Effect of Direct Acting Antivirals (DAAs) on Myeloid-Derived Suppressor Cells Population in Egyptian Chronic Hepatitis C Virus Patients: A Potential Immunomodulatory Role of DAAs

Chronic hepatitis C is a major health concern with high morbidity and mortality rates. The introduction of direct acting antivirals (DAAs) as a first-line treatment for hepatitis C virus (HCV) has significantly enhanced HCV eradication. However, DAA therapy is facing rising concerns regarding long-term safety, viral resistance, and reinfection. HCV is associated with different immune alteration mechanisms that can evade immunity and establish persistent infection. One of these suggested mechanisms is the accumulation of myeloid-derived suppressor cells (MDSCs), which is known to accumulate in chronic inflammatory conditions. Moreover, the role of DAA in restoring immunity after successful viral eradication is still unclear and needs further investigations. Thus, we aimed to investigate the role of MDSCs in chronic HCV Egyptian patients and its response to DAA in treated compared with untreated patients. Fifty untreated chronic hepatitis C (CHC) patients, 50 DAA-treated CHC patients, and 30 healthy individuals were recruited. We used flow cytometer analysis to measure MDSCs frequency and enzyme-linked immunosorbent assay analysis to evaluate the serum level of interferon (IFN)-gamma. We found a significant elevation in MDSC% among the untreated group (34.5 +/- 12.4%) compared with the DAA-treated group (18.3 +/- 6.7%), while the control group had a mean of (3.8 +/- 1.6%). IFN-gamma concentration was higher in treated patients compared with untreated. We also found a significant negative correlation (rs -0.662) (p < 0.001) between MDSC% and IFN-gamma concentration among treated HCV patients. Our results revealed important evidence of MDSCs accumulation in CHC patients and partial retrieval of the immune system regulatory function after DAA therapy.