Kalahasthi Ravibabu, Nagaraju Raju, Balachandar Rakesh, Bagepally Bhavani Shankara
Biochemistry, Regional Occupational Health Centre (Southern), ICMR-National Institute of Occupational Health, Bengaluru, Karnataka, India.
Clinical Epidemiology, ICMR-National Institute of Occupational Health, Ahmedabad, Gujarat, India.
Toxicology. 2022 Jan 15;465:153047. doi: 10.1016/j.tox.2021.153047. Epub 2021 Nov 24.
Recent evidences suggest the role of chronic lead (Pb) exposure in altering immunological parameters. Present study aimed to systematically review existing literature and synthesize quantitative evidence on the association between chronic Pb exposure and changes in immunological markers. Observational studies reporting immunological markers such as leukocyte derivative counts (CD3, CD4, CD8, CD45, CD56, lymphocyte, and total leukocyte), cytokine, Immunoglobulin (Igs), C-reactive protein (CRP) among Pb-exposed and unexposed controls were systematically searched from PubMed, Scopus and Embase digital databases from inception to January 2021. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were adhered during systematic review. Mean differences in the immunological markers between Pb-exposed and control groups were pooled using random-effects model. The heterogeneity was assessed using Cochran-Q test and I statistic. The review included forty studies reporting immunological markers in Pb-exposed and unexposed control groups. The occupational Pb-exposed group exhibited significantly higher BLL, impaired immunological markers, characterized by a marginal lowering in lymphocyte count, lymphocyte subsets (CD3, CD4, CD4/CD8 ratio), IFN-γ and IgG levels, while CD8, IgM, IgA, IgE, and cytokines (IL-4, IL-6, IL-10, and TNF-α) exhibited a trend of higher values in comparison to the control group. Further, inflammatory marker viz., total leukocyte count was significantly higher among Pb-exposed. The included studies exhibited high levels of heterogeneity. In conclusion, Occupational Pb exposure alters the immunological markers such as the circulating cytokines and leukocyte counts. However, high-quality, multicentered studies are required to strengthen present observations and further understand the Pb's role on the immune system. Prospero Registration ID: CRD42021228252.
近期证据表明慢性铅（Pb）暴露在改变免疫参数方面的作用。本研究旨在系统回顾现有文献，并综合关于慢性铅暴露与免疫标志物变化之间关联的定量证据。从PubMed、Scopus和Embase数字数据库中，系统检索了从数据库建立到2021年1月期间报告铅暴露组和未暴露对照组中免疫标志物（如白细胞衍生计数（CD3、CD4、CD8、CD45、CD56、淋巴细胞和总白细胞）、细胞因子、免疫球蛋白（Igs）、C反应蛋白（CRP））的观察性研究。在系统回顾过程中遵循了系统评价和Meta分析的首选报告项目（PRISMA）指南。使用随机效应模型汇总铅暴露组和对照组之间免疫标志物的平均差异。使用Cochran-Q检验和I统计量评估异质性。该综述纳入了40项报告铅暴露组和未暴露对照组免疫标志物的研究。职业性铅暴露组的血铅水平显著更高，免疫标志物受损，表现为淋巴细胞计数、淋巴细胞亚群（CD3、CD4、CD4/CD8比值）、干扰素-γ和IgG水平略有降低，而CD8、IgM、IgA、IgE和细胞因子（IL-4、IL-6、IL-10和肿瘤坏死因子-α）与对照组相比呈现出更高值的趋势。此外，炎症标志物即总白细胞计数在铅暴露组中显著更高。纳入的研究表现出高度的异质性。总之，职业性铅暴露会改变免疫标志物，如循环细胞因子和白细胞计数。然而，需要高质量、多中心的研究来加强当前的观察结果，并进一步了解铅在免疫系统中的作用。国际前瞻性系统评价注册平台注册号：CRD42021228252。
