HHV-6A infection might increase infertility in Women
Human herpesvirus 6 (HHV-6) was the 6th herpesvirus found. HHV-6 was separated in 1986 during endeavors to discover novel infections in patients with lymphoproliferative diseases. HHV-6 involves 2 variants HHV-6A and HHV-6B. HHV-6B infection causes the roseola infantum, where as HHV-6A pathology are still unclear. After basic contamination, HHV-6 stays dormant unless the invulnerable framework is traded off, at which time the infection may reactivate. HHV-6 remains latent in lymphocytes and monocytes and persists at low levels in cells and tissues. The other diseases associated with HHV-6 infection includes pneumonitis, liver disease, multiple sclerosis, myocarditis, drug induced hypersensitivity syndrome and autoimmune diseases.
Both HHV-6 types contaminate basically T-cells. However, HHV-6A can reproduces in human neural stem cells, oligodendrocyte progenitor cells and hepatocytes, while HHV-6B disease in astrocytes and hepatocytes result in abortive infections. In addition HHV-6A can also infect CD8+ T cells, natural killer cells and gamma/delta T cells. Some proof proposes that HHV-6 can likewise contaminate and duplicate in the human genital tract as HHV-6 genetic materials were detected from pregnant and non-pregnant women. A few studies have reported low-level HHV-6 shedding from the genital tract in up to 25% of ladies with pregnant ladies portrayed by the most elevated commonness of shedding. The conceivable pathogenic significance for the genital nearness of HHV-6 merits watchful assessment.
The understudied aspects of HHV-6 infections in women genital tracts during pregnancy are of real interests to two research groups at University of Ferrara and University of Geneve. The groups investigated the nearness of HHV-6 disease in two cohorts of ladies with varying levels of fertility. Uterine flushing and endometrium biopsies were analysed for HHV-6A and HHV-6B infections from group of women with primary infertile visiting infertility clinic in Italy as well as second cohort of fertile women. From the biopsies collected from two different women cohorts, HHV-6 DNA presence was quantified. The first line of defense against HHV-6 infection are endometrial Natural Killer cells, hence the team analyzed the percentage and immune-phenotype of resident of NK cells harboring HHV-6 infection.
HHV-6A DNA was found in 43% of endometrial biopsies from primary infertile women cohort, yet not in control cohort. Endometrial NK cells displayed an alternate conveyance in infertile women cohort HHV-6A contamination compared to fertile with no HHV-6A infections. Results acquired from several biochemical studies and cytokine evaluations, the current study suggest that HHV-6A infection as the important contributor for infertility development in women due to changes in endometrial NK cells profile and ability to sustain successful pregnancy.
Marci R, Gentili V, Bortolotti D, Lo Monte G, Caselli E, Bolzani S, et al. Presence of HHV-6A in Endometrial Epithelial Cells from Women with Primary Unexplained Infertility. PLoS One. 2016;11(7):e0158304. doi: 10.1371/journal.pone.0158304. PubMed PMID: 27367597