Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University.
Center of Research and Innovation, Faculty of Medical Technology, Mahidol University.
Asian Pac J Allergy Immunol. 2017 Mar;35(1):20-26. doi: 10.12932/AP0788.
Avian influenza H5N1 and H7N9 viruses have jumped across species from avian to humans and become a threat to public health. Not much is known about pre-existing cross-reactive antibodies against these avian viruses in human population.
To determine the prevalence of cross-reactive anti-HA and anti-NA antibodies to avian influenza H5N1 and H7N9 viruses in Thai population.
Archival serum samples from 100 blood donors and 21 patients infected with 2009 pandemic influenza A (H1N1) (pdmH1N1) virus were investigated by hemagglutination-inhibition (HAI) and neuraminidase-inhibition (NAI) assays for anti-HA and anti-NA antibodies, respectively. The test antigens comprised 2 human viruses (pdmH1N1 and H3N2 viruses), and 6 reassortant viruses carrying HA and NA genes of avian H5N1 or H7N9 virus generated by reverse genetics.
HAI antibody titers ≥ 10 were found in 58, 89, 0 and 15% of blood donors as tested against pdmH1N1, H3N2, H5N1 and H7N9 viruses, respectively. On the other hand, NAI antibodies were detected in 98, 94, 73 and 53% of blood donors when reverse genetic-derived viruses harboring NA gene from pdmH1N1, H3N2, H5N1 or H7N9 virus were used as the test antigens. Moreover, 66.7% of pdmH1N1 patients who had > 4 fold increase in HAI antibody titers in paired sera developed > 4 fold increase in NAI antibody titers.
Anti-NA antibody has broader reactivity than anti-HA antibody, therefore, it can be a supplement to anti-HA antibody in the prevention against novel influenza viruses.
禽流感 H5N1 和 H7N9 病毒已经从禽类跨越物种传播到人类，并对公共卫生构成威胁。目前对于人类群体中针对这些禽流感病毒是否存在预先存在的交叉反应性抗体知之甚少。
确定泰国人群中针对禽流感 H5N1 和 H7N9 病毒的交叉反应性抗 HA 和抗 NA 抗体的流行率。
通过血凝抑制（HAI）和神经氨酸酶抑制（NAI）试验分别检测来自 100 名献血者和 21 名感染 2009 年大流行性流感 A（H1N1）（pdmH1N1）病毒患者的存档血清样本中的抗 HA 和抗 NA 抗体。测试抗原包括 2 种人类病毒（pdmH1N1 和 H3N2 病毒）以及通过反向遗传学产生的携带禽流感 H5N1 或 H7N9 病毒的 HA 和 NA 基因的 6 种重配病毒。
在针对 pdmH1N1、H3N2、H5N1 和 H7N9 病毒的检测中，献血者的 HAI 抗体滴度≥10 的比例分别为 58%、89%、0%和 15%。另一方面，当使用携带 pdmH1N1、H3N2、H5N1 或 H7N9 病毒的 NA 基因的反向遗传衍生病毒作为测试抗原时，在 98%、94%、73%和 53%的献血者中检测到 NAI 抗体。此外，在配对血清中 HAI 抗体滴度增加 4 倍以上的 66.7%的 pdmH1N1 患者中，NAI 抗体滴度也增加了 4 倍以上。
抗 NA 抗体的反应性比抗 HA 抗体更广泛，因此，它可以作为预防新型流感病毒的抗 HA 抗体的补充。
