We evaluated the expression of human glucocorticoid receptor beta (hGRbeta) in patients with severe autoimmune hepatitis (AIH). The subjects were 27 patients with AIH, including 6 with severe type (prothrombin time [PT] < 40%) and 21 with non-severe type (PT>40%). Total RNA extracted from peripheral blood mononuclear cells (PBMCs) was reversed using reverse transcriptase. The resultant complementary DNA was amplified by reverse transcription polymerase chain reaction (RT-PCR) using specific primers for hGR alpha and beta. The six patients with severe AIH were female; three presented fulminant hepatic failure with hepatic encephalopathy. In all patients with AIH, hGR a was detected. The incidence of hGR beta expression in patients with non-severe type was 42.9% (9/21) ; it was 100% (6/6) in those with severe type. The positive ratio was significantly higher in severe-type patients. These results suggest that hGR beta expression in PBMCs is a novel predictor of AIH severity.