Value of ELISA Using A60 Antigen in the Serodiagnosis of Tuberculosis

Abstract

This study was set in a general, university hospital in the Canary Islands, with the objective to evaluate an enzyme-linked immunosorbent assay (ELISA) using A60 in the serodiagnosis of tuberculosis. IgG antibody to A60 was determined in 205 patients with active disease [149 culture-positive patients with pulmonary tuberculosis (positive sputum smear 94, negative sputum smear 55) and 56 patients with extrapulmonary tuberculosis], 20 patients with inactive disease, 22 patients with lepromatous leprosy, and 51 controls. The mean levels of anti-A60 antibodies were significanctly higher in patients with active disease as compared with controls or patients with inactive disease. Differences were also found between tuberculous patients with pulmonary and extrapulmonary disease. In patients with pulmonary disease, significant differences were detected between smear-positive and smear-negative patients. The overall sensitivity of the test (cutoff 240 ELISA units) was 52.2%. The highest sensitivity was found among smear-positive patients with pulmonary tuberculosis (67%) and the lowest among those with extrapulmonary tuberculosis (32.1%). We conclude that ELISA for the measurement of IgG antibody to Mycobacterium tuberculosis antigen A60 could be of interest, specially in smear-negative cases and extrapulmonary tuberculosis.

A systematic review of commercial serological antibody detection tests for the diagnosis of extrapulmonary tuberculosis

“…[41][42][43][44][45][46][47] As seen in table 2 (and in online supplementary fig S1A available at http://thorax.bmj.com/supplemental), sensitivity estimates ranged from 0.26 to 1.00 and specificity estimates from 0.59 to 1.00. The specificity forest plot (online supplementary fig S1B available at http://thorax.bmj.com/ supplemental) includes 7 unique studies as 4 of the total 10 studies were conducted with the same comparison population.…”

“…[41][42][43][44][45][46][47][48][49] None of the studies reported the method (eg, consecutive or random) of subject selection. Only one study 48 ELISA was used in 20 studies and immunochromatography in one study.…”

Serodiagnosis of tuberculosis by enzyme immunoassay using A60 antigen

“…The sensitivity and specificity for IgG against A60 in pulmonary tuberculosis cases were found to be 36–91% and 68–98%, respectively [16–24]. In this study, we found the sensitivity and specificity values for IgG A60 to be 53.6% and 94.7%, considering the active tuberculosis group and healthy individuals.…”

Needle Aspiration and Cytology for Suspected Osteoarticular Tuberculosis in Children

“…The enzyme-linked immunosorbent assay (ELISA) has a reported sensitivity of 32% with EPTB against the mycobacterial antigen A60 25 . The technique of DNA amplification (CBNAAT/Genexpert) by polymerase chain reaction (PCR) has further improved sensitivity by detecting the presence of extremely small quantities of MTB in clinical samples 26 .…”