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

W Shi, J Wu, Q Tan, CM Hu, X Zhang… - Infection and drug …, 2019 - Taylor & Francis
W Shi, J Wu, Q Tan, CM Hu, X Zhang, HQ Pan, Z Yang, MY He, M Yu, B Zhang, WP Xie…
Infection and drug resistance, 2019Taylor & Francis
Purpose 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. Patients and methods 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 …
Purpose
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.
Patients and methods
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.
Results
We found that plasma IDO activity was significantly higher in the MDR-TB patients than in the DS-TB patients (p=0.012) and in the LC patients (p=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 (p=0.042), proving a positive correlation between lung cavity number and cavity size (p<0.05, separately) among all the TB patients studied.
Conclusion
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.
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