INVITRO LYMPHOCYTE STIMULATION IN LEPROSY - SIMULTANEOUS STIMULATION WITH MYCOBACTERIUM-LEPRAE ANTIGENS AND PHYTOHEMAGGLUTININ

  • 1 January 1979
    • journal article
    • research article
    • Vol. 36  (3) , 479-487
Abstract
Peripheral blood lymphocytes from 105 subjects with different forms of leprosy and healthy contacts of leprosy patients were stimulated in vitro with different preparations of mycobacterial antigens [Ag] alone or in combination with a suboptimal dose of phytohemagglutinin (PHA). In nearly all individuals sonicated leprosy bacilli and PHA together gave a lower 3H-thymidine incorporation than did the same dose of PHA alone. There was no difference in the degree of inhibition seen in the different patient groups or the healthy contacts. High doses of whole, washed M. leprae combined with PHA led to an increased tbymidine incorporation in borderline tuberculoid leprosy patients who had experienced a reversal reaction and in healthy contacts with more than 6 mo. of exposure, while most lepromatous patients and contacts with less than 6 mo. exposure did not show an augmentation of the PHA-induced thymidine incorporation. The inhibition exerted by sonicated M. leprae was dose-dependent, seen with very low doses of Ag and was not due to direct cytotoxicity. M. bovis, strain BCG, was weakly suppressive in combination with PHA and sonicated M. duvalii had a very marked suppressive effect. There was no correlation between the suppressive effect of M. leprae Ag and the other mycobacteria nor was there any correlation with the responses to the mycobacterial Ag alone. Many lepromatous leprosy patients showed significant suppression of background incorporation with addition of M. leprae Ag. The apparent ''non-responsiveness'' in lepromatous leprosy could be due to active suppressor mechanisms operative in vivo.