The role of circulating hepatitis B antigen/antibody immune complexes in the pathogenesis of vascular and hepatic manifestations in polyarteritis nodosa

Abstract

To investigate the role of hepatitis B antigen (HB Ag) and specific immune complexes in polyarteritis, sera from 55 histologically confirmed cases were tested for the presence of hepatitis B antigen associated particles and hepatitis B antibody (anti HB) by solid phase radioimmunoassay, electron microscopy, and passive hemagglutination. Results of these findings were correlated with the clinical course of the disease. HB Ag was detected in 30 patients (54.5%) and anti HB in 13/45 (28%). Subtyping in 20 patients revealed that 11 were Y and 9 D. Thirty seven cases (69%) demonstrated either HB Ag or anti HB and 5/45 (11%) had both. Electron microscopic examination showed 20 nm spherical and tubular particles in sera of 20/27 patients with 42 nm particles in 11 cases and clumped particles in 12 (60%). No correlation was found between detection of immune complexes and liver disease whereas the presence of coexisting hepatitis B antigen and antibody or aggregated particles was restricted to cases of active vasculitis. Seroconversion or the presence of hepatitis B antibody alone was associated with improved prognosis. Circulating hepatitis B antigen antibody complexes may be responsible for vasculitis or polyarteritis but do not appear to be pathogenic for the liver.