Autoimmune implications of immune complexes in clinical variants of hepatitis B.

Immune complexes (IC) were investigated in sera from 208 individuals with various clinical types of viral hepatitis diagnosed by clinical and laboratory criteria, including liver biopsy. Immune complexes were assessed by platelet aggregation (PI A) and by radioimmunoassay (RIA). The data were related to autoimmune phenomena (especially rheumatoid factors) and to the role that the IgM class of hepatitis B (HB) antibody might have in IC formation. Although the highest frequency of P1 A was in the few sera from patients with cirrhosis or hepatoma, the next highest was in sera from acute hepatitis patients (71%), and the lowest in sera from chronic active (57%) and chronic persistent (46%) hepatitis patients. A proportional number of patients with IC's were positive for hepatitis B surface antigen (HBs). A parallel prevalence was noted between P1 A and autoantibodies, with anti-Ig's being found more frequently in sera from acute hepatitis and chronic active hepatitis patients. The relationship between RIA results for complexes and RIA results for anti-IgG was inverse, as though anti-IgG interfered with IC reactivity by RIA. Anti-IgM pre-incubated with sera increased the amount of P1 A in sera from patients with acute hepatitis as well as in those from patients with chronic persistent hepatitis, suggesting a more frequent IgM involvement in IC's in these diseases than in chronic active hepatitis. Whereas liver cell damage in acute and active hepatitis may reflect elevated autoantibodies, the IgM class of HBs antibody may be involved in acute as well as chronic persistent hepatitis.