Clinicopathological evaluation of the programmed cell death 1 (PD1)/programmed cell death-ligand 1 (PD-L1) axis in post-transplant lymphoproliferative disorders: association with Epstein-Barr virus, PD-L1 copy number alterations, and outcome.

The clinical implications of the programmed cell death 1 (PD1)/programmed cell death-ligand 1 (PD-L1) axis in patients with post-transplant lymphoproliferative disorders are largely unknown, and its association with Epstein-Barr virus (EBV) status and PD-L1 copy number alterations (CNAs) has not been thoroughly studied. PD1/PD-L1 expression was studied in 50 adult post-transplant lymphoproliferative disorders, and the correlations with PD-L1 CNAs, EBV, clinicopathological features and outcome were evaluated. Thirty-seven (74%) cases were classified as diffuse large B-cell lymphoma (DLBCL), nine (18%) cases were classified as polymorphic, and four (8%) cases were classified as classic Hodgkin lymphoma. Thirty-four cases were EBV-positive, with 29 of 34 (85%) having latency II or III, and 15 of 34 (44%) having viral replication. PD-L1 expression in tumour cells and tumour-associated macrophages was observed in 30 (60%) and 37 (74%) cases, respectively. PD1 positivity was seen in 16 (32%) cases. PD-L1 expression was associated with EBV with latency II or III (P = 0.001) and organ rejection (P = 0.04), and, in DLBCL, with non-germinal centre type DLBCL (P < 0.001). Cases with PD-L1-positive tumour cells showed a higher number of PD-L1 CNAs than PD-L1-negative cases (P = 0.001). Patients with EBV/latency III/replication and simultaneous PD-L1 expression showed the worst overall survival (P < 0.001). The PD1/PD-L1 axis is deregulated in post-transplant lymphoproliferative disorders, with frequent PD-L1 expression and PD1 negativity. PD-L1 expression is associated with EBV latency II or III and PD-L1 CNAs, and probably reflects a proinflammatory tumour microenvironment. The combined analysis of EBV status and PD-L1 expression may help to identify deeply immunosuppressed patients who can benefit from immune reconstitution approaches.

Veloza L ，Teixido C ，Castrejon N ，Climent F ，Carrió A ，Marginet M ，Soldini D ，González-Farré B ，Ribera-Cortada I ，Lopez-Guillermo A ，González-Barca E ，Sierra A ，Herrera M ，Gómez C ，Garcia A ，Balagué O ，Campo E ，Martinez A ... -  《-》

Programmed cell death-ligand 1 (PD-L1)(+) tumour cells and low-reacting programmed cell death 1 (PD1)(+) tumour-infiltrating lymphocytes predict poor prognosis in Epstein-Barr virus(+) diffuse large B-cell lymphoma.

Epstein-Barr virus (EBV)+ diffuse large B-cell lymphoma (DLBCL) has specific tumour cell characteristics, and these patients have worse outcomes than EBV-negative DLBCL patients. We compared 38 EBV+ DLBCL patients with 43 methotrexate-associated EBV+ B-cell lymphoproliferative disorders (MTX+/EBV+ BLPDs) and 30 non-germinal centre (GC) subtype DLBCL. Lymphoma cells of the EBV+ DLBCL group were positive for BCL2 in 17 patients (44.7%), CMYC in 23 patients (60.5%), and p53 in 33 patients (86.8%), which was significantly higher than in the MTX+/EBV+ BLPD group (P < 0.05), and were positive for CD30 in 29 patients (76.3%), compared with two in non-GC subtype DLBCL (6.7%) (P < 0.0001). Significantly more EBV+ DLBCL patients (n = 16, 42.1%) had programmed cell death-ligand 1 (PD-L1)+ tumour cells than patients with non-GC subtype DLBCL (n = 5, 16.7%; P = 0.024), and PD-L1+ tumour cells were more common in advanced stages than in early stages (P = 0.048). Twenty-five EBV+ DLBCL patients (69.4%) had few reactive PD1+ tumour-infiltrating lymphocytes (TILs), compared with 12 patients with MTX+/EBV+ BLPDs (37.5%) (P = 0.008). In the EBV+ DLBCL group, CD30, BCL2, CMYC, and p53 expression was not related to patient prognosis. Poor outcomes were associated with PD-L1+ tumour cells (P = 0.001) and low-reacting PD1+ TILs (P = 0.02), while their combination conferred a worse outcome (P < 0.0001). Immune evasion by PD-L1+ tumour cells and exhaustion of PD1+ TILs may occur in EBV+ DLBCL patients, and PD-L1/PD1 interactions may influence tumour progression and poor prognosis.

Kimura S ，Oshiro Y ，Iwasaki H ，Kadowaki M ，Mihashi Y ，Sakata T ，Kawauchi S ，Wang Z ，Takamatsu Y ，Takeshita M ... -  《-》

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.

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. 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. 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.

Sakakibara A ，Kohno K ，Eladl AE ，Klaisuwan T ，Ishikawa E ，Suzuki Y ，Shimada S ，Nakaguro M ，Shimoyama Y ，Takahara T ，Kato S ，Asano N ，Nakamura S ，Satou A ... -  《-》

The perivascular microenvironment in Epstein-Barr virus positive primary central nervous system lymphoma: The role of programmed cell death 1 and programmed cell death ligand 1.

It has been shown that high expression of certain immune checkpoint molecules, including those of the programmed death protein 1/programmed death ligand 1 (PD-1/PD-L1) axis, can be utilized to regulate immunosuppression in the microenvironment of malignant neoplasms. For the purpose of clarifying the immune-escape mechanism of primary central nervous system lymphomas (PCNSLs), particularly in Epstein-Barr virus (EBV)-positive cases, markers for PD-1, PD-L1, tumor-associated macrophages (TAMs), and tumor-infiltrating lymphocytes (TILs) in 39 surgical specimens of PCNSLs (17 EBV-positive, 22 EBV-negative) were investigated by immunohistochemistry. Staining for PD-L1 was scored as follows: (-), no staining; (1+), 0-30% positive cells; (2+), 30-60% positive cells; and (3+), >60% positive cells. In EBV-positive cases, PD-L1 was detected in both lymphoma cells and TAMs in 12/17 cases, and in TAMs only in 4/17 cases. The mean number of PD-1, TIA-1 (a marker for cytotoxic T-cells), and FOXP3 (a marker for regulatory T-cells)-positive TILs in EBV-positive cases was 36.4 ± 45.9, 390 ± 603, and 9.88 ± 15.1, respectively. In EBV-negative cases, PD-L1 was detected in both lymphoma cells and TAMs in 11/22 cases, and in TAMs only in 4/22 cases. The mean of PD-1, TIA-1 and FOXP3-positive lymphocytes in EBV-negative cases was 67.3 ± 82.0, 158 ± 206 and 9.32 ± 17.5, respectively. We found no significant difference in the number of FOXP3-positive, lymphocytes between EBV-positive and negative cases. However, there were significantly higher numbers of PD-1-positive lymphocytes in the former, and significantly higher numbers of TIA-1-positive lymphocytes in the latter (P < 0.05). The combined data indicate that expression of PD-L1 by lymphoma cells and TAMs mediate the trafficking of TILs, which may explain the immune-escape process of PCNSLs. In addition, EBV infection appears to affect the trafficking mechanism of TILs, and may thus play an important role in the microenvironment immunity of these tumors.

Sugita Y ，Furuta T ，Ohshima K ，Komaki S ，Miyoshi J ，Morioka M ，Abe H ，Nozawa T ，Fujii Y ，Takahashi H ，Kakita A ... -  《-》

Enhanced PD-L1 Expression in LMP1-positive Cells of Epstein-Barr Virus-associated Malignant Lymphomas and Lymphoproliferative Disorders: A Single-cell Resolution Analysis With Multiplex Fluorescence Immunohistochemistry and In Situ Hybridization.

Epstein-Barr virus (EBV) is associated with various types of human malignancies and with programmed death ligand (PD-L) 1 expression in neoplastic cells. However, in EBV-associated malignant lymphomas and lymphoproliferative disorders (LPDs), there is limited information regarding PD-L1 expression profiles among different histologic types and patterns of EBV latency. First, we investigated PD-L1 and EBV latent gene expression using conventional immunohistochemistry and in situ hybridization in 42 EBV-associated malignant lymphomas and LPDs. Classic Hodgkin lymphoma showed the highest PD-L1 expression with diffuse expression in all cases, followed by diffuse large B-cell lymphoma/Burkitt lymphoma, LPDs, and extranodal NK/T-cell lymphoma. EBV latency at the case level was not associated with PD-L1 expression. We further evaluated the expression of PD-L1 and EBV latent genes in tumor cells at single-cell resolution using multiplex fluorescence imaging. This analysis revealed that positivity rates of latent membrane protein (LMP) 1 in tumor cells were 1.0% to 89.5% (mean 35.4%) in latency type II/III cases, and LMP1 + cells showed more frequent PD-L1 expression than LMP1 - cells ( P &lt;0.0001, paired t test). In contrast, no association was observed between EBV nuclear antigen 2 and PD-L1 expression. Notably, tumor cells exhibiting Hodgkin/Reed-Sternberg cell-like morphology co-expressed PD-L1 and LMP1 more often than those that do not. Our observations suggested that LMP1 upregulates PD-L1 expression and is a potential biomarker for predicting the efficacy of immune checkpoint inhibitors. In addition, the heterogeneous expression of PD-L1 and EBV latent genes may produce diverse tumor cells with different oncogenic and immune-evasive properties, leading to resistance to targeted therapies.

Kume A ，Shinozaki-Ushiku A ，Kunita A ，Kondo A ，Ushiku T ... -  《-》