Leprosy can be a devastating
chronic infection that causes nerve function impairment and associated disfigurement. Despite the recent reduction in the number of registered worldwide
leprosy cases as a result of the widespread use of multidrug
therapy, the number of new cases detected each year remains relatively stable. The diagnosis of
leprosy is currently based on the appearance of clinical signs and requires expert clinical, as well as labor-intensive and time-consuming laboratory or histological, evaluation. For the purpose of developing an effective, simple, rapid, and low-cost diagnostic alternative, we have analyzed the serologic antibody response to identify Mycobacterium leprae
proteins that are recognized by
leprosy patients. More than 100 recombinant
antigens were analyzed in a
protein array format to select those with discriminatory properties for
leprosy diagnosis. As expected,
multibacillary leprosy patients recognized more
antigens with stronger antibody responses than
paucibacillary leprosy patients. Our data indicate, however, that multibacillary patients can be distinguished from paucibacillary patients, and both of these groups can be segregated from endemic control groups. We went on to confirm the diagnostic properties of
antigens ML0405 and ML2331 and the LID-1 fusion construct of these two
proteins by
enzyme-linked
immunosorbent assay. We then demonstrated the performance of these
antigens in rapid test formats with a goal of developing a point-of-care diagnostic test. A serological diagnostic test capable of identifying and allowing treatment of
leprosy could reduce transmission, prevent functional disabilities and stigmatizing
deformities, and facilitate
leprosy eradication.