Characterization of the cellular immune defect in lepromatous leprosy: a specific lack of circulating Mycobacterium leprae-reactive lymphocytes.

Abstract

The blastogenic response of leucocyte cultures from patients with tuberculoid and lepromatous leprosy has been studied. The leucocytes from the two groups were studied simultaneously and cultivated in the same pool of normal human serum. While the leucocytes from twenty-eight tuberculoid patients responded quite strongly to Mycobacterium leprae after 7 days of culture (average lymphocyte transformation 11·1%), there was a complete lack of response in similar cultures from twenty-seven lepromatous patients (average 0·1% transformed cells). These results were confirmed by studies on cellular incorporation of 3H-thymidine in the cultures from four tuberculoid and four lepromatous patients.