Immunohistochemical assessment of the diagnostic utility of PD-L1: a preliminary analysis of anti-PD-L1 antibody (SP142) for lymphoproliferative diseases with tumour and non-malignant Hodgkin–Reed-Sternberg (HRS)-like cells

• Main Authors: Ayako Sakakibara, Kei Kohno, Ahmed E. Eladl, Teerada Klaisuwan, Eri Ishikawa, Yuka Suzuki, Satoko Shimada, Masato Nakaguro, Yoshie Shimoyama, Taishi Takahara, Seiichi Kato, Naoko Asano, Shigeo Nakamura, Akira Satou
• Format: Journal
• Published: 2018
• Subjects: Medicine
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85043362757&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/58914
• Institution: Chiang Mai University

© 2018 John Wiley & Sons Ltd Aims: The programmed death 1 (PD1)/PD1 ligand (PD-L1) axis plays an important role in tumour cells escape from immune control. PD-L1 immunohistochemistry is a useful predictor of immunotherapy response, but is still not used widely in the diagnostic setting. Here we describe results using PD-L1 immunohistochemistry during routine diagnostics in lymphoma. Methods and results: Ninety-one lymphoproliferative disease cases sharing tumour and non-malignant Hodgkin–Reed-Sternberg (HRS)-like cells with and without Epstein–Barr virus (EBV) association were investigated by immunohistochemistry for PD-L1 (clone SP142). PD-L1 expression was present in more than 5% of tumour or non-malignant HRS-like cells in 100% of EBV+classical (C) Hodgkin lymphoma (HL) (n = 10) and EBV-negative nodular sclerosis CHL (n = 8); 40% of EBV+diffuse large B cell lymphoma, not otherwise specified (DLBCL–NOS) (n = 20); and 4% of nodal peripheral T cell lymphoma of follicular helper T cell type (PTCL-TFH) (n = 22). In contrast, nodular lymphocyte-predominant HL (n = 4), lymphocyte-rich CHL (n = 6), EBV+hyperplasia (n = 8), plasmablastic lymphoma (n = 3) and anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (n = 5) seldom exhibited PD-L1 in their large cells. Assessing PD-L1 positivity in tumour and non-malignant large cells was helpful in differentiating between CHL versus nodal PTCL–TFH (P < 0.0001) or EBV+DLBCL–NOS (P = 0.0052) and between EBV+DLBCL–NOS versus nodal PTCL-TFH (P = 0.0052), with PD-L1 expression indicating the first diagnosis in each of those sets. Conclusion: Immunohistochemical evaluation of PD-L1 expression in tumour and non-malignant HRS-like large cells may be useful for assessing either immune escape or immunodeficiency in their pathogenesis.