Performance of T-Track(®) TB, a Novel Dual Marker RT-qPCR-Based Whole-Blood Test for Improved Detection of Active Tuberculosis

Tuberculosis (TB) is one of the leading causes of death by an infectious disease. It remains a major health burden worldwide, in part due to misdiagnosis. Therefore, improved diagnostic tests allowing the faster and more reliable diagnosis of patients with active TB are urgently needed. This prospective study examined the performance of the new molecular whole-blood test T-Track(®) TB, which relies on the combined evaluation of IFNG and CXCL10 mRNA levels, and compared it to that of the QuantiFERON(®)-TB Gold Plus (QFT-Plus) enzyme-linked immunosorbent assay (ELISA). Diagnostic accuracy and agreement analyses were conducted on the whole blood of 181 active TB patients and 163 non-TB controls. T-Track(®) TB presented sensitivity of 94.9% and specificity of 93.8% for the detection of active TB vs. non-TB controls. In comparison, the QFT-Plus ELISA showed sensitivity of 84.3%. The sensitivity of T-Track(®) TB was significantly higher (p < 0.001) than that of QFT-Plus. The overall agreement of T-Track(®) TB with QFT-Plus to diagnose active TB was 87.9%. Out of 21 samples with discordant results, 19 were correctly classified by T-Track(®) TB while misclassified by QFT-Plus (T-Track(®) TB-positive/QFT-Plus-negative), and two samples were misclassified by T-Track(®) TB while correctly classified by QFT-Plus (T-Track(®) TB-negative/QFT-Plus-positive). Our results demonstrate the excellent performance of the T-Track(®) TB molecular assay and its suitability to accurately detect TB infection and discriminate active TB patients from non-infected controls.