A Belgian ring trial for pan-TRK immunohistochemistry (IHC) staining was organised to harmonise pan-TRK IHC staining protocols and interpretation. As a reference method, the VENTANA pan-TRK Assay (clone EPR17341) on the Benchmark Ultra platform was selected. Six samples were selected: 2 negative, 2 fusion positive and 2 samples with wild-type endogenous TRK expression. Each participating laboratory stained the slides using their routine pan-TRK IHC and reported their results. In addition, they were asked to return one TRK-stained slide from each case. The coordinating lab evaluated these slides, compared them with the reference method and scored them. Two clones were used during the ring trial: A7H6R (Cell Signaling) and EPR17341 (Abcam/Ventana). Seven protocols achieved a sufficient performance mark, and three labs were advised to further optimise the protocol. Interpretation of pan-TRK IHC proved to be challenging in cases with physiological TRK expression. In addition, depending on the NTRK fusion partner, the staining can vary strongly in both intensity and staining pattern. Labs using the Ventana ready-to-use system based on the EPR17341 clone and using the recommended protocol settings scored best. However, given some small optimisation, all labs scored well on the technical staining and the succeeding evaluation.

组织了一项针对泛 TRK 免疫组织化学 (IHC) 染色的比利时环形试验，以协调泛 TRK IHC 染色方案和解释。选择 Benchmark Ultra 平台上的 VENTANA pan-TRK Assay（克隆 EPR17341）作为参考方法。选择了 6 个样本：2 个阴性、2 个融合阳性和 2 个具有野生型内源性 TRK 表达的样本。每个参与的实验室使用他们的常规 pan-TRK IHC 对载玻片进行染色并报告他们的结果。此外，他们还被要求从每个病例中归还一张 TRK 染色的载玻片。协调实验室评估了这些载玻片，将它们与参考方法进行了比较并进行了评分。环形试验期间使用了两个克隆：A7H6R (Cell Signaling) 和 EPR17341 (Abcam/Ventana)。七个协议达到了足够的性能标记，并建议三个实验室进一步优化协议。在生理性 TRK 表达的情况下，泛 TRK IHC 的解释被证明具有挑战性。此外，根据NTRK融合伙伴，染色在强度和染色模式上都有很大差异。使用基于 EPR17341 克隆的 Ventana 即用型系统并使用推荐的协议设置的实验室得分最高。然而，经过一些小的优化，所有实验室在技术染色和后续评估方面都取得了不错的成绩。