Abstract: Objective  To evaluate the diagnostic value of a loop-mediated isothermal amplification (LAMP) method for rapid detection of Mycobacterium tuberculosis.  Methods  2129 sputum samples of suspected TB patients from 6 cities in Guangdong province and 337 enriched sputum samples randomly selected from Guangzhou and Shantou cities were collected. M. tuberculosis in 2129 sputum samples were detected by smear, Roche solid culture and LAMP methods. M. tuberculosis in 337 sputum samples were detected by quantitative polymerase chain reaction (qPCR) and LAMP methods.  Results  For 2129 sputum samples, the positive rates of smear, culture and LAMP were 13.2%（282/2129）, 21.7%（463/2129）and 20.3%(432/2129), respectively. Compared with Roche culture method, sensitivity, specificity, positive predictive value and negative predictive value of the LAMP method were 89.1%(432/485), 95.5%(1570/1644), 85.4%(432/506) and 96.7%(1570/1623), respectively. For 337 enriched sputum samples, the positive rates of qPCR and LAMP were 35.0% (118/337) and 35.9% (121/337), respectively. Compared LAMP with smear, culture and qPCR, the consistent rate of the results were 87.9%（K=0.612）, 96.1%（K=0.89）and 91.4%（K=0.812）, respectively. Conclusion  The LAMP method was equivalent to culture and qPCR, superior to smear method in detecting M. tuberculosis of sputum specimens. In addition, LAMP method showed the advantages of rapid, simple operation and no equipment, indicating good prospects for clinical application and promotion in the diagnosis of tuberculosis.

Key words: Mycobacterium tuberculosis, Nucleic acid amplification techiques