IMMUNITY IN CHILDREN WITH EXPOSURE TO ENVIRONMENTAL LEAD

拟议的研究涉及环境铅对环境污染的影响 幼儿免疫系统发育。在动物模型系统中，铅 远低于公开毒性所需的水平被发现是 免疫抑制。很难把这些数据外推到人类身上 系统。城市儿童(9个月至6岁)研究人群 血液浓度超过10微克/100毫升已被确认为 密苏里州斯普林菲尔德-格林县地区通过参与 当地妇女、婴儿和儿童与铅中毒预防 程序。这群孩子，加上来自 同样的计划，提供了一个理想的机会，开始 评估血铅浓度和血铅浓度之间的可能相关性 各种免疫系统参数。初步研究的结果是 建议选择一些具体的化验方法以评估可能的 铅对细胞数量的影响(白细胞类型计数，包括分类 淋巴细胞亚类)；对B细胞功能的影响(血清Ig 浓度，包括IgE；细胞表面II类密度；细胞表面 激活抗原CD71(转铁蛋白RC)和B7的密度]；影响 T细胞功能(对IL-2的增殖反应；细胞表面密度 激活抗原CD25(IL-2RC)、CD71和CD28的作用； 协同免疫反应(疫苗的特异性抗体效价； 对抗原的增殖反应；可溶性细胞因子受体的释放 (CD25和CD27)；感染和过敏的频率)。初步 数据还允许确定适当的样本量和 生成这些选定参数的基本控制数据。 具体目标如下： 1.收集筛选化验数据，样本量为30-35 每个对照组和实验组的儿童，年龄在9个月到6岁之间 年龄。 2.进行筛选分析，确定免疫的哪一种成分(S) 系统对铅暴露很敏感。 3.对选定的12个月和24个月的儿童进行纵向研究 后续样本。 4.对数据进行详尽的统计分析。 这项研究将提供关于一种 环境毒素对高危人群免疫系统的影响 曝光。此外，纵向研究将提供以下方面的信息 慢性铅暴露对发育中免疫系统的影响。在……里面 在这个过程中，对幼儿正常免疫功能的了解将是 增加了。

The proposed study addresses the impact of environmental lead on the developing immune system of young children. In animal model systems, lead levels far below those necessary for overt toxicity are found to be immunosuppressive. It is difficult to extrapolate these data to human systems. A study population of urban children (9 months to 6 years of age) with blood levels greater than 10 micrograms/1OO ml has been identified in the Springfield-Greene County area of Missouri through participation in local WIC (Women, Infants, and Children) and Lead Poisoning Prevention programs. This pool of children, with appropriately matched controls from the same programs, have offered an ideal opportunity to begin an assessment of possible correlations between blood lead concentrations and various immune system parameters. Preliminary studies have resulted in the selection of a number of specific assays proposed to assess possible effects of lead on cell numbers (counts of WBC types, including classes and subclasses of lymphocytes); effects on B cell function (serum Ig concentrations including IgE; cell surface class II density; cell surface density of the activation antigens CD71 (transferrin Rc) and B7]; effects on T cell function (proliferative response to IL-2; cell surface density of the activation antigens CD25 (IL-2 Rc), CD71, and CD28); and effects on concerted immune responses (specific antibody titers to vaccines; proliferative responses to antigens; release of soluble cytokine receptors (CD25 and CD27); frequencies of infections and allergies). Preliminary data have also allowed a determination of appropriate sample size and generation of essential control data for these selected parameters. Specific aims are as follow: 1. Gather data on screening assays to reach a sample size of 30-35 children per control and experimental group, age 9 months to 6 years of age. 2. Perform screening assays to determine which component(s) of the immune system are sensitive to lead exposure. 3. Conduct a longitudinal study of selected children, with 12 and 24 month follow-up samples. 4. Conclude with exhaustive statistical analysis of data. The study will provide invaluable information on the effects of an environmental toxin on the immune system in a population at great risk for exposure. In addition, the longitudinal study will provide information on the effects of chronic lead exposure on the developing immune system. In the process, knowledge of normal immune function in young children will be increased.