Hepatitis E Virus (HEV) is a globally widespread pathogen that causes acute hepatitis infection. Beyond hepatic pathogenesis, HEV has been proven to cause several extrahepatic manifestations, such as neurological, renal, and hematological manifestations. It was also associated with mortality in pregnant females. Several studies have investigated the impact of HEV on the male reproductive system; however, the available data are limited and conflicting. Assessment of the patients’ ejaculates/semen samples revealed that HEV particles are excreted in these fluids in cases of chronic infection but not acute infection. The excreted HEV particles are infectious to in vivo animal models and in vitro cell culture. However, the effect of HEV infection on male infertility is not confirmed. One study including human samples showed male infertility associated with HEV genotype 4 infection. Studies of HEV infection in animal models such as pigs, gerbils, and mice showed that HEV infection caused distortion on the testes, damage of the blood–testis barrier, and induction of inflammatory responses leading to abnormalities in the sperm. The excretion of HEV in the semen fluids raises concerns about HEV transmission via sexual transmission. However, all available data do not confirm the transmission of HEV through sexual intercourse. This review aims to summarize and critically assess the available studies investigating the influence of different HEV genotypes on the male reproductive system, providing insights into whether HEV contributes to reproductive impairment in men.

Dendritic cells (DCs) play a crucial role in controlling viral infections. Little is known about the changes in frequencies of the DC subsets in patients with chronic hepatitis C (CHC), particularly in the era of interferon-free regimens. We aimed to evaluate the impact of sofosbuvir/daclatasvir on the frequency of different peripheral DC subsets, the expression of the inhibitory CD200R and its ligand CD200 on DC, and their relation to the treatment outcome. A total of 1000 patients with CHC were enrolled and treated with a fixed oral dose of 400 mg of sofosbuvir and 60 mg of daclatasvir for 12 weeks. A total of 940 patients achieved sustained virologic response (SVR), and only 60 patients were non-responders (NRs). The frequencies of the peripheral plasmacytoid (pDC) and myeloid (mDCs) subsets and their surface expressions of CD200R and CD200 molecules were analyzed using flow cytometry. This analysis included 60 non-responders (NR group), 60 randomly selected sustained virologic responders (SVR group) at baseline, and at the end of treatment, and 60 healthy controls. HCV infection was associated with a down-regulation in the frequency of mDC, compared to healthy controls. In addition, mDC in HCV-infected patients showed lower levels of CD200R. However, neither the pDC frequency nor their CD200R expression was significantly altered. Interestingly, by the end of therapy, the frequencies of circulating mDCs and CD200R⁺mDC increased significantly in the SVR group and were even comparable to healthy controls. The levels of these cells were not normalized in the NR group. Percentages of mDCs and CD200R⁺mDC subsets showed good prognostic accuracy for predicting virologic response to therapy. Our results showed that HCV infection was associated with modulation of the mDC frequency and their surface expression of CD200R. Successful daclatasvir and sofosbuvir combined therapy was associated with the normalization of the percentages of mDC and CD200R⁺mDC.