Rabies virus glycoprotein serology ELISA for measurement of neutralizing antibodies in sera of vaccinated human subjects

BackgroundVaccination provides protection against infection by inducing VNAs mainly against RABV surface GP. The measurement of VNAs to RABV is commonly used to assess the level of immunity in humans and animals after vaccination. A VNA titer of ≥ 0.5 IU/mL of sera indicates adequate response to vaccination. Here, we report the development and validation of a RABV GP serology ELISA kit for semi-quantitative measurement of VNA titers in sera of vaccinated human subjects.MethodsUsing a recombinant RABV GP expressed in mammalian cells as the capture antigen, the ELISA method was established using HuMAb NM57 reference initially and HRIG reference subsequently. The limit of detection (LOD), linear range, reproducibility, and precision of the method were examined. Specificity and sensitivity were established to assess the diagnostic accuracy.ResultsRABV GP for ELISA plate coating and optimal dilution of human serum sample was 1 µg/mL and 1:20, respectively. Multiple assays were carried out by different technicians at different laboratories for assay standardization. Using the HRIG reference, the LOD was found to be 0.02–0.06 IU/mL and the linear range was 0.2–10.0 IU/ mL. The inter-assay CVs were in the range of 6.60–10.79%, indicating the reproducibility. None of the 12 known negative human sera, tested positive by ELISA, highlighting the specificity. A total of 415 unknown positive human sera were double-blind tested by the RFFIT and ELISA. The VNA titer cut-off value of ELISA was set at 1.5 IU/mL to ensure no false-positive. The diagnostic specificity and sensitivity were 100% and 91.1%, respectively.ConclusionsThe validation data characterize this ELISA as a suitable method for semi-quantitative measurement of VNA titers in human serum samples to assess vaccination status. The ELISA kit can offer simplicity, speed, low cost and high throughput, making it a practical tool for monitoring the immune response following vaccination.     

Infección por el virus de la hepatitis C y nuevas estrategias de tratamiento

Hepatitis C is a major public health problem worldwide. This disease is caused by the hepatitis C virus, which is characterised by its genetic diversity. The infection is usually asymptomatic. However, between 60% and 80% of HCV-infected individuals will progress to chronic hepatitis, 20% to liver cirrhosis in the medium-to long-term and, each year, between 1% and 4% of these patients with cirrhosis will develop hepatocellular carcinoma (HCC). A Spanish consensus document has recently been drafted to diagnose hepatitis C in a single step, consisting of active investigation (antibodies and viremia) in a single sample, which according to the experts, would reduce the time to access treatment and avoid tracking losses. To definitively change the hepatitis C treatment paradigm, direct-acting antiviral drugs (DAAs) have been approved, whose development has been based on achieving cure rates close to 100% regardless of the genotype of the virus, ie, pangenotypes, with good tolerance and bioavailability. These drugs have constituted a real therapeutic revolution. Supplement information: This article is part of a supplement entitled «SEIMC External Quality Control Programme. Year 2016», which is sponsored by Roche, Vircell Microbiologists, Abbott Molecular and Francisco Soria Melguizo, S.A.© 2019 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosasy Microbiología Clínica. All rights reserved.     

Vacunas contra el virus del papiloma humano

Persistent infection by human papilloma virus (HPV) is considered to be the main cause of cervical cancer and other ano-genital cancers. Of more than 30 genotypes able to infect the anogenital tract, it is estimated that, worldwide, HPV 16 and 18 cause 70% of cervical cancers and that HPV 6 and 11 cause more than 90% of genital warts. In the last few years, the morbidity and mortality and health costs associated with cervical cancer and its precursor lesions have stimulated intense research activity to achieve primary prevention of this disease through prophylactic vaccines.     

非鼻咽部T细胞淋巴瘤与EB病毒的相关性

目的：探讨EB病毒（EBV）感染与非鼻咽部T细胞淋巴瘤的关系。方法：用单克隆抗体UCHL-1、L26及EB病毒编码的潜在膜蛋白-1（LMP-1），免疫组化染色确定肿瘤的免疫表型及EB病毒转化蛋白的表达。采用原位杂交方法检测EBV编码的EBERs。结果：21例非鼻咽部T细胞淋巴瘤EBERs5例阳性的（23．8％），其中给内淋巴瘤3例，肺和胃肠淋巴瘤各1例。阳性细胞约占肿瘤细胞的10％～70％。5例EBERs阳性病例中仅1例表达LMP-1，为结内淋巴瘤。结论：非鼻咽部T细胞淋巴瘤可能与EBV的感染有关，LMP-1的阳性率较EBERs低。     

乙肝患者血清抗心磷脂抗体的检测

目的 :了解抗心磷脂抗体 (ACA)在乙型肝炎病毒 (HBV)感染中的检出率。方法 :采用ELISA法测定 83例HBV患者和 6 6例正常对照者血清的ACA。结果 :HBV患者ACA阳性率为 16 .9% ,与正常对照组 (4.5 % )比较有显著性升高 (P <0 .0 1) ;在HBV患者中 ,肝功能异常者ACA阳性率明显高于肝功能正常者 (P <0 .0 1)。结论 :ACA可常见于乙型肝炎患者 ,并可能与乙型肝炎的病情有一定关系。     

慢性乙型肝炎患者病毒e系统状态与肝纤维化关系的研究

目的:观察慢性乙型肝炎患者乙型肝炎病毒e系统状态和复制指标在肝纤维化发生过程中的变化及其与血清纤维化标志的关系,探讨它们在肝纤维化发生过程中的作用及其可能的临床意义.方法:188例慢性乙型肝炎患者根据肝纤维化程度分为S0～S4期等5组,分别用定量PCR及放免法检测患者血清中HBV-DNA及肝纤维化标志透明质酸、Ⅳ型胶原、Ⅲ型前胶原和层粘连蛋白的含量;HBeAg和抗-HBe采用酶联免疫吸附法(ELISA)检测,并观察其在不同肝病理纤维化分期时的变化.结果:随着肝纤维化程度加重,血清HBV-DNA含量逐渐升高,从S1期开始显著增加(P＜0.01);而HBeAg阳性率逐渐降低,S3、S4期较S0显著减少(P＜0.05和P＜0.01);抗-HBe阳性率呈相反的变化趋势,在S3和S4期的阳性率明显高于S0期(P＜0.05和P＜0.01).血清HBV-DNA( )HBeAg( )组血清纤维化标志最低,HBV-DNA(-)抗-HBe( )组最高,两者差异有显著性(P＜0.01).结论:HBV复制和e系统状态的改变与肝纤维化程度密切相关,肝内病毒复制标志与血清纤维化标志联合检测,对于判断肝纤维化程度和指导抗病毒治疗有重要的价值.     

干燥综合征与病毒感染的关系研究进展

干燥综合征是一种以口眼干燥为特征,主要累及外分泌腺的弥漫性结缔组织病。其发病可能与病毒感染、遗传和性激素异常等多种因素有关,在这些因素的共同作用下,机体免疫异常,组织损伤。与该病关系较密切的病毒有EB病毒、丙型肝炎病毒、巨细胞病毒、反转录病毒等。病毒在干燥综合征的发病机制中可能起重要的作用。