Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA.
School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Int J Environ Res Public Health. 2020 Apr 27;17(9):3035. doi: 10.3390/ijerph17093035.
Characterizing child immunological responses to enteric infections with antibody detection in serum can be challenging in resource-constrained field settings, because sample collection requires trained individuals and its invasive procedure may lead to low response rates, especially among children. Saliva may present a promising non-invasive alternative. The objectives of this research were to compare salivary antibody levels in children to enteric infections and biomarkers of environmental enteric dysfunction (EED). We collected saliva samples from children aged one to six years enrolled in a sanitation trial in Maputo, Mozambique, and characterized salivary secretory immunoglobulin A (SIgA) concentrations with enzyme-linked immunosorbent assays. We used multilevel linear models to analyze cross-sectional associations between salivary SIgA and the number of concurrent enteric pathogen infections, as well as EED biomarkers in matched stool samples. Median salivary SIgA concentrations in this study population were 54 μg/mL (inter-quartile range (IQR): 34, 85 μg/mL), and SIgA levels were similar between children of different ages. SIgA was lower in children experiencing a higher number of concurrent infections -0.04 log μg/mL (95% confidence interval (CI): -0.08 to -0.005 log μg/mL), but was not associated with any of the included EED biomarkers. Contrary to evidence from high-income countries that suggests salivary SIgA increases rapidly with age in young children, the high prevalence of enteric infections may have led to a suppression of immunological development in this study sample and could in part explain the similar SIgA levels between children of different ages.
在资源有限的实地环境中，通过血清抗体检测来描述儿童对肠道感染的免疫反应具有挑战性，因为样本采集需要经过培训的人员，而且其侵入性程序可能导致低反应率，尤其是在儿童中。唾液可能是一种有前途的非侵入性替代方法。本研究的目的是比较唾液抗体水平与肠道感染和环境肠道功能障碍 (EED) 的生物标志物在儿童中的相关性。我们从莫桑比克马普托参加卫生试验的 1 至 6 岁儿童中收集了唾液样本，并使用酶联免疫吸附测定法对唾液分泌型免疫球蛋白 A (SIgA) 浓度进行了特征描述。我们使用多水平线性模型分析了唾液 SIgA 与同时发生的肠道病原体感染数量以及匹配粪便样本中 EED 生物标志物之间的横断面相关性。本研究人群的唾液 SIgA 中位数浓度为 54 μg/mL（四分位距 (IQR)：34，85 μg/mL），不同年龄组儿童的 SIgA 水平相似。经历更多同时感染的儿童的 SIgA 水平较低 -0.04 log μg/mL（95%置信区间 (CI)：-0.08 至 -0.005 log μg/mL），但与任何纳入的 EED 生物标志物均无关。与高收入国家的证据相反，该证据表明，在幼儿中，唾液 SIgA 随年龄快速增长，本研究样本中肠道感染的高患病率可能导致免疫发育受到抑制，这在一定程度上可以解释不同年龄组儿童之间相似的 SIgA 水平。
