Assessment of cell free mitochondrial DNA as a biomarker of disease severity in different viral infections

Objective: Cell Free mitochondrial DNA (CF mt-DNA) has emerged as a novel biomarker to investigate disease pathophysiology of different infections. The present study was designed to elucidate the association between CF mt-DNA, IL-6 and viral load in HIV, HBV and HCV infections and predict its role as a potential biomarker to assess the disease severity in viral infections.

Methods: Total 120 blood samples were collected from January 2018 to December 2018 of HIV, HBV and HCV patients and healthy controls (30 samples in each group). DNA and RNA were extracted from the serum to determine the levels of CF mt-DNA and viral load, respectively. IL-6 from the serum of infected individuals was quantified with ELISA.

Results: HCV patients showed the highest levels of CF mt-DNA, IL-6 and viral load, followed by HBV and HIV. Significant correlation was found between CF mt-DNA and IL-6 among the HBV patients (p=0.017). However, no significant correlation of CF mt-DNA was observed with IL-6 in HIV and HCV or with the viral load in any of the three infections.

Conclusion: Elevated CF mt-DNA indicates its role in severity of viral infections. Independence of CF mt-DNA expression from viral load and IL-6 in case of HIV and HCV suggests involvement of other inflammatory pathways regulating CF mt-DNA elevation.