Rheumatoid Vasculitis: Effect of Cyclophosphamide on the Clinical Course and Levels of Circulating Immune Complexes

Publisher Website
Google Scholar
Abstract
Five patients with severe rheumatoid vasculitis treated with cyclophosphamide were studied to determine whether immune complexes were present in serum and if their levels correlated with disease activity and response to treatment. Circulating immune complexes were measured by various techniques including the Clq [q fragment of complement component 1] binding and [human Burkitt''s lymphoma] Raji cell radioimmunoassays and determination of the presence of cryoglobulins. Elevated levels of circulating immune complexes, hypocomplementemia and high titer rheumatoid factor were present during active vasculitis. Clinical and serologic remissions were induced in all patients on cyclophosphamide. In 2 patients in remission, a rise in rheumatoid factor titer and immune complex levels was associated with an exacerbation of vasculitis, and resolved on increased cyclophosphamide dosage. The Clq binding assay and rheumatoid factor titer correlated best with clinical activity. Circulating immune complexes appear to be involved in the immunopathogenesis of rheumatoid vasculitis, which can be successfully treated with cyclophosphamide.