Sintilimab-Induced Myocarditis in a Patient with Gastric Cancer: A Case Report and Literature Review

Immune checkpoint inhibitors (ICIs) have emerged as a powerful and efficacious therapeutic approach for many cancer patients. Sintilimab is a fully human IgG4 monoclonal antibody that binds with programmed cell death receptor-1 (PD-1) to block its interaction with ligands, thereby enhancing the antitumor effects of T cells. However, ICIs may induce immune-related adverse events (irAEs) in various systems and organs, with fulminant myocarditis being the most severe one. We report the case of a 45-year-old female with gastric cancer who developed chest pain two weeks after chemotherapy with sintilimab; she was diagnosed with immune-associated fulminant myocarditis and experienced an Adams-Stokes syndrome attack in the hospital. Eventually, she was discharged after being treated with methylprednisolone, immunoglobulin, and an IABP.

Relationship Between the Expression of PD-1 and CTLA-4 on T Lymphocytes and the Severity and Prognosis of Sepsis

Purpose

The study aimed to investigate the relationship between the expression of PD-1 and CTLA-4 on the surface of peripheral blood T lymphocyte subsets in patients with sepsis and the severity and prognosis of the disease.

Patients and Methods

The study included patients with sepsis who were admitted to the intensive care unit. The expression of PD-1 and CTLA-4 on T lymphocyte subsets was detected by flow cytometry, and the severity of sepsis was assessed using the SOFA score.

Results

The expression of PD-1 on CD4⁺T cells, PD-1 on Tregs, and CTLA-4 on Tregs increased with the severity of the disease (P<0.05). Multivariate logistic regression analysis showed that PD-1 expression on CD4⁺T cells, CTLA-4 expression on Tregs, and the SOFA score were independent risk factors for 28-day mortality in patients with sepsis (P<0.05). The area under the curve of the SOFA score combined with the expression of PD-1 on CD4⁺T cells and CTLA-4 on Treg cells was significantly higher than any single indicator (P<0.05). Patients with high expression of PD-1 on CD4⁺T cells (>31.25%) and CTLA-4 on Tregs (>12.64%) had a lower 28-day survival rate (P<0.05).

Conclusion

The increased expression of PD-1 and CTLA-4 on CD4⁺T cells and Tregs is significantly associated with the severity and prognosis of sepsis patients. The combination of the SOFA score and the expression of PD-1 on CD4⁺T cells and CTLA-4 on Tregs can further improve the prognostic predictive value. These findings may be promising biomarkers for prognostic assessment, risk stratification, and identification of immunosuppression in patients with sepsis.

PD-L1 heterogeneity in patients with non-small cell lung cancer

AIMS

Programmed death receptor ligand-1 (PD-L1) expression has been identified as the main predictor of responsiveness to programmed death receptor-1 (PD-1)-targeted immunotherapy in patients with advanced non-small cell lung cancer (NSCLC). In this retrospective study, we explored the inter- and intratumoral PD-L1 heterogeneity in patients who received two separate pathologically verified NSCLC diagnoses at Shandong Provincial Hospital Affiliated to Shandong First Medical University and Linyi People's Hospital.

METHODS

Patients were classified into four groups according to the type of intra- and intertumoral heterogeneity: Group 1 included patients in whom primary tumor heterogeneity was observed between biopsy and surgical specimens; in Group 2, heterogeneity was observed between primary tumors and paired dissected regional lymph nodes; in Group 3, heterogeneity was observed between resected primary tumors and distant metastases or recurrent disease; in Group 4, heterogeneity was observed before and after microwave ablation. Of the 221 enrolled patients, 97, 36, 57, and 31 were allocated to groups 1, 2, 3, and 4, respectively.

RESULTS

Significant heterogeneity was observed among all patients (P = 0.026) and within Group 1 (P = 0.022) when using a PD-L1 tumor proportion score (TPS) cut-off of 5%. However, no heterogeneity was observed in the other groups or with a PD-L1 TPS cut-off value of 1%.

CONCLUSIONS

Intratumoral PD-L1 expression heterogeneity between the biopsy and surgical specimens of primary tumors was more frequently detected than intertumoral heterogeneity in advanced NSCLC.

[Identifying protein epitopes recognized by monoclonal antibodies]

To establish a method for identifying protein epitopes recognized by therapeutic monoclonal antibodies, the programmed death receptor-1 (PD-1) was selected as the target protein. Based on the alanine scanning strategy, a rapid expression method of antigen mutants combining site-directed mutagenesis with mammalian cell expression system was established, the conditions for eukaryotic expression element amplification and cell transfection expression were established. 150 PD-1 protein mutants were co-expressed, and the binding ability of these mutants to anti-PD-1 antibody Pembrolizumab was identified. The epitopes of Pembrolizumab were determined based on the binding ability of protein mutants to antibodies and combined with protein structure analysis, which was highly consistent with the reported crystal structure-based epitopes, indicating that this method is simple and accurate and can be used for epitope mapping of therapeutic monoclonal antibodies.

A Gallbladder Carcinoma Patient With Pseudo-Progressive Remission After Hydrogen Inhalation

Background

Hydrogen therapy has been reported to convert exhausted programmed cell death receptor (PD-1)+CD8+ T cells to PD-1-CD8+ T cells, in advanced colorectal cancer patients, which is associated with significantly prolonged survival.

Case presentation

A 72-year-old female patient presented with metastatic gallbladder cancer and underwent symptomatic treatment combined with hydrogen therapy. The tumors were initially enlarged and displayed increased tumor marker expression following hydrogen inhalation therapy, after which they continued to remit, similar to the pseudo-progression that occurs after anti-PD-1 treatment. During one month of hydrogen therapy, the patient's gallbladder and liver tumors continued to progress, and intestinal obstruction occurred. The intestinal obstruction was gradually relieved after symptomatic treatment, and the metastases in the abdominal cavity gradually decreased in size, anemia and hypoalbuminemia were corrected, and both the lymphocyte and tumor marker levels returned to normal. The patient was able to resume normal life two and a half months after hydrogen inhalation and survived over 10 months.

Conclusion

This is the first report of pseudo-progression followed by sustained remission after hydrogen inhalation. This phenomenon is similar to the pseudo-progression-remission pattern that occurs following PD-1 antibody treatment. These findings suggest that hydrogen may have an inhibitory effect on PD-1 expression.

A novel role for programmed cell death receptor ligand 2 in sepsis-induced hepatic dysfunction

The liver is an organ that, when dysfunctional in a septic patient, is strongly associated with morbidity and mortality. Understanding the pathophysiology of liver failure during sepsis may lead to improved diagnostics and potential therapeutic targets. Historically, programmed cell death receptor (PD) ligand 1 (PD-L1) has been considered the primary ligand for its checkpoint molecule counterpart, PD-1, with PD-L2 rarely in the immunopathological spotlight. PD-1 and PD-L1 contribute to liver dysfunction in a murine cecal ligation and puncture (CLP) model of sepsis, but virtually nothing is known about PD-L2's role in sepsis. Therefore, our central hypothesis was that sepsis-induced changes in hepatic PD-L2 expression contributed to worsened liver function and, subsequently, more pronounced morbidity and mortality. We found that although PD-L1 gene deficiency attenuated the hepatic dysfunction seen in wild-type mice after CLP, the loss of PD-L2 appeared to actually worsen indices of liver function along with a trend toward higher liver tissue vascular permeability. Conversely, some protective effects of PD-L2 gene deletion were noted, such as reduced liver/peritoneal bacterial load and reduced IL-6, IL-10, and macrophage inflammatory protein 2 levels following CLP. These diverse actions, as well as the unique expression pattern of PD-L2, may explain why no overt survival advantage could be witnessed in the septic PD-L2^-/- mice. Taken together, these data suggest that although PD-L2 has some selective effects on the hepatic response seen in the septic mouse, these factors are not sufficient to alter septic mortality in this adult murine model. NEW & NOTEWORTHY Our study shows not only that ligands of the checkpoint protein PD-1 respond inversely to a stressor such as septic challenge (PD-L2 declines, whereas PD-L1 rises) but also that aspects of liver dysfunction increase in septic mice lacking the PD-L2 gene. Furthermore, these differences in PD-L2 gene-deficient animals culminated in the abrogation of the survival advantage seen in the septic PD-L1-knockout mice, suggesting that PD-L2 may have roles beyond a simple immune tolerogen.

Program Cell Death Receptor-1-Mediated Invariant Natural Killer T-Cell Control of Peritoneal Macrophage Modulates Survival in Neonatal Sepsis

We have shown that invariant natural killer T (iNKT) cells mediate sepsis-induced end-organ changes and immune responses, including macrophage bacterial phagocytosis, a finding regulated by the check point protein program cell death receptor-1 (PD-1). Furthermore, PD-1 mediates mortality in both adult and neonatal murine sepsis as well as in surgical patients. Given our previous findings, we hypothesize that iNKT cells will also modulate neonatal sepsis survival, and that this effect is regulated in part through PD-1. We utilized a polymicrobial intra-peritoneal cecal slurry (CS) sepsis model in wild type (WT), iNKT^−/− or PD-1^−/− 5–7 day old neonatal pups. Typically, tissues were harvested at 24 h for various bioassays/histology and, in some cases, survival was assessed for up to 7 days. Interestingly, similar to what we recently reported for PD-1^−/− mice following CS, iNKT^−/−-deficient animals exhibit a markedly improved survival vs. WT. Histologically, minor alterations in liver architectural, which were noted in WT pups, were attenuated in both iNKT^−/− and PD-1^−/− pups. Following CS, PECAM-1 expression was unchanged in the WT pups but increased in both iNKT^−/− and PD-1^−/− pups. In WT, following CS the emergence of a Ly6C^low subpopulation was noted among the influxed peritoneal macrophage population. Conversely, within iNKT^−/− pups, there were fewer peritoneal macrophages and a greater percentage of Ly6C^high macrophages. We show not only a key role for iNKT cells in affecting end-organ damage as well as alterations in phagocytes phenotypes in neonatal sepsis but that this iNKT cell mediated effect is driven by the central checkpoint protein PD-1.

Association between PD-1/PD-L1 and T regulate cells in early recurrent miscarriage

In this study, we try to testify the relationship between the programmed cell death receptor-1 (PD-1)/programmed cell death ligand 1 (PD-L1) passway and Treg cells in maternal-fetal immune regulation through PD-1 blockade on lymphocytes of normal early pregnancy in vitro and investigation of the PD-1 and PD-L1 changes in early recurrent miscarriage patients. CD4+ CD25+ Treg cells and PD-1 (CD279) positive cell were detected in deciduas in early recurrent miscarriage patients by flow cytometry. And the normal early pregnant women were as controls. Meanwhile the mRNA level of PD-1 and molecular expression of PD-L1 in deciduas of early recurrent miscarriage patients were detected by real time RT-PCR test and Immunohistochemical staining respectively. Also through antibody blocking assay to block PD-1 on lymphocytes of normal early pregnancy in vitro further testify the relationship between PD-1/PD-L1 and Treg cells, the results were analyzed by flow cytometry. CD4+ CD25+ Treg cells decreased both in deciduas in RM (P < 0.05), and for all almost 100% Treg cells (CD4+ CD25+) expressed PD-1, but there was no difference between the PD-1 positive cells in decidual lymphocytes in RM and that in normal pregnancy women (P > 0.05). PD-L1 mRNA in deciduas decreased in RM (P < 0.001), but PD-1 mRNA no difference (P > 0.1). After PD-1 blockade there was no change in CD4+ CD25+ Treg cells percentage, while the CD4+ T cell percentage increased (P < 0.01), as well as the level of IFN-gamma in cells supernatant (P < 0.01). PD-1 blockade has a little influence on the number of Treg cells, and may lead to impaired Treg cells function, the decrease of PD-L1 may closely relates to the occurrence of early recurrent miscarriage and implies that Treg cells may through PD-1/PD-L1 pathway play a role of immunosuppression regulation, and the impairment of Treg cells function in recurrent early abortion cases may be due to PD-L1 decrease in deciduas or trophoblast cells rather than PD-1 change.