A comparison of lymphoproliferative responses to Mycobacterium leprae in healthy contacts, tuberculoid and long-treated lepromatous leprosy patients

Abstract

The lymphoproliferative responses to Mycobacterium leprae and BCG, for comparative purposes, were studied in three groups of individuals: 1) a group of 8 healthy contacts (HC) of leprosy patients, 2) a group of 3 tuberculoid leprosy (TT) patients and 3) a group of 3 long-treated lepromatous leprosy (TLL) patients. All subjects in the study responded positively to M. leprae with mean responses of 27565 cpm. 36489 cpm and 8312 cpm in the HC, TT and TLL groups respectively. The similar response patterns in the three groups to the 18 and 65 kDa antigens of M. leprae showed that these antigens could not be used to discriminate between patients and normals or between TT and LL patients. Analysis of the CD4/ CD8 percentages of the lymphoproliferative responses to M. leprae (62/28 in HC, 76/24 in TT & 51/18 in TLL) revealed that the HC, TT and TLL groups of individuals showed a similar CD4:CD8 ratio with the CD4 cell being the predominant responding cell. The αβ/γδ analysis of the lymphoproliferative responses to M. leprae revealed that the γδ percentages were comparable in the three groups of individuals (19 % in HC, 13 % in TT & 19 % in TLL).