Polymorphism in programmed cell death 1 gene is strongly associated with lung and kidney allograft survival in recipients from CMV-positive donors

The Association of Programmed Death 1 Gene Polymorphisms of PD1.3 G/A and PD1.5 C/T with Risk of COVID-19 in an Iranian Population: A Case-Control Study

Programmed death 1 (PD-1) has a central role in maintaining T cell tolerance and terminating cellular responses after eliminating antigens. Variation in PD-1 gene products caused by polymorphisms has been linked to several malignancies and autoimmune diseases. However, there is little known about the effects of its single-nucleotide polymorphisms (SNPs) on viral infections, particularly COVID-19. The primary aim of this study was to explore the function of genotypes, alleles, and haplotypes of two SNPs within the programmed cell death protein 1 (PDCD1) gene at PD1.3 G/A and PD1.5 C/T on susceptibility to COVID-19 in an Iranian population. The secondary objective was to evaluate the effects of these SNPs on the outcome of the disease. We got blood samples from COVID-19 patients (n = 195) and healthy subjects (n = 500) for genotypic determination of PD1.3 G/A (rs11568821) and PD1.5 C/T (rs2227981) SNPs, using the polymerase chain reaction-restriction fragment length polymorphism method, and constructed four haplotypes for PDCD1 SNPs. We used Pearson's chi-squared test, Fisher's exact test, and T-test for this study and incorporated effect sizes of odds ratio (OR) and standardized mean difference. The frequency of CT genotype of PD1.5 was meaningfully higher in COVID-19 patients (49.2%) than in healthy subjects (37.4%) (p = 0.005). However, these significant differences were not observed in the frequencies of PD1.3 genotypes between the two groups (p > 0.05). Of all estimated haplotypes for PDCD1, only AT was significantly and largely associated with COVID-19 susceptibility (p = 0.01, OR: 7.79 [95% confidence interval = 1.56-38.79]), however, this finding is inconclusive. In addition, the present study showed that the PD1.3 and PD1.5 SNPs were not associated with the outcome of the disease (p > 0.05). These results may propose that the PD1.5 CT genotype and AT haplotype of PDCD1 indecisively contribute to COVID-19 susceptibility in the Iranian population.

Immune Checkpoint Inhibitors in Special Populations

Cancer is the second leading cause of death in the worldwide. With the growing burden of cancer, the studies on early diagnosis, treatment and prevention of cancer are rapidly increasing. Recently, many new therapeutic strategies have been discovered, among which immunotherapy has dramatically changed the outlook for cancer treatment. Several clinical trials are underway around the world to produce potential treatments. However, these trials set certain strict joining conditions, so that the clinical data cannot be fully applied in the real world. To help clinical oncologists with treatment decision-making, this review collected recent studies on special populations receiving immunotherapy, including organ transplant patients, pregnant women, pediatric patients, patients with pulmonary tuberculosis, patients with human immunodeficiency virus, and patients with autoimmune diseases and mental illness.

Considerations for immunotherapy in patients with cancer and comorbid immune dysfunction

Immune checkpoint inhibitors have been widely incorporated for cancer treatment in a variety of solid and hematologic malignancies. Multiple clinical trials have demonstrated the efficacy of PD-1/PD-L1 and CTLA-4 axis inhibition in the metastatic and adjuvant settings. Due to the risks of autoimmune toxicity with these agents, stringent inclusion/exclusion criteria were employed in those initial clinical trials. These criteria led to exclusion or underrepresentation of a variety of patient populations with underlying immune dysfunction. These populations included patients with preexisting autoimmune diseases, solid organ or bone marrow transplant recipients, patients with HIV or viral hepatitis infections, patients receiving concurrent chronic steroid therapy, as well as patients who were elderly, pregnant, or had poor performance status. Thus, established guidelines on the use of immune checkpoint inhibitors in these patients are lacking, and evidence to support efficacy or toxicity are overall limited to retrospective studies and case series. Fortunately, ongoing clinical trials are now including these patients and are shedding light on whether these underrepresented populations can also safely benefit from immune checkpoint inhibitor therapies. In this review, we summarize the most clinically relevant available data on the use of checkpoint inhibitors in immunocompromised patient groups with a primary focus on safety.

Hypertension in kidney transplantation: a consensus statement of the 'hypertension and the kidney' working group of the European Society of Hypertension

Hypertension is common in kidney transplantation recipients and may be difficult to treat. Factors present before kidney transplantation, related to the transplantation procedure itself and factors developing after transplantation may contribute to blood pressure (BP) elevation in kidney transplant recipients. The present consensus is based on the results of three recent systematic reviews, the latest guidelines and the current literature. The current transplant guidelines, which recommend only office BP assessments for risk stratification in kidney transplant patients should be reconsidered, given the presence of white-coat hypertension and masked hypertension in this population and the better prediction of adverse outcomes by 24-h ambulatory BP monitoring as indicated in recent systematic reviews. Hypertension is associated with adverse kidney and cardiovascular outcomes and decreased survival in kidney transplant recipients. Current evidence suggests calcium channel blockers could be the preferred first-step antihypertensive agents in kidney transplant patients, as they improve graft function and reduce graft loss, whereas no clear benefit is documented for renin-angiotensin system inhibitor use over conventional treatment in the current literature. Randomized control trials demonstrating the clinical benefits of BP lowering on kidney and major cardiovascular events and recording patient-related outcomes are still needed. These trials should define optimal BP targets for kidney transplant recipients. In the absence of kidney transplant-specific evidence, BP targets in kidney transplant recipients should be similar to those in the wider chronic kidney disease population.

Precision Medicine in Kidney Transplantation: Just Hype or a Realistic Hope?

Desirable outcomes including rejection- and infection-free kidney transplantation are not guaranteed despite current strategies for immunosuppression and using prophylactic antimicrobial medications. Graft survival depends on factors beyond human leukocyte antigen matching such as the level of immunosuppression, infections, and management of other comorbidities. Risk stratification of transplant patients based on predisposing genetic modifiers and applying precision pharmacotherapy may help improving the transplant outcomes. Unlike certain fields such as oncology in which consistent attempts are being carried out to move away from the "error and trial approach," transplant medicine is lagging behind in implementing personalized immunosuppressive therapy. The need for maintaining a precarious balance between underimmunosuppression and overimmunosuppression coupled with adverse effects of medications calls for a gene-based guidance for precision pharmacotherapy in transplantation. Technologic advances in molecular genetics have led to increased accessibility of genetic tests at a reduced cost and have set the stage for widespread use of gene-based therapies in clinical care. Evidence-based guidelines available for precision pharmacotherapy have been proposed, including guidelines from Clinical Pharmacogenetics Implementation Consortium, the Pharmacogenomics Knowledge Base National Institute of General Medical Sciences of the National Institutes of Health, and the US Food and Drug Administration. In this review, we discuss the implications of pharmacogenetics and potential role for genetic variants-based risk stratification in kidney transplantation. A single score that provides overall genetic risk, a polygenic risk score, can be achieved by combining of allograft rejection/loss-associated variants carried by an individual and integrated into practice after clinical validation.

Host Genetics of Cytomegalovirus Pathogenesis

Human cytomegalovirus (HCMV) is a ubiquitous herpes virus (human herpes virus 5) with the highest morbidity and mortality rates compared to other herpes viruses. Risk groups include very young, elderly, transplant recipient, and immunocompromised individuals. HCMV may cause retinitis, encephalitis, hepatitis, esophagitis, colitis, pneumonia, neonatal infection sequelae, inflammatory, and age-related diseases. With an arsenal of genes in its large genome dedicated to host immune evasion, HCMV can block intrinsic cellular defenses and interfere with cellular immune responses. HCMV also encodes chemokines, chemokine receptors, and cytokines. Therefore, genes involved in human viral defense mechanisms and those encoding proteins targeted by the CMV proteins are candidates for host control of CMV infection and reactivation. Although still few in number, host genetic studies are producing valuable insights into biological processes involved in HCMV pathogenesis and HCMV-related diseases. For example, genetic variants in the immunoglobulin GM light chain can influence the antibody responsiveness to CMV glycoprotein B and modify risk of HCMV-related diseases. Moreover, CMV infection following organ transplantation has been associated with variants in genes encoding toll-like receptors (TLRs), programmed death-1 (PD-1), and interleukin-12p40 (IL-12B). A KIR haplotype (2DS4+) is proposed to be protective for CMV activation among hematopoietic stem cell transplant patients. Polymorphisms in the interferon lambda 3/4 (IFNL3/4) region are shown to influence susceptibility to CMV replication among solid organ transplant patients. Interestingly, the IFNL3/4 region is also associated with AIDS-related CMV retinitis susceptibility in HIV-infected patients. Likewise, interleukin-10 receptor 1 (IL-10R1) variants are shown to influence CMV retinitis development in patients with AIDS. Results from genome-wide association studies suggest a possible role for microtubule network and retinol metabolism in anti-CMV antibody response. Nevertheless, further genetic epidemiological studies with large cohorts, functional studies on the numerous HCMV genes, and immune response to chronic and latent states of infection that contribute to HCMV persistence are clearly necessary to elucidate the genetic mechanisms of CMV infection, reactivation, and pathogenesis.

Precision medicine: integration of genetics and functional genomics in prediction of bronchiolitis obliterans after lung transplantation

PURPOSE OF REVIEW

Lung transplantation (LTx) can be a life saving treatment in end-stage pulmonary diseases, but survival after transplantation is still limited. Posttransplant development of chronic lung allograft dysfunction with bronchiolits obliterans syndrome (BOS) as the major subphenotype, is the main cause of morbidity and mortality. Early identification of high-risk patients for BOS is a large unmet clinical need. In this review, we discuss gene polymorphisms and gene expression related to the development of BOS.

RECENT FINDINGS

Candidate gene studies showed that donor and recipient gene polymorphisms affect transplant outcome and BOS-free survival after LTx. Both selective and nonselective gene expression studies revealed differentially expressed fibrosis and apoptosis-related genes in BOS compared with non-BOS patients. Significantly, recent microarray expression analysis of blood and broncho-alveolar lavage suggest a role for B-cell and T-cell responses prior to the development of BOS. Furthermore, 6 months prior to the development of BOS differentially expressed genes were identified in peripheral blood cells.

SUMMARY

Genetic polymorphisms and gene expression changes are associated with the development of BOS. Future genome wide studies are needed to identify easily accessible biomarkers for prediction of BOS toward precision medicine.

CMV-infected kidney grafts drive the expansion of blood-borne CMV-specific T cells restricted by shared class I HLA molecules via presentation on donor cells

We aimed to determine the role of cytomegalovirus (CMV)-infected donor cells in the development of a CMV-specific immune response in kidney transplant recipients. We assessed the CMV pp65-specific immune response by using interferon-ɣ ELISPOT and dextramers in peripheral blood mononuclear cells from 115 recipients (D+R- 31, D+R + 44, D-R + 40) late after transplantation (mean 59 ± 42 months). Receiving a kidney from a D+ donor resulted in a higher number of IFN-ɣ-producing anti-CMV T cells (P = .004). This effect disappeared with the absence of shared HLA class I specificities between donors and recipients (P = .430). To confirm the role of donor cells in stimulating the expansion of newly developed CMV-specific CD8⁺ T cells after transplantation, we compared the number of HLA-A2-restricted CMV-specific CD8⁺ T cells in primo-infected recipients who received an HLA-A2 or non-HLA-A2 graft. The median of anti-CMV pp65 T cells restricted by HLA-A2 was very low for patients who received a non-HLA-A2 graft vs an HLA-A2 graft (300 [0-14638] vs. 17972 [222-85594] anti-CMV pp65 CD8⁺ T cells/million CD8⁺ T cells, P = .001). This adds new evidence that CMV-infected kidney donor cells present CMV peptides and drive an inflation of memory CMV-specific CD8⁺ T cells, likely because of frequent CMV replications within the graft.

Immune checkpoint inhibitors in challenging populations

Immune checkpoint inhibitors, including those targeting the programmed cell death 1/programmed cell death ligand 1 and cytotoxic T lymphocyte antigen 4 pathways, are revolutionizing cancer therapeutics. Both activity and toxicities largely stem from unleashing tumor- or host-specific cytotoxic T cells. Many patients seen in routine clinical practice have not qualified for or have been seriously underrepresented in immune checkpoint inhibitor clinical trials. Thus, a major gap in knowledge regarding the safety and efficacy of these agents persists in many populations, even after regulatory approval. To address this challenge, this review aggregates and synthesizes the available preclinical and clinical data surrounding immune checkpoint inhibitor therapy in challenging clinical populations to assist both academic and community oncologists in treatment decision making. Specifically, this review focuses on the safety and activity of immune checkpoint inhibitors in patients with autoimmune disorders, organ transplant patients, patients with chronic viral infections, patients with ongoing immunosuppressant use, patients with organ dysfunction, pregnant patients, patients with brain metastases, patients at extremes of age, and patients with an impaired functional status. Cancer 2017;123:1904-1911. © 2017 American Cancer Society.