Meta-analysis of genetic polymorphisms in programmed cell death 1. Associations with rheumatoid arthritis, ankylosing spondylitis, and type 1 diabetes susceptibility

Immunotherapy for colorectal cancer: insight from inherited genetics

Immunotherapy shows efficacy for multiple cancer types and potential for expanded use. However, current immune checkpoint inhibitors (ICIs) are ineffective against microsatellite-stable colorectal cancer (CRC), which is more commonly diagnosed. Immunotherapy strategies for non-responsive CRC, including new targets and new combination therapies, are being tested to address this need. Importantly, a subset of inherited germline genetic variants associated with CRC risk are predicted to regulate genes with immune functions, including genes related to existing ICIs, as well as new potential targets in the major histocompatibility complex (MHC) region and immunoregulatory cytokines. We review discoveries in the inherited genetics of CRC related to the immune system and draw connections with ongoing developments and emerging immunotherapy targets.

Associations of toll-like receptor polymorphisms with systemic lupus erythematosus: A meta-analysis

Objective

The objective of this study was to examine whether polymorphisms in toll-like receptors 7 and 4 (TLR7 and 4) contribute to vulnerability to systemic lupus erythematosus (SLE).

Methods

We searched MEDLINE, Embase, and Web of Science for relevant articles and performed a meta-analysis to investigate the relationship between TLR7 rs179008, rs3853839, rs1790010, TLR4 rs4986791, and rs798690 polymorphisms and SLE.

Results

Eighteen studies and 16 papers including 8022 patients with SLE and 9822 healthy controls were retrieved. Meta-analysis revealed that the TLR7 rs179008 T variant was not associated with SLE (OR = 1.008, 95% CI = 0.849-1.394, P = 0.504). Ethnic classification revealed no association between the TLR7 rs179008 T gene and SLE in either European or Latin American groups. Additionally, homozygous comparison, recessive, and dominant models revealed no association between the TLR7 rs179008 variant and SLE. In contrast, a significant association between SLE and the TLR7 rsrs3853839 GG + GA allele (OR = 2.135, 95% CI = 1.502-3.035, <0.001; OR = 23.20, 95% CI = 14.13-38.08, <0.001) was observed in the Arab and Asian groups. The T variant of TLR7 rsrs179010 was also associated with SLE in Asians (OR = 1.177, 95% CI = 1.048-1.321, P = 0.006). In contrast, the TLR4 rs4986791 variant was not associated with SLE in Europeans when allele, homozygous comparison, recessive, and dominant models were used. Furthermore, no association between the TLR4 rs4986790 variant and SLE risk in Europeans was found using any genomic model.

Conclusions

Meta-analysis revealed that the TLR7 rs3853839 variant is associated with SLE risk in Asians and Arabs and that TLR7 rs179010 is associated with SLE in Asians. However, TLR7 rs179008, TLR4 rs4986791, and TLR rs798690 polymorphisms were not associated with SLE risk.

Association between systemic sclerosis and venous thromboembolism, pulmonary embolism, and deep vein thrombosis: a meta-analysis

OBJECTIVE

This study aimed to analyze the published data pertaining to the correlation between venous thromboembolism (VTE) and systemic sclerosis (SSc).

METHODS

We conducted manual searches and explored MEDLINE, EMBASE, and Cochrane databases to review papers reporting the risk of VTE in patients with SSc. A meta-analysis was performed exploring the relative risks (RRs) of deep vein thrombosis (DVT), pulmonary embolism (PE), and VTE in these individuals.

RESULTS

Six trials that included 41,105 patients with SSc were eligible for inclusion. A meta-analysis of the six included studies revealed a statistically significant correlation (RR 2.372, 95% confidence interval [CI] = 1.608-3.500, p < 0.001) between the risk of VTE and SSc. Regional subgroup study revealed a strong correlation between SSc and VTE risk in Americans, Europeans, and Asians. Additionally, a significant correlation between SSc and PE risk was observed (RR 3.154, 95% CI = 1.320-7.539, p = 0.010). Finally, the meta-analysis revealed a substantial correlation (RR 5.190, 95% CI = 1.513-17.01, p = 0.009) between the risk of DVT and SSc.

CONCLUSION

This meta-analysis showed that SSc is linked to an increased risk of DVT, PE, and VTE. This finding underscores the importance of close monitoring for the emergence of these conditions in patients with SSc.

What do we know about co-stimulatory and co-inhibitory immune checkpoint signals in ankylosing spondylitis?

Ankylosing spondylitis is the main entity of a family of inflammatory diseases affecting many musculoskeletal (sacroiliac joints, spine, and peripheral joints) and extra-musculoskeletal sites, termed spondyloarthritis. While it is debated whether disease onset is primarily driven by autoimmune or autoinflammatory processes, what is certain is that both innate and adaptive immune responses orchestrate local and systemic inflammation, which leads to chronic pain and immobility. Immune checkpoint signals are one key player in keeping the immune system in check and in balance, but their role in disease pathogenesis is still rather elusive. Therefore, we ran a MEDLINE search utilizing the PubMed platform for a variety of immune checkpoint signals in regard to ankylosing spondylitis. In this review, we summarize the experimental and genetic data available and evaluate the relevance of immune checkpoint signalling in the pathogenesis of ankylosing spondylitis. Markers such as PD-1 and CTLA-4 have been extensively studied and facilitate the concept of an impaired negative immune regulation in ankylosing spondylitis. Other markers are either neglected completely or insufficiently examined, and the data is conflicting. Still, some of those markers remain interesting targets to decipher the pathogenesis of ankylosing spondylitis and to develop new treatment strategies.

Analysis of Programmed Cell Death-1 (PD-1) Gene Variations (re11568821 and rs41386349) in HTLV-1 Infection Using One Primer Pair and Proviral Load

About 90% of people infected with Human T lymphotropic virus type-1 (HTLV-1) virus are asymptomatic, so it can be said that the prevalence of this virus is not completely clear. During chronic infection, the expression of programmed cell death-1 (PD-1) protein increases and causes exhausted phenotype in T cells. Considering the role of host genetics and immune responses in HTLV-1 infection, in this case-control study, included 81 asymptomatic carriers (ACs) and 162 healthy controls (HCs), rs11568821 and rs41386349 polymorphisms of PD-1 gene were evaluated by Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method which investigated by one primer pair for both polymorphisms also, proviral load (PVL) measured by quantitative real-time PCR (Q-RT-PCR). The results showed that the mutant allele of rs11568821 (A) and rs41386349 (T) polymorphisms is associated with an increase in HTLV-1 infection significantly (p = 0.019 and p = 0.000 respectively). But there was no significant relationship between PVL and polymorphisms.

Autoimmunity and Cancer-Two Sides of the Same Coin

Autoimmune disease results from the immune response against self-antigens, while cancer develops when the immune system does not respond to malignant cells. Thus, for years, autoimmunity and cancer have been considered as two separate fields of research that do not have a lot in common. However, the discovery of immune checkpoints and the development of anti-cancer drugs targeting PD-1 (programmed cell death receptor 1) and CTLA-4 (cytotoxic T lymphocyte antigen 4) pathways proved that studying autoimmune diseases can be extremely helpful in the development of novel anti-cancer drugs. Therefore, autoimmunity and cancer seem to be just two sides of the same coin. In the current review, we broadly discuss how various regulatory cell populations, effector molecules, genetic predisposition, and environmental factors contribute to the loss of self-tolerance in autoimmunity or tolerance induction to cancer. With the current paper, we also aim to convince the readers that the pathways involved in cancer and autoimmune disease development consist of similar molecular players working in opposite directions. Therefore, a deep understanding of the two sides of immune tolerance is crucial for the proper designing of novel and selective immunotherapies.

B7 immune checkpoint family members as putative therapeutics in autoimmune disease: An updated overview

Autoimmune diseases, especially among young people in the US, are one of the leading causes of morbidity and death. The immune responses are the fundamental pathogenicity of autoimmune disorders. The equilibrium between stimulatory and inhibitory signals is critical for the stimulation, migration, survival, and T cell-related immune responses. The B7 family can substantially regulate T cell-mediated immune responses. Nevertheless, recent breakthroughs in immune checkpoint blockade in cancer immunotherapy have facilitated autoimmune diseases, especially among the prone populations. In the current study, we tried to concisely review the role of the B7 family in regulating immune reactions and the influence of immune checkpoint inhibitors on autoimmunity development.

Bridging the Gap: Connecting the Mechanisms of Immune-Related Adverse Events and Autoimmunity Through PD-1

The emergence of anti-cytotoxic T-lymphocyte antigen 4 (anti-CTLA-4), anti-programmed cell death 1 ligand (anti-PD-1), and anti-PD-L1 antibodies as immune checkpoint inhibitors (ICIs) revolutionized the treatment of numerous types of tumors. These antibodies, both alone and in combination, provide great clinical efficacy as evidenced by tumor regression and increased overall patients' survival. However, with this success comes multiple challenges. First, while patients who respond to ICIs have outstanding outcomes, there remains a large proportion of patients who do not respond at all. This all-or-none response has led to looking downstream of programmed cell death 1 (PD-1) for additional therapeutic targets and for new combination therapies. Second, a majority of patients who receive ICIs go on to develop immune-related adverse events (irAEs) characterized by end-organ inflammation with T-cell infiltrates. The hallmarks of these clinically observed irAEs share many similarities with primary autoimmune diseases. The contribution of PD-1 to peripheral tolerance is a major mechanism for protection against expansion of self-reactive T-cell clones and autoimmune disease. In this review, we aim to bridge the gaps between our cellular and molecular knowledge of PD-1 signaling in T cells, ICI-induced irAEs, and autoimmune diseases. We will highlight shared mechanisms and the potential for new therapeutic strategies.

Programmed cell death-1 rs11568821 and interleukin-28B rs12979860 polymorphisms in autoimmune hepatitis

BACKGROUND

Autoimmune hepatitis (AIH) is a relatively rare chronic liver disease of unknown etiology. The genetic background affects susceptibility, clinical phenotype, and prognosis. The programmed cell death-1 rs11568821 polymorphism (PD1.3) has been associated with susceptibility to autoimmune diseases. The interleukin-28B (IL28B) rs12979860 polymorphism has been associated with steatosis, inflammation, and fibrosis in liver diseases.

AIM

Our aim was to investigate for the first time the incidence and clinical significance of PD1.3 and IL28B rs12979860 in AIH.

METHODS

Two hundred patients with AIH were evaluated, while 100 healthy subjects were used as controls. Genotyping was performed with in-house allelic discrimination End-Point PCR.

RESULTS

The SNP PD1.3/A was present in 36/200 (18%) AIH patients compared to 28/100 (28%) healthy controls (p = 0.065). The AA/GA genotypes were not associated with the mode of presentation of AIH, the histological grade or stage, the presence of cirrhosis, risk of disease progression, response to treatment and survival. The IL28B rs12979860 genotype distribution was CC 79/200 (39.5%), TT 36/200 (18%) and CT 85/200 (42.5%), in similar rates with healthy controls (p = 0.878). Inflammatory activity and fibrosis stage did not differ between CC homozygotes and CT/TT carriers. LDL cholesterol was significantly higher in CC than CT/TT patients (P = 0.027), though no differences was found regarding the presence of steatosis or steatohepatitis. On-treatment response to immunosuppressive treatment was not affected by the IL28B rs12979860 polymorphism. However, CC homozygotes AIH patients achieved treatment withdrawal in significantly higher rates (OR 2.3, 95%CI: 1.1-4.7, P = 0.02) irrespective of the presence of steatosis or steatohepatitis.

CONCLUSIONS

The PD1.3 and IL28B rs12979860 variants are unlikely to contribute to AIH susceptibility, disease presentation and prognosis. The IL28B rs12979860 is not associated with the presence of concurrent steatosis or steatohepatitis. However, although on-treatment response rates to immunosuppression were not affected by the IL28B rs12979860 polymorphism, AIH patients with CC homozygosity were more likely to achieve complete treatment withdrawal. This novel finding needs validation and further clarification from larger multicenter studies.

Computational design of a synthetic PD-1 agonist

Programmed cell death protein-1 (PD-1) inhibitory antibodies, often referred to as checkpoint inhibitors, have revolutionized the treatment of cancer. However, there is an unmet need for PD-1 agonists to treat autoimmune disorders. Herein, we describe the de novo design of a small, stable PD-1 binding protein and development of a synthetic PD-1 agonist.

Programmed cell death protein-1 (PD-1) expressed on activated T cells inhibits T cell function and proliferation to prevent an excessive immune response, and disease can result if this delicate balance is shifted in either direction. Tumor cells often take advantage of this pathway by overexpressing the PD-1 ligand PD-L1 to evade destruction by the immune system. Alternatively, if there is a decrease in function of the PD-1 pathway, unchecked activation of the immune system and autoimmunity can result. Using a combination of computation and experiment, we designed a hyperstable 40-residue miniprotein, PD-MP1, that specifically binds murine and human PD-1 at the PD-L1 interface with a K_d of ∼100 nM. The apo crystal structure shows that the binder folds as designed with a backbone RMSD of 1.3 Å to the design model. Trimerization of PD-MP1 resulted in a PD-1 agonist that strongly inhibits murine T cell activation. This small, hyperstable PD-1 binding protein was computationally designed with an all-beta interface, and the trimeric agonist could contribute to treatments for autoimmune and inflammatory diseases.

Genetic determinants of immune-related adverse events in patients with melanoma receiving immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) can cause profound immune-related adverse events (irAEs). The host genetic background is likely to play a role in irAE susceptibility because the presentation of toxicity varies among patients and many do not develop irAEs despite continued ICI use. We sought to identify potential genetic markers conferring risk for irAEs.

METHODS

We conducted a pilot exploratory study in 89 melanoma patients who received ICIs (44 with irAEs, and 45 without irAEs after at least 1 year from starting treatment). Genotyping was performed using the Infinium Multi-Ethnic Global-8 v1.0 Bead Chip. The genotype data were extracted using PLINK (v1.90b3.34) and processed for quality control. Population structure-based clustering was carried out using IBS matrix, pairwise population concordance test (p < 1 × 10-3), and phenotype distribution for all study participants, resulting in seven population structure-based clusters. In the analytical stage, 599,931 variants in autosomal chromosomes were included for the association study. The association test was performed using an additive genetic model with exact logistic regression, adjusted for age, sex, and population cluster.

RESULTS

A total of 30 variants or single-nucleotide polymorphisms with p < 1 × 10-4 were identified; 12 were associated with an increased risk of irAEs, and the remaining 18 were associated with a decreased risk. Overall, nine of the identified single-nucleotide polymorphisms mapped to eight unique genes that have been associated with autoimmunity or inflammatory diseases.

CONCLUSION

Several genetic variants associated with irAEs were identified. Additional larger studies are needed to validate these findings and establish their potential functional relevance.

Ankylosing spondylitis risk factors: a systematic literature review

Radiographic axial spondyloarthritis (also known as ankylosing spondylitis [AS]) is a chronic immune-mediated arthritis characterized by inflammation of the axial skeleton, peripheral joints, and entheses. It is estimated that 1 in every 200 people are affected by AS, making it an important healthcare and socioeconomic issue. In this review, we aim to explore the current understanding of AS risk factors and provide a comprehensive update. Multiple search strings were used to identify articles of interest published in PubMed between January 1, 2013, and February 1, 2021. On the basis of the literature review and analysis, we present up-to-date information on the risk factors of developing AS and our viewpoints on disease onset and progression. Multiple genetic and nongenetic risk factors have been suggested in the onset of AS. HLA-B27 is known to have a strong association with the disease, but other genes have been implicated in disease development. Aside from genetics, other factors are thought to be involved; up to 70% of patients with AS have subclinical intestinal inflammation, suggesting that the origin of the disease may be in the gut. The exact mechanism by which AS onset begins is most likely complex and multifactorial. Key Points • It remains unclear how interactions between genes, microbes, mechanical stress, gender, and other environmental and lifestyle factors predispose patients to the development of ankylosing spondylitis (AS). • The exact mechanisms of AS are complex and multifactorial which will require much future research • Recognizing the risk factors, as well as understanding gene-environment interactions, may offer valuable insights into the etiology of AS and have important implications for diagnosis and treatment strategies.

Germline Variation in PDCD1 Is Associated with Overall Survival in Patients with Metastatic Melanoma Treated with Anti-PD-1 Monotherapy

A substantial number of melanoma patients do not benefit from therapy with anti-PD-1. Therefore, we investigated the predictive value of single nucleotide polymorphisms (SNPs) in genes related to the PD-1 axis in patients with metastatic melanoma. From 119 consecutive melanoma patients who were treated with pembrolizumab or nivolumab monotherapy, blood samples were genotyped for 11 SNPs in nine genes. Associations between SNPs and OS were tested using Cox regression analysis and internally validated by bootstrapping. For SNPs with a statistical significance, an expression quantitative trait loci (eQTL) analysis was performed. In a subset of patients, immunophenotyping was performed. Patients with a SNP in PDCD1 (804C > T; rs2227981) had a significantly poorer OS with a 3-year OS rate of 51.8%, as compared to 71% in wild type patients (hazard ratio [HR] 2.37; 95% CI: 1.11-5.04; p = 0.026). eQTL analysis showed that this SNP was associated with decreased gene expression. In addition, PDCD1 804C > T carriers had a reduced fraction of peripheral PD-1⁺CD4⁺ T cells. No other associations between SNPs and OS were found. PDCD1 804C > T is associated with poorer OS after anti-PD-1 monotherapy in patients with metastatic melanoma. This SNP may affect clinical benefit from ICIs by decreasing transcription initiation and expression of PD-1 in T cells.

Predictive Biomarkers of Immune Checkpoint Inhibitors-Related Toxicities

The emergence and continuous development of immune checkpoint inhibitors (ICIs) therapy brings a revolution in cancer therapy history, but the major hurdle associated with their usage is the concomitant ICIs-related toxicities that present a challenge for oncologists. The toxicities may involve non-specific symptoms of multiple systems as for the unique mechanism of formation, which are not easily distinguishable from traditional toxicities. A few of these adverse events are self-limiting and readily manageable, but others may limit treatment, cause interruption and need to be treated with methylprednisolone or tumor necrosis factor-α (TNF-α) antibody infliximab, and even directly threaten life. Early accurate recognition and adequate management are critical to the patient's prognosis and overall survival (OS). Several biomarkers such as the expression of programmed cell death ligand 1 (PD-L1), tumor mutation burden (TMB), and microsatellite instability-high (MSI-H)/mismatch repair-deficient (dMMR) have been proved to be the predictors for anti-tumor efficacy of ICIs, but there is a gap in clinical needs for effective biomarkers that predict toxicities and help filter out the patients who may benefit most from these costly therapies while avoiding major risks of toxicities. Here, we summarize several types of risk factors correlated with ICIs-related toxicities to provide a reference for oncologists to predict the occurrence of ICIs-related toxicities resulting in a timely process in clinical practice.

Immune checkpoint inhibitors and diabetes: Mechanisms and predictors

The emergence of immune checkpoint inhibitors in the arsenal of cancer immunotherapy was a breakthrough which provided hope to many cancer patients. However, not long has passed since their discovery that some adverse effects were associated with these promising therapeutic agents. Immune checkpoint inhibitors dysregulate host immunity and may precipitate autoimmune diseases including diabetes mellitus. In this review, we go beyond the case reports towards understanding the underlying mechanisms by which Programmed cell death 1 (PD-1) and Programmed death ligand-1 (PD-L1) inhibitors precipitate diabetes. We discuss the role of PD-1/PD-L1 in autoimmunity and the use of mice models to describe their involvement in diabetes. We also reviewed the genetic anomalies in PD-1/PD-L1genes and their link to diabetes. Finally, we present the studies conducted to identify patients at risk of developing autoimmune diseases as an adverse effect for PD-1/PD-L1 use. Understanding these issues can guide researchers to find a way to circumvent the autoimmune adverse reactions seen with PD-1/PD-L1 inhibitors without affecting their antitumor activity.

Sintilimab-Induced Autoimmune Diabetes in a Patient With the Anti-tumor Effect of Partial Regression

Context

Immune checkpoint blockades (ICBs) have been approved widely to treat various malignancies. Autoimmune diabetes mellitus, which can be caused by programmed cell death protein 1 (PD-1) inhibitors, is rare. Sintilimab, a monoclonal anti-PD-1 antibody, has been approved in China for the treatment of Hodgkin’s lymphoma and was used in our clinical trial for patients with unresectable hepatocellular carcinoma (HCC).

Case Presentation

We present the first case of autoimmune diabetes during Sintilimab treatment in a patient with unresectable HCC, accompanied by a remarkable anti-tumor effect of partial regression. A 56-year-old male with typical symptoms presented with diabetic ketoacidosis (DKA) at 24 weeks after Sintilimab initiation. His fasting plasma glucose level was 22.2 mmol/L, HbA1c was 7.8%, fasting insulin was 1.5 mIU/L, and fasting C-peptide was 1.12 ng/mL, which further decreased to 0.21 ng/mL 4 days later. The patient was diagnosed with new-onset diabetes mellitus using the oral glucose tolerance test. The anti-glutamic acid decarboxylase 65 antibody, anti-islet cell antibody, and anti-insulin antibody tests were all negative. For the type 1 diabetes-associated alleles of human leukocyte antigen (HLA) class I and II, the most relevant type was identified as HLA-A^∗0201. A diagnosis of PD-1 inhibitor-induced autoimmune diabetes was made. After rectification of DKA, he was treated with insulin therapy daily, which has since controlled his plasma glucose well. Thereafter, Sintilimab was been continued with sustained therapeutic effect.

Conclusion

Due to unpredictability of this rare immune related adverse event (irAE), diabetes-related autoantibodies and C-peptide are recommended to be tested before immunotherapy, and plasma glucose monitoring should be performed. After plasma glucose is well controlled using insulin therapy, PD-1 inhibitor treatment might be continued, especially when the immunotherapy is effective.

SAP interacts with CD28 to inhibit PD-1 signaling in T lymphocytes

T cell co-stimulation is important for the maintenance of immunologic tolerance. Co-inhibitory receptors including programmed cell death-1 (PD-1) confer peripheral tolerance to prevent autoimmunity. SAP (SH2D1A) is an adaptor molecule that is important in T cell signaling and has been shown to interact with signaling lymphocytic activation molecule (SLAM) family receptors also in the context of self-tolerance. We recently reported that SAP interferes with PD-1 function. In the current study, we investigated the levels of SAP and PD-1 in patients with rheumatoid arthritis (RA) to further understand what role they play in disease activity. We observed increased SAP levels in lymphocytes of RA patients and found that PD-1 levels correlated positively with RA disease activity. Additionally, we found that SAP interacts with CD28 to inhibit T cell signaling in vitro. This work demonstrates a putative molecular mechanism for SAP mediated PD-1 inhibition.

The Inhibitory T Cell Receptors PD1 and 2B4 Are Differentially Regulated on CD4 and CD8 T Cells in a Mouse Model of Non-alcoholic Steatohepatitis

Infiltrating CD4 and CD8 T cells have been shown to worsen inflammatory liver damage in non-alcoholic steatohepatitis (NASH). Inhibitory T cell receptors such as the programmed cell death protein 1 (PD1) and the natural killer cell receptor 2B4 regulate the activity of CD4 and CD8 T cells and therefore play an important role in immune tolerance required in the liver. In this study, we investigated the expression profile of inhibitory T cell receptors on CD4 and CD8 T cells in a mouse model of NASH. Male B57BL/6J mice were fed a Western diet for 24 weeks. The expression levels of inhibitory receptors on the surface of intrahepatic and peripheral T cells were measured and correlated with markers of activation (CD107a, CD69, and CD44), metabolic disorder (serum triglycerides, serum cholesterol, γ-glutamyl transferase, hepatic triglycerides), inflammation (serum alanine aminotransferase and aspartate aminotransferase) and hepatic fibrosis (collagen 1A1, α-smooth muscle actin, hydroxyproline). Under Western diet, PD1 is exclusively upregulated on intrahepatic and peripheral CD8⁺ T cells, whereas the expression level on CD4 T cells is unaffected. In contrast, 2B4 is upregulated liver-specifically on both CD4 and CD8 T cells and unchanged on peripheral T cells. Upregulation of PD1 on CD8 T cells is restricted to CD8 effector memory T cells and correlates with lower levels of degranulation. Similarly, the inhibitory function of PD1 on intrahepatic CD4 T cells is shown by a lower CD69 and CD44 expression on PD1-positive CD4 T cells. In murine steatohepatitis, the upregulation of PD1 on CD8 T cells and 2B4 on CD4 and CD8 T cells potentially limits T cell-mediated liver damage. Therefore, these inhibitory T cell receptors could serve as promising targets of immune-modulatory NASH therapy.

Analysis of expression of the PD-1/PD-L1 immune checkpoint system and its prognostic impact in gastroenteropancreatic neuroendocrine tumors

The immune checkpoint based therapy targeting the programmed death-1 (PD-1) receptor and its PD-L1 ligand has recently been approved for the therapy of different malignant conditions, but not yet for gastroenteropancreatic neuroendocrine tumors (GEP-NETs). In this context, we evaluated the expression of PD-1 and PD-L1 in GEP-NETs and its potential correlations with clinical outcomes. Expression of PD-1/PD-L1 was analyzed by immunohistochemistry in 116 GEP-NETs and 48 samples of peritumoral tissue. In addition, the expression of these molecules was assessed by flow cytometry in peripheral blood mononuclear cells (PBMC) from patients with GEP-NETs (n = 32) and healthy controls (n = 32) and in intratumoral mononuclear cells (TMCs) (n = 3). Expression of PD-L1 and PD-1 was detected by immunohistochemistry in 6% and 1% of tumor tissue samples, respectively, and in 8% of peritumoral tissue samples, for both markers. We also observed that PD-1 expression by TMCs was associated with metastatic disease at diagnosis, and the levels of circulating PD-1+ PBMCs were associated with progressive disease upon follow-ups. In addition, circulating PD-1+ PBMCs were significantly correlated with PD-L1 expression by tumor cells. Our data suggest that PD-1/PD-L1 is expressed in 1 to 8% of GEP-NETs, and that this feature is significantly associated with disease evolution (p < 0.01).

Immune Checkpoints as Therapeutic Targets in Autoimmunity

Antibodies that block the immune checkpoint receptors PD1 and CTLA4 have revolutionized the treatment of melanoma and several other cancers, but in the process, a new class of drug side effect has emerged—immune related adverse events. The observation that therapeutic blockade of these inhibitory receptors is sufficient to break self-tolerance, highlights their crucial role in the physiological modulation of immune responses. Here, we discuss the rationale for targeting immune checkpoint receptors with agonistic agents in autoimmunity, to restore tolerance when it is lost. We review progress that has been made to date, using Fc-fusion proteins, monoclonal antibodies or other novel constructs to induce immunosuppressive signaling through these pathways. Finally, we explore potential mechanisms by which these receptors trigger and modulate immune cell function, and how understanding these processes might shape the design of more effective therapeutic agents in future.

Immune checkpoint inhibitors in the onset of myasthenia gravis with hyperCKemia

Immune checkpoint inhibitors sometimes cause neuromuscular adverse events. Although a few cases of myasthenia gravis with hyperCKemia triggered by immune checkpoint inhibitors have been described, conclusive evidence remains limited. We conducted a systematic review of published cases of myasthenia gravis with hyperCKemia related to immune checkpoint inhibitors. Moreover, we tested anti‐striational antibodies in the case of myasthenia gravis with myositis after nivolumab administration. We located 17 published case reports. Anti‐striational antibodies were tested in six cases and five cases were positive. Our systematic analyses revealed poor prognosis in myasthenia gravis combined hyperCKemia with immune checkpoint inhibitors.

Case-control Association Study of Autoimmunity Associated Variants in PDCD1 and Juvenile Idiopathic Arthritis

PURPOSE

Variants in the gene encoding Programmed Cell Death-1 (PDCD1) have been associated with susceptibility to Systemic Lupus Erythematosus and other autoimmune diseases. Given that clinically distinct autoimmune phenotypes share common genetic susceptibility factors, variants in PDCD-1 were tested for a possible association with Juvenile Idiopathic Arthritis (JIA).

METHODS

Four Single Nucleotide Polymorphisms (SNPS) in the PDCD1 gene were genotyped and analyzed: rs7421861, rs11568821, rs10204525, and rs7568402 in 834 cases and 855 controls of Northern European ancestry. Each variant was examined for possible associations with JIA and then analyzed for association with JIA categories.

RESULTS

PDCD1 variants showed no association with JIA in the cohort overall (rs7421861 p=0.63, rs11568821 p=0.13, rs10204525 p=0.31, and rs7568402 p=0.45). Stratification by JIA categories indicated a significant association between systemic JIA and PDCD1 rs7568402 (OR=0.53, p=0.0027), which remained significant after 10,000 permutations, but was not replicated in an independent multi-ethnic systemic JIA cohort. A nominal association between enthesitis-related arthritis and rs115668821 was also observed (OR=0.22, p=0.012).

CONCLUSION

Unlike other multiple autoimmune disease associated genetic variants, there was no association between PDCD1 variants and JIA or JIA categories.

Occurrence of type 1 and type 2 diabetes in patients treated with immunotherapy (anti-PD-1 and/or anti-CTLA-4) for metastatic melanoma: a retrospective study

Anti-PD-1 and anti-CTLA-4 antibodies cause immune-related side effects such as autoimmune type 1 diabetes (T1D). It has also been suggested that by increasing TNF-α, IL-2 and IFN-γ production, anti-PD-1 and/or anti-CTLA-4 treatment could affect pancreatic beta cell function and insulin sensitivity. This study was based on a retrospective observational analysis from 2 July 2014 to 27 June 2016, which evaluated the occurrence of T1D and changes in glycemia and C-reactive protein (CRP) plasma concentrations in patients undergoing anti-PD-1 and/or anti-CTLA-4 treatment for melanoma at the Saint Louis Hospital. All cases of T1D that developed during immunotherapy registered in the French Pharmacovigilance Database (FPVD) were also considered. Among the 132 patients included, 3 cases of T1D occurred. For the remaining subjects, blood glucose was not significantly affected by anti-PD-1 treatment, but CRP levels (mg/l) significantly increased during anti-PD-1 treatment (p = 0.017). However, 1 case of type 2 diabetes (T2D) occurred (associated with a longer therapy duration). Moreover, glycemia of patients pretreated (n = 44) or concomitantly treated (n = 8) with anti-CTLA-4 tended to increase during anti-PD-1 therapy (p = 0.068). From the FPVD, we obtained 14 cases of T1D that occurred during immunotherapy and were primarily characterized by the rapidity and severity of onset. In conclusion, in addition to inducing this rare immune-related diabetes condition, anti-PD-1 treatment appears to increase CRP levels, a potential inflammatory trigger of insulin resistance, but without any short-term impact on blood glucose level.

Rs2227982 and rs2227981 in PDCD1 gene are functional SNPs associated with T1D risk in East Asian

AIMS

To investigate whether PDCD1 gene polymorphisms are functional, and their associations with T1D risk and related clinical characteristics.

METHODS

A total of 3060 Chinese Han individuals (1019 T1D patients and 2041 healthy controls) were genotyped for 4 tag single nucleotide polymorphisms (SNPs) within the PDCD1 region (rs2227982, rs7421861, rs10204525, and rs6710479) and another most studied synonymous SNP, rs2227981. In addition, 251 healthy individuals underwent an oral glucose tolerance test (OGTT); measures of insulin release and sensitivity were estimated from insulinogenic, BIGTT, Matsuda. Further, we performed in silico bioinformatics analysis to explore potential functional annotation of the investigated SNPs in PDCD1 gene.

RESULTS

Both rs2227982 and rs2227981 polymorphisms were associated with T1D risk in Chinese Han population under additive model (OR = 0.84, 95% CI 0.75-0.93 and OR = 1.23, 95% CI 1.08-1.40, respectively), but not the other three SNPs in PDCD1 gene. Our meta-analysis revealed that rs2227982 and rs2227981 polymorphisms also have significant associations with T1D risk in East Asians (OR = 0.82, 95% CI 0.74-0.90 and OR = 1.23, 95% CI 1.12-1.36, respectively), but not Europeans. And the T allele of rs2227982 polymorphism is associated with increased 30 min post OGTT glucose level (P = 0.023) and 120 min post OGTT insulin level (P = 0.033). Furthermore, the genetic and regulatory architecture suggested all the 5 investigated SNPs in PDCD1 are putatively functional.

CONCLUSIONS

Both rs2227982 and rs2227981 polymorphisms were associated with T1D risk in East Asians, and rs2227982 also had a significant association with glycemic traits, which suggested PDCD1 gene polymorphisms might participate in facilitating T1D risk.

Association between single-nucleotide polymorphisms and adverse events in nivolumab-treated non-small cell lung cancer patients

Background

Treatment with PD-1 inhibitors can be hampered by severe auto-immune-related toxicities. Our objective was to identify single-nucleotide polymorphisms (SNPs) in genes previously associated with auto-immunity, which are associated with toxicities in nivolumab-treated NSCLC patients. This was in order to identify patients prone to develop severe toxicities and to gain more insight into the underlying pathobiology.

Methods

We analysed 322 nivolumab-treated patients and assessed the association with toxicities for seven SNPs in four genes, which are considered contributors to PD-1-directed T-cell responses, i.e., PDCD1, PTPN11, ZAP70 and IFNG. Every SNP was tested for its association with toxicity endpoints. Significant associations were tested in a validation cohort.

Results

A multivariable analysis in the exploration cohort showed that homozygous variant patients for PDCD1 804C>T (rs2227981) had decreased odds for any grade treatment-related toxicities (n = 96; OR 0.4; 95% CI 0.2–1.0; p = 0.039). However, this result could not be validated (n = 85; OR 0.9; 95% CI 0.4–1.9; p = NS).

Conclusions

Our results show that it is unlikely that the investigated SNPs have a clinical implication in predicting toxicity. A finding, even though negative, that is considered timely and instructive towards further research in biomarker development for checkpoint inhibitor treatments.

Biomarkers for immune-related toxicities of checkpoint inhibitors: current progress and the road ahead

INTRODUCTION

Immune checkpoint pathways are key immune regulatory pathways that play a physiologic role in maintaining immune-homeostasis and are often co-opted by cancer cells to evade the host immune system. Recent developments in cancer immunotherapy, mainly drugs blocking the immune checkpoint pathways, have revolutionized the treatment paradigm for many solid tumors. A wide spectrum of immune-related adverse events (irAEs) have been described with the use of these agents which necessitate treatment with immunosuppression, lead to disruption of therapy and can on occasion be life-threatening. There are currently no clinically validated biomarkers to predict the risk of irAEs. Areas covered: In this review, the authors describe the current progress in identifying biomarkers for irAEs and potential future directions. Literature search was conducted using PubMed-MEDLINE, Embase and Scopus. In addition, abstracts from major conference proceedings were reviewed for relevant content. Expert commentary: The discovery of biomarkers for irAEs is currently in its infancy, however there are a lot of promising candidate biomarkers that are currently being investigated. Biomarkers that can identify patients at a higher risk of developing irAEs or lead to early detection of autoimmune toxicities are crucial to optimize patient selection for immune-oncology agents and to minimize toxicity with their use.

Association of PD-1 and PD-L1 Genetic Polymorphyisms with Type 1 Diabetes Susceptibility

AIMS

The programmed death- (PD-) 1/PD-1 ligand (PD-L) pathway plays an important role in regulating T cell activation and maintaining peripheral tolerance. Accumulated studies showed that PD-1/PD-L1 pathway was involved in the development of type 1 diabetes (T1DM). Since the genetic background of type 1 diabetes differs greatly among the different population, we aim to investigate the association of genetic polymorphisms in PD-1 and PD-L1 with T1DM susceptibility in Chinese population.

METHODS

In total, 166 T1DM patients and 100 healthy controls were enrolled into the study. Genomic DNA was extracted from 4 mL peripheral blood samples collected from each subject. Genotyping of 8 selected SNPs of PD-1 and PD-L1 was carried out by the pyrosequencing PSQ 24 System using PyroMark Gold reagents (QIAGEN).

RESULTS

SNP rs4143815 in PD-L1 was significantly associated with T1DM. People carrying the C allele of rs4143815 suffering less risk of T1DM and T1DM patients with G/G genotype showed higher levels of autoantibody (AAB) positive incidence compared with C allele carriers. No significant associations were found in other SNPs.

CONCLUSIONS

Our results indicate that rs4143815 of PD-L1 is significantly associated with T1DM and may serve as a new biomarker to predict the T1DM susceptibility.

Rheumatic disorders associated with immune checkpoint inhibitors in patients with cancer—clinical aspects and relationship with tumour response: a single-centre prospective cohort study

Objectives

To evaluate the prevalence and type of rheumatic immune-related adverse events (irAEs) in patients receiving immune checkpoint inhibitors (ICIs), as well as the correlation with tumour response.

Methods

This was a single-centre prospective observational study including all cancer patients receiving ICIs. The occurrence of irAEs and tumour response was assessed on a regular basis. Patients who experienced musculoskeletal symptoms were referred to the department of rheumatology for clinical evaluation and management.

Results

From September 2015 to May 2017, 524 patients received ICIs and 35 were referred to the department of rheumatology (6.6%). All but one of the rheumatic irAEs occurred with anti-programmed cell death protein 1(PD-1)/PD-1 ligand 1(PD-L1) antibodies, with a median exposure time of 70 days. There were two distinct clinical presentations: (1) inflammatory arthritis (3.8%) mimicking either rheumatoid arthritis (n=7), polymyalgia rheumatica (n=11) or psoriatic arthritis (n=2) and (2) non-inflammatory musculoskeletal conditions (2.8%; n=15). One patient with rheumatoid arthritis was anti-cyclic citrullinated peptide (anti-CCP) positive. Nineteen patients required glucocorticoids, and methotrexate was started in two patients. Non-inflammatory disorders were managed with non-steroidal anti-inflammatory drugs, analgesics and/or physiotherapy. ICI treatment was pursued in all but one patient. Patients with rheumatic irAEs had a higher tumour response rate compared with patients without irAEs (85.7% vs 35.3%; P<0.0001).

Conclusion

Since ICIs are used with increasing frequency, knowledge of rheumatic irAEs and their management is of major interest. All patients were responsive either to low-to-moderate doses of prednisone or symptomatic therapies and did not require ICI discontinuation. Furthermore, tumour response was significantly higher in patients who experienced rheumatic irAEs.

Are programmed cell death 1 gene polymorphisms correlated with susceptibility to rheumatoid arthritis?: A meta-analysis

BACKGROUND

Several studies investigated the relationship between programmed cell death 1 (PDCD1) gene polymorphisms and rheumatoid arthritis (RA) risk, but the results were controversial. To explore whether PDCD1 gene polymorphisms have an effect on RA risk, we conducted this meta-analysis to investigate the relationships between PDCD1 polymorphisms (rs36084323 [PD-1.1 G/A], rs11568821 [PD-1.3 G/A] and rs2227981 [PD-1.5 C/T]) and RA risk under 4 genetic models.

METHODS

PubMed, EMBASE, Web of Science, Cochrane Library China National Knowledge Infrastructure (CNKI), and Chinese Biomedical Literature Database (CBLM) were systematically searched for all eligible case-control studies. The last search was updated on September 10, 2016. Studies were accessed using Newcastle-Ottawa Scale case control study (NOS), and the combined effect size was calculated using STATA software, version 12.0. The pooled odds ratio (OR) with 95% confidence interval (CI) was calculated to assess the association. Heterogeneity analysis and subgroup analysis were also performed. Sensitivity analysis and publication bias were also performed if necessary.

RESULTS

This meta-analysis included 6 studies. The result demonstrated null association between rs36084323 (PD-1.1 G/A) polymorphism and RA susceptibility in all 4 genetic models. With regard to rs11568821 (PD-1.3 G/A), statistically significant association with RA risk was observed under allele model in Caucasians (allele model A vs G, OR = 1.19, 95% CI = 1.03-1.41). There was no significant association between rs2227981 (PD-1.5 C/T) polymorphism and RA risk.

CONCLUSION

The present study suggests that mutant A allele in rs11568821 (PD-1.3 G/A) might increase the susceptibility to RA in Caucasians.

Adverse Events in Cancer Immunotherapy

Cancer immunotherapy has resulted in durable responses in patients with metastatic disease, unseen with traditional chemotherapy. Several therapies have been approved by the Food and Drug Administration for the treatment of various cancers, including: immune checkpoint inhibitors, cytokines - interleukin 2 (IL-2) and interferon alpha (IFN), and the cancer vaccine sipuleucel-T. These therapies upregulate the immune system to enhance antitumor responses. As a consequence, they can cause inflammatory and immune-related adverse events that can affect one or more organs, can be serious, and on occasion lifethreatening. The management of these adverse events is complex, and requires a multidisciplinary approach involving not only oncologists, but also other internal medicine specialists, to ensure prompt diagnosis and optimal management of these complications.

Pretreatment Predictors of Response to PegIFN-RBV Therapy in Egyptian Patients with HCV Genotype 4

BACKGROUND

Egypt has the highest prevalence of a difficult to treat chronic hepatitis C virus (HCV), genotype 4. Pretreatment factors could guide individualization of therapy which aids in treatment optimization and interleukin IL28B gene polymorphism has been shown to closely relate to HCV treatment response. Polymorphisms in genes encoding inhibitors of T-cell response, which have role in disease progression as Programmed Cell Death 1 (PD-1), and Cytotoxic T-Lymphocytes Antigen-4 (CTLA-4), could be candidate markers predicting treatment response.

METHODS

This cohort study consisted of 200 chronic HCV genotype 4 infected patients treated with PegIFN α-2a and RBV in 2 hepatology centers. Genotyping of the polymorphisms in the IL28B gene region (rs12979860), PD1.3 (rs11568821) and CTLA-4 (rs231775) was performed on DNA collected from each patient using TaqMan® genotyping assay. Groups were classified according to response into sustained virological responders (SVR), or non-responders (NR). A multivariate logistic regression analysis was used to identify potential markers, host pretreatment clinical and viral predictive factors including viral load, insulin resistance, and alpha fetoprotein (AFP) related to treatment response.

RESULTS

Our results showed that in a multivariate analyses IL28B C/C genotype was the most significant predictor for SVR (OR = 10.86; p<0.0001) followed by AFP (OR = 0.915; p = 0.001) then CTLA-4/G genotypes (OR = 1.948; p = 0.022). However, PD-1.3/A genotypes and platelets count were significantly related to response in univariate analysis only (OR = 1.973; p = 0.023; OR = 1.007; p = 0.009 respectively).

CONCLUSION

IL28B SNP, AFP level, and CTLA-4 SNP could be used in conjunction to predict treatment response in HCV genotype 4 infected Egyptian patients.

Immune-related adverse events with immune checkpoint blockade: a comprehensive review

Cancer immunotherapy is coming of age; it has prompted a paradigm shift in oncology, in which therapeutic agents are used to target immune cells rather than cancer cells. The first generation of new immunotherapies corresponds to antagonistic antibodies that block specific immune checkpoint molecules cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death protein (PD-1) and its ligand PD-L1. Targeting these checkpoints in patients living with cancer had led to long-lasting tumour responses. By unbalancing the immune system, these new immunotherapies also generate dysimmune toxicities, called immune-related adverse events (IRAEs) that mainly involve the gut, skin, endocrine glands, liver, and lung but can potentially affect any tissue. In view of their undisputed clinical efficacy, anti-CTLA-4 and anti-PD-1 antibodies are entering in the routine oncological practice, and the number of patients exposed to these drugs will increase dramatically in the near future. Although steroids can be used to treat these IRAEs, the associated immunosuppression may compromise the antitumour response. Oncologists must be ready to detect and manage these new types of adverse events. This review focuses on the mechanisms of IRAE generation, putative relationship between dysimmune toxicity and antitumour efficacy, as a basis for management guidelines.

The associations between PD-1, CTLA-4 gene polymorphisms and susceptibility to ankylosing spondylitis: a meta-analysis and systemic review

Previous surveys had evaluated the effects of the PD-1, CTLA-4 gene polymorphisms on susceptibility to ankylosing spondylitis (AS), but the results remained controversial. To briefly examine these consequences, a comprehensive meta-analysis was conducted to estimate the relationships between PD-1 rs11568821, rs2227982, rs2227981, CTLA-4 +49 A/G and -318 C/T polymorphisms and AS risk. The available articles dated to December 2014 were searched in the PUBMED, MEDLINE and EMBASE databases. The data of the genotypes and/or alleles for the PD-1 rs11568821, rs2227982, rs2227981, CTLA-4 +49 A/G and -318 C/T polymorphisms in the AS and control subjects were extracted, and statistical analysis was conducted by STATA 11.2 software. Summary odds ratios (ORs) with their 95 % confidence intervals (95 % CIs) were calculated to determine the strength of associations with fixed-effects or random-effects models. A total of eight published studies were finally involved in this meta-analysis. Meta-analysis of PD-1 rs2227982 polymorphism under the T allele versus C allele (OR 1.744, 95 % CI 1.477-2.059, P < 0.0001), TT+TC versus CC (OR 2.292, 95 % CI 1.654-3.175, P < 0.0001), TT versus CC (OR 1.883, 95 % CI 1.299-2.729, P = 0.001) revealed a significant association with AS. Our meta-analysis demonstrated that the rs2227982 polymorphism in the PD-1 gene might contribute to AS susceptibility. However, further studies with large sample sizes and among different ethnicity populations should be required to confirm this association.

Low programmed cell death-1 (PD-1) expression in peripheral CD4(+) T cells in Japanese patients with autoimmune type 1 diabetes

Programmed cell death-1 (PD-1) is a co-stimulatory molecule that inhibits T cell proliferation. We aimed to clarify PD-1 expression in CD4(+) T cells and the association between PD-1 expression and the 7785C/T polymorphism of PDCD1, with a focus on the two subtypes of type 1 diabetes, type 1A diabetes (T1AD) and fulminant type 1 diabetes (FT1D), in the Japanese population. We examined 22 patients with T1AD, 15 with FT1D, 19 with type 2 diabetes (T2D) and 29 healthy control (HC) subjects. Fluorescence-activated cell sorting (FACS) and real-time PCR were utilized to analyse PD-1 expression quantitatively. Genotyping of 7785C/T in PDCD1 was performed using the TaqMan method in a total of 63 subjects (21 with T1AD, 15 with FT1D and 27 HC). FACS revealed a significant reduction in PD-1 expression in CD4(+) T cells in patients with T1AD (mean: 4.2 vs. 6.0% in FT1D, P=0.0450; vs. 5.8% in T2D, P=0.0098; vs. 6.0% in HC, P=0.0018). PD-1 mRNA expression in CD4(+) T cells was also significantly lower in patients with T1AD than in the HC subjects. Of the 63 subjects, PD-1 expression was significantly lower in individuals with the 7785C/C genotype than in those with the C/T and T/T genotypes (mean: 4.1 vs. 5.9%, P=0.0016). Our results indicate that lower PD-1 expression in CD4(+) T-cells might contribute to the development of T1AD through T cell activation.