ANALYSES OF HEPATITIS A VIRUS GENOME FROM PATIENTS WITH FULMINANT TYPE A HEPATITIS

甲型肝炎不仅在不发达国家而且在发达国家仍然存在相当大的问题。目前还没有揭示为什么有些患者进展为暴发性甲型肝炎，而另一些则没有。为了研究甲型肝炎病毒（HAV）基因组差异是否与临床严重程度有关，我们分析了暴发型和急性甲型肝炎患者血清中HAV RNA的全核苷酸序列。我们阐明了甲型肝炎的严重程度似乎与HAV 5'非翻译区中部附近的替换有关，因为在暴发性肝炎病例中仅观察到少量替换，而在自限性急性肝炎病例中观察到相当数量的替换。并对3例重型肝炎和3例急性甲型肝炎患者血清进行了检测。用长链逆转录-聚合酶链反应（RT-PCR）扩增HAV RNA的结构区和非结构区，其中结构蛋白区3188 bp，非结构蛋白区4688 bp。将每个PCR产物克隆，并通过自动测序仪测定结构蛋白区的核苷酸序列。检测病例的基因型均为1A型，重型肝炎与急性甲型肝炎在结构蛋白区无5'端非翻译区的明显差异，现对甲型肝炎病毒非结构蛋白区进行序列测定。

Hepatitis A still possess a considerable problem not only in underdeveloped but also in developed countries. It is not revealed why some patients progress to fulminant hepatitis A and others do not. To examine whether genomic differences of hepatitis A virus (HAV) are responsible for the clinical severity, we are analyzing whole nucleotide sequences of HAV RNA in sera from fulminant and acute hepatitis A patients. We clarified that the severity of hepatitis A appears to be associated with the substitutions near the central part of the 5' nontranslated region of HAV,because in the cases with fulminant hepatitis only a small number of substitutions were observed while in the cases with self limited acute hepatitis considerable numbers of substitutions were observed. We further determined the sequences of structural protein region of HAV.Sera from 3 fulminant and 3 acute hepatitis A patients were examined. Structural region and non-strauctural regions of HAV RNA were amplified by long reverse transcription-polymerase chain reaction (RT-PCR) devided into 3188 bp including structural protein region and 4688 bp including non-structural protein region. Each PCR product was cloned and the nucleotide sequence of structural protein region was sequenced by automated sequencer. The genotypes of examined cases were all genotype1A.There were no such obvious differeces in structural protein region as found in 5' nontranslated region between fulminant and acute hepatitis A.We are now examining the sequences of non-structural protein region of HAV.