The Plasma Exosomal MicroRNA let-7c-5p as a Potential Circulating Biomarker for Mycobacterium Infection in HIV Population

Background Mycobacterium infection is common in the HIV population. Traditional diagnostic methods have low sensitivity and are time-consuming (smear and culture), and GeneXpert technology is economically expensive. Current testing methods rely on obtaining specimens at the site of the lesion, which is a limitation. Therefore, new biomarkers are urgently needed for the diagnosis of Mycobacterium infection in the HIV population. This study aimed to explore aberrant exosomal miRNA profiles by using miRNA high-throughput sequencing and to identify more accurate molecular biomarkers of Mycobacterium infection in HIV patients. Methods Exosomes were isolated from the plasma of HIV patients infected with Mycobacterium and negative controls and identified by electron microscopy, nanoparticle tracking analysis, and Western blotting. Exosomal miRNAs were profiled by miRNA high-throughput sequencing. The expression of selected plasma exosomal miRNAs was validated by qRT‒PCR. A receiver operating characteristic (ROC) curve was generated to explore the diagnostic value of the selected miRNAs. Results In this study, the plasma exosomal miRNA let-7c-5p, which is significantly upregulated in HIV patients with Mycobacterium infection, was screened by high-throughput sequencing as a candidate biomarker. qRT‒PCR verified that the plasma exosomal miRNA let-7c-5p was significantly upregulated in Mycobacterium-infected HIV patients. The ROC curve showed an area under the curve value of 0.9833 for exosomal miRNA let-7c-5p. Conclusion Our findings suggested that exosomal let-7c-5p was significantly increased in the plasma of Mycobacterium-infected HIV patients. Exosomal let-7c-5p may be a useful potential biomarker for the diagnosis of Mycobacterium infection in HIV patients.