Fels L M, Wünsch M, Baranowski J, Norska-Borówka I, Price R G, Taylor S A, Patel S, De Broe M, Elsevier M M, Lauwerys R, Roels H, Bernard A, Mutti A, Gelpi E, Roselló J, Stolte H
Division of Nephrology, Medical School Hannover, Germany.
Nephrol Dial Transplant. 1998 Sep;13(9):2248-56. doi: 10.1093/ndt/13.9.2248.
Children have been considered a risk group for lead (Pb) toxicity, mainly because of neurophysiological or neuro-cognitive deficits following Pb exposure. Blood Pb levels (b-Pb) of 100 microg/l currently have been defined as the lowest adverse effect level. The aim of this study was to compare, with the help of urinary markers, the kidney function of children with b-Pb just above this threshold with that of unexposed children, to assess from a nephrological point of view whether the current threshold is justified and whether children really are a particularly vulnerable risk group in terms of Pb-induced kidney damage.
In a cross-sectional study, 112 children, either from unexposed areas (controls, n=50) or Pb-contaminated areas (n=62), the latter partly with a known history of elevated b-Pb, were examined. Twenty nine urinary or serum markers mostly related to the function or integrity of specific nephron segments were determined (e.g. filtered plasma proteins, tubular enzymes, tubular antigens, eicosanoids).
b-Pb were 39+/-13 microg/l in controls and 133+/-62 microg/l in exposed children. The main findings were increased excretion rates of prostaglandins and thromboxane B2, epidermal growth factor, beta2-microglobulin and Clara cell protein in the exposed children. A relationship between b-Pb and the prevalence of values above the upper reference limits was observed.
With the help of urinary markers, nephron segment-specific effects of chronic low-level Pb exposure could be detected in children. The pattern of effects on glomerular, proximal and distal tubular and interstitial markers was similar to that previously observed in adults. The changes, however, occur at lower b-Pb levels than in adults. The current threshold appears to be justified also from a nephrological point of view, and children can indeed be considered a special risk group.
儿童一直被视为铅（Pb）中毒的风险群体，主要是因为铅暴露后会出现神经生理或神经认知缺陷。目前，血铅水平（b-Pb）100微克/升已被定义为最低不良反应水平。本研究的目的是借助尿标志物，比较血铅水平略高于该阈值的儿童与未接触铅儿童的肾功能，从肾脏病学角度评估当前阈值是否合理，以及儿童在铅诱导的肾脏损伤方面是否真的是特别脆弱的风险群体。
在一项横断面研究中，对112名儿童进行了检查，这些儿童要么来自未受污染地区（对照组，n = 50），要么来自铅污染地区（n = 62），后者部分儿童有血铅升高的已知病史。测定了29种主要与特定肾单位节段功能或完整性相关的尿或血清标志物（例如滤过血浆蛋白、肾小管酶、肾小管抗原、类花生酸）。
对照组的血铅水平为39±13微克/升，暴露儿童的血铅水平为133±62微克/升。主要发现是暴露儿童中前列腺素、血栓素B2、表皮生长因子、β2-微球蛋白和克拉拉细胞蛋白的排泄率增加。观察到血铅水平与高于参考上限值的患病率之间存在关联。
借助尿标志物，可以在儿童中检测到慢性低水平铅暴露对肾单位节段的特异性影响。对肾小球、近端和远端肾小管及间质标志物的影响模式与先前在成人中观察到的相似。然而，这些变化发生的血铅水平低于成人。从肾脏病学角度来看，当前阈值似乎也是合理的，儿童确实可以被视为一个特殊的风险群体。
