The leprosy spectrum and possible mechanisms of tissue damage

Clinical spectrum of tuberculoid (TT), borderline tuberculoid (BT), borderline borderline(BB), borderline lepromatous (BL), and lepromatous (LL) leprosy. Each has characteristic cell-mediated or humoral immune profile. Lepromatous leprosy is characterized by aTh2 T-cell immune response, antibody complex formation, the absence of granulomas, and failure to restrain M. leprae growth. Tuberculoid leprosy features Th1 T-cell cytokine response, vigorous T-cell responses to M. leprae antigen, and containment of the infection in well-formed granulomas.