COMPARATIVE-ASSESSMENT OF THE LEPROSY ANTIBODY ABSORPTION TEST, MYCOBACTERIUM-LEPRAE EXTRACT ENZYME-LINKED-IMMUNOSORBENT-ASSAY, AND GELATINPARTICLE AGGLUTINATION-TEST FOR SERODIAGNOSIS OF LEPROMATOUS LEPROSY

A comparative assessment of three serological methods for leprosy diag nosis (the fluorescent leprosy antibody absorption [FLA-ABS] test, the Mycobacterium leprae soluble-extract enzyme-linked immunosorbent assa y [ELISA], and the M. leprae particle agglutination [MLPA] test) was c arried out. The objective was to identify their performance in clinica l and epidemiological diagnosis of leprosy. The study group included 4 5 lepromatous leprosy patients under treatment. Specificity was >95% f or all three assays, and sensitivity was 95, 58, and 74% for the FLA-A BS test, the MLPA test, and the ELISA, respectively. The only cross-re activity for M. tuberculosis-infected patients was with the soluble-ex tract ELISA. Although the FIA-ABS test displayed the highest specifici ty and sensitivity values, it can only be used in well-developed labor atories, and the patient's clinical and epidemiological background mus t be considered when results are interpreted because the test remains positive after therapeutic success and could be positive for some hous ehold contacts. The MLPA test is easier to perform and interpret, and it is adequate for small laboratories and epidemiological studies inte nded to detect active untreated or irregularly treated leprosy cases. Therefore, the FLA-ABS and MLPA tests are complementary, and both shou ld be used for serodiagnosis of leprosy.