Decrease in CD4+CD25+ and CD8+CD28+ T cells in interstitial pneumonitis associated with rheumatic disease.

ABSTRACT

The expression of CD25 or CD28 on T cells was examined in patients with rheumatic diseases associated with interstitial pneumonitis (IP), in order to investigate the conditions of CD4+CD25+ regulatory T cells and CD8+CD28- suppressor T cells. Fifty-five patients with various rheumatic diseases and 23 normal controls were enrolled. CD4+CD25+ T cells of patients with IP were significantly decreased in comparison with non-IP patients, and the ratio of CD8+CD28- T cells in patients with IP was significantly higher than that in non-IP patients or normal controls. These results for CD8+CD28- T cells were in accord with the decrease in CD8+CD28+ T cells, and may be related to activation-induced CD8+CD28+ T-cell death. Thus, the abnormality of CD4+CD25+ regulatory T cells may be related to the pathogenesis of IP, and the survival and activation of CD8+ T cells.