Improved serodiagnosis of tuberculosis using two assay test.

Abstract

SUMMARY An antigen capture immunoassay was developed for the detection of mycobacterial antigens in sera from patients with tuberculosis. The assay was evaluated together with an antibody measuring enzyme immunoassay in a clinical trial for serodiagnosis of tuberculosis.Sensitivity of the antibody assay for active pulmonary tuberculosis, including relapsed infections, was 75%, and specificity with other lung diseases was 97%. Sensitivity for extrapulmonary tuberculosis was 84-5% and specificity 84%. Sensitivity of the antigen assay for active tuberculosis was 45% with no false positive reactions. Combination of the results from the two assays increased total sensitivity to 96-5% with a positive predictive value of 0-81 and a negative predictive value of 0-98.The two assay test was relatively simple to perform and offered improved serological diagnosis of tuberculosis over a single antibody test.

Development of Antigen Detection Assay for Diagnosis of Tuberculosis Using Sputum Samples

“…Preliminary results have been published on new diagnostic tests for tuberculosis based on detection of mycobacterial antigens in cerebrospinal fluid (10,13), serum (11,14), and sputum (4,22). The authors reported sensitivity rates of 45 to 88% and specificity rates of 91 to 100%.…”

Serodiagnostic efficiency of phospholipid associated protein of Mycobacterium tuberculosis H37Rv

“…Although ELISA may not confirm active tuberculosis infection in these samples it is definitely helpful in discriminating between the persons with tuberculosis infection and those with other infections. To recognise mycobacterial infection with high predictability, two assay tests one detecting antigen the other antibodies in the same clinical sample have been proposed [18]. However, in our study a single assay detecting IgG antibodies showed quite promising operational validity with 93% sensitivity and 100% specificity which are comparable to the two-assay tests [18].…”

“…To recognise mycobacterial infection with high predictability, two assay tests one detecting antigen the other antibodies in the same clinical sample have been proposed [18]. However, in our study a single assay detecting IgG antibodies showed quite promising operational validity with 93% sensitivity and 100% specificity which are comparable to the two-assay tests [18]. Polyclonal antisera that can be used for detecting mycobacterial infection have been documented [29].…”

Serodiagnosis of tuberculosis

“…The problem of the immune complex must also be solved in order to decrease the false negatives. It is likely that future tests will include assays for both antigens from and antibodies against the tuberculous organism [20]. Monoclonal antibodies will remain important in many respects: for the purification of specific antigens, for competitive inhibition tests, or for antigen capturing assays.…”