Evaluation of an enzyme immunoassay based on sonicate supernatant antigens of Mycobacterium w for immunodiagnosis of leprosy.

ABSTRACT

An enzyme immunoassay (EIA) based on sonicate supernatant antigens of a cultivable, atypical bacterium, Mycobacterium w (M. w), for immunodiagnosis of leprosy is described. M. w was selected after screening of sonicate supernatant antigens of seven cultivable mycobacteria in EIA. The results of the assay were compared with that of EIA using phenolic glycolipid-I (PGL-I). The M. w assay was more sensitive than PGL-I based EIA, for detection of leprosy patients of all categories, including long term treated patients with low bacterial load. The M. w assay was highly sensitive (93.49%) for detection of active LL patients, and the difference in the positivity of the two assays for LL patients was statistically significant (p 0.05). The combined positivity of the assays with M. w and PGL-I for LL was higher than that with either antigen alone. M. w assay, in addition, was also highly sensitive for detection of patients with active pulmonary tuberculosis.