Tkachenko Andriy, Chen Yang, Petrey Marissa, Fritz Scott, Walsh Tim, Rotstein David, Miller Megan R, Williams Bruce, Dark Michael, Kmet Matthew, Reddy Ravinder, Tyson Gregory, Nemser Sarah M
US Food and Drug Administration, Center for Veterinary Medicine, Laurel, MD 20708, USA.
US Food and Drug Administration, Human Foods Program, Bedford Park, IL 60501, USA.
Toxicol Rep. 2025 Jan 26;14:101925. doi: 10.1016/j.toxrep.2025.101925. eCollection 2025 Jun.
Participation in Proficiency Tests (PTs) is an important component of quality assurance in testing laboratories. In a typical chemistry PT, blind-coded samples are sent to participants for analysis of specific chemical agents, and results are compared to a pre-determined key (e.g., expected concentrations) to assess proficiency. In the animal diagnostic PT presented here, organizers evaluated not only the analytical component of the diagnostic investigation but also the entire investigative process as a multi-step, holistic multidisciplinary approach. Fourteen veterinary diagnostic laboratories (VDLs) participated in an exercise to identify the root cause of a simulated case of lead (Pb) toxicosis. VDLs received a case description outlining neurological signs in cattle, a digitized brain histology slide, and liver and brain tissue samples for optional chemistry analysis. Thirteen of 14 VDLs successfully diagnosed lead toxicosis by completing the following stages: (a) correctly identifying histological abnormalities, (b) providing three adequate differential diagnoses, (c) selecting adequate chemistry analyses to rule in or rule out possible causes, (d) accurately detecting lead concentration in the liver, and (e) interpreting the diagnostic significance of their results correctly. Importantly, participants first had to determine which chemistry analyses were appropriate and then to accurately quantify the target analytes. This approach provided greater confidence in the diagnostic capability of the laboratory by reducing the bias associated with being given a known chemical contaminant for which to test, typical of most chemistry PTs, and may therefore be of interest to PT providers and accreditation committees.
参加能力验证测试（PTs）是检测实验室质量保证的重要组成部分。在典型的化学PT中，将盲编码样本发送给参与者以分析特定化学物质，然后将结果与预先确定的标准（如预期浓度）进行比较，以评估能力水平。在此处介绍的动物诊断PT中，组织者不仅评估了诊断调查的分析部分，还将整个调查过程作为一种多步骤、整体的多学科方法进行了评估。14个兽医诊断实验室（VDL）参与了一项活动，以确定一例模拟铅（Pb）中毒病例的根本原因。VDL收到了一份病例描述，概述了牛的神经症状、一张数字化的脑组织学切片以及用于可选化学分析的肝脏和脑组织样本。14个VDL中的13个通过完成以下阶段成功诊断出铅中毒：（a）正确识别组织学异常；（b）提供三种充分的鉴别诊断；（c）选择充分的化学分析以确定或排除可能的病因；（d）准确检测肝脏中的铅浓度；（e）正确解释其结果的诊断意义。重要的是，参与者首先必须确定哪些化学分析是合适的，然后准确地对目标分析物进行定量。这种方法通过减少与大多数化学PT中提供已知化学污染物进行检测相关的偏差，增强了对实验室诊断能力的信心，因此可能会引起PT提供者和认证委员会的兴趣。
