Study On The Relation Between HBV Genotype, Mutations In The "A" Determinant Region And Intrauterine Transmission

Objective To study: ①HBV infection status of pregnant women and intrauterineinfection status of their newborns in TaiYuan. ②distribution of HBV genotypesin pregnant women and their newborns in TaiYuan. ③relation between HBVgenotype and intrauterine transmission. ④mutation status in the HBV S gene "a"determinant region of pregnant women and their newborns. ⑤relation betweenHBV S gene "a" determinant region and viral genotypes.Methods Sera from HBsAg positive pregnant women and their newbornsbetween Nov, 2001 and Jul, 2004 in TaiYuan infectious hospital. This paperperformed following study: ①HBsAg, HBeAg, HBV DNA in pregnant womenand their newborns' sera were tested by ELISA and nested PCR. ②HBVgenotypes were determined by nPCR-RFLP and PCR-directed nucleotidesequencing. ③viral's sequence was analyzed through DNAMAN5.5.2. HBV Sgene mutation was analyzed through multiple sequence alignment with sequencesof known genotypes in the Genbank. Amino acid substitutions was analyzedthrough protein translation. ④All data were analyzed by the statistical packagesSPSS 10.0 for windows.Results 1. 62 of 170 HBsAg positive pregnant women's sera were HBeAgpositive , 91 were HBV DNA positive. 8 of 172 newborns sera were HBsAgpositive, 1 was HBeAg positive , 53 were HBV DNA positive. The rate of HBVintrauterine infection was 31.98%.2. In pregnant women , genotype C was 89.86%, genotype B was 8.7%, genotypeD was 1.45%. In newborns, genotype C was 91.89%, genotype B was 8.11%.Other genotype was not found.3. The difference of HBV intrauterine infection rate was not significant betweengenotype B carriers and C carriers.4. S gene sequencing results proved mutation positions in "a" determinantregion were aa125, 126, 127, 131, 135, 137, 140, 143 and 145, with amino acidsubstitutions in most positions.5. The rate of HBV intrauterine infection was not significantly higher inmutant-type carriers than in wild-type carriers(50.00%vs40.00%, p>0.05).6. The rate of "a" determinant region mutation was 11.76%, 16.67% separately ingenotype C and B carriers. The difference was not significant.7. The homogeneity of HBV sequences between mothers and their childrenwere above 98.67.Conclusions 1. Either HBsAg or HBV DNA positive in serum was defined asHBV intrauterine infection. HBV intrauterine infection rate was 31.98% from Nov,2001 to Aug, 2003 in TaiYuan.2. There were three genotypes-B, C and D in pregnant women and newborns inTaiYuan. Genotype C was the major genotype.3. There was was no significant difference in the rate of HBV intrauterineinfection between genotype B and C.4. HBV S gene "a" determinant cluster mutation exist in pregnant womencarriers.5. There are HBV S gene mutation , but HBV genotype was not changed inintrauterine transmission.6. There was was no significant difference in the rate of HBV S gene "a"determinant mutation between genotype B and C.7. The difference of HBV intrauterine infection rate was not significant between"a" determinant region mutant-type carriers and wild-type carriers .