Diagnostic Value of T-Cell Interferon-γ Release Assays on Cerebrospinal Fluid for Tuberculous Meningitis.

Ling Qin,Lifan Zhang,Xiaochun Shi,Xiaoqing Liu,Yueqiu Zhang,Yao Zhang,Lei Gao

doi:10.1371/journal.pone.0141814

Abstract

Diagnosis of tuberculous meningitis (TBM) remains a challenge. This study aimed to evaluate the performance of T-SPOT.TB test on cerebrospinal fluid mononuclear cells (CSFMCs) for suspected TBM patients. 43 consecutive patients with suspected TBM were enrolled in the study from June 2011 to September 2014. T-SPOT.TB was performed on both CSFMCs and peripheral blood mononuclear cells (PBMCs). The final diagnosis of TBM was independent of the T-SPOT.TB result. The diagnostic sensitivity, specificity, predictive value, and likelihood ratio of T-SPOT.TB on CSFMCs and PBMCs were analyzed. Of the 43 patients, 12 (27.9%) were finally diagnosed with TBM, 28 (65.1%) with non-TBM, and 3 (7.0%) with indeterminate diagnoses. Of 40 cases with definite diagnoses, the sensitivity and specificity were 92.0% and 96.0% for T-SPOT.TB on CSFMCs, and 83.0% and 82.0% for T-SPOT.TB on PBMCs, respectively. The positive predictive value (PPV) and negative predictive value (NPV) of T-SPOT.TB on CSFMCs were 85.0% and 96.0%, respectively. The PPV and NPV were 67.0% and 92.0% for T-SPOT.TB on PBMCs. The difference of T-SPOT.TB between CSFMCs and PBMCs was not significant so far as sensitivity, specificity, PPV, and NPV were concerned (P>0.05 for each). However, T-SPOT.TB on CSFMC and CSFMC: PBMC in TBM cases seemed higher than that in non-TBM cases. Our study further showed that T-SPOT.TB on CSFMCs might be a rapid and accurate diagnostic test for TBM. CSFMC: PBMC T-SPOT.TB ratio might be useful for the early diagnosis of TBM.

Highlights

Tuberculosis (TB) which is caused by Mycobacterium tuberculosis (MTB) primarily infects the lungs but it affects other parts of the body
Our study further showed that TSPOT.TB on cerebrospinal fluid mononuclear cells (CSFMCs) might be a rapid and accurate diagnostic test for Tuberculous meningitis (TBM)
We found that T-SPOT.TB on CSFMC is a useful diagnostic test for assessment of patients with suspected TBM, with higher sensitivity (92%, 95% confidence intervals (CI) [62%, 100%]) and specificity (93%,95%CI [76%, 99%]) than traditional standard diagnostic tests

Summary

Introduction

Tuberculosis (TB) which is caused by Mycobacterium tuberculosis (MTB) primarily infects the lungs but it affects other parts of the body. Tuberculous meningitis (TBM) is one of the most severe forms of TB. The mortality of TBM is 20–41% in the developed world, and 44– 69% in developing nations[1]. Diagnosis is challenging due to the non-specific symptoms or signs of TBM and the low sensitivity of tubercle bacilli culture in cerebrospinal fluid (CSF). T-Cell Interferon-γ Release Assays and Tuberculous Meningitis

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