T cell subset composition in remission phase of systemic connective tissue diseases

The proportions and numbers of peripheral blood mononuclear cells bearing T-cell markers (CD3/HLA-DR, CD4/CD29, CD4/CD45, CD8/CD56) were analyzed using two-color flow cytometric analysis in patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and Sjögren's syndrome (SS) in the remission phase of the diseases. The number of T cells (CD3+) in the blood was significantly decreased in SLE patients only; in these patients, but also in RA patients, an increased number of activated T cells (CD3+ HLA-DR+) was found. The number and proportion of helper T cells (CD4+) were decreased in SLE and SS, and normal in RA patients. In contrast, helper-inducer (CD4+ CD29+) and suppression-inducer (CD4+ CD45+) cells were both significantly increased in RA patients, decreased in SLE (only CD4+ CD45+ significantly) and unchanged in SS patients. Interestingly, however, the proportions of helper-inducer cells relative to total helper (CD4+) cell pool were significantly increased in all three groups of patients, whereas the proportion of suppression-inducer (CD4+ CD45+) cells was significantly decreased, but in SLE patients only. It is thus possible that this parameter is most pertinent to the disease status in the model studied. The population of CD8+ cells appeared more abundant in SLE patients, and the pool of CD8+ CD56+ cell was significantly enlarged in RA patients. It appears that the remission phase of disease in RA, SLE and SS patients still contains a substantial activation of the immune system, but the respective mechanisms are quite different in RA patients on one side, and SLE and SS patients on the other side.(ABSTRACT TRUNCATED AT 250 WORDS)