STUDIES ON THE DELAYD TYPE ALLERGY BY MURINE LEPROSY BACILLUS

I. RELATION BETWEEN LEPROMIN TEST AND TUBERCULIN TEST

Abstract

Studies have been made by many investigators on the allergic reaction to leprosy bacilli and the presence of common antigens between tubercle bacilli and leprosy bacilli. In the present investigation, the experiments were undertaken to show that a similar antigen as P.P.D, would be contained in murine leprosy bacilli, using skin reaction in guinea pigs.
Groups of guinea pigs were sensitized with tubercle bacilli (H37RV), killed by phenol treatment, B.C.G. and suspensions of murine leprosy bacilli, obtained from the leproms of infected mice. These antigens, suspended in paraffin oil, were used for sensitization. The old tuberclin, P.P.D, and the suspension of murine leprosy bacilli (S. D. antigen) prepared by the Dharmendra's method, gave definite allegic reactions in all groups of sensitized guinea pigs, indicating these results of cross-reaction between tubercle bacilli and murine leprosy bacilli.
The allergic reactions appeared several hours after the injection of the antigens, reached maxium 24 to 48 hours later.
The similar allergic skin reactions were observed in guinea pigs passively sensitized with peritoneal cells of the actively sensitized animals but not in the guinea pigs sensitized with immunosera. An immediate increase of capillary permeability of the skin was not detected by the injection of S.D. antigen to both guinea pigs, sensitized with either tubercle bacilli or murine leprosy bacilli, in spite of the definite wheal and redness after 24 to 48 hours suggesting that the reaction is delayd type. Also the reaction of cornea, which is characteristic for delayd type allergy was observed by the intra-corneal injection of O.T. or P.P.D. to the guinea pigs sensitized with murine leprosy bacilli. From these findings, it became obvious that murine leprosy bacilli contains a similar antigen as the tuberculo-protein and that the allergic reaction observed are delayd type in nature.