TCR gamma/delta+ cell subsets in the synovial membranes of patients with rheumatoid arthritis and juvenile rheumatoid arthritis.

Using a peroxidase/anti-peroxidase immunohistochemical staining method, we examined sections of inflammatory synovial membranes from 13 patients with juvenile rheumatoid arthritis (JRA) and 11 with rheumatoid arthritis (RA). The relative numbers of TCR gamma/delta+ cells and the proportions of V delta 1+ and V delta 2+ subsets were recorded in the areas of the membranes most heavily infiltrated by CD3+ cells. In the JRA group, the majority (8/13) of the membranes had TCR gamma/delta+ cells which contributed between 5 and less than 10% of the total number of CD3+ cells. In the RA synovial membranes examined, 5/11 samples had between 5 and 10% TCR gamma/delta+ cells, but in another 5 TCR gamma/delta+ cells contributed to between 10 and 20% of CD3+ cells. No significant difference was noted between the two patient groups. However, the range of values found in the RA membranes appeared to be slightly higher in comparison to previously reported values for RA synovial fluid, peripheral blood and eluted synovial membrane T cells. Analysis of the relative proportions of the V delta 1+ and V delta 2+ subsets revealed a significant dominance of V delta 1+ cells in RA membranes and approximately equal numbers of the two populations in the JRA patients. As the majority of peripheral blood TCR gamma/delta+ cells use the V delta 2 segment this suggests a preferential homing or expansion of the V delta 1+ cells in both RA and JRA synovium. The overall distribution pattern of the TCR gamma/delta+ and V delta 1+ and V delta 2+ cells was also recorded. These cells mostly accumulated in the lymphoid-like tissues and in the perivascular area in the tissues of both RA and JRA patients. Occasionally, augmented numbers of these cells were found in the subsynovial layer or in the loose connective tissue. In the majority of cases, only a few TCR gamma/delta+ cells were located in the synovial layer. The function and the possible pathogenetic importance of these TCR gamma/delta+ cells have not so far been determined.