Tuberculous meningitis (TBM) is the most severe manifestation of tuberculosis and its diagnosis remains a challenge even today due to the lack of an adequate test. TBM is the most common form of neuro-tuberculosis and the fifth most common form of extra-pulmonary TB. Early diagnosis and prompt treatment are the cornerstones of effective disease management and to address this challenge scientists in India have come forth.
Through the Department of Biotechnology (DBT) and Biotechnology Industry Research Assistance Council (BIRAC) funding a diagnostic test for TB meningitis (the most severe form of TB that affects the central nervous system) with nearly 100% sensitivity and about 91% specificity has been developed by All India Institute of Medical Science (AIIMS) and Translational Health Science and Technology Institute (THSTI) team lead by Jaya Sivaswami Tyagi from Department of Biotechnology-AIIMS and Dr. Tarun Kumar Sharma from Centre for Bio-design and Diagnostics THSTI. In this research collaborative support of these institutes also played a very significant role: Dr. RML Hospital, IIT-Indore and Uttarakhand Technical University (UTU).
An aptamer based test is developed. This aptamer-based test will bridge the current diagnostic gap for TBM and can be used in hospitals in near future for the rapid diagnosis of TBM.
This test is based on a high affinity DNA aptamer that can efficiently recognize HspX, a potent TBM biomarker of Mycobacterium tuberculosis in cerebrospinal fluid. The clinical utility of HspX was established for the detection of TBM by Prof. Jaya Tyagi of AIIMS and Dr Sagarika Halder of THSTI using an antibody-based ELISA. However, antibody evinces high level of batch-to-batch variation and poses difficulty in maintaining the uniform quality of a diagnostic reagent.
To address the afore-mentioned challenge, Prof. Tyagi -led team that includes Mr. Abhijeet Dhiman (a Ph.D student at AIIMS) and Dr. Tarun K. Sharma (an aptamer expert at THSTI) have developed a DNA aptamer that can efficiently detect HspX antigen in cerebrospinal fluid. Further, being a synthetic DNA molecule, aptamer can provide a constant supply of a uniform quality reagent for rapid diagnosis of TBM. Scientists have adapted this test to a sensor format that can give sample-to-answer in ~30min.
This aptamer-based diagnostic test for TB meningitis has been patented by AIIMS and THSTI and licensed to AptaBharat Innovation Pvt. Limited, a THSTI spinoff founded by Dr. Tarun K. Sharma.
Inputs from :
Dr. Tarun Kumar Sharma
Translational Health Science and Technology Institute
Dr. Jyoti M Logani
Department of Biotechnology