Santos Kemper Nunes dos, Almeida Marcella Kelly Costa de, Fecury Amanda Alves, Costa Carlos Araújo da, Martins Luísa Caricio
Laboratório de Patologia Clínica das Doenças Tropicais, Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, PA, BR.
Arq Gastroenterol. 2015 Jul-Sep;52(3):222-7. doi: 10.1590/S0004-28032015000300013.
The hepatitis C virus has been recognized as the leading cause of chronic liver disease in the world. Host genetic factors have been implicated in the persistence of hepatitis C virus infection. Single nucleotide polymorphisms at positions -607 C/A (rs1946518) and -137 G/C (rs187238) in the IL-18 gene promoter have been suggested to be associated with delayed hepatitis C virus clearance and persistence of the disease.
Identify these polymorphisms in a population infected with hepatitis C virus from the Brazilian Amazon region.
In a cross-sectional analytical study conducted in Belém, Pará, Brazil, 304 patients infected with hepatitis C virus were divided into two groups: group A, patients with persistent infection; group B, patients with spontaneous clearance. The control group consisted of 376 volunteers not infected with hepatitis C virus. Samples were analyzed by RT-PCR for the detection of viral RNA and by RFLP-PCR to evaluate the presence of the -137 G/C and -607 C/A IL-18 gene promoter polymorphisms.
Comparison of polymorphism allele frequencies between the patient and control groups showed a higher frequency of allele C at position -607 among patients (P=0.02). When the association between the polymorphisms and viral infection was analyzed, patients carrying genotype C/A at position -607 were found to be at higher risk of persistent hepatitis C virus infection (P=0.03).
The present results suggest a possible role of the -607 IL-18 gene promoter polymorphism in the pathogenesis of hepatitis C virus infection.
丙型肝炎病毒已被公认为全球慢性肝病的主要病因。宿主遗传因素与丙型肝炎病毒感染的持续存在有关。白细胞介素-18基因启动子中-607 C/A（rs1946518）和-137 G/C（rs187238）位点的单核苷酸多态性被认为与丙型肝炎病毒清除延迟和疾病持续存在有关。
在巴西亚马逊地区的丙型肝炎病毒感染人群中鉴定这些多态性。
在巴西帕拉州贝伦市进行的一项横断面分析研究中，304例丙型肝炎病毒感染患者被分为两组：A组为持续感染患者；B组为自发清除患者。对照组由376名未感染丙型肝炎病毒的志愿者组成。通过逆转录聚合酶链反应（RT-PCR）分析样本以检测病毒RNA，并通过限制性片段长度多态性聚合酶链反应（RFLP-PCR）评估-137 G/C和-607 C/A白细胞介素-18基因启动子多态性的存在。
患者组与对照组多态性等位基因频率比较显示，患者中-607位点C等位基因频率较高（P=0.02）。在分析多态性与病毒感染之间的关联时，发现-607位点携带C/A基因型的患者持续感染丙型肝炎病毒的风险较高（P=0.03）。
目前的结果表明-607白细胞介素-18基因启动子多态性在丙型肝炎病毒感染发病机制中可能起作用。
