Bolon Brad, Krinke Georg, Butt Mark T, Rao Deepa B, Pardo Ingrid D, Jortner Bernard S, Garman Robert H, Jensen Karl, Andrews-Jones Lydia, Morrison James P, Sharma Alok K, Thibodeau Michael S
1 GEMpath, Inc., Longmont, Colorado, USA.
2 AnaPath GmbH, Oberbuchsiten, Switzerland.
Toxicol Pathol. 2018 Jun;46(4):372-402. doi: 10.1177/0192623318772484. Epub 2018 May 22.
Peripheral nervous system (PNS) toxicity is surveyed inconsistently in nonclinical general toxicity studies. These Society of Toxicologic Pathology "best practice" recommendations are designed to ensure consistent, efficient, and effective sampling, processing, and evaluation of PNS tissues for four different situations encountered during nonclinical general toxicity (screening) and dedicated neurotoxicity studies. For toxicity studies where neurotoxicity is unknown or not anticipated (situation 1), PNS evaluation may be limited to one sensorimotor spinal nerve. If somatic PNS neurotoxicity is suspected (situation 2), analysis minimally should include three spinal nerves, multiple dorsal root ganglia, and a trigeminal ganglion. If autonomic PNS neuropathy is suspected (situation 3), parasympathetic and sympathetic ganglia should be assessed. For dedicated neurotoxicity studies where a neurotoxic effect is expected (situation 4), PNS sampling follows the strategy for situations 2 and/or 3, as dictated by functional or other compound/target-specific data. For all situations, bilateral sampling with unilateral processing is acceptable. For situations 1-3, PNS is processed conventionally (immersion in buffered formalin, paraffin embedding, and hematoxylin and eosin staining). For situation 4 (and situations 2 and 3 if resources and timing permit), perfusion fixation with methanol-free fixative is recommended. Where PNS neurotoxicity is suspected or likely, at least one (situations 2 and 3) or two (situation 4) nerve cross sections should be postfixed with glutaraldehyde and osmium before hard plastic resin embedding; soft plastic embedding is not a suitable substitute for hard plastic. Special methods may be used if warranted to further characterize PNS findings. Initial PNS analysis should be informed, not masked ("blinded"). Institutions may adapt these recommendations to fit their specific programmatic requirements but may need to explain in project documentation the rationale for their chosen PNS sampling, processing, and evaluation strategy.
在非临床常规毒性研究中，对周围神经系统（PNS）毒性的检测并不一致。这些毒理病理学会的“最佳实践”建议旨在确保在非临床常规毒性（筛选）和专门的神经毒性研究中遇到的四种不同情况下，对PNS组织进行一致、高效且有效的采样、处理和评估。对于神经毒性未知或未预期的毒性研究（情况1），PNS评估可能仅限于一条感觉运动性脊神经。如果怀疑存在躯体PNS神经毒性（情况2），分析至少应包括三条脊神经、多个背根神经节和一个三叉神经节。如果怀疑存在自主PNS神经病变（情况3），应评估副交感神经节和交感神经节。对于预期有神经毒性作用的专门神经毒性研究（情况4），PNS采样遵循情况2和/或3的策略，具体取决于功能或其他化合物/靶点特异性数据。对于所有情况，双侧采样单侧处理是可以接受的。对于情况1 - 3，PNS采用常规方法处理（浸入缓冲福尔马林中、石蜡包埋以及苏木精和伊红染色）。对于情况4（以及情况2和3，如果资源和时间允许），建议使用无甲醇固定剂进行灌注固定。在怀疑或可能存在PNS神经毒性的情况下，至少一条（情况2和3）或两条（情况4）神经横截面应在用硬塑料树脂包埋前用戊二醛和锇进行后固定；软塑料包埋不是硬塑料的合适替代品。如有必要，可使用特殊方法进一步明确PNS的发现。PNS的初始分析应提供信息，而不是设盲。机构可根据其特定的项目要求调整这些建议，但可能需要在项目文档中解释其选择的PNS采样、处理和评估策略的理由。
