To evaluate the effect of soluble Fas antigen (sFas) and soluble Fas ligand (sFasL) in the pathogenesis of hepatitis B. Methods Serum sFas and sFasL were detected by ELISA in 39 patients with hepatitis B. 8 healthy persons served as normal control. These levels were compared with the index of disease activity

including ALT levels

STB and PT levels. Results Serum sFas levels in moderate and severe degree CHB patients (CAH

5.38±3.50ng/ml) were significantly higher than those in other groups(Ｐ<0.01)

and serum sFasL levels in hepatic failure patients (FH

2.76±0.49ng/ml) were notably higher than those in other groups(Ｐ<0.01). Serum sFas and sFasL levels were correlated with disease activity

and most cases of the former had favourable prognosis. Conclusion The soluble form of Fas antigen in serum seemed to inhibit Fas-mediated apoptosis

and serum sFasL may reflect the severity of liver inflammation. They play important roles in hepatic apoptosis and necrosis

and may be responsible symbols for diagnosing pathogenetic condition and prognosis in hepatitis B.