Relationship of serum alpha-fetoprotein to circulating immune complexes and complements in patients with hepatitis B surface antigen-positive hepatocellular carcinoma.

Circulating immune complexes (CIC), complement and alpha-fetoprotein (AFP) were detected in 93 hepatitis B surface antigen (HBsAg)-positive patients with hepatocellular carcinoma (HCC), 16 patients with liver cirrhosis (LC) and 54 healthy controls. The CIC and complements were significantly higher in HCC patients than in LC patients. The complement and polyethylene glycol(PEG)-CIC in HCC patients with LC were higher than those in LC only (P less than 0.0001). The complement levels in LC patients were significantly lower than in controls. There was no difference in C3 and C4 between HCC patients and controls, while the C3 proactivator was higher in HCC patients (P less than 0.02). The C1q-CIC was higher in HCC and LC patients when compared to controls (P less than 0.0001). In patients with HCC, there was no difference in the CIC and complement levels between patients with cirrhosis and those without. There were inverse correlations between C1q-CIC and C3 (P less than 0.05), C1q-CIC and C4 (P less than 0.04). The mean level of 3% PEG-CIC and C1q-CIC increased significantly as AFP elevated, but decreased as AFP was higher than 1599 ng/ml (P less than 0.05). These results imply that CIC increase with tumor growth but further tumor burden may result in a fall in CIC, there was a shifting of CIC from complement-fixing to non-complement-fixing as AFP increased gradually.