OBJECTIVETo explore the pathogenesis of thrombocytopenia in viral hepatitis.

METHODS84 viral hepatitis patients and 20 healthy controls were divided into three groups: Group A: 48 viral hepatitis patients with thrombocytopenia; Group B: 36 viral hepatitis patients with normal platelet count; and Group C: 20 healthy controls. Serum thrombopoietin (TPO) levels were measured in all subjects by enzyme linked immunosorbent assay. The levels of PAIg, PAIgG, PAIgA, PAIgM were detected in all subjects by flow cytometry. Spleen size was assessed in all subjects by abdominal color ultrasound B Scan. Bone marrow cells were examined in 74 subjects with bone marrow punctures.

RESULTSSerum thrombopoietin level was lower in group A than in group C and in group B. Serum TPO levels were correlated with platelet counts in the patients with advanced liver diseases. PAIg, PAIgG levels were significantly higher in group A than in group B and in group C. An inverse correlation was found between platelet counts and PAIg levels. An inverse correlation was also observed between platelet counts and PAIgG levels. The incidence of splenomegaly was significantly higher in group A (77.1%) than in group B (47.2%), while group C had no splenomegaly. An inverse correlation between spleen size and platelet count was observed (r = -0.581). There were 4 patients in group A with hypoplasia of bone marrow karyocytes, but there were no such cases in groups B and C.

CONCLUSIONSTPO level decreasing in patients with severe liver function impairments correlates with thrombocytopenia in advanced liver diseases. Autoimmune mechanism mediated by PAIg may play an important role in thrombocytopenia associated with viral hepatitis. Splenomegaly is the influencing factor leading to thrombocytopenia in viral hepatitis. Patients with chronic liver diseases had bone marrow depression, which may be a factor inducing thrombocytopenia in patients with viral hepatitis.