OBJECTIVEIn order to provide a reliable basis for the diagnosis and treatment of autoimmune hepatitis (AIH) and its overlap syndrome, we investigated the clinical, immunological characteristics of and the therapeutic methods for AIH and AIH-primary biliary cirrhosis (PBC) overlap syndrome.

METHODSOne hundred seven patients (77 with AIH and 30 with AIH-PBC overlap syndrome) were enrolled in the study. Their clinical manifestations, serum liver function tests (LFTs) findings, serum immunoglobulins, liver histopathological changes and their responsiveness to the therapies were investigated.

RESULTSThe age distribution of AIH patients showed a single peak during their fifties and their main clinical manifestations were malaise, abdominal distension, anorexia and jaundice. Serum gamma globulin and IgG were significantly higher than their normal levels. 74% of the patients were positive for anti-nuclear antibody (ANA), 32% of the patients were positive for anti-smooth muscle antibody (AMA), and over 50% of the patients suffered from concurrent extrahepatic autoimmune diseases. The main histological changes in the liver biopsies were interface hepatitis (65%), lobular hepatitis and rosette formation of liver cells. Bridging necrosis was observed in severe AIH cases. In the AIH-PBC overlap syndrome patients, the levels of serum ALT, AST, GGT, ALP and incidences of ANA and AMA/AMA-M2 were all significantly higher than those of the AIH group. After treating AIH patients with prednisolone and azathioprine (Aza), complete response was seen in 42 cases (70%), sustained response was seen in 26 cases (43%). Sixteen cases had relapses after the withdrawal of the treatment or prednisolone dosage was reduced lower than 10 mg/d. The cases having normal serum ALT, AST, gamma-globulin and IgG levels after treatment were still responding to the reduced prednisolone dosage of 5-10 mg/d without azathioprine added. After combination with ursodeoxycholic acid (UDCA) treatment, the liver function tests (AST, ALT, TBil) of AIH-PBC overlap syndrome patients also significantly improved compared to those before the treatment (P<0.01).

CONCLUSIONAIH and AIH-PBC overlap syndrome are not rare in our clinics. Their diagnoses should be based on the clinical presentations, biochemical and immunological indices and liver histological changes. In AIH cases, once their AST, ALT, gamma-globulin and IgG levels return to normal, the prednisolone dosage can be maintained at 5-10 mg/d and Aza can even be withdrawn. Good improvement for patients with AIH-PBC overlap syndrome can be obtained with UDCA and immunosuppression treatment.