A study of antibody response in leprosy.

Serologic reactions in leprosy infection have not been studied with as much interest as other aspects of the infection, for various reasons. Inability to cultivate the causative agent in vitro has made preparation of even relatively purc antigens difficult. Positive serologic tes ts are not characterized by an absolute specificity for leprosy, in part because no antigen. specific f~r the leprosy bacillus has been Isolated. FInally, serologic reactions are of little use to the clinician, because of the lack of specificity mentioned and because the presence of antibodies is in no way correlated with the state of resistance of the patient. In spite of these factors, there are a growing number of noteworthy observations concerning antibody production in leprosy. Reports by Rees and co-workers (7) , Sushida and Hirano (8), Navalkar et al. (5), and others indicate that antibodies reactive in precipitin tests with a wide variety of mycobacterial antigens are produ ced by most patients with lepromatous leprosy and many patients with borderline leprosy. In contrast, very few patients with tuberculoid leprosy have detectable circulating antibody against mycobacterial antigens. Nonspecific serologic activities also are pronounced in lepromatous leprosy. Sera from these patients often give false positive tests for syphilis, and more recently Bonomo et al. (I) and Matthews and Trautman (4), among others, have reported the presence of auto-immune antibodies.