Follicular dendritic cells and virus-like particles in AIDS-related lymphadenopathy.

Follicular labyrinthine foci, consisting of an association of retrovirus-like particles with expanded dendritic reticular ("antigen trapping") cells, are described in lymph nodes from four immunodeficient homosexual men with unexplained persistent lymphadenopathy. One patient has severe acquired immunodeficiency syndrome (AIDS) with complicating Pneumocystis carinii infection, and the others have AIDS-related lymphadenopathy syndrome. The findings support a role for routine electron microscopy as an aid to diagnostic evaluation of nodal tissue from patients with suspected AIDS. Viral non-lymphoid-cell tropism may be a significant factor in the pathogenesis of the disease.