Diagnostic accuracy study of Loop mediated isothermal amplification in detaction of Mycobacterium Tuberculosis in Pakistan
Umme Farwa; Asim Saeed; Afreenish Hassan; Umme Farwa; Shahid Ahmad Abbasi; Asim Ali Shah
Abstract:
The study has been conducted in Armed Forces Institute of Pathology, Rawalpindi Pakistan from 2015 to 2017. The study was done to determine the adequacy of Loop-mediated Isothermal Amplification for the detection of Mycobacterium tuberculosis. A cross sectional study was done on 72 clinical sputum samples taken from the patient suspected of tuberculosis using a novel technique LAMP targeting IS6110 gene sequence for the first time in Pakistan. Six primers recognizing eight distinct regions on the target sequence were employed. The assay was performed in total volume of 25 μl containing primers, DNA polymerase, Fluorescent dye and sample incubated at 65°C for 60 minutes along with positive and negative controls. LAMP amplicons were detected by their fluorescence under UV light and compared with gold standard MGIT culture system and smear microscopy. Out of 72 total samples 60(83.3%) were LAMP positive and 61(84.7%) were MGIT positive. Its specificity, sensitivity is 100% and 98.36% respectively with PPV 100% and NPV 91.6%. According to our study the LAMP assay is suggested to be a potential nucleic acid based diagnostic method for TB detection in developing countries.
Keywords: Loop Mediated Isothermal Amplification (LAMP), IS6110 gene, Mycobacterium tuberculosis. Mycobacterium Growth Indicator Tube (MGIT)