MicroRNA-155 from sputum as noninvasive biomarker for diagnosis of active pulmonary tuberculosis.

OBJECTIVES

Tuberculosis (TB), caused by , is a widespread infectious disease around the world. Early diagnosis is always important in order to avoid spreading. At present, many studies have confirmed that microRNA (miRNA) could be a useful tool for diagnosis. This study aimed to evaluate whether miRNAs could be regarded as a noninvasive diagnosis biomarker from sputum for pulmonary tuberculosis (PTB).

MATERIALS AND METHODS

The strain H37Rv was incubated and cultured with human macrophage line THP-1. The total RNA was extracted from the THP-1 cells for detection. Six increased expressions of miRNAs were selected by miRNA microarray chips and the miRNAs were confirmed by qRT-PCR in the infection cell model. At last, the efficiency of other methods was compared with using miRNA.

RESULTS

Only miR-155 showed a better diagnostic value for PTB than the other five miRNAs to distinguish PTB from non-PTB, including pneumonia, lung cancer, and unexplained pulmonary nodules. Next, we detected and analyzed the results of 68 PTB patients and 122 non-PTB, the sensitivity and specificity of miR-155 detection was 94.1% and 87.7%, respectively. It was higher than sputum smear detection and anti-TB antibody detection. But slightly lower than ELISpot (97%, 0.404). Interestingly, the ranking of sputum smear by Ziehl-Neelsen staining had positive correlation with the expression level of miR-155 in smear-positive sputum (R=0.8443, <0.05).

CONCLUSION

Our research suggested that miR-155 may be an efficiency biomarker for active PTB diagnosis and bacteria-loads evaluation.