The application of IS6110-baced loop-mediated isothermal amplification (LAMP) in the early diagnosis of tuberculous meningitis

Abstract

Here, we evaluated the potential activity of rapid Mycobacterium tuberculosis detection with loop-mediated isothermal amplification (LAMP), for the early diagnosis of tuberculous meningitis (TBM). Patients with suspected TBM from January 2014 to December 2015 were reviewed retrospectively. The cerebrospinalfluid(CSF) was collected. Acid-fast bacillus (AFB) staining, MGIT 960 culture, real-time fluorescent quantitative polymerase chain reaction (RTFQ PCR) and LAMP were performed. A total of 200 patients were included in the study. Of which, 172 of them were diagnosed with TBM (86.00%). The sensitivities of AFB staining, MGIT 960 culture, LAMP and RTFQ PCR for TBM diagnosis were 2.91% (5/172), 12.79% (22/172), 43.02% (74/172), and 34.30% (59/172), respectively. The sensitivity of LAMP for TBM was significantly higher than those of AFB staining and MGIT960 culture (χ2 = 75.11, P < 0.001; χ2 = 43.88, P = 0.002). LAMP’s sensitivity was however comparable to RTFQ PCR assay (χ2 = 2.08, P = 0.130). The specificity, positive predictive value and negative predictive value of LAMP in the diagnosis of TBM were 92.86% (26/28), 97.37% (74/76) and 20.97 % (26/124), respectively. The overall consistency between LAMP and RTFQ PCR in the diagnosis of TBM was 88.5% (177/200), with Kappa value of 0.870. The consistency between LAMP and MGIT960 culture was 71% (142/200), with Kappa value of 0.730. Among all the methods, LAMP had high sensitivity, specificity and positive predictive value, showing high consistency with MGIT960 culture and RTFQ PCR.