The demonstration of two types of suppressor mechanism in leprosy patients and their contacts by quadruple skin-testing with mycobacterial reagent mixtures

Abstract

Summary A previous study in Nepal involving skin-testing simultaneously with four different mycobacterial reagents (three of them mixtures) re vealed that the addition, in the same skin-test site, of pooled reagents from fast-g rowing mycobacteria locally suppressed the response to pooled slow growers. This finding has been confirmed in Bombay . It has also been shown that the addition of reagents prepared from certain fast-growing species to that prepared from slow-growers in one skin-test site will suppress the re sponse to the same slow-grower reagent injected alone in the other arm. This type of suppression probably requires recognition of species-specific antigens of the fast-growing species concerned. The importance of the observations in relation to leprosy and possible mechanisms underlying them are discussed.In a preliminary investigation of responsiveness to shared and species-specific mycobacterial antigens carried out in a Nepalese leprosy hospital! it was shown that patients had a markedly reduced response to both groups i and ii antigens as defined previously . 2 It was also demonstrated that a proportion of people exhibited suppression of their responses to the group iv antigens of slowly growing species when injected as a mixture with the antigens of rapidly growing species. This suppression appeared to be specifically triggered by the group iv antigens of some of the rapidly growing species.

Tuberculosis into the next century: Proceedings of a symposium held on 4 February 1995 at the Liverpool School of Tropical Medicine

“…The value of killed M. vaccae as an immunotherapeutic agent was suggested both by the enhanced recognition of group i, common, mycobacterial antigen found after vaccination of healthy persons, and by a series of mixed skin test studies [255]. Sonicates of M. vaccae and of a few other species, when mixed with reagents expected to induce large and potentially necrotic responses, controlled the size and quality of the response locally and at distant sites [256] where the reagent being controlled was injected alone.…”