Effect of corticosteroid on lymphocyte adhesion.

Pulse steroid therapy is utilised in the treatment of vasculitis and active rheumatoid arthritis. Decreased entry of lymphocytes to sites of cell-mediated immune reactions is well recognised, though the mechanism is not fully understood. It may involve adhesion to endothelium. We have therefore measured the effect of methylprednisolone on lymphocyte adhesion to porcine lamina propria endothelium. A marked decrease in adhesion was found after incubating cells at 4 degrees C or at room temperature, with a clear dose response effect, from 0.46mM to 6.3mM. We have previously demonstrated binding of rheumatoid synovial fluid mononuclear cells to lamina propria endothelium. It is suggested that the ameliorating effect of steroid pulsing may be mediated by down-regulating adhesin expression of a gut-seeking population of cells.