STUDIES ON THE LEPROMIN TEST SENSITIZATION OF GUINEA PIGS WITH HUMAN LEPROSY BACILLI SEPARATED FROM LEPROUS NODULES BY TRYPSIN DIGESTION

Abstract

1) Throughly homogenized leprous nodules were treated with trypsin. The digested material was dialyzed and then centrifuged at 10, 000 r.p.m.. The precipi-tate obtained consisted of leprosy bacilli in almost a pure state after being separate from the tissue components.
2) The leprosy bacilli (3 mg) thus obtained and incorporated with Freund's adjuvant were injected into guinea pigs.
Sensitivity to lepromin turned positive as early as 3 weeks after immunization. This sensitivity lasted for at least 24 hours. In addition, these animals responded more strongly to lepromin of 20 mcg per 0.1 ml than to a 1: 100 dilution of OT.
3) There was a slight difference in lepromin sensitivity between guinea pigs inoculated with 3 mg of leprosy bacilli than those which received 15 mg.
4) Guinea pig injected with leprosy bacilli (3 mg) in combination with 2 mg of the pure wax of tubercle bacillus responded to both tuberculin and lepromin with larger size of skin reaction than those immunized with leprosy bacilli alone. This was particularly true with the former antigen. Consequently, no difference was observed in the reaction size between these two kinds of skin reaction.
5) Skin reactions to both lepromin and tuberculin at 18 weeks after immuniza-tion reached their maximum intensity in 10 to 24 hours after the injection of the antigen. The affected area then gradually decreased until the reaction lesion faded away completely after 7 days.