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

Wen-Wen Sun,Qing Zhang,Li-Ping Yan,Qin Sun

doi:10.18632/oncotarget.15734

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.

Highlights

Tuberculous meningitis (TBM) patients often show no specific clinical manifestations
In the 172 TBM patients, Acid-fast bacillus (AFB), MGIT960 culture, Loop-mediated isothermal amplification (LAMP) and RTFQ PCR were performed for the diagnosis of TBM
It is characterized by the cerebrovascular and brain parenchyma lesions caused by the blood-borne spread of Mycobacterium tuberculosis, leading to subsequent implantation in the meninges, pia mater and the subarachnoid space

Summary

Introduction

Tuberculous meningitis (TBM) patients often show no specific clinical manifestations. The positive rate of pathogen detection is low [1]. The change in cerebrospinal fluid (CSF) parameters is atypical, which is similar to those of new cryptococcal meningitis and viral meningitis [1]. Early diagnosis of TBM is difficult [1]. Loop-mediated isothermal amplification (LAMP) is a new nucleic acid amplification method in the detection of Mycobacterium tuberculosis complex (MTBC) [2]. It is simple and sensitive method, which doesn’t require expensive instruments and laboratory environments [3]

Methods

Results

Conclusion