Hepatitis B surface antigen- and immunoglobulin-specific circulating immune complexes in acute hepatitis B virus infection.

For assessing the role of circulating immune complexes (CICs) in acute hepatitis B, CICs containing HBsAg, IgM, and IgG were determined, by C1q and conglutinin (K) assays, in 242 patients with acute hepatitis B and 60 healthy controls. CIC is a common feature of acute hepatitis B with 90.9% of cases having at least one abnormal test result. Patients with shorter interval (< 1 week) between onset of symptoms and patient presentation have significantly higher frequency of abnormal IgM class CIC, HBsAg-specific CIC, and higher frequency of raised alanine aminotransferase activity (> 30-fold upper limit of normal). The prevalence of raised alanine aminotransferase in patients with CIC containing HBsAg and IgM is higher than those without (P = 0.001). There is significant association between HBsAg-CIC and C1q-CIC. In conclusion, HBsAg-CIC and IgM class CIC correlate with disease activity. C1q-binding CIC is the predominant CIC that may play a role in the pathogenesis of acute hepatitis B.