What is the rt-LAMP Assay?
- The rt-LAMP assay is a molecular diagnostic tool similar to GeneXpert and Truenat, providing high sensitivity and specificity. It can detect TB DNA even when only 10 copies per microlitre are present, enabling early-stage diagnosis.
- Unlike RT-PCR, which requires three different temperature cycles, rt-LAMP works at a single temperature, simplifying the testing process.
- The test uses six primers for DNA amplification (compared to two in RT-PCR), ensuring faster and more specific detection.
- The researchers used a fluorescent dye (Syto 16)—commonly used in cell biology—which does not inhibit the reaction, solving the long-standing issue of false negatives in earlier LAMP tests.
- Results can be detected in 10–20 minutes, significantly reducing diagnostic time compared to RT-PCR.
Regulatory Status
- The rt-LAMP assay has been licensed to the industry for production.
- It has received approval from the Central Drugs Standard Control Organisation (CDSCO).
- The Indian Council of Medical Research (ICMR) is currently validating the technology.
- The World Health Organization’s Health Technology Access Pool (HTAP) also evaluates the test, pending ICMR validation.
Significance for India’s TB Control Strategy
- As of 2023, around 79% of presumptive TB cases in India were still being diagnosed using sputum smear microscopy, while only 21% used molecular tests.
- Despite the rise in molecular testing labs (from 5,090 in 2022 to 6,496 in 2023), India still falls short of the targets set under the National Strategic Plan (2017–2025) to reduce reliance on smear microscopy.
- The indigenous rt-LAMP assay could help bridge the diagnostic gap, by providing a low-cost, rapid, scalable, and accurate alternative to outdated smear techniques.
- It supports the National TB Elimination Programme (NTEP) by enabling faster case detection, reducing disease transmission, and improving public health outcomes.
