Fluorescent leprosy antibody absorption (FLA-ABS) test for early serodiagnosis of leprosy

The conventional parameters for the diagnosis of leprosy i.e. clinical symptoms aided by smear and histological examinations, have certain limitations. With the conventional parameters, it is difficult to diagnose new cases in the early stage of leprosy. Recently Abe et al (1976) and Abe and Yoshino (1978) suggested that Florescent Leprosy Antibody Absorption (FLA-ABS) test developed by one of the authors (Abe) might be useful for early serodiagnosis of leprosy. Following this, the FLA-ABS test was standardised at the Central Jalma Institute for Leprosy, Agra to study the usefulness of the test in early serodiagnosis and detection of sub-clinical infections. In the present study sera were collected from 136 cases of different types of leprosy which includes 11 cases with lesions suspected to be leprosy, 58 healthy contacts and 19 healthy controls. Using FLA-ABS test, anti M. leprae antibodies were detected in all types of leprosy irrespective of the type and duration of the disease. The test has shown significantly high positive results in very early cases of leprosy with a duration of 3-6 months and having very small lesions measuring below 2 cms.