论文部分内容阅读
There are two subtypes of hepatitis B virus genotype A (HBV/ A) and they are p rovisionally designated Aa (“a”standing for Africa/Asia) and Ae (“e”for Euro pe). In a case-control study, 78 HBV/Aa, 78HBV/Ae, and 78HBV/D carriers from several co untries were compared. The prevalence of HBe antigen (HBeAg) in serum was signif icantly lower in carriers of HBV/Aa than in carriers of HBV/Ae (31%vs. 49%; P = .033), with a difference more obvious in the carriers aged 30 years or younger (34%vs. 67%; P = .029). HBV DNA levels in the carriers of HBV/Aa (median, 3.4 6 log copies/mL; 95%CI, 2.93-3.95)were significantly lower than those of carri ers of HBV/Ae (6.09 log copies/mL; 95%CI, 4.24-7.64) or of carriers ofHBV/D (5 .48 log copies/mL; 95%CI, 4.06-7.02), regardless of the HBeAg status (P< .001) . The most specific and frequent substitutions in 54 HBV/Aa isolates were double substitutions for T1809 (100%) and T1812 (96%) immediately upstream of the pr ecore initiation codon, which would interfere with the translation of HBeAg in H BV/Aa infections. They were not detected in 57 HBV/Ae or 61 HBV/D isolates exami ned. The double mutation in the core promoter (T1762/A1764)was more frequent in both HBV/Aa (50%) and HBV/Ae (44%) than in HBV/D isolates (25%; P< .01), wher eas the precore mutation (A1896) occurred in HBV/D isolates only (48%; P < .000 1). In conclusion, the clearance of HBeAg from serum may occur by different mec hanisms in HBV/Aa, HBV/Ae, and HBV/D infections, which may influence clinical ma nifestations in the Western countries where both genotypes A and D are prevalent .
There are two subtypes of hepatitis B virus genotype A (HBV / A) and they are p rovisionally designated Aa (“a” standing for Africa / Asia) and Ae (“e” for Euro pe). In a case-control study, 78 prevalence of HBe antigen (HBeAg) in serum was signif icantly lower in carriers of HBV / Aa than in carriers of HBV / Ae (31 % vs 49%; P = .033) with a difference more significantly in the carriers aged 30 years or younger (34% vs 67%; P = .029). HBV DNA levels in the carriers of HBV / Aa ( median of 3.4 6 log copies / mL; 95% CI, 2.93-3.95) were significantly lower than those of carri ers of HBV / Ae (6.09 log copies / mL; 95% CI, 4.24-7.64) or of carriers of HBV / D (5 .48 log copies / mL; 95% CI, 4.06-7.02), regardless of the HBeAg status (P <.001). The most specific and frequent substitutions in 54 HBV / Aa isolates were double substitutions for T1809 ) and T1812 (96%) immediately upstream of the pr ecore initiation codon, which woul d interfere with the translation of HBeAg in H BV / Aa infections. They were not detected in 57 HBV / Ae or 61 HBV / D isolates exami ned. The double mutation in the core promoter (T1762 / A1764) was more frequent in both HBV / Aa (50%) and HBV / Ae (44%) than in HBV / D isolates (25%; P <.01), wher eas the precore mutation (A1896) occurred in HBV / D isolates only <.000 1). In conclusion, the clearance of HBeAg from serum may occur by mechanisms in HBV / Aa, HBV / Ae, and HBV / D infections, which may influence clinical ma nifestations in the Western countries where both genotypes A and D are prevalent.