Development of a highly sensitive rapid diagnostic test for TB meningitis.

An accurate diagnostic test for TB meningitis was developed through a DBT and BIRAC funded collaborative study between AIIMS, New Delhi, Translational Health Science and Technology Institute, Faridabad and Dr. RML Hospital, Indian Institute of Technology Indore. TB meningitis is the most severe form of TB and the rapid diagnosis of TBM remains as an unmet need even today.

In 2009 Dr. Jaya Tyagi’s laboratory at AIIMS reported that CSF filtrate was superior to sediment for detection of TB DNA to make an accurate diagnosis of TB meningitis ¹. Subsequently in 2012, it was demonstrated that the detection of TB antigens such as HspX, was as efficient, without the disadvantage of amplifying TB DNA. In this way, antibody-based detection of HspX antigen enabled accurate ELISA based diagnosis of TB meningitis in a large number of pediatric CSF samples collected at Dr RML Hospital ².

Considering the challenges of upscaling an antibody-based ELISA assay to a point-of-care format, an alternative strategy was utilized to generate a high affinity DNA aptamer against HspX in collaboration with THSTI. An Indian patent application for the aptamers was filed in 2016 ³. Using an aptamer, we have developed a same-day ALISA test having 100% sensitivity and about 91% specificity. This work was recently published in Tuberculosis journal ⁴. We have already converted the test into an electrochemical sensing (ECS) format which becomes point-of-care and gives the result in 30 minutes (manuscript submitted). The latest study ⁴ and previous work ^1,2 were recently covered in media by The Hindu ⁵ and Science chronicle ^6,7 (a Science and Technology blog).

Publications, Patent and Media Coverage: 

1. Haldar S, Sharma N, Gupta VK & Tyagi JS (2009) Efficient diagnosis of tuberculous meningitis by detection of Mycobacterium tuberculosis DNA in cerebrospinal fluid filtrates using PCR. J Med Microbiol. 58: 616-624.

2. Haldar S, Sankhyan N, Sharma N, Bansal A, Jain V, Gupta VK, Juneja M, Mishra D, Kapil A, Singh UB, Gulati S, Kalra V, Tyagi JS. (2012) Detection of Mycobacterium tuberculosis GlcB or HspX Antigens or devR DNA Impacts the Rapid Diagnosis of Tuberculous Meningitis in Children. PLoS ONE 7(9): e44630.

3. A. Dhiman, S. Haldar, S.K. Mishra, N. Sharma, A. Bansal, Y. Ahmad, A. Kumar, T.K. Sharma and J.S. Tyagi. 2018. Generation and application of DNA aptamers against HspX for accurate diagnosis of tuberculous meningitis. Tuberculosis. 112: 27-36. https://doi.org/10.1016/j.tube.2018.07.004.

4. A. Dhiman, T.K. Sharma and J.S. Tyagi. 2018. Novel DNA aptamers against heat shock protein HspX of mycobacterium tuberculosis and uses thereof. Indian patent: 201611001550. http://thsti.res.in/patent_lic_dtl.php?id=31.

5. AIIMS-led team develops highly sensitive, portable test for TB meningitis. The Hindu. July 29, 2018. https://www.thehindu.com/sci-tech/science/aiims-led-team-develops-highly-sensitive-portable-test-for-tb-meningitis/article24541516.ece

6. AIIMS-led team develops highly sensitive, portable test for TB meningitis. Science chronicle (a science and technology blog). Posted on July 28, 2018. https://journosdiary.com/2018/07/28/aiims-tb-meningitis-diagnostics/

7. Podcast: Ten-year journey to develop a diagnostic test for TB meningitis. Science chronicle (a science and technology blog). Posted on July 28, 2018. https://journosdiary.com/2018/07/28/podcast-diagnostic-test-tb-meningitis/