Journal Article

Diagnostic Accuracy of Intracellular Mycobacterium tuberculosis Detection for Tuberculous Meningitis

Yang, Yi-ning, Niu, Guo-qiang, Hao, Xiao-ke, Duan, Li-xin, Su, Xiu-chu, Ma, Lei, Zhang, Jin-she, Wang, Shou-lian, Han, Cui-juan, Liu, Jian-jun, Lin, Zhi-hui, Liu, Jia-yun, Wu, Hai-qin, Lin, Hong, Liu, Ting-ting, Xue, Xin, Dai, Wen, He, Ying, Bian, Ting, Li, Jin-ge, Zhou, Bai-yu, Tian, Ye, Xue, Chang-hu, Zhao, Gang, Feng, Guo-dong, Zhang, Li, Shi, Ming, Chang, Xiao-lin, Song, Yun-zhang, Wang, Jing, Zhang, Min, Jian, Qian, Chen, Ping, Han, Xiao-fang, Wang, Bing-ju, Thwaites, Guy E., Fan, Xin-hong, Wang, Jian-feng

2014

Overview

Abstract Rationale Early diagnosis and treatment of tuberculous meningitis saves lives, but current laboratory diagnostic tests lack sensitivity. Objectives We investigated whether the detection of intracellular bacteria by a modified Ziehl-Neelsen stain and early secretory antigen target (ESAT)-6 in cerebrospinal fluid leukocytes improves tuberculous meningitis diagnosis. Methods Cerebrospinal fluid specimens from patients with suspected tuberculous meningitis were stained by conventional Ziehl-Neelsen stain, a modified Ziehl-Neelsen stain involving cytospin slides with Triton processing, and an ESAT-6 immunocytochemical stain. Acid-fast bacteria and ESAT-6–expressing leukocytes were detected by microscopy. All tests were performed prospectively in a central laboratory by experienced technicians masked to the patients’ final diagnosis. Measurements and Main Results Two hundred and eighty patients with suspected tuberculous meningitis were enrolled. Thirty-seven had Mycobacterium tuberculosis cultured from cerebrospinal fluid; 40 had a microbiologically confirmed alternative diagnosis; the rest had probable or possible tuberculous meningitis according to published criteria. Against a clinical diagnostic gold standard the sensitivity of conventional Ziehl-Neelsen stain was 3.3% (95% confidence interval, 1.6–6.7%), compared with 82.9% (95% confidence interval, 77.4–87.3%) for modified Ziehl-Neelsen stain and 75.1% (95% confidence interval, 68.8–80.6%) for ESAT-6 immunostain. Intracellular bacteria were seen in 87.8% of the slides positive by the modified Ziehl-Neelsen stain. The specificity of modified Ziehl-Neelsen and ESAT-6 stain was 85.0% (95% confidence interval, 69.4–93.8%) and 90.0% (95% confidence interval, 75.4–96.7%), respectively. Conclusions Enhanced bacterial detection by simple modification of the Ziehl-Neelsen stain and an ESAT-6 intracellular stain improve the laboratory diagnosis of tuberculous meningitis.

• Publisher: Oxford University Press,American Thoracic Society
• Subject: Acids / Adolescent / Adult / Aged / Aged, 80 and over / Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy / Antigens / Antigens, Bacterial - cerebrospinal fluid / Bacteria / Bacterial diseases / Bacterial diseases of the nervous system. Bacterial myositis / Bacterial Proteins - cerebrospinal fluid / Biological and medical sciences / Biomarkers - cerebrospinal fluid / Cerebrospinal fluid / Child / Child, Preschool / Confidence intervals / Consent / Diagnostic tests / Female / Human bacterial diseases / Humans / Immunohistochemistry / Infectious diseases / Intensive care medicine / Laboratories / Leukocytes / Leukocytes - microbiology / Male / Medical sciences / Meningitis / Microscopy / Middle Aged / Mycobacterium tuberculosis - immunology / Mycobacterium tuberculosis - isolation & purification / Original / Patients / Pneumology / Prospective Studies / Sensitivity and Specificity / Staining and Labeling / Stains & staining / Tuberculosis / Tuberculosis and atypical mycobacterial infections / Tuberculosis, Meningeal - cerebrospinal fluid / Tuberculosis, Meningeal - diagnosis / Young Adult