Cytomegalovirus (CMV) viremia continues to cause significant morbidity and mortality in kidney transplant patients with clinical complications including organ rejection and death. Whole blood gene expression dynamics in CMV viremic patients from onset of DNAemia through convalescence has not been well studied to date in humans. To evaluate how CMV infection impacts whole blood leukocyte gene expression over time, we evaluated a matched cohort of 62 kidney transplant recipients with and without CMV DNAemia using blood samples collected at multiple time points during the 12-month period after transplant. While transcriptomic differences were minimal at baseline between DNAemic and non-DNAemic patients, hundreds of genes were differentially expressed at the long-term timepoint, including genes enriching for pathways important for macrophages, interferon, and IL-8 signaling. Amongst patients with CMV DNAemia, the greatest amount of transcriptomic change occurred between baseline and 1-week post-DNAemia, with increase in pathways for interferon signaling and cytotoxic T cell function. Time-course gene set analysis of these differentially expressed genes revealed that most of the enriched pathways had a significant time-trend. While many pathways that were significantly down- or upregulated at 1 week returned to baseline-like levels, we noted that several pathways important in adaptive and innate cell function remained upregulated at the long-term timepoint after resolution of CMV DNAemia. Differential expression analysis and time-course gene set analysis revealed the dynamics of genes and pathways involved in the immune response to CMV DNAemia in kidney transplant patients. Understanding transcriptional changes caused by CMV DNAemia may identify the mechanism behind patient vulnerability to CMV reactivation and increased risk of rejection in transplant recipients and suggest protective strategies to counter the negative immunologic impact of CMV. These findings provide a framework to identify immune correlates for risk assessment and guiding need for extending antiviral prophylaxis.
Immunosuppression withdrawal can be safely performed in select liver transplantation recipients, but the long‐term outcomes and sustainability of tolerance have not been well studied. We completed a 10‐year prospective, observational study of 18 pediatric liver transplantation recipients with operational tolerance to (1) assess the sustainability of tolerance over time, (2) compare the clinical characteristics of patients who maintained versus lost tolerance, (3) characterize liver histopathology findings in surveillance liver biopsies; and (4) describe immunologic markers in patients with tolerance. Comparator patients from two clinical phenotype groups termed “stable” and “nontolerant” patients were used as controls. Of the 18 patients with operational tolerance, the majority of patients were males (n = 14, 78%) who were transplanted for cholestatic liver disease (n = 12, 67%). Median age at transplantation was 1.9 (range, 0.6–8) years. Median time after transplantation that immunosuppression had been discontinued was 13.1 (range, 2.9–22.1) years. As many as 11 (61%) maintained tolerance for a median of 10.4 (range, 1.9–22.1) years, whereas 7 (39%) lost tolerance after a median of 3.2 (range, 1.5–18.6) years. Populations of T regulatory cells (%CD4+ CD25hi CD127lo) were significantly higher in patients with tolerance (p = 0.02). Our results emphasize that spontaneous operational tolerance is a dynamic and nonpermanent state. It is therefore essential for patients who are clinically stable off immunosuppression to undergo regular follow‐up and laboratory monitoring, as well as surveillance biopsies to rule out subclinical rejection.
2562 Background: Tumors produce high levels of extracellular adenosine which suppress anti-tumor immune responses. Blocking A2A receptors, predominantly expressed on tumor-infiltrating immune cells, can reverse the immunosuppressive effect of adenosine. Inupadenant is a non brain-penetrant, potent and highly selective small molecule antagonist of the A2A receptor that remains active even at the high adenosine concentrations found in tumors. Methods: This is the phase I portion of an ongoing first-in-human, clinical trial (NCT02740985) to evaluate safety/tolerability, pharmacokinetic, pharmacodynamic and anti-tumor activity of inupadenant in adult patients with solid tumors who have exhausted standard treatment options. In addition, tumor biomarkers, including adenosine-pathway markers by immunohistochemistry (IHC), are being evaluated. We present updated results of the dose escalation, new results from the monotherapy expansion and new analysis of tumor biomarkers. Results: Overall, 42 patients (21 patients in the dose escalation and an additional 21 patients in a monotherapy expansion) with a median of 3 prior regimens were treated as of the data cut off (DCO, 30Nov20).The dose levels investigated, along with the most frequent (>20%) treatment-emergent adverse events (TEAEs) across all dose levels are presented in the table. 7 AEs led to discontinuation; 2 (atrial fibrillation and myocardial infarction) were considered possibly study drug-related by the investigator. No dose reductions were required. Two partial responses (PRs) were reported: melanoma (NRAS-mutant; received prior immunotherapy), and prostate cancer (received antiandrogen and chemotherapy). At the DCO, both PRs were ongoing with a duration of response >230 days. 12 patients had stable disease (SD) as best response and SD >6 months was observed in 3 patients. Response and stable disease were associated with a higher number of cells expressing the A2A receptor within the tumor at baseline, as measured by IHC. Conclusions: Inupadenant monotherapy was generally well-tolerated as of the DCO at a dose of 80 mg twice daily with initial evidence of clinical benefit, including 2 durable PRs in patients who have exhausted standard treatment options. Analysis of pre-treatment tumor biopsies has identified the A2A receptor as a biomarker which may be associated with clinical benefit. Clinical trial information: NCT03873883. [Table: see text]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.