Comparative study of the 48-hour response to soluble antigens obtained from human and armadillo leprosy material in lepromatous leprosy patients and normal persons, contacts of leprosy patients.

We prepared antigens by precipitating with 80% ammonium sulfate supernatants of human and armadillo antigen at a concentration of 160 X 10(6) bacteria per ml. The precipitate was resuspended, dialyzed and filtered. The antigen obtained was inactivated with trypsin during 30 minutes. The tests made with these antigens were negative for the 48-hour test in lepromatous patients and highly positive in normal persons who were contacts of leprosy patients.