EXPERIMENTAL LEPROSY IN MONKEYS .2. LONGITUDINAL SEROLOGICAL OBSERVATIONS IN SOOTY MANGABEY MONKEYS

In this study, 11 SMM were grouped and inoculated with differing doses of SMM-origin Mycobacterium leprae (ML) between 4.5 x 10(8) and 1 x 1 0(9) by either combined IV/IC routes or by IV or IC route alone. The c ombined route was the most effective in eliciting progressive, dissemi nated LL leprosy. In all, 6 of 7 SMM inoculated by the combined routes developed leprosy requiring treatment at some point. Only 1 of 4 inoc ulated by a single route developed persisting leprosy requiring chemot herapy. Either no disease or spontaneous regression of initial disease occurred in the other 3 animals inoculated by a single route. Doses i n excess of 1 x 10(9) ML were more effective than lesser doses. An ass ociation was observed between the development of IgG anti-PGL-I ELISA OD values and resistance to leprosy and between IgM anti-PGL-I and lep rosy progression or susceptibility. Serum PGL-I antigen levels, determ ined by dot ELISA, paralleled disease severity longitudinally. High po sitive OD values of anti-LAM IgG prior to ML inoculation were observed in the majority of leprosy-susceptible SMM in contrast to negative le vels in more resistant animals. Anti-LAM IgG OD values exceeded the po sitive cut-off point after inoculation in 5 of 11 SMM; 3 of these 5 ha d concurrent detectable serum levels of PGL-I antigen.