The effect of BCG in lepromatous cases of leprosy.

As we have recently reported (2), in cases of lepromatous leprosy, which almost by defiI1ition are lepromin negative, the administration of BCG causes in some cases an increase in the reactivity to lepromin as well as the usual tuberculin conversions. The following are the data there reported, now slightly revised: One hundred and four lepromatous cases, negative to both tuberculin and lepromin, were given one intradermal injection of 0.1 gm. of BCG, and the tuberculin and lepromin tests were repeated after two months. The results were as follows: Tuberculin test.-Of the 104 previously negative cases, 88 showed positive reactions, 10 showed doubtful ' reactions, and 6 remained negative. Lepromin test.-Of the 104 previously negative cases, 12 became definitely positive, 18 showed very slight (1+) late reactions, 15 showed slight early reactions only, and 59 showed no reaction whatever. The two tests together.-Of the 88 becoming tuberculin positive, 11 also became lepromin positive. Of 16 remaining tuberculin negative, 1 became lepromin positive. Of 25 becoming strongly positive to tuberculin, 8 also became lepromin positive. Of 79 not becoming strongly positive to tuberculin (cuti), 4 became lepromin positive. Of 12 who became lepromin positive, 11 also became tuberculin positive. Of 92 who di~ not become lepromin positive, 59 became tuberculin positive. In brief, the definite tuberculin conversions were 88 out of 104, or 84.6 per cent. The definite lepromin conversions were 12 out of 104, or 11.5 per cent, although there were 34 others (32.7%) who showed slight reactions, early or late, but not