Immune complex mediated vasculitis in hepatitis B and C infections and the effect of antiviral therapy

Case reports of seven patients with vasculitis and past or present viral hepatitis infection are presented, including studies on circulating immune complexes (CICs) and cryoglobulins by sucrose density gradient centrifugation or gel filtration, before and after antiviral therapy. Three patients had unusual vasculitic manifestations: coronary, large vessel, and muscle vasculitis, respectively. All the patients had high levels of CICs by the above methods, but only two had CICs by the C1q binding and conglutinin methods. The CICs/ cryoglobulins contained HBV and/or HCV antibodies, antigens, and genome. The concentration of hepatitis antibodies in immune complex form was severalfold higher than in the free form in serum. In one patient, the HBs antigen was present only in the CICs and in another, only hepatitis antibodies (no antigen/genome) were present in the serum or the cryoglobulins. With antiviral therapy, six patients went into long-lasting remissions. There was a temporal relationship between the regression of the vasculitic lesions and the decline in the levels of CICs/cryoglobulins.