Epidemiology International, Hunt Valley, Maryland, USA.
Environ Health Perspect. 2012 Aug;120(8):1067-75. doi: 10.1289/ehp.1104652. Epub 2012 May 2.
Although case-control studies conducted to date have largely affirmed the relationship between polychlorinated biphenyls (PCBs) and non-Hodgkin lymphoma (NHL), occupational cohort studies of PCB-exposed workers have been generally interpreted as negative, thereby raising doubts about a potential causal association. A common theme of immune dysregulation unifies many of NHL's strongest risk factors, and several authors have posited that subclinical immune dysregulation may increase NHL risk by decreasing host resistance, reducing control of cellular proliferation and differentiation, and diminishing tumor surveillance mechanisms.
The goals of this review were a) to evaluate the epidemiological research examining the association between PCB exposure and NHL and discuss the contribution to the weight of evidence of case-control studies and occupational cohort studies; and b) to summarize the evidence for immune dysregulation as a means by which PCBs may cause NHL.
We performed a literature search using PubMed and seven additional online biomedical and toxicological referencing libraries to identify literature published through August 2011.
Overall, we conclude that the weight of evidence supports a causal role of PCBs in lymphomagenesis. The strongest epidemiological evidence for the relationship between PCBs and NHL comes from case-control studies conducted among the general population. Epidemiological and toxicological data demonstrating immunosuppressive and inflammatory effects of PCBs further contribute to the weight of evidence by providing a plausible explanation for how PCBs can cause NHL through immune dysregulation.
尽管迄今为止进行的病例对照研究在很大程度上肯定了多氯联苯（PCBs）与非霍奇金淋巴瘤（NHL）之间的关系，但针对接触 PCB 工人的职业队列研究通常被解释为阴性结果，从而对潜在的因果关联提出了质疑。免疫失调的一个共同主题将 NHL 的许多最强风险因素统一起来，有几位作者提出，亚临床免疫失调可能通过降低宿主抵抗力、减少细胞增殖和分化的控制以及减少肿瘤监测机制来增加 NHL 的风险。
本综述的目的是 a）评估检查 PCB 暴露与 NHL 之间关联的流行病学研究，并讨论病例对照研究和职业队列研究对证据权重的贡献；b）总结免疫失调作为 PCBs 引起 NHL 的一种可能机制的证据。
我们使用 PubMed 以及其他七个在线生物医学和毒理学参考库进行了文献检索，以确定截至 2011 年 8 月发表的文献。
总体而言，我们的结论是，证据权重支持 PCBs 在淋巴瘤发生中的因果作用。PCB 与 NHL 之间关系的最强流行病学证据来自针对普通人群进行的病例对照研究。证明 PCBs 具有免疫抑制和炎症作用的流行病学和毒理学数据通过提供一个合理的解释，进一步为证据权重做出了贡献，即 PCBs 如何通过免疫失调导致 NHL。
