Department of Biomedical Sciences-Histology, University of Sassari, Viale S. Pietro 43b, 07100, Sassari, Italy.
National Institute of Biostructure and Biosystem, Rome, Italy.
Neurol Sci. 2022 Oct;43(10):5851-5859. doi: 10.1007/s10072-022-06237-y. Epub 2022 Jul 9.
To combine the current scientific literature evidence and elucidate the differences of lead (Pb) bioaccumulation in human tissues by comparing amyotrophic lateral sclerosis (ALS) patients and healthy controls.
We systematically searched for case-control studies on the association of Pb levels with ALS, in human cells, tissues, and body fluids (nervous tissue, muscle, blood, cerebrospinal fluid, urine, skin appendages). Then, we performed a meta-analysis for all the tissues in which at least five case-control studies were available: whole blood (9 studies), serum/plasma (5 studies), and cerebrospinal fluid (CSF) (6 studies). Differences between cases and controls were evaluated using standardized mean difference, and combined estimates were derived using random effect maximum likelihood (REML) meta-analyses.
Among 1734 records, we identified 46 full-text studies, of which 14 case-control studies met the meta-analysis inclusion criteria. We found higher Pb levels in ALS cases than controls in blood (standardized mean difference (SMD) = 0.61; 95% confidence interval (CI) 0.20, 1.01; p = 0.003), plasma/serum (SMD = 0.27; 95% CI - 0.16, 0.70; p = 0.26), and CSF (SMD = 0.53; 95% CI - 0.09, 1.15; p = 0.09).
This work provides further evidence of the association between Pb bioaccumulation and ALS in body fluids. The lack of association studies in solid tissues did not allow a robust meta-analysis. Future prospective studies are needed to clarify the causality in the association of Pb bioaccumulation with ALS.
通过比较肌萎缩侧索硬化症（ALS）患者和健康对照者，结合当前科学文献证据，阐明人体组织中铅（Pb）生物积累的差异。
我们系统地检索了关于 Pb 水平与 ALS 相关的病例对照研究，涉及人体细胞、组织和体液（神经组织、肌肉、血液、脑脊液、尿液、皮肤附属物）。然后，我们对至少有 5 项病例对照研究的所有组织进行了荟萃分析：全血（9 项研究）、血清/血浆（5 项研究）和脑脊液（CSF）（6 项研究）。使用标准化均数差评估病例与对照之间的差异，并使用随机效应最大似然（REML）荟萃分析得出合并估计值。
在 1734 条记录中，我们确定了 46 篇全文研究，其中 14 项病例对照研究符合荟萃分析纳入标准。我们发现 ALS 病例的血液（标准化均数差（SMD）=0.61；95%置信区间（CI）0.20，1.01；p=0.003）、血浆/血清（SMD=0.27；95%CI-0.16，0.70；p=0.26）和脑脊液（SMD=0.53；95%CI-0.09，1.15；p=0.09）中 Pb 水平高于对照者。
这项工作进一步提供了 Pb 生物积累与 ALS 之间在体液中存在关联的证据。在实体组织中缺乏关联研究，因此无法进行稳健的荟萃分析。需要开展未来的前瞻性研究，以阐明 Pb 生物积累与 ALS 之间关联的因果关系。
