Immunoregulatory T cell subpopulations in patients with scleroderma using monoclonal antibodies

Twenty-eight patients with scleroderma were compared with 22 healthy age-matched subjects. Monoclonal antibodies were used to detect the whole T cell population (OKT3), T helper cells (OKT4), and T suppressor/cytotoxic cells (OKT8) by indirect immunofluorescence on isolated peripheral blood mononuclear cells. A subset of scleroderma patients (i.e. 30% or eight of 28 patients) exhibited an elevated ratio of OKT4/OKT8 cells which could be accounted for, mainly by a reduction in OKT8 cells compared with controls. The scleroderma patients with an elevated OKT4/OKT8 ratio tended to be younger, have a shorter disease duration and more extensive skin involvement than patients with a normal OKT4/OKT8 ratio. There was no correlation with the presence of autoantibodies, drug therapy, or HLA-DR type. In order to further determine whether this imbalance in immunoregulatory cell subpopulations was specific for scleroderma, we further studied 16 patients with psoriatic arthritis but without manifest autoimmunity and delineated a similar subset of patients with an elevated OKT4/OKT8 cell ratio (i.e. 38% or six of 16 patients). The results demonstrate similar immunoregulatory T cell imbalances in patients with scleroderma and psoriatic arthritis. These findings suggest that numerical imbalances in lymphocyte subpopulations may not be specific for autoimmune disorders.