Immunoblastic lymphadenopathy with pulmonary infiltrates, hypocomplementemia and vasculitis. A hyperimmune syndrome.

A detailed description of the clinical and morphologic characteristics of four patients with immunoblastic lymphadenopathy, pulmonary infiltrates, hypocomplementemia and vasculitis is presented. Noteworthy in the patients described here is the clinical similarity to patients with collagen-vascular diseases and systemic drug reactions. The frequent occurrence of pulmonary symptoms, bilateral interstitial infiltrates and pleural effusions is emphasized. The morphology suggests stimulation of the immune system by antigenic agents, and the low complement levels and the presence of vasculitis suggest that circulating immune complexes may be present. Immunoblastic lymphadenopathy may represent a syndrome in which the adenopathy is but a nonspecific part of a systemic hyperimmune response to unknown antigens. The clinical course of the patients reviewed suggests that supportive treatment and corticosteroids constitute the safest therapeutic approach.