HIV associated arthropathy: HIV antigen demonstration in the synovial membrane.

Light and electron microscopic studies were performed on the synovial membranes of 5 patients with HIV associated arthropathy. An immunoperoxidase technique with the use of monoclonal antibodies against CD4, CD8, B and DR lymphocytes, and HIV p24 antigen was also used. Mild to moderate nonspecific proliferative changes and increased vascularity of the subsynovial space were seen. Electron dense deposits and viral-like particles were not observed. Immunohistochemical staining revealed HIV p24 positive staining in cells of the synovial lining layer and in the mononuclear cells of the subsynovial space. CD4, CD8, with predominance of CD8, and B and DR cells were also present. The presence of HIV p24 antigen may be indicative of a role, yet to be defined, in the pathogenesis of HIV associated rheumatic disorders.