PSORIASIS PATIENTS HAVE T-CELLS WITH REDUCED RESPONSIVENESS TO COMMONMYCOBACTERIAL ANTIGENS

Heparinised blood samples were obtained from 20 patients with chronic plaque psoriasis and from 13 age-matched healthy controls. After preli minary titration, mononuclear cells separated over Ficoll-Tryoson were cultured for 5 days with 10 mu g ml(-1) of 15 mycobacterial preparati ons, or with pokeweed mitogen and concanavalin A. Stimulation indices were determined for each reagent and means were determined for patient s and controls. Results for patients showed a striking reduction of re sponsiveness to mycobacteria, apparently due to loss of responses to g roup i, common mycobacterial antigens, and no differences in responses to mitogens. These observations relate psoriasis to certain other dis eases, notably mycobacterial infections, rheumatoid arthritis, Chagas' disease and human immunodeficiency virus infection. The observations may be relevant to the aetiology of psoriasis, and to potential immuno therapy for the disease. (C) 1998 Published by Elsevier Science B.V.