Aptamer-Based TB Antigen Tests for the Rapid Diagnosis of Pulmonary Tuberculosis: Potential Utility in Screening for Tuberculosis.
ACS Infect Dis
; 4(12): 1718-1726, 2018 12 14.
Article
em En
| MEDLINE
| ID: mdl-30350564
ABSTRACT
Pulmonary tuberculosis is the most common manifestation of tuberculosis, and to this day, sputum smear microscopy remains the most widely used diagnostic test in resource-limited settings despite its suboptimal sensitivity. Here we report the development of two DNA aptamer-based diagnostic tests, namely aptamer linked immobilized sorbent assay (Aptamer ALISA) and electrochemical sensor (ECS), for the direct detection of a TB biomarker HspX in sputum. First we compared the performance of Aptamer ALISA with anti-HspX polyclonal antibody-based enzyme linked immunosorbent assay (Antibody ELISA) in a blinded study of 314 sputum specimens. Aptamer ALISA displayed a high sensitivity of 94.1% (95% CI 86.8-98%) as compared to 68.2% sensitivity (95% CI 57.2-77.9%) of Antibody ELISA ( p-value < 0.05) using culture as the reference standard without compromising test specificity of 100%. Out of nine smear-negative culture-positive samples, six were positive by Aptamer ALISA and only two were detected by Antibody ELISA. ALISA detected as positive 80 of 85 culture-positive TB as compared to 57 of 81 diagnosed as TB by X-ray ( p-value < 0.0001). These findings demonstrate the superiority of the aptamer-based test over smear microscopy, antibody-based ELISA, and chest X-ray for TB detection ( p-value < 0.0001 for all). Further, we have developed a â¼30 min point-of-care ECS test that discriminates between tuberculous and nontuberculous sputum with a sensitivity of â¼92.3% and specificity of 91.2%. The tests developed in the current study cost â¼$1-3/test and have potential utility in active case finding in high-risk groups and screening for pulmonary TB among presumptive TB subjects.
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MEDLINE
Assunto principal:
Tuberculose Pulmonar
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Ensaio de Imunoadsorção Enzimática
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Aptâmeros de Nucleotídeos
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Mycobacterium tuberculosis
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article