Lymphocyte subsets and inflammatory indices in synovial fluid and blood of patients with rheumatoid arthritis.

Lymphocyte subsets defined by monoclonal antibodies, C reactive protein (CRP), immune complexes (IC), rheumatoid factor (RF), C3, C4 and neutrophil and lymphocyte numbers were measured in synovial fluid (SF) and blood samples from 11 patients with rheumatoid arthritis. SF showed an increased percentage of T cells, Ia+ cells and OKT8+ cells and a reduced percentage of B cells and OKT4+ cells, when compared with blood. Reduced levels of CRP, RF, C3 and C4 were found in SF compared with blood. Comparisons between cellular subsets and other indices in SF revealed a positive correlation between neutrophil numbers and IC, CRP, and RF with a negative correlation between neutrophil numbers and numbers of T cells and OKT8+ cells. A similar negative correlation was found in blood between OKT8+ cells and both CRP and RF. These results indicate an association between increasing disease activity and a lack of suppressor/cytotoxic cells in both circulating and intraarticular compartments. An additional important finding was the lack of correlation of Ia+ cells in both SF and blood with neutrophil numbers, CRP, IC, C3 and C4 or RF.