Plasma indoleamine 2,3-dioxygenase activity as a potential biomarker for early diagnosis of multidrug-resistant tuberculosis in tuberculosis patients

• Published in: Infection and drug resistance Vol. 12; pp. 1265 - 1276
• Main Authors: Shi, Wen, Wu, Juan, Tan, Qi, Hu, Chun-Mei, Zhang, Xia, Pan, Hong-Qiu, Yang, Zhen, He, Meng-Yu, Yu, Min, Zhang, Bo, Xie, Wei-Ping, Wang, Hong
• Format: Journal Article
• Language: English
• Published: New Zealand Dove Medical Press Limited 01.05.2019; Dove; Dove Medical Press
• Subjects: Cancer; Cancer patients; CAT scans; cavitary lung lesion; Chromatography; Diagnostic imaging; Evaluation; High performance liquid chromatography; IDO; LC-MS/MS; Liquid chromatography; Lung cancer; Lung diseases; Mass spectrometry; MDR-TB; Medical research; Microbial drug resistance; Original Research; Spectroscopy; Tomography; Tryptophan; Tuberculosis; China; LC-MS/MS; MDR-TB; IDO; cavitary lung lesion
• ISSN: 1178-6973; 1178-6973
• DOI: 10.2147/IDR.S202369

Multidrug-resistant tuberculosis (MDR-TB) remains a challenge of global TB control, with difficulty in early detection of drug-sensitive tuberculosis (DS-TB). We investigate the diagnostic significance of IDO as a potential biomarker to discriminate MDR patients among the TB patients. Plasma indoleamine 2,3-dioxygenase (IDO) was measured by the ratio of kynurenine (Kyn) to tryptophan (Trp) concentrations, using high performance liquid chromatography-mass spectrometry (LC-MS/MS). Chest computed tomography (CT) imaging signs from TB patients were collected and analyzed in 18 DS-TB patients, 16 MDR-TB patients, 6 lung cancer (LC) patients, and 11 healthy individuals. Lung imaging signs from TB patients were collected and analyzed. We found that plasma IDO activity was significantly higher in the MDR-TB patients than in the DS-TB patients ( =0.012) and in the LC patients ( =0.003). We evaluated the diagnostic significance of plasma IDO activity in discriminating the MDR-TB group from the DS-TB group using a receiver operating characteristic (ROC) curve. With a cutoff level of 46.58 uM/mM, the diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for IDO activity were 87.50%, 72.22%, 73.68%, and 86.67%, respectively. Plasma IDO activity was higher in cavity cases than in non-cavity cases ( =0.042), proving a positive correlation between lung cavity number and cavity size ( <0.05, separately) among all the TB patients studied. Our findings confirmed that plasma IDO activity might have an auxiliary diagnosis value for early discrimination of MDR-TB patients from DS-TB patients. Among the TB patients with cavitary lung lesions, higher plasma IDO activity can indicate a higher risk of MDR-TB.