Comparison of loop-mediated isothermal amplification and real-time PCR for the diagnosis of tuberculous pleurisy

Aims: Tuberculous pleurisy is an important cause of pleural effusions in areas with a high incidence of tuberculosis. In this study, we developed an IS1081-based LAMP for the detection of Mycobacterium tuberculosis complex and investigated its usefulness in the diagnosis of tuberculous pleurisy. Methods and Results: Investigation of pleural effusion samples from patients with tuberculous pleurisy, majority of them smear-/culture-negative, and control individuals with non-TB diseases showed that the LAMP assay with incubation time of 60 min has much higher specificity and the LAMP assay with incubation time of 90 min has significantly higher sensitivity in the diagnosis of tuberculous pleurisy, as compared with fluorescent real-time PCR. Conclusions: The MTBC-LAMP is a useful assay for the diagnosis of tuberculous pleurisy, especially in pleural effusion smear-/culture-negative patients. Significance and Impact of the Study: Tuberculous pleural effusion usually contains low number of mycobacteria, which leads to low diagnostic sensitivity of acid-fast staining and mycobacterial culture methods. In this study, we developed a simple and sensitive LAMP assay for the diagnosis of tuberculous pleurisy. This assay should have broad application in resource-limited settings.