RECURRENT EPISODES OF ACUTE HEPATITIS ASSOCIATED WITH LKM-1 (CYTOCHROME-P450 2D6) ANTIBODIES IN IDENTICAL TWIN BROTHERS

Background/Aims: Liver/kidney microsomal antibodies have been noted in liver disease of different etiology, e.g, in autoimmune hepatitis, ch ronic hepatitis C and D virus infection and in drug-induced liver dise ase. Unlike these, acute hepatitis of unknown etiology associated with high-titer liver/kidney microsomal-l antibodies (cytochrome P450 2D6) is reported in identical twin brothers.Methods: Patients were studied using clinical, biochemical, serological and immunological methods, a s well as liver biopsy. Results: The acute icteric episodes were follo wed by spontaneous remission with complete normalization of liver func tion tests and liver histology. During the acute phase, serum titer fo r liver/kidney microsomal-l antibodies (detected by indirect immunoflu orescence, ELISA and Western blot analysis) was exceedingly high and d ecreased gradually thereafter. Hepatitis C and D virus infection were excluded by repeated serological testing; exposure to drugs or chemica ls was not evident. Concomitant autoimmune disease was not detectable. HLA typing for class 1 and 2 antigens was positive for the HLA haplot ype DQ2, but negative for HLA B4, B8, DR3 and DR4. Conclusions: The pr esent observations might suggest a hitherto unreported form of acute h epatitis of unknown etiology, distinct from other liver diseases in wh ich liver/kidney microsomal antibodies have been described so far.