Immunologic Reactions of Lepromatous Leprosy

To the Editor: In his recent editorial, Waksman (N Engl J Med 286:431–432, 1972), in discussing measurement of cell-mediated immunity (CMI), makes reference to dysfunction of the CMI system as being responsible for reaction in lepromatous leprosy (known as erythema nodosum leprosum or ENL). Although patients with lepromatous leprosy have defective CMI,¹⁴ which may be one factor responsible for the development of lepromatous disease in the first place,⁵ the specific immunologic reaction referred to in the editorial is mediated by the humoral antibody system. Antibody reacts with excess mycobacterial antigen from dead bacilli. In a zone of “excess antigen” these.