The Research Of Hepatitis B Virus Father-to-neonate Vertical Transmission

BackgroudThe infection of Hepatitis B virus(HBV) is a global problem which threatens the human being health. According to statistics ,one third of the world population ,about 20 billion, had got HBV in 2004, containing 350 million HBV carriers, and 10 million people died of liver failure, liver cirrhosis, primary liver cancer caused by HBV. It is highly endemic in Asia and Africa, especially there is 120 million taking up one tenth of the whole population in China.About 80% of the whole HBV carriers got HBV through the family and the other 20% through blood, body fluid and medical paths .It has been proved that mother-to-neonate vertical transmission can be effectively cut by the active and passive immune blockers.The hypothesis of HBV father-to-neonate transmission : Early in 70s, foreign researcher had detected the hepatitis B virus surface antigen(HbsAg), indicating that semen may be infectious. In 1985, Hadchoul discovered the presence of HBV DNA sequence in two samples which integrated in spermatozoa was consistent with the restriction enzyme patterns of celluar DNA using molecular hybridization when they studied the presence and state of HBV DNA in sperm samples, indicating the possibility of true vertical transmission to HBV via the germ line. And they proposed the hypothesis of HBV vertical transmission via the germ line. Recently, several scientists did lots of researches from clinical investigation ,molecular level and animal models experiments to find the proof and path of vertical transmission from father to neonate since the hypothesis had been proposed.This study is to analyze if it is possible that vertical transmission from father to neonate happens and there is a relationship between HBV serum gene type and variance in gene with vertical transmission from father to neonate through investigation of infective rate of vertical transmission from father to neonate and through the molecular level study.Objective:1. To discuss the possibility of HBV transmission from father to neonate with molecular methods through HBV DNA polymerase chain reaction with the cord blood of neonates whose father was positive of HBV, and whose mother was negative of HBV in serum.2. To study the serum gene type of HBV of cord blood samples positive in HBV DNA PCR tests through detecting the base sequence of HBV DNA S zone.3. To study the variation of HBV DNA S zone gene . Methods:1 .TO detect the presence of HBV in cord blood of neonate from 56 pairs of couples whose father was positive with HBV, and whose mother was negative of HBV and without other kinds of hepatitis causing by virus, using HBV DNA polymerase chain reaction .2 .To analyze the gene type of the cord blood which had been detected the presence of HBV by detecting the HBV DNA S zone sequence through the DNA synthesis termination method chain end.3 .To detect the variation of S zone gene sequence of the cord blood which had been detected the presence of HBV.Results:1 .There was two samples(4%,2/56) which detected HBV DNA in cord blood from neonate of couples with positive HbsAg father and negative HbsAg mother by using HBV DNA PCR technology.2 .To found that two samples serum gene type of HBV DNA is type B, when detecting the HBV DNA S zone gene base sequence .3 .To found the variation of the nucleotide in the sequence of HBV DNA S zone sequence of that two samples by detecting the base sequcence .Conclusion:1. HBV can be transmitted from HbsAg positive father to next generation with the proof of detecting HBV DNA in the cord blood of neonates of couples in which father carried HbsAg, but mother didn't.2. Indicating that HBV was easy to transmitting to next generation with increasing of HBV copies, and had relationship with HBeAg.3. Found the hemology of S zone sequence of gene in HBV between the two pairs of positive samples and HBV genotype B , the similarity was 97.19%,98.50% and 98.69%,98.89%.4. Found the hemology of S zone sequence of gene in HBV between the two pairs of fathers and neonates , the similarity was 98.56% and 99.06%,and the neonate's HBV DNA sequence got variation.