I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Germany.
I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Germany.
J Clin Virol. 2018 Aug;105:26-30. doi: 10.1016/j.jcv.2018.05.013. Epub 2018 May 29.
Globally, an estimated 20 million Hepatitis E infections occur every year. The course of viremia and antibody response has been investigated in patients with symptomatic hepatitis E. However, the majority of HEV infections in industrialized countries take a subclinical course.
To investigate the course of HEV viremia and epitope specific anti-HEV IgM/IgG response in asymptomatic blood donors in order to understand the immune response and viral clearance in asymptomatic blood donors with HEV infections.
In this study 27 HEV viremic donors were identified by HEV-PCR during routine screening of blood donors and the course of anti-HEV IgM/IgG and HEV-RNA was retrospectively studied using RT-PCR and a commercial immunoblot (Mikrogen®) allowing classification of the antibody response according to HEV epitopes.
At time of donation, serological testing failed to identify viremic donors as 70.4% had no detectable antibody response. Anti-HEV IgM could be detected in 22.2% of viremic donors while anti-HEV IgG could be found in 7.4%. At least three donors experienced prolonged viremia beyond 100 days. Spontaneous HEV-RNA clearance within a median time span of 57 days was observed in all 27 donors. In all donors anti-HEV IgG specific for the immunogenic viral epitope O2C could be detected in close temporal association with viral clearance.
Serological testing is inappropriate for identifying HEV-viremic blood donors. Acute HEV infection in asymptomatic blood donors can persist for more than 100 days. HEV-RNA clearance coincided with the appearance of anti-HEV IgM/IgG confirming the importance of a B-cell mediated response in clearing acute infections. Anti-HEV IgM and IgG specific for the epitope O2C are associated with the clearance of HEV-viremia.
据估计，每年全球有 2000 万例戊型肝炎感染。已有研究调查了有症状戊型肝炎患者的病毒血症和抗体反应过程。然而，在工业化国家，大多数 HEV 感染呈亚临床过程。
研究无症状献血者中 HEV 病毒血症和抗原特异性抗-HEV IgM/IgG 反应的过程，以了解无症状 HEV 感染者的免疫反应和病毒清除情况。
在这项研究中，通过常规献血者筛查，用 HEV-PCR 鉴定出 27 例 HEV 血症供者，并回顾性研究抗-HEV IgM/IgG 和 HEV-RNA 的过程，使用 RT-PCR 和商业免疫印迹（Mikrogen®），根据 HEV 表位对抗体反应进行分类。
在献血时，血清学检测未能识别病毒血症供者，因为 70.4%的供者没有检测到抗体反应。22.2%的病毒血症供者可检测到抗-HEV IgM，而 7.4%的供者可检测到抗-HEV IgG。至少有 3 名供者的病毒血症持续时间超过 100 天。在所有 27 名供者中，均观察到中位时间为 57 天的自发 HEV-RNA 清除。在所有供者中，都可以在病毒清除的同时检测到针对免疫原性病毒表位 O2C 的抗-HEV IgG。
血清学检测不适合识别 HEV 病毒血症供者。无症状献血者的急性 HEV 感染可持续 100 天以上。HEV-RNA 清除与抗-HEV IgM/IgG 的出现相吻合，证实了 B 细胞介导的反应在清除急性感染中的重要性。针对 O2C 表位的抗-HEV IgM 和 IgG 与 HEV 病毒血症的清除有关。
