The Centre for Research & Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
Institute for Global Nutrition, Department of Nutrition, University of California, Davis, CA, USA.
J Nutr. 2020 Aug 1;150(8):2204-2213. doi: 10.1093/jn/nxaa037.
Zinc deficiency impairs immune function and is common among children in South-East Asia.
The effect of zinc supplementation on immune function in young Laotian children was investigated.
Children (n = 512) aged 6-23 mo received daily preventive zinc tablets (PZ; 7 mg Zn/d), daily multiple micronutrient powder (MNP; 10 mg Zn/d, 6 mg Fe/d, plus 13 other micronutrients), therapeutic dispersible zinc tablets only in association with diarrhea episodes (TZ; 20 mg Zn/d for 10 d after an episode), or daily placebo powder (control). These interventions continued for 9 mo. Cytokine production from whole blood cultures, the concentrations of T-cell populations, and a complete blood count with differential leukocyte count were measured at baseline and endline. Endline means were compared via ANCOVA, controlling for the baseline value of the outcome, child age and sex, district, month of enrollment, and baseline zinc status (below, or above or equal to, the median plasma zinc concentration).
T-cell cytokines (IL-2, IFN-γ, IL-13, IL-17), LPS-stimulated cytokines (IL-1β, IL-6, TNF-α, and IL-10), and T-cell concentrations at endline did not differ between intervention groups, nor was there an interaction with baseline zinc status. However, mean ± SE endline lymphocyte concentrations were significantly lower in the PZ than in the control group (5018 ± 158 compared with 5640 ± 160 cells/μL, P = 0.032). Interactions with baseline zinc status were seen for eosinophils (Pixn = 0.0036), basophils (Pixn = 0.023), and monocytes (P = 0.086) but a significant subgroup difference was seen only for eosinophils, where concentrations were significantly lower in the PZ than in the control group among children with baseline plasma zinc concentrations below the overall median (524 ± 44 compared with 600 ± 41 cells/μL, P = 0.012).
Zinc supplementation of rural Laotian children had no effect on cytokines or T-cell concentrations, although zinc supplementation affected lymphocyte and eosinophil concentrations. These cell subsets may be useful as indicators of response to zinc supplementation.This trial was registered at clinicaltrials.gov as NCT02428647.
锌缺乏会损害免疫功能，在东南亚儿童中很常见。
研究补锌对老挝儿童免疫功能的影响。
6-23 月龄儿童（n=512）每天接受预防性锌片（PZ；7mg Zn/d）、多种微量营养素粉（MNP；10mg Zn/d、6mg Fe/d 及其他 13 种微量营养素）、仅在腹泻发作时服用的治疗性可分散锌片（TZ；腹泻发作后 10d 每天 20mg Zn/d）或每日安慰剂粉（对照）。这些干预措施持续 9 个月。在基线和终点时测量全血培养的细胞因子产生、T 细胞群浓度和全血细胞计数及白细胞分类。采用协方差分析（ANCOVA）比较终点时的平均值，控制结局的基线值、儿童年龄和性别、区、入组月份和基线锌状态（低于或等于、高于）。
TZ 组、PZ 组和 MNP 组的 T 细胞细胞因子（IL-2、IFN-γ、IL-13、IL-17）、LPS 刺激细胞因子（IL-1β、IL-6、TNF-α和 IL-10）和 T 细胞浓度在终点时均无差异，与基线锌状态也无相互作用。然而，PZ 组的平均淋巴细胞浓度显著低于对照组（5018±158 与 5640±160 个/μL，P=0.032）。基线锌状态与嗜酸性粒细胞（Pixn=0.0036）、嗜碱性粒细胞（Pixn=0.023）和单核细胞（P=0.086）存在交互作用，但仅在嗜酸性粒细胞中观察到显著的亚组差异，即在基线血浆锌浓度低于总体中位数的儿童中，PZ 组的嗜酸性粒细胞浓度显著低于对照组（524±44 与 600±41 个/μL，P=0.012）。
对老挝农村儿童补锌对细胞因子或 T 细胞浓度没有影响，但锌补充剂影响淋巴细胞和嗜酸性粒细胞浓度。这些细胞亚群可能是反映锌补充反应的有用指标。本试验在 clinicaltrials.gov 上注册为 NCT02428647。
