PT  - JOURNAL ARTICLE
AU  - M Baeres
AU  - J Herkel
AU  - A J Czaja
AU  - I Wies
AU  - S Kanzler
AU  - E L R Cancado
AU  - G Porta
AU  - M Nishioka
AU  - T Simon
AU  - C Daehnrich
AU  - W Schlumberger
AU  - P R Galle
AU  - A W Lohse
TI  - Establishment of standardised SLA/LP immunoassays: specificity for autoimmune hepatitis, worldwide occurrence, and clinical characteristics
AID  - 10.1136/gut.51.2.259
DP  - 2002 Aug 01
TA  - Gut
PG  - 259--264
VI  - 51
IP  - 2
4099  - http://gut.bmj.com/content/51/2/259.short
4100  - http://gut.bmj.com/content/51/2/259.full
SO  - Gut2002 Aug 01; 51
AB  - Background: Antibodies to soluble liver antigen/liver pancreas (SLA/LP) are specific markers of autoimmune hepatitis. Their target antigen has recently been cloned.Aims: To establish standardised immunoassays using the recombinant antigen, and to assess the frequency and significance of seropositivity in patients from different countries.Methods: An enzyme linked immunoassay was developed using purified recombinant antigen and validated by testing sera from 200 healthy blood donors and 1026 patients with various liver and non-liver diseases. The assay was then applied to 454 sera from 419 patients with autoimmune hepatitis from different countries. All sera were also tested by inhibition immunoassay and western blot.Results: Antibodies were reliably detected by the recombinant immunoassay and occurred exclusively in patients with autoimmune liver disease. Twenty three of 149 patients from the USA (15%), 23/132 from Brazil (17%), 21/108 from Germany (19%), and 2/30 from Japan (7%) were seropositive. Clinical features at presentation were similar between seropositive and seronegative patients. However, relapse after corticosteroid withdrawal or during maintenance therapy occurred more commonly in seropositive patients.Conclusions: Antibodies to SLA/LP can be reliably detected by these standardised immunoassays based on recombinant antigen. Antibodies to SLA/LP occur with similar frequencies in different geographical regions, races, and age groups, and are of exquisite diagnostic specificity. Whether SLA/LP positive patients represent a clinically distinct subgroup remains to be determined; relapse during treatment reduction appeared to be more common in the SLA/LP group.