Smith Jacquelyn, Robida Mark D, Acosta Krista, Vennapusa Bharathi, Mistry Amita, Martin Greg, Yates Alton, Hnatyszyn H James
Companion Diagnostics Pharma Services, Assay Development, Ventana Medical Systems Inc., Roche Tissue Diagnostics, 1910 E Innovation Park Drive, Tucson, AZ, 85755, USA.
Companion Diagnostics Pharma Services, Pathology Office, Ventana Medical Systems Inc., Roche Tissue Diagnostics, 1910 E Innovation Park Drive, Tucson, AZ, 85755, USA.
Diagn Pathol. 2016 May 18;11(1):44. doi: 10.1186/s13000-016-0494-2.
Programmed Death Ligand 1 (PD-L1) is an immune modulating protein expressed on the surface of various inflammatory cells, including T Cells, B Cells, dendritic cells, and macrophages. PD-L1 represents an important diagnostic target; expression of PD-L1 on the surface of tumor cells, or within tumor-associated immune cells, is an important predictor of likely response to targeted therapies. In this study, we describe the optimization of immunohistochemistry (IHC) assays using two PD-L1 antibodies (SP263 and E1L3N) and compare the performance of the optimized assays.
Fully automated immunohistochemical assays were optimized for the VENTANA PD-L1 (SP263) Rabbit Monoclonal Antibody and the PD-L1 (E1L3N®) XP® Rabbit mAb using instruments and detection chemistries from Ventana Medical Systems, Inc. ("SP263 assay" and "E1L3N assay," respectively). Tissue microarrays (TMAs) containing formalin fixed paraffin embedded (FFPE) non-small cell lung cancer (NSCLC) cases were used for the optimization and comparison staining. H scores were used for membrane scoring whereas percent positivity was used for tumor-associated immune cell scoring.
One-hundred NSCLC TMA case cores each stained with the SP263 and E1L3N assays were evaluated by two pathologists in a blinded study. Analysis of these specimens showed that the SP263 assay was more sensitive and had a wider dynamic range than the E1L3N assay. For sensitivity, many cases were found to be negative for membrane staining with the E1L3N assay, but had measurable staining with the SP263 assay. Dynamic range was demonstrated by the SP263 assay having well-distributed H scores while the E1L3N assay had a significantly higher proportion of cases clustered in the lowest H score bins. For tumor-associated immune cell staining, the two assays identified similar amounts of cells staining in each case, but the SP263 assay gave overall darker staining.
Since PD-L1 status is important for targeted therapies, having a specific and accurate diagnostic test is crucial for identifying patients who could benefit from these treatments. Due to its staining intensity, scoring range, and pathologist preference, the SP263 IHC assay has been deemed superior to the E1L3N IHC assay. Future clinical utility remains to be determined.
程序性死亡配体1（PD-L1）是一种免疫调节蛋白，表达于包括T细胞、B细胞、树突状细胞和巨噬细胞在内的多种炎症细胞表面。PD-L1是一个重要的诊断靶点；肿瘤细胞表面或肿瘤相关免疫细胞内PD-L1的表达是靶向治疗可能反应的重要预测指标。在本研究中，我们描述了使用两种PD-L1抗体（SP263和E1L3N）优化免疫组织化学（IHC）检测方法，并比较优化后检测方法的性能。
使用Ventana Medical Systems公司的仪器和检测化学方法，分别针对VENTANA PD-L1（SP263）兔单克隆抗体和PD-L1（E1L3N®）XP®兔单克隆抗体优化全自动免疫组织化学检测方法（分别称为“SP263检测法”和“E1L3N检测法”）。使用包含福尔马林固定石蜡包埋（FFPE）非小细胞肺癌（NSCLC）病例的组织微阵列（TMA）进行优化和比较染色。H评分用于膜染色评分，而阳性百分比用于肿瘤相关免疫细胞评分。
在一项盲法研究中，两名病理学家对分别用SP263和E1L3N检测法染色的100个NSCLC TMA病例核心进行了评估。对这些标本的分析表明，SP263检测法比E1L3N检测法更敏感，动态范围更广。在敏感性方面，发现许多病例用E1L3N检测法进行膜染色为阴性，但用SP263检测法有可测量的染色。SP263检测法的H评分分布良好，证明了其动态范围，而E1L3N检测法有显著更高比例的病例聚集在最低H评分区间。对于肿瘤相关免疫细胞染色，两种检测法在每个病例中识别出的染色细胞数量相似，但SP263检测法总体染色更深。
由于PD-L1状态对靶向治疗很重要，拥有一种特异且准确的诊断检测方法对于识别可能从这些治疗中受益的患者至关重要。由于其染色强度、评分范围和病理学家的偏好，SP263 IHC检测法被认为优于E1L3N IHC检测法。其未来的临床应用仍有待确定。
