Cell-mediated and humoral immunity in leprosy in children

Cell-mediated and humoral immunity were studied in 25 children between 0 and 14 years with leprosy. Cell-mediated immunity was studied in vivo by lepromin and epicutaneous sensitization with dinitrochlorobenzene (DNCB) and T-lymphocytes and their subpopulations (T4 and T8) in the peripheral blood. Humoral immunity was evaluated by B-lymphocyte count and immunoglobulins (IgG, IgM and IgA). Along with complement, component C3 was also measured in the serum. Lepromin (Mitsuda) and DNCB responses were significantly poor in mid-borderline (BB) leprosy. The hematological profile, including T-lymphocytes, their subpopulations, B-lymphocytes, serum immunoglobulins, and C3, were found to be normal in all forms of leprosy. The relatively short duration of disease and the low bacterial load may explain these findings.