Numerical changes in T cell subsets (T gamma and T mu) in leprosy patients.

Eighty-six leprosy patients (49 active lepromatous, 24 inactive lepromatous 7 borderline, and 6 tuberculoid) and nine healthy controls were examined for numerical changes in T cell subsets (T gamma and T mu), and complement levels in peripheral blood to determine the roles of T cell subsets and complement in the etiology of leprosy. The percentage and number of T gamma and T mu showed no significant differences among the different clinical groups, but 4 out of 49 active lepromatous, 3 out of 24 inactive lepromatous and 3 out of 7 borderline cases showed a high prcentage of T gamma cells. Serum concentrations of C4, C3c, and C3 activator, an important factor in the alternative pathway of complement activation, were not significantly different among the groups. However, C3 activator and C3c concentrations were significantly high in active lepromatous patients complicated by an immune complex disease called "erythema nodosum leprosum" (ENL) compared with ENL-free active lepromatous leprosy.