Immunoglobulins in leprosy.

Serum immunoglobulins IgG, IgA and IgM were estimated in 22 lepromatous (LL) patients, 28 tuberculoid (TT), 9 borderline tuberculoid (BT), and 8 borderline lepromatous (BL), and compared with 50 normal healthy adult males belonging to a low socio-economic class. Immunoglobulin IgM was invariably significantly raised in TT, BT and LL subgroups of leprosy patients compared to the control but variation among different subgroups was statistically insignificant. Mean serum IgA levels were also raised in TT, BL and LL subgroups but statistically the rise was not significant. In the BT subgroup, significantly low IgA levels were observed both compared to the control and the other leprosy subgroups. Immunoglobulin G levels were significantly raised only in the LL subgroups compared to the control and the other subgroups of leprosy patients. It is proposed that persistently raised gamma globulins and immunoglobulin G, A and M levels observed in lepromatous leprosy patients could be caused by macrophage blockade hindering the suppressor T-cell mediated homeostatic control for immunoglobulins.