A combination of Mycobacterium tuberculosis-derived sRNA and endogenous miRNA in circulation as novel auxiliary diagnostic markers for patients with multidrug-resistant tuberculosis.

OBJECTIVE: Circulating non-coding small RNAs (sRNAs) have recently emerged as promising biomarkers for Mycobacterium tuberculosis (Mtb). However, little is known about the expression patterns and combined diagnostic potential of M. tuberculosis-derived sRNA (TB-sRNA) and endogenous miRNA in the circulation of patients with multidrug-resistant tuberculosis (MDR-TB).

METHODS: Illumina sequencing by synthesis technology and quantitative real-time polymerase chain reaction were used to identify TB-sRNAs in serum and sputum from patients infected with drug-resistant TB, drug-sensitive TB (DS-TB), and controls. Simultaneously, four endogenous miRNAs - miR-29c, miR-132, miR-320b, and miR-548e - were chosen for further study. The diagnostic performance of significantly altered sRNAs and miRNAs was analysed using receiver operating characteristic (ROC) curves.

RESULTS: Illumina sequencing by synthesis combined with individual quantitative real-time polymerase chain reaction verification successfully identified one TB-encoded sRNA, named TB-sRNA015, and endogenous miR-132 were significantly elevated in patients with MDR-TB compared to patients with DS-TB and controls (P < 0.01). ROC analyses showed that the area under the ROC curve (AUC) for serum sRNA015 discriminating patients with MDR-TB from controls and patients with DS-TB were 0.774 (95% confidence interval [CI], 0.653-0.895) and 0.692 (95% CI, 0.560-0.825), respectively. For serum miR-132, the AUCs were 0.841 (95% CI, 0.735-0.946) for MDR-TB vs. controls and 0.655 (95% CI, 0.518-0.793) for MDR-TB vs. DS-TB. Importantly, combining sRNA015 with miR-132 increased the AUC to 0.860 (95% CI, 0.760-0.960) for discriminating MDR-TB from controls.

CONCLUSIONS: The combination of serum sRNA015 and miR-132 may serve as an auxiliary diagnostic tool for MDR-TB infection.