Steroid pulse therapy for rheumatoid arthritis: effect on lymphocyte subsets and mononuclear cell adhesion

Eighteen patients with clinically active rheumatoid arthritis, satisfying the ARA criteria, were admitted to hospital for i.v. methylprednisolone pulse therapy. Studies of circulating lymphocyte subsets 1 h before and 24 h after pulsing were carried out together with studies on their adhesion to endothelium-containing lamina propria of porcine gut at various time points. Additionally, circulating VCAM-1 was estimated pre- and post-pulse by ELISA. We observed a marked fall (59%) in mononuclear cell adhesion 24 h post-pulse therapy (P < 0.001). Accompanying this was a significant, though slight, fall in circulating mononuclear cells (P < 0.01), mainly involving T cells. However, the degree of reduction in cell adhesion did not appear to reflect change in any particular circulating subset, but was more likely due to changes in adhesion molecule expression of several subsets. No significant change in circulating VCAM-1 was observed. It would appear, therefore, that the early beneficial effect of steroid pulsing in rheumatoid arthritis coincides with a demonstrable reduction in cell adhesion to gut. This may have implications for the pathogenesis of this disease.