Multi-targeted loop mediated amplification PCR for diagnosis of extrapulmonary tuberculosis.

Aims: The present study was conceived to evaluate multi-targeted loop mediated amplification (MLAMP) for the rapid diagnosis of extrapulmonary tuberculosis (EPTB).
Methods and Results: A total of 700 patients were included who were classified into 2 groups: Group 1 (n = 400) included a 100 culture confirmed EPTB patients and 300 culture negative, suspected EPTB patients. Group 2 (n = 300) included negative controls from non-tubercular patients. All samples were subjected to Ziehl-Neelsen microscopy, solid culture on Lowenstein Jensen media, Polymerase chain reaction (PCR) targeting IS6110 gene and LAMP targeting both IS6110 and MPB64 individually and as MLAMP. The overall sensitivity of microscopy, culture, IS6110 PCR, IS6110 LAMP, MPB64 LAMP and the MLAMP assay were 12%, 25%, 72.5%, 80% and 86.6% respectively and the specificity of all the tests was 100%.
Conclusion: MLAMP is a rapid robust tool for the diagnosis of EPTB and utilizing two targets for M. tuberculosis can improve the overall sensitivity and increase the yield of detection from extrapulmonary samples. The rapidity, ease of performance and low cost make MLAMP an excellent alternative in low-income, resource limited settings.
Competing Interests: Conflicts of interest All authors have none to declare.
(Copyright © 2020 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.)