LIMITED T-CELL RECEPTOR V-BETA-CHAIN REPERTOIRE OF LIVER-INFILTRATINGT-CELLS IN AUTOIMMUNE HEPATITIS

Background/Aims: To characterize the cellular immune reactions in auto immune hepatitis, the T cell receptor repertoire of liver-infiltrating and circulating T cells was studied. Methods: Nucleic acids of liver- tissue and peripheral blood-derived T cells from 12 patients with untr eated autoimmune hepatitis, four patients with chronic hepatitis C and three patients with toxic liver injury were extracted and analysed us ing a semiquantitative RT-PCR with a panel of T cell receptor V beta f amily specific primers, After agarose gel electrophoresis, the distrib ution of T cell receptor (TCR) V beta molecules was assessed by densit ometry, Furthermore, results were compared to the TCR V beta distribut ion of 10 healthy blood donors. Results: Four of 12 patients with untr eated autoimmune hepatitis but no patients with chronic hepatitis C an d toxic liver injury showed a significant overexpression of TCR V beta 3 (17.8%+/-2.6% vs. 9.3%+/-4.6%; p=0.01) and three an overexpression of V beta 13.1 (14.6%+/-2.3% vs, 6.6%+/-3.5%; p=0.02) molecules compar ed to the TCR V beta-distribution in healthy blood donors, In addition , V beta 3+ T cells were found enriched in the liver tissue compared t o autologous peripheral blood in three autoimmune hepatitis patients ( 15.3%+/-7.0% vs, 5.2%+/-3.1%; L/B ratio: 2.9), while V beta 13.1+ T ce lls were enriched in the liver tissue from one of three patients with overexpression, Conclusions: In autoimmune hepatitis a disease specifi c compartmentalisation of TCR V beta 3+ T cells was observed in the li ver tissues, Although their specificity was unknown, this might indica te that these infiltrating T cells could have relevance for abnormal i mmunoregulation.