The expression patterns of programmed cell death-1 (PD-1) and programmed cell death-ligand-1 (PD-L1) and their clinicopathological implications were investigated in peripheral T cell lymphoma (PTCL) including angioimmunoblastic T cell lymphoma (AITL) and PTCL-not otherwise specified (PTCL-NOS). PTCL-NOS was further classified into nodal PTCL with follicular helper T cell (Tfh) phenotype (“PTCL-Tfh_new”) and “PTCL-NOS_new”. PD-1 and PD-L1 expression on tumor cells and reactive immune cells was evaluated using immunohistochemistry. PD-1 and PD-L1 expression on tumor cells (PD-1^T and PD-L1^T, respectively) was interpreted as positive when more than 5% of tumor cells expressed PD-1 or PD-L1. For PD-1 and PD-L1 on tumor cells and/or reactive immune cells (PD-1^T + IC and PD-L1^T + IC, respectively), a cutoff of 10% of cells was used. PD-1^T, PD-L1^T, and PD-L1^T + IC expressions tended to be higher in AITLs than in PTCLs-NOS. PD-1^T, PD-1^T + IC, PD-L1^T, and PD-L1^T + IC expressions tended to be higher in PTCLs with Tfh phenotype including AITLs and “PTCL-Tfh_new” than in PTCLs without Tfh phenotype. The serum LDH level was significantly elevated in patients with PTCL positive for PD-L1^T (P = 0.006) and PD-L1^T + IC (P < 0.001). Patients with PTCL who were positive for combined expression of PD-1^T/PD-L1^T + IC presented at older ages (P = 0.010), nodal diseases (P = 0.001), higher IPI (P = 0.060), and elevated LDH (P = 0.030). Combined PD-1^T/PD-L1^T + IC positivity was related to shorter overall survival in patients with AITL (P = 0.051). Combined PD-1^T/PD-L1^T + IC positivity was a significant poor prognostic factor in patients with stage IV AITL, independent of B symptoms and performance status (HR = 6.282 [CI, 1.655–23.844], P = 0.007). In summary, the PD-1/PD-L1 pathway could be a potential prognostic and therapeutic biomarker for PTCL.

研究了程序性细胞死亡1（PD-1）和程序性细胞死亡配体-1（PD-L1）的表达模式及其在周围T细胞淋巴瘤（PTCL）中的临床病理意义，包括血管免疫母细胞性T细胞淋巴瘤（AITL）和PTCL-除非另有说明（PTCL-NOS）。PTCL-NOS进一步分为具有滤泡辅助性T细胞（Tfh）表型（“ PTCL-Tfh_new”）和“ PTCL-NOS_new”的结节PTCL。使用免疫组织化学评估肿瘤细胞和反应性免疫细胞上PD-1和PD-L1的表达。当超过5％的肿瘤细胞表达PD-1或PD-L1时，肿瘤细胞上的PD-1和PD-L1表达（分别为PD-1 ^T和PD-L1 ^T）被解释为阳性。对于肿瘤细胞和/或反应性免疫细胞上的PD-1和PD-L1（PD-1 ^{T + IC}和PD-L1 ^{T + IC}）分别使用10％的细胞截止值。AITL中的PD-1 ^T，PD-L1 ^T和PD-L1 ^{T + IC}表达倾向于高于PTCLs-NOS。具有Tfh表型（包括AITL）和“ PTCL-Tfh_new”的PTCL中的PD-1 ^T，PD-1 ^{T + IC}，PD-L1 ^T和PD-L1 ^{T + IC的}表达倾向于比没有Tfh表型的PTCL高。血清LDH水平的患者PTCL阳性PD-L1被显著升高^Ť（P  = 0.006）和PD-L1 ^{T + IC}（P  <0.001）。PDL联合表达阳性的PTCL患者^T / PD-L1 ^{T + IC}出现在较高年龄（P  = 0.010），淋巴结疾病（P  = 0.001），更高的IPI（P  = 0.060）和LDH升高（P  = 0.030）。PD-1 ^T / PD-L1 ^{T + IC联合}阳性与AITL患者总体生存期缩短有关（P  = 0.051）。合并PD-1 ^T / PD-L1 ^{T + IC}阳性是IV期AITL患者的显着不良预后因素，与B症状和表现状态无关（HR = 6.282 [CI，1.655–23.844]，P = 0.007）。总之，PD-1 / PD-L1途径可能是PTCL的潜在预后和治疗生物标志物。