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I read with interest the debate pertaining to screening for coeliac disease (CD). Although one can argue that CD fulfils the tenets of any screening programme, however, we do not know the natural history of screen detected patients with CD.
Logistically when would we decide to screen—at what age and how often thereafter? Serological markers may be highly sensitive and specific but the value of these tests decrease when they are used in the general population.
Although the investigational process for population screening and case finding may be the same, there is an important ethical difference between them. If a patient seeks medical help then the physician is attempting to diagnose the underlying condition (for example: patients with CD who present with symptoms of irritable bowel syndrome). This would be classified as case finding and clearly it is the patient who has initiated the consultation and in some sense is consenting for investigation. Conversely, individuals (who are not patients) found to have CD through screening programmes, may have considered themselves as “well” and it is the physician or healthcare system that is identifying them as potentially ill.
We recently performed a primary care based cross sectional study using immunoglobulins, IgA/IgG antigliadin antibodies and endomysial antibodies to initially recognise CD. 1200 volunteers were recruited from January 1999 to June 2001 from 5 general practices in South Yorkshire, UK. Any participant with a positive IgA antigliadin antibody, positive endomysial antibody or only IgG antigliadin antibody in the presence of IgA deficiency was offered a small bowel biopsy to confirm the diagnosis of CD. Twelve new cases of CD were diagnosed from 1200 samples. The prevalence of CD in this primary care population sample is 1% (95% CI 0.4–1.3%).1 In this screening study, 9/12 diagnosed cases of CD ultimately had symptoms which could be attributed to CD (for example, anaemia or subtle gastrointestinal symptoms). We, and others have demonstrated a delay in the diagnosis of CD—surely the important change in our clinical practice (both in primary and secondary care) is to have a low threshold for case finding.2–4 If you look for CD you will find it.
If I interpret Dr Sanders’ position correctly, he favours population screening, provided that a case finding approach is applied. His letter gives me the opportunity to expand further on my opinion on the appropriateness for coeliac disease (CD) population screening. As I mentioned in my final remarks and in the summary of my debate, while CD fulfils the criteria for mass screening, currently we lack the evidence based elements to justify a universal screening in European and North American populations. Therefore, my current position does not diverge substantially from that of Dr Sanders. I firmly believe that an “open-minded approach”, in which increased awareness and low threshold are applied to populations at risk, is ethical, logistical, and socially acceptable. This attitude was extremely effective in the USA, where the healthcare community had the perception that CD was extremely rare. We have recently subverted this wisdom by showing that the overall prevalence of CD in the USA is 1:133 in not-at-risk groups and between 2%–9% in at-risk groups, so proving that this disease was historically overlooked in the USA.1 If some reports in the literature indicating that prolonged gluten exposure can lead to increased morbidity2 and mortality3 are confirmed, we should be ready to change our attitude and embrace new guidelines for CD mass screening.
Epidemiological data published worldwide suggest that CD is one of the most frequent genetically based chronic diseases of humankind. Therefore, there has been no better time to establish the appropriateness for CD mass screening by performing well designed studies, rather than look in the opposite direction and ignore the problem. If we are not humble enough to embrace this approach to resolve this issue, we will not only be ethically and logistically incorrect, but also morally responsible for a poor outcome of our medical mission.