Department of Biostatistics, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, USA.
Department of Biology, University of Florida, Gainesville, Florida, USA.
J Infect Dis. 2023 Aug 16;228(4):383-390. doi: 10.1093/infdis/jiad029.
Serological surveys are used to ascertain influenza infection and immunity, but evidence for the utility of mucosal immunoglobulin A (IgA) as a correlate of infection or protection is limited.
We performed influenza-like illness (ILI) surveillance on 220 individuals living or working in a retirement community in Gainesville, Florida from January to May 2018, and took pre- and postseason nasal samples of 11 individuals with polymerase chain reaction (PCR)-confirmed influenza infection and 60 randomly selected controls. Mucosal IgA against 10 strains of influenza was measured from nasal samples.
Overall, 28.2% and 11.3% of individuals experienced a 2-fold and 4-fold rise, respectively, in mucosal IgA to at least 1 influenza strain. Individuals with PCR-confirmed influenza A had significantly lower levels of preseason IgA to influenza A. Influenza-associated respiratory illness was associated with a higher rise in mucosal IgA to influenza strains of the same subtype, and H3N2-associated respiratory illness was associated with a higher rise in mucosal IgA to other influenza A strains.
By comparing individuals with and without influenza illness, we demonstrated that mucosal IgA is a correlate of influenza infection. There was evidence for cross-reactivity in mucosal IgA across influenza A subtypes.
血清学调查用于确定流感感染和免疫情况，但黏膜免疫球蛋白 A（IgA）作为感染或保护相关性的证据有限。
我们对 2018 年 1 月至 5 月期间居住或工作在佛罗里达州盖恩斯维尔的退休社区的 220 人进行了流感样疾病（ILI）监测，并对 11 名经聚合酶链反应（PCR）确诊流感感染的个体和 60 名随机选择的对照个体进行了前后鼻样本采集。从鼻样本中测量了针对 10 株流感的黏膜 IgA。
总体而言，分别有 28.2%和 11.3%的个体对至少 1 株流感病毒的黏膜 IgA 出现了 2 倍和 4 倍的升高。经 PCR 确诊为流感 A 的个体在流感 A 前季的 IgA 水平显著较低。与流感相关的呼吸道疾病与相同亚型流感株的黏膜 IgA 升高呈正相关，而 H3N2 相关的呼吸道疾病与其他流感 A 株的黏膜 IgA 升高呈正相关。
通过比较有和没有流感疾病的个体，我们证明了黏膜 IgA 是流感感染的相关性指标。黏膜 IgA 存在针对流感 A 亚型的交叉反应证据。
