Increment of Tal positive cells in peripheral blood from patients with rheumatoid arthritis

Recently it was demonstrated that the Tal antigen is a marker for activated T cells and the population of Tal+ cells includes memory T cells. Our study was undertaken to analyze Tal+ cells in peripheral blood from patients with rheumatoid arthritis (RA) and examine the correlation between the proportion of Tal+ cells and disease activity. Using a dual immunofluorescent method, T cell subsets were analyzed in peripheral blood from 46 patients with RA, 10 patients with osteoarthritis (OA) and 10 healthy subjects. Patients with RA had a significantly higher percentage of T cells bearing the Tal antigen than patients with OA and healthy subjects. Furthermore, the percentage of CD3+Tal+ cells in peripheral blood from patients with RA was significantly correlated with disease activity including erythrocyte sedimentation rate, morning stiffness and the Lansbury index, whereas CD3+ HLA-DR+ cells did not correlate. In serial observations in patients with RA, the percentage of CD3+ Tal+ cells decreased in accordance with the improvement of disease activity. Thus, we suggest that the percentage of Tal+ cells may be a marker of the disease activity in patients with RA.