Ghamari Shiva, Alavian Seyed Moayed, Rizzetto Mario, Olivero Antonella, Smedile Antonina, Khedive Abulfazl, Alavian Seyed Ehsan, Zolfaghari Mohammad Reza, Jazayeri Seyed Mohammad
Hepatitis B Molecular Laboratory, Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, IR Iran.
Hepat Mon. 2013 Aug 16;13(8):e6731. doi: 10.5812/hepatmon.6731. eCollection 2013.
Probably 5% of the HBV carriers have HDV super infection. The risk of fulminant hepatitis, cirrhosis and hepatocellular carcinoma is higher in superinfection than the settings when HBV is alone.
The aim of this study was to evaluate the prevalence of HDV in Iranian HBV isolates and to compare their clinical and virological pictures as well as their HDV genetic variations with other worldwide isolates.
81 carriers with positive results for HBsAg with upper limit ranges of ALT and low or undetectable levels of HBV viral load who did not respond to HBV therapy were selected. After RT amplification of HDV Delta antigen, direct sequencing and phylogenetic study were performed to explore the genotype(s) and nucleotide/amino acid variations.
12 (14.8%) patients had positive results for both HDV RNA and anti-HDV. The mean ALT level was higher in HDV positive patients (75.9 U/ML) than HBV-mono-infected individuals; however, the mean HBV viral load was lower in coinfected patients than HBV-mono-infected patients. Phylogenetically, genotype I was the only detected genotype, and the most closely related isolates were of Turkish, Italian and Mongolian origin. Within the delta Ag, there were 326 nucleotide mutations, of which 111 and 215 were silent and missense, respectively. The total number of amino acid substitution was 148; most were located in known functional/epitopic domains. There was no correlation between the numbers of amino acid mutations, with clinical, virological status of the patients.
HDV should be suspected in HBV carriers with unusual clinical and virological pictures. Relatedness of Iranian HDV isolates to Italian and Turkish sequences proposed a common Caucasian origin for the distribution of HDV genotype I in this ethnic group.
约5%的HBV携带者发生丁型肝炎病毒（HDV）重叠感染。与单纯HBV感染相比，重叠感染时发生暴发性肝炎、肝硬化和肝细胞癌的风险更高。
本研究旨在评估伊朗HBV分离株中HDV的流行率，并比较其临床和病毒学特征以及HDV基因变异与全球其他分离株的差异。
选择81例HBsAg阳性、ALT上限值升高且HBV病毒载量低或检测不到、对HBV治疗无反应的携带者。在对HDVδ抗原进行逆转录扩增后，进行直接测序和系统发育研究，以探索基因型及核苷酸/氨基酸变异。
12例（14.8%）患者的HDV RNA和抗HDV均呈阳性。HDV阳性患者的平均ALT水平（75.9 U/ML）高于单纯HBV感染个体；然而，合并感染患者的平均HBV病毒载量低于单纯HBV感染患者。在系统发育上，仅检测到基因型I，与之关系最密切的分离株来自土耳其、意大利和蒙古。在δ抗原内，有326个核苷酸突变，其中111个和215个分别为沉默突变和错义突变。氨基酸替代总数为148个；大多数位于已知的功能/表位区域。氨基酸突变数量与患者的临床、病毒学状态之间无相关性。
对于临床和病毒学表现异常的HBV携带者，应怀疑有HDV感染。伊朗HDV分离株与意大利和土耳其序列的相关性表明，HDV基因型I在该种族群体中的分布有共同的高加索起源。
