An ELISA-inhibition test using monoclonal antibody for the serology of leprosy.

In this study a mouse monoclonal antibody (47-9) is described, which recognized an epitope on the 36 kD protein antigen of M. leprae. The monoclonal antibody showed specificity for M. leprae. An ELISA-inhibition test based on the competitive inhibition by antibodies from human test sera of the binding of the enzyme labelled monoclonal antibody to M. leprae was developed. Seropositivity was found in 100% of the multibacillary leprosy patients group and in 91% of the paucibacillary patients. Only 5% of the 223 control sera were positive. Because of the high seropositivity found in both multi- and paucibacillary patients, it is suggested that the epitope on the 36 kD antigen is immuno-dominant. Therefore the ELISA-inhibition test described herein might well be a suitable tool for diagnosis of leprosy.