Analysis of the synovial cell infiltrate in early rheumatoid synovial tissue in relation to local disease activity

Abstract

Objective. To define variations in the cellular infiltrate and in the expression of monokines in synovial tissue (ST) from rheumatoid arthritis (RA) patients with different durations of disease and different levels of disease activity. Methods. The immunohistologic features of synovial biopsy specimens from 31 patients with early RA (<1 year) and 35 patients with longstanding RA (>5 years) were compared. The possible associations between these features and local disease activity, as measured by the score for pain in the biopsied knee joint, were also evaluated. Results. The immunohistologic features were not dependent on disease duration. We found a positive correlation between the scores for knee pain and the semiquantitative scores for the number of macrophages, as well as the expression of interleukin-6 and tumor necrosis factor α, whereas the correlation with the scores for CD4+ T cells was negative. Multivariate analysis showed that these correlations were highly statistically significant (P < 0.003). Conclusion. The results do not support the view that inflammatory mechanisms in the synovial tissues of RA patients differ between early and late stages of the disease. The findings presented here are consistent with the concept that early RA is the result of a synovitis process of longer duration and that macrophage-derived cytokines play an important role in maintaining the clinical signs of inflammation.