Late‐onset intrauterine growth restriction and HHV‐6 infection: A pilot study

Background Late onset intra-uterine growth restriction (IUGR) refers to impaired growth and development of the fetus, characterized by placental morphological abnormalities that affect the fetus supply of nutrients. Human Leukocyte Antigen-G (HLA-G) is physiologically expressed during pregnancy, but in normal placenta decreased during the last weeks of gestation possibly inducing childbirth. Several viruses involved in congenital infection, such as herpesviruses, exploit HLA-G expression as an immune-escape mechanism. To date, despite different congenital herpetic infections have been associated with late IUGR, no direct implication of HHV-6 infection, has been reported. Methods We evaluated HLA-G expression and HHV-6 infection in 11 placentas from late onset IUGR newborns and 11 placentas from uncomplicated pregnancies by histopathological and immunohistochemistry analysis. Results We found higher levels of HLA-G expression and HHV-6 presence in IUGR placenta samples compared with control placenta samples. Conclusions We report HHV-6 staining in IUGR placenta samples, characterized by high HLA-G expression. These preliminary data suggest a possible involvement of HHV-6 infection in HLA-G deregulation that might affect vessel remodeling and prevent the correct pregnancy outcome in IUGR condition. This article is protected by copyright. All rights reserved.