T cell subsets in patients with rheumatoid arthritis: reduction of cells with Leu 2A phenotype in patients with serum IgG immunocomplexes.

The distribution of T cell subsets in the peripheral blood lymphocytes of 50 patients with rheumatoid arthritis (RA) and 28 controls was evaluated using the monoclonal anti-human T cell antibodies, alpha-Leu 1, alpha-Leu 2a and alpha-Leu 3a. A reduced number of cells with Leu 2a phenotype was observed in the group of patients with active RA. When patients were classified according to both disease activity and the presence of IgG or IgM immunocomplexes, a good correlation was observed between reduced Leu 2a+ numbers and the presence of IgG immunocomplexes. Patients without serum IC had normal numbers of Leu 2a T cells, independently of the activity of the disease. The significance of these results to the understanding of the aetiopathogenesis of RA is discussed.