The relationship between reactivity to tuberculin (PPD-R123) and reactivities to antigens of Mycobacterium leptae (Fernadez, Mitsuda and to a Soluble Protein antigen of M. leprae) was studied using three methods. A clear relationship could be demonstrated with two of the methods. A statistically significant correlation coul be demonstrated by the method of regression analysis between tuberculin and all three types of reactivities; however the level of correlation was unusually low. This study also revealed an increase of all three types of reactivity with BCG vaccination.
