Real-time fluorescence Loop-Mediated Isothermal Amplification (LAMP) for rapid and reliable diagnosis of pulmonary tuberculosis

• Real-time fluorescence LAMP can detect the standard MTB strains.
• Limit of detection of real-time fluorescence LAMP was 102 CFU/mL.
• Real-time fluorescence LAMP is superior to Q-PCR to detect PTB infection.

A reliable, simple and rapid diagnostic method that can be helpful in pulmonary tuberculosis diagnosis is urgently needed. Loop-mediated Isothermal Amplification (LAMP) allows DNA to be amplified rapidly at a constant temperature. In this study, real-time fluorescence LAMP was evaluated to rapidly detect Mycobacterium tuberculosis in sputum and was compared to the performance of real-time fluorescence quantitative PCR (Q-PCR). All the standard MTB strains were successfully detected and limit of detection (LOD) was 102 CFU/mL by real-time fluorescence LAMP within 20 min. In light of MTB in sputum, the real-time fluorescence LAMP method yielded a sensitivity of 98.0% and a specificity of 78.3%, compared to Q-PCR assay, which yielded a sensitivity of 96.0% and a specificity of 82.6% for PTB diagnosis. There was an excellent overall agreement between LAMP and Q-PCR for PTB (κ = 0.315) and non-PTB (κ = 0.862). Therefore, the real-time fluorescence LAMP assay is a rapid, sensitive, and specific method to detect pulmonary tuberculosis.