Department of Pediatrics and Neonatology, Fukuoka Tokushukai Hospital, Kasuga, Fukuoka, Japan.
Department of Pediatrics, Fukuoka University, Fukuoka, Japan.
PLoS One. 2022 Sep 28;17(9):e0275295. doi: 10.1371/journal.pone.0275295. eCollection 2022.
Due to the coronavirus disease 2019 (COVID-19) pandemic, hygienic behaviors became a new norm since January 2020. The hygiene hypothesis predicts that an excessively hygienic environment may adversely affect human health.
We quantified the effect of COVID-19 on immunological parameters linked to the hygiene hypothesis.
We examined age-specific levels of total nonspecific immunoglobulin G (IgG) and IgE in individuals who visited Fukuoka Tokushukai Hospital between 2010 and 2021. Pre-COVID (2010-2019) and COVID (2020-2021) periods were compared.
IgG levels steadily decreased throughout Pre-COVID period. IgG levels fell abruptly from the pre-COVID period to the COVID period in all age groups (P = 0.0271, < 0.3 years; P = 0.0096, 0.3-5 years; P = 0.0074, ≥ 5 years). The declines in IgG in < 0.3 years and that in ≥ 5 years accelerated during the COVID period. IgE levels were seasonal, but did not change noticeably from the pre-COVID to COVID period. IgG levels recorded for patients with Kawasaki disease (KD) (mean 709 mg/dL) were significantly lower than for matched control subjects (826 mg/dL) (P<0.0001).
Hygienic behaviors during the COVID-19 outbreak decreased the chance of infection, which may explain the decreases in IgG levels in children and adults. Neonatal IgG declined, possibly because of the decrease in maternal IgG.
Hygienic behaviors decreased the IgG levels in all age groups, from neonates to adults. This downturn in IgG may lead to vulnerability to infections as well as to KD.
自 2020 年 1 月以来，由于 2019 年冠状病毒病（COVID-19）大流行，卫生行为成为一种新规范。卫生假说预测，过于卫生的环境可能对人类健康产生不利影响。
我们量化了 COVID-19 对与卫生假说相关的免疫参数的影响。
我们检查了 2010 年至 2021 年间访问福冈徳寿会医院的个体的特定年龄的总非特异性免疫球蛋白 G（IgG）和 IgE 水平。比较了 COVID-19 前（2010-2019 年）和 COVID-19 期间（2020-2021 年）。
在 COVID-19 前期间，IgG 水平稳步下降。在所有年龄组中，IgG 水平从 COVID-19 前时期急剧下降到 COVID-19 期间（P = 0.0271，<0.3 岁；P = 0.0096，0.3-5 岁；P = 0.0074，≥5 岁）。COVID-19 期间，<0.3 岁和≥5 岁的 IgG 下降加速。IgE 水平呈季节性变化，但从 COVID-19 前到 COVID-19 期间没有明显变化。川崎病（KD）患者（平均 709 mg/dL）记录的 IgG 水平明显低于匹配的对照（826 mg/dL）（P<0.0001）。
COVID-19 爆发期间的卫生行为减少了感染的机会，这可能解释了儿童和成人 IgG 水平下降的原因。新生儿 IgG 下降，可能是由于母体 IgG 减少。
卫生行为降低了所有年龄段（从新生儿到成年人）的 IgG 水平。这种 IgG 下降可能导致对感染以及 KD 的易感性增加。
