Cell-mediated immunity in the rheumatoid diseases. I. Skin testing and mitogenic responses in sero-negative arthritides.

Cellular immunity has been investigated in patients with various kinds of sero-negative arthritis. The incidence of cutaneous response to recall antigen streptokinase-streptodornase (SK-SD), and the ability to mount a primary cutaneous response to dinitrochlorobenzene (DNCB) have been examined in patients with ankylosing spondylitis and psoriatic arthritis. The results were not significantly different from normal. In vitro lymphocyte transformation in the presence of phytohaemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM) has been measured using peripheral blood lymphocytes from patients with ankylosing spondylitis, psoriatic arthritis and Reiter's disease. In comparison with a control group, significantly reduced responses were found to a low dose of PHA in the ankylosing spondylitis and Reiter disease patients. Significant increase in response occurred to a high dose of PHA, in patients with psoriatic arthritis and Reiter's disease, and to PWM in Reiter's disease patients. The in vitro results in the ankylosing spondylitis, psoriatic arthritis and Reiter's disease patients suggest some abnormality in the T-cell population in sero-negative arthritis.