Genetic Polymorphism Of Human Cytomegalovirus Glycoprotein H And Its Relation To The Clinical Features Of Cytomegaloviral Hepatitis In Infants From Zhejiang Region,China

Objectives:Human cytomegalovirus (HCMV) infection in children is very common in our country and mostly happens in the infant period. Liver is one of the important target organs of infant HCMV infection. Cytomegaloviral hepatitis is the most common liver disease seriously affecting the children’s health in China. Most gene sequences of HCMV are highly conserved, but some of them are polymorphic, such as the genes encoding envelope glycoproteins. At present, many studies have confirmed that the viral genetic polymorphism is associated with different pathogenic patterns. The aim of this study is to explore the genetic polymorphism of envelope glycoprotein H (gH) in clinical HCMV strains isolated from infants with cytomegaloviral hepatitis and its relation to the clinical features of HCMV hepatitis. The results revealed in this study will be helpful for further research on the pathogenesis and subunit vaccines of HCMV infection.Methods:1) The fresh urine samples of infants with cytomegaloviral hepatitis were collected. The results of quantitative HCMV-DNA test of urine samples were positive, and at least one result of serum HCMV-IgM antibody and PP65 antigen in peripheral blood was positive in all patients. All of the patients had different levels of liver function damage.2) A method based on Taqman probes and fluorescence quantitative PCR for detecting gH genotypes was established.3) The gH genotypes of clinical HCMV strains were analyzed using fluorescence quantitative PCR. The polymorphism of different gH genotypes was analyzed by gel electrophoresis and DNA sequencing.4) SPSS 17.0 was used to carry out the statistical analysis of T test and Chi square test, P<0.05 was considered as statistically significant.Results:1) All of the 101 cases were divided into two types,68 cases were infected with HCMV type gHl,29 cases were infected with HCMV type gH2 and 4 cases were infected with both of them. gH1 was the dominant genotype of HCMV gH gene in 101 cases of clinical specimens and the difference was statistically significant (x 2=67.045, P<0.01).2) The distribution of HCMV gH genotypes in each age group was not different, and the gHl type was the dominant type in all age groups.3) The infants of the jaundice hepatitis group were mainly below 3 months and there were no differences in age distribution among the patients with non-jaundice hepatitis. There were no differences in HCMV gH genotypes in the patients with jaundice and non-jaundice hepatitis.4) The values of ALT and AST in the patients infected with HCMV genotype gHl were significantly higher than those infected with HCMV genotype gH2, while the values of TB and DB in the patients infected with HCMV genotype gH2 were significantly higher than those infected with HCMV genotype gHl and the differences were statistically significant.Conclusion:1) A rapid, sensitive and specific method based on Taqman probes and fluorescence quantitative PCR for HCMV gH genotyping was established in this study.2) The dominant gH genotype of HCMV clinical strains isolated from infants with HCMV hepatitis in Zhejiang region was gHl, and the sequence of gH gene was relatively conservative, but there was still a certain polymorphism.3) The HCMV gH genotypes were related to the clinical characteristics of HCMV hepatitis in. infants...