IMMUNOTHERAPY WITH MYCOBACTERIUM-VACCAE IN THE TREATMENT OF PSORIASIS

A placebo-controlled study of immunotherapy with Mycobacterium vaccae for chronic plaque psoriasis showed improvement in the psoriasis area severity index in 19 of 21 immunotherapy recipients (P < 0.005). Minor improvement, not reaching statistical significance for the group, occ urred in nine of 14 placebo recipients. There were losses to follow-up and the placebo used, tetanus toroid, was not ideal. Clinical improve ment after immunotherapy persisted for 6 months and another injection of the immunotherapeutic given to a few volunteers from either group r esulted in benefits lasting a year. Lymphoproliferative tests were car ried out at each clinic visit, and on 50 matched controls. Starting wi th reduced responses to mycobacterial antigens and concanavalin A, bot h treatment groups showed a fall after 3 months, and diverged at 6 mon ths with M. vaccae recipients rising to values similar to those of hea lthy controls, whereas placebo recipients continued to fall. Conclusio ns reached were that immunotherapy with M. vaccae gave long-lasting cl inical benefit to most patients, with minimal side effects. This accom panied a return towards normal cellular immune responsiveness to mycob acterial antigens, which did not follow the use of the placebo. (C) 19 98 Published by Elsevier Science B.V.