Protein Biomarkers and Host RNA Expression Profiles in Congenital Cytomegalovirus Infection

Overview

This study seeks to identify and test host protein biomarkers and RNA expression profiles in dried blood spot samples as novel diagnostic markers of congenital cytomegalovirus sequelae and to improve the understanding of the pathogenesis of the disease.

Background: Human cytomegalovirus (CMV) is one of the most common causes of congenital viral infection, leading to a significant number of children with permanent disabilities. It is recognized as the major infectious cause of sensorineural hearing loss (SNHL) and neurodevelopmental abnormalities in infants. Its pathogenesis is largely unknown due to the complex interplay between viral, maternal, placental, and child factors. In Western Europe the incidence is estimated to 0.5-0.7% of all live births. In Denmark there are 240-480 children born every year with CMV infection, but the incidence has not been studied since 1979. Among the congenitally infected infants, approximately 10% are estimated to have symptoms at birth, ranging from mild, such as petechiae, to severe, such as microcephaly. Approximately half of these symptomatic children develop permanent long-term disabilities, such as hearing loss, cognitive and motor developmental delay. Asymptomatic children are also at risk for CMV-related disabilities, and 10-15% will develop SNHL. SNHL after congenital CMV infection may be present at birth or occur later in childhood and therefore, a significant part of these will not be detected in time for diagnosis and appropriate treatment, e.g., ganciclovir within the first 30 days of life. At present, there is no reliable virological marker to determine which infants will develop sequelae. Method: A nationwide retrospective case-control study of all neonates with congenital CMV infection in Denmark from 2010 through 2025. DBS samples will be obtained from the Danish Neonatal Screening Biobank, Statens Serum Institut. Proteomic analyses and RNA sequencing will be performed at the Department for Congenital Disorders, Statens Serum Institut. Cases will be randomly assigned to a "Discovery cohort" and compared to a control group of neonates matched on gestational age, sex, birthweight and age at DBS sample collection. Perspectives: New molecular-based diagnostic tools may contribute to improve early diagnosis and treatment of infants with congenital CMV infection and potentially prevent development of sequelae. Additionally, understanding of the pathogenesis at a molecular level of severe disease manifestations of the disease, could form the basis for development of novel interventions for better prevention and treatment.