Background:Evaluation of risk-factors in rare types AIH.Material/Methods: From 112 patients with AIH,15 patients with non-characteristic course of diseases have been selected. AIH has been diagnosed on biochemical,serological and morphological criteria. Results: In 1.male patient AIH type 1 was diagnosed accidentally during routine laboratory blood-tests before employment in medical service.In two female patients,with AIH type 1,and AIH type 2a – polyendocrynologic syndrome APS-1 were present.Hepatic failure presented first in further 3 cases: acute liver failure in an 8-year old boy (AIH type 2a), subacute liver failure in two women with APS-1 syndrome followed by AIH type 2a and AIH type 1.All patients with hepatic insufficiency died before OLT.In 10 patients –2 men, 8 women -overlap syndromes had been observed. During the 5 –7 years period prior to diagnosis of AIH,8 out of the 10 patients demanded treatment for autoimmune diseases.In all cases laboratory evidence of intrahepatic cholestasis was observed and auto-antibodies (ANA,AMA,ANCA)were detected in high titers.8 patients presented overlapping signs of AIH and PBC and 2 patients had signs of AIH and PSC.Conclusions:Further analysis of atypical AIH is necessary for evaluation of the pathogenesis of this disease,early diagnosis and more effective treatment.

Keywords: autoimmune hepatitis