Use of serological assays for diagnosis of hepatitis E virus genotype 1 and 3 infections in a setting of low endemicity
Use of serological assays for diagnosis of hepatitis E virus genotype 1 and 3 infections in a setting of low endemicity
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DOI：
10.1128/cvi.00231-06
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发表时间：
2007-05-01
影响因子：
--
通讯作者：
Koopmans, M. P. G.
中科院分区：
文献类型：
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作者：
Herremans, M.;Bakker, J.;Koopmans, M. P. G.
由于基因3型戊型肝炎病毒（HEV）在低流行地区的发生，验证目前用于诊断属于该谱系的病毒感染的血清学检测是很重要的，因为这些检测仅使用来自基因1型和2型病毒的抗原。我们评估了Genelabs酶联免疫吸附试验（ELISA）和Mikrogen公司的RecomBlot在低流行条件下检测hev特异性免疫球蛋白M （IgM）和IgG的能力。我们比较了16例本地获得性基因3型肝炎患者、8例基因1型肝炎患者、167例普通人群健康对照和101例其他病毒引起的肝炎患者的检测结果。ELISA测定的特异性（98%）和RecomBlot测定的特异性（97%）与制造商给出的IgM测定的特异性相当，但IgG测定的特异性明显较低（ELISA测定的特异性为93%，免疫印迹测定的特异性为66%，而ELISA测定的特异性为98%，免疫印迹测定的特异性为95%）。除IgM ELISA检测外，基因3型感染后检测到的抗体水平低于基因1型感染后检测到的抗体水平。分析了基因1型患者和基因3型患者对四种抗原的免疫印迹反应，发现基因1型患者和基因3型患者的IgM免疫印迹反应存在差异。ORF3抗原是最特异的抗原。通过对所有ELISA阳性结果进行免疫印迹确认的联合检测方案和提高IgG免疫印迹检测的截止时间而不丧失敏感性，可以提高特异性。我们得出结论，在低流行条件下，需要结合ELISA和免疫印迹法来获得可接受的特异性和敏感性。
Because of the occurrence of genotype 3 hepatitis E virus (HEV) in regions of low endemicity, it is important to validate the currently used serological assays for diagnosing infections with viruses belonging to this lineage, since these assays only use antigens derived from genotype 1 and 2 viruses. We evaluated the Genelabs enzyme-linked immunosorbent assay (ELISA) and the RecomBlot from Mikrogen for the detection of HEV-specific immunoglobulin M (IgM) and IgG under conditions of low endemicity. We compared test results of 16 patients with locally acquired genotype 3 HEV, 8 genotype 1 patients, 167 healthy controls from the general population, and 101 cases with hepatitis due to other viral causes. The measured specificities of the ELISA (98%) and the RecomBlot (97%) were comparable to those given by the manufacturer for IgM but were significantly lower for IgG (93% by ELISA and 66% by immunoblotting, versus reported values of 98% for ELISA and 95% for blotting). Antibody levels detected following infections with genotype 3 were lower than those following genotype 1 infections except for those measured in the IgM ELISA. Reactivity to the four antigens used in the immunoblot assay were analyzed and showed differences in the IgM immunoblot reactions between genotype 1 patients and genotype 3 patients. The ORF3 antigen was the most specific antigen. The specificity could be improved by a combined testing regimen with confirmation by immunoblotting of all positive ELISA results and by raising the cutoff of the IgG immunoblot assay without loss of sensitivity. We conclude that a combination of ELISA and immunoblotting is needed for acceptable specificity and sensitivity of HEV assays under conditions of low endemicity.