The detection of human immunodeficiency virus DNA in dendritic cells from the joints of patients with aseptic arthritis.

Three patients with inflammatory arthritis were found to be seropositive for human immunodeficiency virus (HIV). Two of these individuals developed synovitis following an episode of yersinia bowel infection. We have studied joint material from all three in an attempt to define the role that HIV may be playing in the aetiology or maintenance of arthritis. Cell-associated HIV DNA was detected within joint fluid by in situ hybridization and the phenotypes of infected cells were established using a double-labelling immunocytochemical technique. Viral DNA was detected in dendritic cells (4-25%) isolated from both the peripheral blood and synovial fluid and in occasional lymphocytes from peripheral blood (less than 0.1%). No infected macrophages were seen. Functional studies using the mixed leucocyte reaction showed that the dendritic cells from synovial fluid were poor stimulators of allogenic peripheral blood lymphocytes whilst being effective at stimulating autologous lymphocytes. In addition, synovial fluid lymphocytes responded poorly to normal control dendritic cells. Infection of these cells with HIV could be contributing to this low stimulatory activity of antigen-presenting cells and to the unresponsiveness of lymphocytes.