The role of programmed death cell protein 1 (PD-1) has already been described in a range of various diseases, including COVID-19. This study provides new, innovative data, related to the expression of PD-1 and the risk of Paediatric Inflammatory Multisystem Syndrome, temporally associated with SARS-CoV-2 infection (PIMS-TS)-a rare, but potentially life-threatening complication of COVID-19. In this study, we evaluated the expression of PD-1 protein in patients with PIMS. Blood samples were taken from patients at the time of diagnosis (n = 33), after 6 weeks (n = 33), 3 months (n = 24), 6 months (n = 24) and 12 months (n = 8). The immunophenotypes were evaluated in flow cytometry. The control group consisted of 35 healthy children with negative SARS-CoV-2 antigen/PCR test, who were asymptomatic and had no history of allergic, autoimmune or oncological diseases. The associations between immunophenotypes, biochemical findings and clinical data were analysed. Significant increases in the expression of PD-1 for CD4+ and CD8+ T cells, compared to the control group, were observed in the day of admission, with a gradual decrease during the first weeks from initiation of treatment. This study sheds new light on the pathogenesis of PIMS-TS, emphasizing the role of PD-1 protein. Future research is essential for early risk prediction in SARS-CoV-2 patients and for devising effective clinical prevention and management strategies.

UNASSIGNED: Chronic active Epstein-Barr virus disease (CAEBV) is a proliferative disease of EBV+ T or natural killer (NK) cells with an unclear pathogenesis. This study aimed to examine the frequency and exhaustion levels of lymphocyte subsets in patients with CAEBV to further investigate the pathogenesis.
UNASSIGNED: Using flow cytometry, we detected the frequency, expression levels of programmed cell death 1 (PD-1) and programmed death ligand 1 (PD-L1), and EBV infection status of peripheral T subsets and NK cells in patients with CAEBV and healthy individuals.
UNASSIGNED: 24 patients and 15 healthy individuals were enrolled in this study. Patients showed notably higher expression levels of PD-1 and PD-L1 in peripheral T subsets and NK cells compared to healthy individuals (P < 0.05). EBV+ lymphocytes exhibited significantly higher PD-L1 expression levels than EBV- lymphocytes. Additionally, the frequency of effector memory T (Tem) cells was significantly increased in patients, and the PD-L1 expression level was positively correlated with the EBV load. Besides, helper T cell 2 (Th2) immune bias, also favoring EBV amplification, was found in patients, including increased Th2 cell frequency, enhanced response capacity, and elevated serum levels of associated cytokines. The distribution and PD-1 expression levels of peripheral T subsets returned to normal in patients who responded to PD-1 blockade therapy.
UNASSIGNED: The up-regulation of the PD-1/PD-L1 pathway of peripheral T and NK cells and Th2 immune predominance jointly promoted EBV replication and the development of CAEBV. PD-1 blockade therapy reduced the PD-1 expression level of lymphocytes and helped normalize the distribution of the T subsets.

BACKGROUND: Although treatment options for gastric cancer (GC) continue to advance, the overall prognosis for patients with GC remains poor. At present, the predictors of treatment efficacy remain controversial except for high microsatellite instability.
OBJECTIVE: To develop methods to identify groups of patients with GC who would benefit the most from receiving the combination of a programmed cell death protein 1 (PD-1) inhibitor and chemotherapy.
METHODS: We acquired data from 63 patients with human epidermal growth factor receptor 2 (HER2)-negative GC with a histological diagnosis of GC at the Cancer Hospital, Chinese Academy of Medical Sciences between November 2020 and October 2022. All of the patients screened received a PD-1 inhibitor combined with chemotherapy as the first-line treatment.
RESULTS: As of July 1, 2023, the objective response rate was 61.9%, and the disease control rate was 96.8%. The median progression-free survival (mPFS) for all patients was 6.3 months. The median overall survival was not achieved. Survival analysis showed that patients with a combined positive score (CPS) ≥ 1 exhibited an extended trend in progression-free survival (PFS) when compared to patients with a CPS of 0 after receiving a PD-1 inhibitor combined with oxaliplatin and tegafur as the first-line treatment. PFS exhibited a trend for prolongation as the expression level of HER2 increased. Based on PFS, we divided patients into two groups: A treatment group with excellent efficacy and a treatment group with poor efficacy. The mPFS of the excellent efficacy group was 8 months, with a mPFS of 9.1 months after excluding a cohort of patients who received interrupted therapy due to surgery. The mPFS was 4.5 months in patients in the group with poor efficacy who did not receive surgery. Using good/poor efficacy as the endpoint of our study, univariate analysis revealed that both CPS score (P = 0.004) and HER2 expression level (P = 0.015) were both factors that exerted significant influence on the efficacy of treatment the combination of a PD-1 inhibitor and chemotherapy in patients with advanced GC (AGC). Finally, multivariate analysis confirmed that CPS score was a significant influencing factor.
CONCLUSIONS: CPS score and HER2 expression both impacted the efficacy of immunotherapy combined with chemotherapy in AGC patients who were non-positive for HER2.

OBJECTIVE: EMPOWER-Lung 3 part 2 (NCT03409614), a double-blind, placebo-controlled phase 3 study, assessed cemiplimab (anti-programmed cell death protein 1) plus chemotherapy versus chemotherapy alone in patients with advanced non-small cell lung cancer (NSCLC) without EGFR, ALK, or ROS1 aberrations, regardless of histology or PD-L1 expression levels. We report results from subgroup analysis of patients with PD-L1 expression ≥ 1 %.
METHODS: Patients were randomized to receive cemiplimab 350 mg or placebo with chemotherapy every 3 weeks for up to 108 weeks. Overall survival (OS), progression-free survival (PFS), overall response rates (ORRs), patient-reported outcomes (PROs), and safety were assessed.
RESULTS: Of the 327 patients with PD-L1 ≥ 1 % (466 in the overall study), 217 received cemiplimab plus chemotherapy and 110 received chemotherapy alone. After median follow-up of 28.0 months, median OS for cemiplimab plus chemotherapy was 23.5 months (95 % confidence interval [CI]: 20.9-27.2) vs. 12.1 months (95 % CI: 10.1-15.7) for chemotherapy alone (hazard ratio [HR] = 0.51, 95 % CI: 0.38-0.69, P < 0.0001); median PFS was 8.3 months (95 % CI: 6.7-10.8) versus 5.5 months (95 % CI: 4.3-6.2; HR = 0.48; 95 % CI: 0.37-0.62, P < 0.0001), and ORR was 47.9 % versus 22.7 %, respectively. PRO results favored cemiplimab plus chemotherapy over chemotherapy alone. Improved efficacy over chemotherapy alone was observed in both squamous and non-squamous histology. Safety was consistent with previous reports.
CONCLUSIONS: In this subgroup analysis from EMPOWER-Lung 3 part 2, cemiplimab plus chemotherapy demonstrated clinical benefit over chemotherapy alone in patients with advanced squamous or non-squamous NSCLC with PD-L1 ≥ 1 %.

There has been rapid advancement in the development of neoadjuvant therapy for non-small cell lung cancer (NSCLC), which holds great promise as an effective treatment strategy. Some clinical trials have confirmed that immunotherapy in combination with chemotherapy can be a recommended first-line regimen for neoadjuvant treatment of NSCLC. The present study describes the case of a male patient aged 65 years who was diagnosed with stage IIIA (cT2N2M0) adenosquamous carcinoma of the lung. After the administration of two cycles of neoadjuvant immunotherapy (sintilimab) in combination with chemotherapy, stable disease was observed in the primary tumor, whereas partial remission was detected in the mediastinal lymph nodes based on imaging assessment. The patient underwent an immediate upper lobectomy of the left lung. Pathological analysis revealed a complete response in the primary lesion, with only minimal presence of tumor cells observed in the lymph nodes surrounding the mediastinum and bronchi. This indicated that the present neoadjuvant therapy could be used in the treatment of stage III adenosquamous lung carcinoma; however, to conclusively determine its efficacy, further studies targeting this specific cancer type are essential.

The adoptive immunotherapy mediated by tumor-infiltrating lymphocytes (TILs) has shown definite efficacy against various solid tumors. However, the inefficiency of the conventional method based on in vitro expansion of TILs fails to achieve the cell count and high tumor-killing activity required for therapeutic purposes. This study investigated the effect of 3D tumor spheroids on the activation and expansion of TILs in vitro, aiming to provide a novel approach for the expansion of TILs. We procured TILs and primary tumor cells from surgical samples of lung cancer patients and then compared the impacts of lung cancer cell line NCI-H1975 and primary lung cancer cells cultured under 2D and 3D conditions on the activation, expansion, and anti-tumor activity of TILs. Furthermore, we added the programmed cell death protein 1 (PD-1) antibody into the co-culture of primary tumor cells and TILs within a 3D environment to assess the effects of the antibody on TILs. The results showed that compared with 2D cultured tumor cells, the 3D cultured H1975 cells significantly enhanced the expansion of TILs, increasing the proportion of CD3+/CD8+ cells in TILs to 61.6%. The 3D primary tumor model also enhanced the proportion of CD3+/CD8+ cells in TILs (45.5%, 54.4%), induced apoptosis of tumor epithelial cells and decreased the overall tumor cells survival rate (16.7%) after co-culture. PD-1 antibodies further improved the in vitro expansion capacity of TILs mediated by 3D tumor spheroids, resulting in the proportions of 50.9% and 57.0% for CD3+/CD8+ cells and enhancing the antitumor activity significantly (reducing the overall tumor survival rate to 9.36%). In summary, the use of 3D tumor spheroids significantly promoted the expansion and improved the anti-tumor effect of TILs, and the use of the PD-1 antibody further promoted the expansion and tumor-killing effect of TILs.

BACKGROUND: Studies evaluating the effectiveness of immune checkpoint inhibitors (ICI) for endometrial cancer (EC) are limited. This study aimed to assess the efficacy of PD-1/PD-L1 inhibitors as monotherapy for EC by conducting a meta-analysis. The predictive significance of MMR status, a biomarker for ICI response, also required further investigation.
METHODS: A systematic literature search was conducted in English databases until September 2023. The analysis included objective response rate (ORR), disease control rate (DCR), adverse events (AEs), and odds ratios (OR), along with their corresponding 95% confidence intervals (CI).
RESULTS: There were twelve trials totaling 685 individuals. PD-1/PD-L1 inhibitor monotherapy resulted in an ORR for 34% (95% CI = 24-44%) of the pooled EC patients. Subgroup analysis revealed a significantly higher ORR in dMMR EC (45%) compared to pMMR EC (8%), with an OR of 6.36 (95% CI = 3.64-11.13). The overall DCR was 42%, with dMMR EC at 51% and pMMR EC at 30% (OR = 2.61, 95% CI = 1.69-4.05). Grade three or higher adverse events (AEs) occurred in 15% of cases (95% CI = 9-24%) of the pooled incidence of AEs, which was 68% (95% CI = 65-72%).
CONCLUSIONS: This meta-analysis provides significant evidence for the effectiveness of PD-1/PD-L1 inhibitors as monotherapy for EC. Notably, dMMR EC patients demonstrated superior treatment efficacy with PD-1/PD-L1 inhibitor immunotherapy. Further research is required to explore subclassifications of EC based on dMMR molecular subtypes, enabling improved treatment strategies and outcomes for EC patients.

OBJECTIVE: This study aimed to investigate the role of the programmed cell death protein 1 (PD-1) pathway and T peripheral helper (Tph) cells in the pathogenesis of lupus nephritis using lupus-prone BXSB-Yaa mice.
METHODS: Male BXSB-Yaa mice and age-matched male C57BL/6 mice were used. The expression of PD-1 and its ligands (programmed cell death 1 ligand-1, PD-L1 and programmed cell death 1 ligand-2, PD-L2) and the phenotypes of kidney-derived cells and splenocytes expressing these molecules were analyzed by immunofluorescence and flow cytometry.
RESULTS: Nephritis spontaneously developed in 16-week-old but not in 8-week-old BXSB-Yaa or C57BL/6 mice. PD-1 was expressed on CD4+ mononuclear cells (MNCs) that infiltrated the glomeruli of 16-week-old BXSB-Yaa mice. The frequency of CD4+PD-1+CXCR5-ICOS+ kidney-derived Tph cells was higher in 16-week-old than in 8-week-old BXSB-Yaa and C57BL/6 mice, whereas the frequency of CD4+PD-1+CXCR5+ICOS+ kidney-derived T follicular helper (Tfh) cells was not significantly different between the mice. PD-L1 was constitutively expressed in the renal tubules. PD-L2 was expressed in the glomeruli of 16-week-old BXSB-Yaa mice. The frequency of PD-L1highCD11c+CD3-CD19- and PD-L2+CD11c+CD3-CD19- kidney-derived MNCs in 16-week-old BXSB-Yaa mice was significantly higher than that of the control mice. The percentage of kidney-derived Tph cells but not Tfh cells was correlated with the urinary protein levels in the nephritic mice.
CONCLUSIONS: The results of this study suggest that kidney-infiltrating PD-1+ Tph cells expanded concomitantly with the upregulation of PD-L1 and PD-L2 in the kidneys and the progression of lupus nephritis.

OBJECTIVE: Immune tolerance and evasion play a critical role in virus-driven malignancies. However, the phenotype and clinical significance of programmed cell death 1 (PD-1) and its ligands, PD-L1 and PD-L2, in aggressive acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin lymphoma (AR-NHL) remain poorly understood, particularly in the Epstein-Barr virus (EBV)-positive subset.
METHODS: We used in situ hybridization with EBV-encoded RNA (EBER) to assess the EBV status. We performed immunohistochemistry and flow cytometry analysis to evaluate components of the PD-1/PD-L1/L2 pathway in a multi-institutional cohort of 58 patients with AR-NHL and compared EBV-positive and EBV-negative cases.
RESULTS: The prevalence of EBV+ in AR-NHL was 56.9% and was associated with a marked increase in the expression of PD-1/PD-L1/PD-L2 in malignant cells. Patients with AR-NHLs who tested positive for both EBER and PD-1 exhibited lower survival rates compared to those negative for these markers (47.4% vs. 93.8%, p = 0.004). Similarly, patients positive for both EBER and PD-L1 also demonstrated poorer survival (56.5% vs. 93.8%, p = 0.043). Importantly, PD-1 tissue-expression demonstrated independent prognostic significance for overall survival in multivariate analysis and was correlated to elevated levels of LDH (r = 0.313, p = 0.031), increased PD-1+ Tregs (p = 0.006), and robust expression of EBER (r = 0.541, p < 0.001) and PD-L1 (r = 0.354, p = 0.014) expression.
CONCLUSIONS: These data emphasize the importance of PD-1-mediated immune evasion in the complex landscape of immune oncology in AR-NHL co-infected with EBV, and contribute to the diagnostic classification and possible definition of immunotherapeutic strategies for this unique subgroup.

UNASSIGNED: In this study, we aimed to investigate the prognostic value of programmed cell death protein 1 (PD-1), programmed cell death ligand 1 (PD-L1), and programmed cell death ligand 2 (PD-L2) expressions on immune and cancer cells in terms of survival in patients with lung adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.
UNASSIGNED: Between January 2000 and December 2012, a total of 191 patients (172 males, 19 females; mean age: 60.3±8.4 years; range, 38 to 78 years) who were diagnosed with non-small cell lung cancer and underwent anatomic resection and mediastinal lymph node dissection were retrospectively analyzed. The patients were evaluated in three groups including lung squamous cell carcinoma (n=61), adenocarcinoma (n=66), and large-cell carcinoma (n=64). The survival rates of all three groups were compared in terms of immunohistochemical expression levels of PD-1, PD-L1, and PD-L2.
UNASSIGNED: The mean follow-up was 71.8±47.9 months. In all histological subtypes, PD-1 expressions on tumor and immune cells were observed in 33% (61/191) and in 53.1% (102/191) of the patients, respectively. Higher expression levels of PD-L1 and PD-L2 at any intensity on tumor and immune cells were defined only in lung adenocarcinomas, and PD-L1 and PD-L2 values were detected in 36.4% (22/64) of these patients. The PD-L1 expressions on tumor and immune cells were observed in 41.7% (10/24) and 25% (6/24) of the patients, respectively. The PD-L2 expressions on tumor and immune cells were detected in 16.7% (4/24) and 8.4% (2/24) of the patients, respectively. Univariate and multivariate analyses revealed that PD-1 expression in tumor cells was an independent prognostic factor in all histological subtypes.
UNASSIGNED: Our study results suggest that PD-1 expression is a poor prognostic factor for overall survival in patients with completely resected adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.