T-lymphocyte subpopulations in chronic inflammatory rheumatism

Monoclonal antibodies to a series of human lymphocytes subpopulations antigens (OKT) specific of the peripheral T cells (OKT3), of the inducer population (OKT4) of the suppressor cytotoxic population (OKT 5, OKT8), and anti-Ia (OKI1) were used to study blood lymphocytes from 50 patients with active or inactive rheumatoid arthritis (RA) and from 23 patients with ankylosing spondylitis (AS). In RA patients, there is a significant decrease of the total T cell population (T3 +) with higher percentages of helper (T4 +) T cells than in controls. In active forms of the disease, there also is a decrease in the suppressor cytotoxic (T5 + and T8 +) subset with a significant increase of the immunoregulating ratios T4 +/T5 + or T4 +/T8 +. Elevated levels of Ia + lymphocytes are found in all RA patients. Corticosteroid treatment seems to erase these abnormalities. On the contrary in AS patients, no significant modification of the T cell populations was evidenced.