Development of diagnosis method for LTBI with circulating miRNA

When exposed to M. tuberculosis, 25-50% become infected, of which 10-20% having several symptoms. Currently, there is no marker for judging the efficacy of M tuberculosis (Mtb) treatment, and it is judged based on the appearance of subjective symptoms and radiological findings. In this study, we attempted to establish a marker to distinguish patients who relapsed after TB treatment from patients who had recurrence after TB treatment using the information of circulating miRNA expression. Thirty two patients with tuberculosis infection aged 18 years or older were enrolled. 16 patients had onset or recurrence of TB and 16 patients with latent tuberculosis infection (LTBI) with positive test for Interferon gamma release assays (IGRA) and no chest X-ray examination. Total RNA from serum in exosome-rich fraction was extracted and then miRNA expression analysis was performed using a next-generation sequencer and NGS data analyzed using miRDeep2. Using expression information of nine miRNAs, TB and LTBI could be separated with 71.8% accuracy. The odds ratio also was 6.16, and the p-value was 3.20e-02, respectively. The expression of hsa-miR-122-5p was significantly different between TB and LTBI (p <0.05). Here we established a novel method to efficiently differentiate LTBI from patients with tuberculosis infection. Since this method can be performed in a low invasive manner such as blood sampling, it is promising tool for utilizing follow-up of TB treatment. Overall design: Examination of circulating miRNA in tuberculosis and latent tuberculosis infection