Environmental determinants of total IgE among school children living in the rural Tropics: importance of geohelminth infections and effect of anthelmintic treatment
Environmental determinants of total IgE among school children living in the rural Tropics: importance of geohelminth infections and effect of anthelmintic treatment
复制标题
DOI：
10.1186/1471-2172-9-33
复制
发表时间：
2008-06-27
期刊：
影响因子：
3
通讯作者：
Griffin, George E.
中科院分区：
文献类型：
--
作者：
Cooper, Philip J.;Alexander, Neal;Griffin, George E.
背景：人们对生活在热带地区的人群中观察到的决定多克隆 IgE 水平升高的环境因素知之甚少，但可能包括土蠕虫感染。我们调查了厄瓜多尔热带农村地区学龄儿童土蠕虫感染与总 IgE 水平之间的关联，并评估了 12 个月内重复驱虫治疗对 IgE 的影响。该研究嵌套在一项整群随机研究中，该研究随机将 68 所学校随机分组，要么一年内每 2 个月接受 400 毫克阿苯达唑治疗，要么不接受治疗。我们研究了完成随访的儿童的随机样本，并根据基线时是否存在土蠕虫感染和治疗分配将其分为四组。我们测量了总 IgE 和抗 A 的水平。在研究开始时和 12 个月后收集的血液样本中，我们观察到该学龄儿童的总 IgE 水平（与标准参考值相比）升高（几何平均值，1,004 IU/mL，范围 12 至 22,608 IU/mL）），并且基线 IgE 水平与土蠕虫感染的参数，但与年龄、营养和社会经济状况无关。 12 个月后，治疗组（下降 35.1%）和未治疗组（下降 10.4%）IgE 水平分别显着下降，但治疗组下降幅度显着更大。 IgE 下降与阿苯达唑治疗、基线土蠕虫感染和高基线抗 A 水平独立相关。蚓螈 IgG。 12 个月时 IgE 的增加与土蠕虫感染的存在和抗 A 水平的增加有关。 12 个月时的蚓螈 IgG 独立于治疗分配。结论：数据提供的证据表明，土蠕虫感染是热带农村地区学童总 IgE 的重要决定因素，并且超过 12 个月的定期驱虫治疗与 IgE 的减少相关。驱虫治疗未能将 IgE 水平降低至工业化国家的正常水平，这可能是由于儿童持续接触土蠕虫或生命早期感染对形成持久的 Th2 偏向免疫的影响。
Background: The environmental factors that determine the elevated levels of polyclonal IgE observed in populations living in the Tropics are poorly understood but may include geohelminth infections. We investigated the association between geohelminth infections and total IgE levels in school children in rural tropical Ecuador, and assessed the effect on IgE of repeated anthelmintic treatments over a period of 12 months. The study was nested within a cluster-randomized study that randomized 68 schools to receive either 400 mg of albendazole every 2 months over a year or no treatment. We studied random samples of children completing follow-up and representing four groups stratified by the presence of geohelminth infection at baseline and treatment allocation. We measured levels of total IgE and anti-A. lumbricoides IgG (used as a measure of past and current geohelminth infectious exposure) in blood samples collected at the start of the study and after 12 months.Results: We observed elevated levels of total IgE (compared to standard reference values) at the start of the study in this population of school children (geometric mean, 1,004 IU/mL, range 12 to 22,608 IU/mL)) and baseline IgE levels were strongly associated with parameters of geohelminth infection but not with age, nutritional and socioeconomic status. After 12 months, levels of IgE fell significantly in the treatment (by 35.1%) and no treatment (by 10.4%) groups, respectively, but the fall was significantly greater in the treatment group. Falls in IgE were independently associated with albendazole treatment, having a baseline geohelminth infection and with high baseline levels of anti-A. lumbricoides IgG. Increases in IgE at 12 months were associated with the presence of geohelminth infections and increasing levels of anti-A. lumbricoides IgG at 12 months independent of treatment allocation.Conclusion: The data provide evidence that geohelminth infections are an important determinant of total IgE in school children in the rural Tropics and that periodic anthelmintic treatments over 12 months are associated with reductions in IgE. The failure of anthelmintic treatment to reduce IgE levels to that considered normal in industrialized countries may be attributed to continued exposure of children to geohelminths or to the effects of infections in early life in programming a long-lasting Th2-biassed immunity.