Cytomegalovirus GH Genotyping In Congenital Cytomegalovirus Infection And Immune Thrombocytopenia In Children

ObjectiveHuman cytomegalovirus(HCMV)infection is prevalent in Chinese children,and primary infections occur mostly in infants and young children.Congenital HCMV infection,immune thrombocytopenia and infantile hepatitis syndrome are the main manifestations of HCMV infection.Many studies have confirmed that HCMV glycoprotein gene polymorphism is related to disease distribution,clinical manifestations and prognosis.Our research explored genetic polymorphism of envelope glycoprotein H(gH)in infant HCMV clinical isolates to investigate the relationship between different gH gene types and congenital HCMV infection and Immune thrombocytopenia(ITP)with HCMV infection,providing clinical clues for further study of the role of glycoproteins in the pathogenesis of HCMV and reference for the diagnosis,treatment,follow-up and vaccine research of HCMV infection-related diseases.Methods1025 HCMV-DNA positive urine samples from patients with HCMV infection were collected in our hospital from July 1,2013 to December 31,2015.HCMV quantitative and gH typing were performed by real-time fluorescence quantitative PCR.Case data of successfully-typed newborns within 3 weeks were retrospectively analyzed for the association between genotype distribution and clinical features and prognosis of patients with congenital HCMV infection.Meanwhile,case data of successfully-typed ITP patients were retrospectively analysed for the relationship between genotype distribution and clinical manifestations and prognosis of ITP patients with HCMV infection.Rusult1.A total of 35 cases were diagnosed as congenital HCMV infection,comprising 21 cases of gHl type HCMV infection and 14 cases of gH2 type HCMV infection.No mixed infections were found.Gestational age of gH1 group was smaller than gH2 group(P<0.05).All the 5 premature infants were infected with gHl type HCMV.Direct bilirubin(DBil)level in the gH1 group was significantly higher than that in the gH2 group(P<0.05).Neonatal Auditory brainstem response showed moderate to severe hearing loss mainly occurred in gH1 type group.The probability of brain retardation were 28.6%in gH1 group and 33.3%in gH2 group(P>0.05).The Alarcon score of Neuroimaging Scale was positively correlated with the probability of brain retardation.Among the 7 children with dysplastic nervous system,2 patients with gH2 type HCMV infection developed without obvious symptoms associated with HCMV infection in the neonatal period.2.There were 37 cases of ITP with HCMV infection,and 36 cases were newly diagnosed as ITP.Among them,there were 23 cases of gH1 type,13 cases ofgH2 type,and 1 case of mixed infection of gH1 and gH2.Among the 36 newly diagnosed ITP patients with HCMV infection,gH1 genotype was dominant in all age groups,with no statistical difference in distribution among different age groups.There was no difference in clinical manifestations between the two genotypes.The platelet recovery rate of gH2 type was lower than that of gH1 type(P<0.05).Conclusion:1.gH1 is the main type of congenital HCMV infection.Compared with gH2 infection,gH1 infection in children has a smaller gestational age and higher direct bilirubin.Early moderate to severe hearing impairment and above were mainly caused by gH1 infection.Among children with dysplasia of nervous system,asymptomatic infection was mainly caused by gH2 type.2.gH1 type is the main glycoprotein genotype of ITP children with HCMV infection while ITP patients with gH2-type HCMV infection are accompanied with high recurrence or prolonged thrombocytopenia.3.The difference of gH genotype is closely related to the clinical manifestations and prognosis of children with HCMV infection,which can provide reference for clinical diagnosis,treatment and follow-up as well as clinical clues for further study of the relationship between HCMV genotype and cell tropism.