Serological studies on leprosy. A comparison of complement-fixation tests using antigens prepared from tubercle bacilli and beef-heart lipids with other serological reactions.

Sera from lepromatous leprosy patients were subjected to a battery of serological tests, including flocculation, agglutination and complement fixation. A correlation was found between the antileprous antibody content and the reactivity with "cardchol" antigen, but not with Trypanosoma cruzi antigen, cardiolipin or Rubino antigen. The reactivity of leprous sera with tubercle bacilli antigen in the quantitative complement-fixation test decreased in three patients with lepromatous leprosy during sulfone treatment. When syphilis was present in a lepromatous leprosy case, it was possible to follow the effect of specific treatment of the two infections, with sulfone and with penicillin, by the drawing of two serological curves-one for leprosy and one for syphilis.