bowel of coeliac patients seems to be an early event, preceding the
development of a more severe mucosal damage.[5,6]
Similarly to
asymptomatic CD patients, also in asymptomatic coeliac patients the
altered permeability of the small bowel toward yeast antigens could
account for the occurrence of ASCA since the very early stage of the
disease as suggested by our 5 coeliac patients with minimally abnormal
mucosal architecture. The “altered permeability” hypothesis should be
investigated further to explain the frequent detection of ASCA also in
autoimmune disorders such as primary biliary cirrhosis and primary
sclerosing cholangitis.[7]
References
1. Israeli E, Grotto I, Gilburd B, et al. Anti-Saccharomyces
cerevisiae and neutrophil cytoplasmic antibodies as predictors of
inflammatory bowel disease. Gut 2005;54:1232-1236.
2. Granito A, Zauli D, Muratori P, et al. Anti-Saccharomyces cerevisiae
and neutrophil cytoplasmic antibodies in coeliac disease before and after
gluten free diet. Aliment Pharmacol Ther 2005;21:881-887.
3. Fasano A, Catassi C. Current approaches to diagnosis and treatment of
coeliac disease: an evolving spectrum. Gastroenerology 2001;120:636-651.
4. Vasquez H, Cabanne A, Sugai E, et al. Serological markers identify
histologically latent coeliac disease among first-degree relatives. Eur J
Gastroenterol Hepatol 1996;8:15-21.
5. van Elburg RM, Uil JJ, Mulder CJ, et al. Intestinal permeability in
patients with coeliac disease and relatives of patients with coeliac
disease. Gut 1993;34:354-357.
6. Clemente MG, De Virgiliis S, Kang JS, et al. Early effects of gliadin
on enterocyte intracellular signalling involved in intestinal barrier
function. Gut 2003;52:218-223.
7. Muratori P, Muratori L, Guidi M, et al. Anti-Saccharomyces cerevisiae
antibodies (ASCA) and autoimmune liver diseases. Clin Exp Immunol
2003;132:473-6.
The recent paper by Thomas and colleagues[1] in the May 2005 issue of
Gut provides further support for an involvement of increased colonic
deoxycholic acid formation and absorption in cholesterol gallstone
pathogenesis. This paper and others in the series[2-4] from Professor R.
Hermon Dowling’s laboratory at Guy’s Hospital, London, was ably placed in
perspective with the accompanying comprehensive co...
The recent paper by Thomas and colleagues[1] in the May 2005 issue of
Gut provides further support for an involvement of increased colonic
deoxycholic acid formation and absorption in cholesterol gallstone
pathogenesis. This paper and others in the series[2-4] from Professor R.
Hermon Dowling’s laboratory at Guy’s Hospital, London, was ably placed in
perspective with the accompanying comprehensive commentary[5] by Dr. Alan F.
Hofmann. He summarized critically the decade-long body of work from the
Dowling group and others on the connection between slow intestinal
propulsion and the biliary tract in octreotide-treated acromegaly. The
salient findings of Dowling’s work may have relevance perhaps to other
subsets of gallstone-prone individuals.
Acromegalic patients treated with octreotide display dysfunctional
gallbladder motility and sluggish intestinal transit rates. Surprisingly,
neither Thomas and colleagues[1] nor Hofmann[5] considered that slower small
in addition to slower large intestinal transit times may have important
pro-lithogenic consequences per se, in that small intestinal hypomotility
may augment biliary cholesterol levels by promoting increased cholesterol
absorption from the small intestine. Octreotide does not appear to have
any appreciable effect on plasma lipoprotein catabolism and “reverse”
cholesterol transport or hepatic cholesterol biosynthesis,[6] hence it is
unlikely to promote biliary cholesterol hypersecretion from lipoprotein
cholesterol or de novo biosynthesis.
We propose therefore, that heightened
cholesterol absorption from the small intestine could provide an important
source of the sterol for biliary cholesterol hypersecretion. Because
octreotide abolishes cholecystokinin (CCK) release from the small
intestine,[7,8] attacks of clinical, presumtively cholelithogenic
cholecystitis and cholangitis, well documented in patients with use of
this long-acting somatostatin analogue, have customarily been attributed
solely to gallbladder hypomotility.[9] However, the loss of post-prandinal
CCK release via octreotide,[9] is likely to have an additional
pathophysiologic effect in humans. Not only is the contractile response of
the gallbladder abolished, but we showed recently that small intestinal
propulsion is also slowed significantly in CCK-1 (previously known as CCK-
A) receptor knockout mice.[10] Hence by inference, a physiological function
of diurnal CCK levels in the healthy mouse and presumably human is to
accelerate small intestinal motility, in addition to contracting the
gallbladder and relaxing Oddi’s sphincter.
Any degree of disruption of the physiologic motors of the small
intestine extends the residence time of cholesterol-rich mixed bile salt
micelles in the intestinal lumen. This allows more time for monomeric
diffusion and cholesterol absorption by small intestinal enterocytes from
the cholesterol-rich mixed micellar reservoir within the chyme. As a
result, any deficit in CCK release will induce significant increases in
fractional cholesterol absorption from the upper small intestine as we
have shown in the CCK-1 receptor knockout mouse compared to wild-type
mice.[10] Not surprisingly, there are reports in the literature that a
dysfunctional CCK-1 receptor may cause cholesterol gallstones in
humans.[11,12] Because the CCK-1 receptor plays such a crucial role in the
physiological regulation of gallbladder and small intestinal motility, it
is likely that in addition to gallbladder hypomotility, gallstone patients
with a dysfunctional CCK-1 receptor also display increased absorption of
dietary cholesterol from the dysmotile small intestine.
In his commentary[5] Dr. Hofmann made the point that in several large
clinical studies,[13-15] investigators failed to find a strong correlation
between biliary deoxycholate levels and cholesterol saturation of bile.
This fact alone should prompt an alternative or additional explanation for
cholesterol gallstones by the occurence of slow transit constipation in
humans. Perhaps the putative increase in cholesterol absorption from the
gut may be the “missing link” in the augmented gallstone risk from
diminished intestinal motility from any cause. As evidenced by human and
animal studies, deoxycholate does not promote cholesterol absorption from
the small intestine as efficiently as does its conjugated cholate
precursor.[16,17] Moreover, from a physical chemical perspective, higher
levels of deoxycholate conjugates in bile may actually
counteract augmented cholesterol absorption for reasons of small
intestinal hypomotility.
The points we make here are not offered to diminish the putative role
of deoxycholic acid in cholesterol gallstone pathogenesis, for which there
is abundant evidence from the work of the Dowling laboratory.[1-4]
Nonetheless, we argue here that increased fractional absorption of
cholesterol from a hypomotile small intestine may result in delivery of
more cholesterol to the liver in chylomicron remnants, and hence may play
a crucial role in hepatic cholesterol hypersecretion and biliary
lithogenicity.[18] Consequently, in the setting of a hypomotile gallbladder,
lithogenic bile will have a greatly prolonged residence time, facilitating
phase separation of cholesterol crystals and their agglomerate into
gallstones.
Two decades ago, Ponz de Leon and colleagues[19] showed that
metaclopramide acceleration of small intestinal transit in humans
significantly decreased intestinal cholesterol absorption, however they
failed to show, in the opposite experiment, that slowing of small
intestinal transit with atropine augmented cholesterol absorption.
Clearly, the small intestinal dysmotility and cholesterol absorption
issues raised here need to be proven in humans but this unique group of
patients affords an easily testable cohort.[10] A salutary result would
afford an intellectually satisfying explanation for the profound
lithogenicity of bile not otherwise accounted for in this group of
patients.
Sincerely yours,
Martin C. Carey, M.D., D.Sc.
Department of Medicine
Brigham & Women’s Hospital
Harvard Medical School
Boston, MA 02115, USA
David Q.-H. Wang, M.D., Ph.D.
Department of Medicine
Beth Israel Deaconess Medical Center
Harvard Medical School
Boston, MA 02215, USA
References
1. Thomas LA, Veysey MJ, Murphy GM, et al. Octreotide induced
prolongation of colonic transit increases faecal anaerobic bacteria, bile
acid metabolising enzymes, and serum deoxycholic acid in patients with
acromegaly. Gut 2005;54:630-5.
2. Hussaini SH, Murphy GM, Kennedy C, et al. The role of bile composition
and physical chemistry in the pathogenesis of octreotide-associated
gallbladder stones. Gastroenterology 1994;107:1503-13.
3. Veysey MJ, Thomas LA, Mallet AI, et al. Prolonged large bowel transit
increases serum deoxycholic acid: a risk factor for octreotide induced
gallstones. Gut 1999;44:675-81.
4. Thomas LA, Veysey MJ, Bathgate T, et al. Mechanism for the transit-
induced increase in colonic deoxycholic acid formation in cholesterol
cholelithiasis. Gastroenterology 2000;119:806-15.
5. Hofmann AF. Increased deoxycholic acid absorption and gall stones in
acromegalic patients treated with octreotide: more evidence for a
connection between slow transit constipation and gall stones. Gut
2005;54:575-8.
6. Olivecrona H, Ericsson S, Angelin B. Growth hormone treatment does not
alter biliary lipid metabolism in healthy adult men. J Clin Endocrinol
Metab 1995;80:1113-7.
7. Lembcke B, Creutzfeldt W, Schleser S, et al. Effect of the somatostatin
analogue sandostatin (SMS 201-995) on gastrointestinal, pancreatic and
biliary function and hormone release in normal men. Digestion 1987;36:108-
24.
8. Milenov K, Rakovska A, Kalfin R. Effects of cholecystokinine on the
gallbladder motility: interaction with somatostatin and vasoactive
intestinal peptide. Acta Physiol Pharmacol Bulg 1995;21:67-76.
9. Fisher RS, Rock E, Levin G, Malmud L. Effects of somatostatin on
gallbladder emptying. Gastroenterology 1987;92:885-90.
10. Wang DQ-H, Schmitz F, Kopin AS, Carey MC. Targeted disruption of the
murine cholecystokinin-1 receptor promotes intestinal cholesterol
absorption and susceptibility to cholesterol cholelithiasis. J Clin Invest
2004;114:521-8.
11. Miller LJ, Holicky EL, Ulrich CD, Wieben ED. Abnormal processing of
the human cholecystokinin receptor gene in association with gallstones and
obesity. Gastroenterology 1995;109:1375-80.
12. Miyasaka K, Takata Y, Funakoshi A. Association of cholecystokinin A
receptor gene polymorphism with cholelithiasis and the molecular
mechanisms of this polymorphism. J Gastroenterol 2002;37(Suppl 14):102-6.
13. Gustafsson U, Sahlin S, Einarsson C. Biliary lipid composition in
patients with cholesterol and pigment gallstones and gallstone-free
subjects: deoxycholic acid does not contribute to formation of cholesterol
gallstones. Eur J Clin Invest 2000;30:1099-106.
14. LaRusso NF, Szczepanik PA, Hofmann AF. Effect of deoxycholic acid
ingestion on bile acid metabolism and biliary lipid secretion in normal
subjects. Gastroenterology 1977;72:132-40.
15. Jüngst D, Muller I, Kullak-Ublick GA, et al. Deoxycholic acid is not
related to lithogenic factors in gallbladder bile. J Lab Clin Med
1999;133:370-7.
16. Sama C, LaRusso NF. Effect of deoxycholic, chenodeoxycholic, and
cholic acids on intestinal absorption of cholesterol in humans. Mayo Clin
Proc 1982;57:44-50.
17. Wang DQ-H, Tazuma S, Cohen DE, Carey MC. Feeding natural hydrophilic
bile acids inhibits intestinal cholesterol absorption: studies in the
gallstone-susceptible mouse. Am J Physiol 2003;285:G494-502.
18. Wang DQ-H, Zhang L, Wang HH. High cholesterol absorption efficiency
and rapid biliary secretion of chylomicron remnant cholesterol enhance
cholelithogenesis in gallstone-susceptible mice. Biochim Biophys Acta
2005;1733:90-9.
19. Ponz de Leon M, Iori R, Barbolini G, et al. Influence of small-bowel
transit time on dietary cholesterol absorption in human beings. N Engl J
Med 1982;307:102-3.
Correspondence to: Dr. Martin C. Carey
Brigham & Women’s Hospital
Department of Medicine
Gastroenterology Division, Thorn 1430
Boston, MA 02115, USA
Email: mccarey@rics.bwh.harvard.edu
We read with great interest the meta-analysis by Kandiel et al., (Gut
2005; 54: 1121-1125) the purpose of which was to provide a more precise
estimate of the relative risk of lymphoma among inflammatory bowel disease
(IBD) patients treated with azathioprine or 6-mercaptopurine (6-MP).
Based on the six studies included in their meta-analysis, Kandiel et al.,
determined that the risk of lymphoma among...
We read with great interest the meta-analysis by Kandiel et al., (Gut
2005; 54: 1121-1125) the purpose of which was to provide a more precise
estimate of the relative risk of lymphoma among inflammatory bowel disease
(IBD) patients treated with azathioprine or 6-mercaptopurine (6-MP).
Based on the six studies included in their meta-analysis, Kandiel et al.,
determined that the risk of lymphoma among IBD patients who did not
receive immunomodulators is similar to that of the general population
while the lymphoma risk among IBD patients treated with azathioprine/6-MP
was increased approximately four-fold. It is reassuring that the largest
study included in their meta-analysis, which utilised the UK General
Practice Research Database, failed to show a significantly higher risk of
lymphoma among 16,996 IBD patients regardless of whether patients received
azathioprine/6-MP or not.[1] While several population-based and hospital-
based studies have similarly failed to identify a significantly increased
risk of lymphoma in IBD patients who never received immunomodulators,[2]
it is worth noting that two studies have recently reported an increased
lymphoma risk in IBD patients independent of immunomodulator or biological
therapy.
In 2000, an Italian study of 920 IBD patients, reported a nine-
fold increased risk of Hodgkin’s disease among ulcerative colitis
patients, but not among Crohn’s disease patients.[3] More recently, a
large population-based study from Manitoba, Canada, compared 2857 Crohn’s
disease and 2672 ulcerative colitis patients with age, sex and geographic
location-matched controls and reported an almost four-fold increased risk
of lymphoma among males with Crohn’s disease.[4] This suggests that
disease activity and underlying disease-related immune alterations in IBD
may be associated with a small but significant inherent risk of lymphoma.
In support of this association, a Swedish nested case-control study
reported a strong linear association between disease activity in
rheumatoid arthritis (RA) patients and risk of developing lymphoma which
was not only independent of immunomodulator treatment but of a larger
magnitude than the risks linked to immunomodulator therapy reported in
other RA studies.[5] Compared with RA patients with low inflammatory
activity, patients with high and medium inflammatory activity had odds
ratios of 25.8 and 5.4, respectively, for the development of lymphoma.
This led the authors to recommend "the use of potent immunosuppressive
treatment to reduce disease activity, not only to prevent joint damage but
possibly also to protect against lymphomas."
The meta-analysis by Kandiel et al., reported a pooled relative risk
of 4.18 for lymphoma risk among IBD patients treated with azathioprine/6-
MP. As the authors acknowledge, previously published population-based and
hospital-based cohort studies have presented conflicting results regarding
the risk of lymphoma in IBD patients treated with azathioprine and 6-MP.
Reasons for these conflicting results may be related to inadequate sample
size given the rarity of the outcome of interest as well as a wide range
of estimates for the expected number of lymphomas. Discrepancies in the
duration and dosage of treatment as well as limited length of follow-up
have also contributed to the conflicting results. Furthermore, it is well
known that cohort studies such as ours [6] and that reported by Kinlen [7]
which compare hospitalised or referral exposed cohorts to unexposed
population-based cohorts can result in artificially inflated relative
risks since hospitalised or referral centre patients are more likely to
have severe disease and multiple illnesses which are not necessarily
related (i.e. Berkson’s bias).[8] Ultimately, since IBD patients receiving
immunomodulators by definition have more severe or refractory disease, it
may be difficult to separate whether an increase in lymphoma risk is
related to immunomodulator therapy or the severity of the underlying
disease activity.
Unfortunately, as this meta-analysis demonstrates, the actual risk of
lymphoma in IBD patients treated remains unknown and our safety data with
respect to azathioprine/6-MP and lymphoma, albeit reassuring, remains
largely based on observational studies. Thus it is not possible to fully
exclude the possibility that an increased risk of lymphoma is associated
with disease severity rather than immunomodulator therapy. Larger-scale,
prospective, population-based studies are necessary to define the actual
risk of lymphoma in IBD and adequately ascertain the influence of
immunomodulators on that risk. Until then, we agree with Kandiel et al,
that the lymphoma risk associated with azathioprine and 6-MP in IBD is
likely to be of minimal clinical significance compared to the established
and more frequent risks of myelosuppression and infection, and is far
outweighed by the benefit of immunosuppression in IBD.
References:
1. Lewis JD, Bilker WB, Brensinger C, et al. Inflammatory bowel
disease is not associated with an increased risk of lymphoma.
Gastroenterology 2001; 121: 1080-7.
2. Karlen P, Lofberg R, Brostrom O, et al. Increased risk of cancer in
ulcerative colitis: a population-based cohort study. Am J Gastroenterol.
1999;94(4):1047-52.
3. Palli D, Trallori G, Bagnoli S, et al. Hodgkin’s disease risk is
increased in patients with ulcerative colitis. Gastroenterology 2000; 119:
647-653.
4. Bernstein CN, Blanchard JF, Kliewer E, et al. Cancer risk in patients
with inflammatory bowel disease. Cancer 2001; 91(4): 854-62.
5. Baecklund E, Ekbom A, Sparen P, et al. Disease activity and risk of
lymphoma in patients with rheumatoid arthritis: nested case-control study.
BMJ 1998; 317: 180-1.
6. Farrell RJ, Ang Y, Kileen P, et al. Increase incidence of non-
Hodgkin’s lymphoma in inflammatory bowel disease patients on
immunosuppressive therapy but overall risk is small. Gut 2000; 47: 514-
19.
7. Kinlen LJ. Incidence of cancer in rheumatoid arthritis and other
disorders after immunosuppressive treatment. Am J Med 1985; 78: 44-9.
8. Berkson J. Limitations of the application of four-fold table analysis
to hospital data. Biomet Bull 1946; 2: 47-53.
We read with great interest the article by Bartolotti et al. (Gut2005;54:852-857) regarding the shift in the predominance of hepatitis C genotype in 373 paediatric patients investigated between 1990 and 2002. The distribution of genotypes showed a major prevalence of HCV genotype 1, recorded in about 60% of children. The genotype 2, 3 and 4 were observed in 17, 15 and 5% of patients respectively. However...
We read with great interest the article by Bartolotti et al. (Gut2005;54:852-857) regarding the shift in the predominance of hepatitis C genotype in 373 paediatric patients investigated between 1990 and 2002. The distribution of genotypes showed a major prevalence of HCV genotype 1, recorded in about 60% of children. The genotype 2, 3 and 4 were observed in 17, 15 and 5% of patients respectively. However, the study after 1990 described a declining prevalence of genotypes 1b and 2 and by an increasing proportion of genotype 3 and 4.
We have conducted an analogous genotype determination in 1095 adults patients analyzed between 2000 to 2004. Subjects were been screening previously for anti-HCV antibodies for different reason, such as exposure to major risk factors, evidence of increased ALT, pregnancy and surgical procedures. Consequently, this population group was characterized by a rather homogenous representation of all age groups and included individuals independently of source of infection and liver disease. All patients were infected with HCV, as demonstrated by HCV-RNA detection obtained by a Polymerase Chain Reaction (PCR) assay, COBAS System Amplicor HCV monitor version 2.0 (Roche Diagnostics Systems Inc. Branchburg, NJ, USA). HCV genotyping/subtyping was done with a line-probe assay (INNO-LiPA HCV II, Innogenetics, Ghent, Belgium). The Simmonds classification was used.[1]
The study population included 555 males and 540 females, in the age range of 15-102 years. 44 (4.0%) out of 1095 patients were younger than 30 years old; 179 (16.3% ) aged between 31 and 40; 189 (17.3%) between 41 and 50; 165 (15.1%) between 51 and 60; 304 (27.8%) between 61 and 70 and 190 (17.4%) between 71 and 80. Finally, 24 (2.3%) samples were obtained by patients older than 80 years. All the 1095 HCV-RNA positive samples included in the study were genotyped, and 1063 (97.1%) were also subtyped. The distribution of genotypes showed a major prevalence of HCV genotype 1 (49,3%). Three hundred seventy-one (33.9%) were infected with type 2 and 136 (12.4%) were suffering from genotype 3. HCV-4 was found in 52 (4.7%) persons. Type 5 could be detected only in one (0.1%) patient. The remaining 9 (0.8%) individuals were infected with more genotypes. The distribution of subtypes showed a major prevalence (39.7%) of subtype 1b. Three hundred thirty-one (30.2%) individuals were infected with subtypes 2a/2c and 122 (11.1%) were suffering from subtype 3a. Seventy-two (6.6%) samples were positive for serotype 1a. The serotype 2a and 4c/4d, were determinate only in 32 (2.9%) 36 (3.3%) patients, respectively. The subtypes 3b and 1a/1b were unusually recorded, (12 and 8 subjects respectively). Exceptional results appeared to be the infections with other subtypes and the co-infections (1-2 patients).
The data of subtype distribution according to age group demonstrates a notable variation in the profiles of the subtypes (Table). Subtype 1a was frequently detectable in young patients, was rarely found in old subjects and tended to disappear in the last age groups (p <0.0001). Subtype 1b appears to be more prevalent in individuals aged ≤30 years compared to patients 31-40 and 41-50 years old ( p 0.013). However, subjects in the age group older than 50 (near 50%) years had most frequent infections with subtypes 1b compared with patients 31-40 and 41-50 years old (p <0.0001). The profile of co-infection 2a/2c showed an evident and progressive increase of the prevalence with the increment of age (p <0.0001). Subtype 3a was described more frequently in the second and third age group compared with the first one (p 0.007). However, prevalence of this subtype declined according to increment of age and became irrelevant in the last age group(p <0.0001). An analogous profile was described for co-infection 4c/4d (p <0.0001).
Our data was in accordance with the predominance of genotype 1, and in particular of subtype 1b, observed previously in Italy and in most countries of Europe and of the Word. With respect to the genotype 2, almost completely represented by subtype 2a/2c, and for genotype 3 our results showed data analogous to those reported from other Italian and European studies. In our study genotype 4 was found in 4.1% of patients. HCV genotype 4 appears to be prevalent in North Africa and Middle East .[2-3] However, recent papers showed an high prevalence (4.5%) of HCV genotype 4 in Southern and Central Italy too.[4]
Moreover, we have evaluated the shift in the predominance of HCV subtypes in age groups. Recently, this tendency for a shift in the prevalence of HCV subtypes was noted in Italian and international study.[5-6] A recent model of HCV spread, based on the coalescent theory, which showed that the circulation of subtype 1a continues to increase whereas the extent of infection with subtypes 1b tends to decrease. This is in line with our results on subtype 1a and probably with the epidemic behaviour of subtype 3a and co-infection 4c/4d.On the other hand, the high prevalence of subtype 1b that was observed in our patients younger than 30 years appears to suggest that the increase in rate of this variant has not yet achieved a plateau in Italy. Analogous data were obtained in an other Italian study conducted recently in North-East Italy.[6]
In conclusion, our study has shown a shift of the epidemiological picture of HCV infection, with the diffusion of subtypes 1a, 3a and 4c/4d. These epidemiological changes reported in our patients reflected the shift in pattern of HCV genotypes described by Bartolotti (Gut2005;54:852-857) in children. These subtypes, prevalent in young adults, may represent the source of future infections transmitted mainly by injection drug use, perinatal, and sexual transmission, and it is expected that these subtypes will be distributed evenly in all cohorts.
References
1. 1 Simmonds P, McOmish F, Yap PL et al. Classification of hepatitis C virus into six major genotypes and series of subtypes by phylogenetic analysis of the NS-5 region. J Gen Virol 1993; 74: 2391-9.
2. Zein NN. Clinical significance of hepatitis C virus genotypes. Clin Microb Rew 2000; 13: 223-35.
3. Maertens G, Stuyver L. Genotypes and genetic variation of hepatitis C virus. In: Harrison TJ, Zuckerman AJ, editors. The Molecular Medicine of Viral Hepatitis. Wiley and Sons Ltd. Chichester, England, 1997: 183-233.
4. Matera G, Lamberti A, Quirino A et al. Changes in the prevalence of hepatitis C virus (HCV) genotype 4 in Calabria, Southern Italy. Diagn Microbiol Infect Dis 2002; 42: 169-73.
5. Ross RS, Viazov S, Renzing-Koholer K, Roggendorf M.. Changes in the epidemiology of hepatitis C infection in Germany: shift in the predominance of hepatitis C subtypes. J Med Virol 2000; 60: 122-5.
6. Dal Molin G, Ansaldi F, Biagi C et al. Changing molecular Epidemiology of hepatitis C virus infection in Northeast Italy. J Med Virol 2002; 68: 352-6.
Table: Prevalence of most frequent HCV-subtype in the different age groups
We read with considerable interest the article by Jarvela et al. (Gut 2005;54:643-647), who investigate the relationship between the genotype of adult-type hypolactasia and the risk of colorectal cancer in
the Finnish, British, and Spanish populations. In this study, the C/C–13910 genotype, a robust molecular marker of lactase non-persistence[1], was found to significantly associate with the risk of c...
We read with considerable interest the article by Jarvela et al. (Gut 2005;54:643-647), who investigate the relationship between the genotype of adult-type hypolactasia and the risk of colorectal cancer in
the Finnish, British, and Spanish populations. In this study, the C/C–13910 genotype, a robust molecular marker of lactase non-persistence[1], was found to significantly associate with the risk of colorectal cancer in the Finnish population; no significant risk was detected in the British or Spanish populations.
Despite the presence of a hereditary component, colorectal cancer is closely associated with environmental factors, such as diet.[2] High consumption of dietary fat, refined carbohydrates and red meat, are associated with high risk of colon cancer. By contrast, fruits, vegetables, whole grain cereals, fish and calcium has been associated with
reduced risk.
The effect of diet on the carcinogenic process could be mediated by changes in metabolic activity and composition of the colonic microflora. Bacteria such as bacteroides, eubacteria and clostridia could play a part in initiation of colon cancer through production of carcinogens,
cocarcinogens, or procarcinogens, while lactic acid producing bacteria (LAB), such as lactobacillus and bifidobacteria, prevent tumorigenesis.[3]
In this regard, probiotics and prebiotics have received peculiar attention. In particular, a prebiotic is a non-digestible food ingredient able to indirectly stimulate growth and/or activity of LAB in the colon.[4] A number of poorly digested carbohydrates fall into this category. Lactose could be included in this group when consumed by
subjects with lactase non-persistence.[5] In these patients, lactose present in dairy products cannot be digested in the small intestine, and instead is fermented by bacteria in the colon, acting as a prebiotic.[6] In addition, a not negligible percentage of lactase non-persistence
patients are asymptomatic.[7]
Lactose is the predominant carbohydrate in milk. Consumption of milk is suggested to be inversely related to colorectal cancer incidence, and some of its component (calcium, vitamin D, lactose) could play a protecting role.[8]
Jarvela found that among the Finns, considered to have the highest consumption of milk in the world, people with lactase non-persistence have a higher risk to develop colorectal cancer. This is in contrast with the theory, that non absorbed lactose, acting as a prebiotic, prevents from
colorectal cancer. He tried to explain this findings in two ways. First of all, he considered down-regulation of lactase activity after weaning as a normal phenomenon; persistence of elevated lactase activity is thought to be a relatively recent human evolutionary mechanism regulated at the
transcription level: so, in terms of evolution, he suggested that milk may not be a nutritional need in adulthood and it may have some dangerous effects. According to this hypothesis, since milk is one of the staple foods of the Finnish diet, this population is submitted to the dangerous
effects of milk, and it is more exposed to risk for colorectal cancer. Otherwise, milk could be protective for colorectal cancer, but it is possible that same malabsorber finnish people exclude from the diet milk because intolerant. Consequently, this group of Finns can not beneficiate of protective effects of milk.
Nevertheless, the role of dairy products in colorectal cancer remain controversial. We can suggest that the prebiotic activity of lactose can principally realise in asymptomatic subjects who do not eliminate dairy products from their diet despite lactose malabsorption. To evaluate this hypothesis it could be useful to stratificate the population with lactase non-persistence into two groups: symptomatic patients and asymptomatic subjects. In the latter, it is possible that milk has a supplementary
protective effect due to the presence of lactose as prebiotic in addition to the other nutrients provided by milk. On the other hand, what is the risk of colorectal cancer in subjects consuming low lactose milk?
References
1) Rasinpera H, Savilahti E, Enattah NS, et al. A genetic test which can be used to diagnose adult-type hypolactasia in children. Gut 2004;53(11):1571-6
2) Guarner F, Malagelada JR. Gut flora in health and disease. Lancet 2003;360:512-519
3) Rowland IR, Gangolli SD. Role of gastrointestinal flora in the metabolic and toxicological activities of xenobiotics, in: B Ballantyne,
TC Mars, Syverson (Eds.), General and Applied Toxicology, Second ed.,
Macmillan Publishers Ltd., London, pp.561-576
4) Burns AJ, Rowland IR. Antigenotoxicity of probiotics and prebiotics on faecal water-induced DNA damage in human colon adenocarcinoma cells. Mutation Research 2004;551:233-243
5) Montalto M, Nucera G, Santoro L, et al. Effect of exogenous â-galactosidase in patients with lactose malabsorption and intolerance: a crossover double-blind placebo-controlled study. Eur J Clin Nutr
2005;59(4):489-93
6) Szilagyi A. Review artiche: lactose – a potential prebiotic.
Aliment Pharmacol Ther 2002;16:1591-1602
7) Montalto M, Curigliano V, Santoro L, et al. Management and
treatment of lactose malabsorption. World J Gastroenterol in press
8) Norat T, Riboli E. Dairy products and colorectal cancer. A review
of possible mechanisms and epidemiological evidence. Eur J Clin Nutr
2003;57:1-17
We read with interest the case report by Buchel et al., published on
the July issue.[1] The authors report a patient with portal hypertension,
nodular regenerative hyperplasia and portal thrombosis that presented an
avascular hip necrosis after a liver transplantation (OLT). The authors
suggest that the whole clinical picture might stem from
hyperhomocysteinaemia (high Hcy) and 677C->T heterozigosi...
We read with interest the case report by Buchel et al., published on
the July issue.[1] The authors report a patient with portal hypertension,
nodular regenerative hyperplasia and portal thrombosis that presented an
avascular hip necrosis after a liver transplantation (OLT). The authors
suggest that the whole clinical picture might stem from
hyperhomocysteinaemia (high Hcy) and 677C->T heterozigosity for the
common gene of methylen-tetrahydrofolate reductase (MTHFR).
Although the history is suggestive of this hypothesis, high Hcy might
also be a secondary phenomenon. It is not clear whether high Hcy was
demonstrated in a sample obtained before – as suggested in Table – or
after OLT – as suggested in the text. In both cases Hcy might be elevated
as a consequence of either liver disease or drug treatment.
Liver disease per se raises Hcy, due to the multiple metabolic
problems generated by a failing liver, including low folate levels,
altered transsulphuration/transmethylation pathway and decreased renal
function. High Hcy is present in 50% of liver disease patients, and values
as high as 30 µmol/L are not uncommon in end-stage disease [2],
independently of MTHFR polymorphism.
After OLT a specific effect of tacrolimus on Hcy metabolism and
concentration is well documented. Both calcineurin inhibitors
(cyclosporine and tacrolimus) are known to interfere with the folate-
dependent remethylation of Hcy, thus raising plasma levels to values in
the pathological range. The problem is well documented in patients
following with renal [3], cardiac [4] and liver transplant [2]. In a
recent analysis of 230 patients submitted to OLT we found 26 cases with
fasting Hcy >= 30 µmol/L in the late post-transplant phase,
independently of MTHFR polymorphism.[5]
Also the relationship between high Hcy and MTHFR polymorphism
deserves a comment. The MTHFR gene independently and unfavourably
influences homocysteine metabolism, but high Hcy levels are mainly
observed in subjects with low folate levels [6], indicating a low
phenotypic expression. Therefore, the presence of the genetic variant,
mainly in its heterozygous form, might be an occasional phenomenon without
any clinical significance. In conclusion, although the clinical history of
the patients raises the suggested pathogenic role of Hcy and genetic
predisposition, no clues can be made on the “egg-chicken” sequence,
particularly in a patient with positive markers for hepatitis B infection.
For sure, an adequate folate intake or pharmacological
supplementation may overcome the genetic predisposition to high Hcy, but
may also decrease Hcy independently of any gene defect, and remains a
suitable therapeutic option to prevent additional vascular problems.
References
1. Buchel O, Roskams T, Van Damme B, et al. Nodular regenerative
hyperplasia, portal vein thrombosis, and avascular hip necrosis due to
hyperhomocysteinaemia. Gut 2005;54:1021-3.
2. Bosy-Westphal A, Ruschmeyer M, Czech N, et al. Determinants of
hyperhomocysteinemia in patients with chronic liver disease and after
orthotopic liver transplantation. Am J Clin Nutr 2003;77:1269-77.
3. Fernandez-Miranda C, Gomez P, Diaz-Rubio P, et al. Plasma
homocysteine levels in renal transplanted patients on cyclosporine or
tacrolimus therapy: effect of treatment with folic acid. Clin Transplant
2000;14:110-4.
4. Cole DE, Ross HJ, Evrovski J, et al. Correlation between total
homocysteine and cyclosporine concentrations in cardiac transplant
recipients. Clin Chem 1998;44:2307-12.
5. Bianchi G, Nicolino F, Passerini G, et al. Plasma total homocysteine and cardiovascular risk in patients submitted to liver transplantation. Liver Transplant (in press).
6. Potena L, Grigioni F, Viggiani M, et al. Interplay between
methylenetetrahydrofolate reductase gene polymorphism 677C-->T and
serum folate levels in determining hyperhomocysteinemia in heart
transplant recipients. J Heart Lung Transplant 2001;20:1245-51.
We have concerns about the recommendation of naso-gastric feeding in
severe acute pancreatitis. Firstly, the recommendation is based on a
feasibility study of 26 patients published in August 2000 in the
International Journal of Pancreatology.
Secondly, it has been graded as grade B evidence. We therefore feel
that this recommendation is misleading and inappropriate. We feel further
evidence...
We have concerns about the recommendation of naso-gastric feeding in
severe acute pancreatitis. Firstly, the recommendation is based on a
feasibility study of 26 patients published in August 2000 in the
International Journal of Pancreatology.
Secondly, it has been graded as grade B evidence. We therefore feel
that this recommendation is misleading and inappropriate. We feel further
evidence would be required to substantiate this recommendation.
A further concern relates to the recommendation for the enteral route
to be used if tolerated (grade A). We feel that this might be misleading
as all three of the papers used as evidence for this recommendation refers
to naso-jejunal feeding rather than generally referring to 'enteral
feeding'.
Dear Editor,
We were interested in the paper by Mutoh et al.[1], showing the development of epithelial intestinal metaplasia and mesenchymal proliferation in human stomach resections and Cdx2 transgenic mice. The authors used alpha-smooth muscle actin (alpha-SMA) staining to mark peri-glandular fibroblasts and failed to show any alpha-SMA positive cells surrounding the en-face glands of normal mouse and human stomach m...
Dear Sir,
Surgery (resection or transplantation) is the first treatment choice for early HCC, but unfortunately it is feasible only in a minority of patients.[1] Local percutaneous ablation has therefore dramatically increase in importance and radio-frequency thermal ablation (RFTA) has showed in recent reports global or disease-free survivals better than those reported for percutaneous ethanol injection (PEI).[2] The...
Dear Editor,
I would like to respond to the commentary written by Dr. R. Balfour Sartor entitled, "Does Mycobacterium avium subspecies paratuberculosis cause Crohn's disease?” The answer to this rhetorical question is yes, and I would like to explain why we now have sufficient information to conclude that Mycobacterium avium paratuberculosis (Map) is a major cause of Crohn's disease.
First, I will address...
Dear Editor,
We read with great interest the paper by Israeli et al. assessing the presence of anti-Saccharomyces cerevisiae antibodies (ASCA) and perinuclear antineutrophil cytoplasmic antibodies (pANCA) before the occurrence of overt clinical manifestations in patients with Crohn’s disease (CD) and ulcerative colitis (UC).[1] They found that ASCA were present in 31% CD patients before clinical diagnosis (but no...
Dear Editor,
The recent paper by Thomas and colleagues[1] in the May 2005 issue of Gut provides further support for an involvement of increased colonic deoxycholic acid formation and absorption in cholesterol gallstone pathogenesis. This paper and others in the series[2-4] from Professor R. Hermon Dowling’s laboratory at Guy’s Hospital, London, was ably placed in perspective with the accompanying comprehensive co...
Dear Editor,
We read with great interest the meta-analysis by Kandiel et al., (Gut 2005; 54: 1121-1125) the purpose of which was to provide a more precise estimate of the relative risk of lymphoma among inflammatory bowel disease (IBD) patients treated with azathioprine or 6-mercaptopurine (6-MP). Based on the six studies included in their meta-analysis, Kandiel et al., determined that the risk of lymphoma among...
Dear Editor,
We read with great interest the article by Bartolotti et al. (Gut2005;54:852-857) regarding the shift in the predominance of hepatitis C genotype in 373 paediatric patients investigated between 1990 and 2002. The distribution of genotypes showed a major prevalence of HCV genotype 1, recorded in about 60% of children. The genotype 2, 3 and 4 were observed in 17, 15 and 5% of patients respectively. However...
Dear Editor,
We read with considerable interest the article by Jarvela et al. (Gut 2005;54:643-647), who investigate the relationship between the genotype of adult-type hypolactasia and the risk of colorectal cancer in the Finnish, British, and Spanish populations. In this study, the C/C–13910 genotype, a robust molecular marker of lactase non-persistence[1], was found to significantly associate with the risk of c...
Dear Editor,
We read with interest the case report by Buchel et al., published on the July issue.[1] The authors report a patient with portal hypertension, nodular regenerative hyperplasia and portal thrombosis that presented an avascular hip necrosis after a liver transplantation (OLT). The authors suggest that the whole clinical picture might stem from hyperhomocysteinaemia (high Hcy) and 677C->T heterozigosi...
Dear Editor,
We have concerns about the recommendation of naso-gastric feeding in severe acute pancreatitis. Firstly, the recommendation is based on a feasibility study of 26 patients published in August 2000 in the International Journal of Pancreatology.
Secondly, it has been graded as grade B evidence. We therefore feel that this recommendation is misleading and inappropriate. We feel further evidence...
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