Spatial transcriptomics reveals distinct tissue niches linked with steroid responsiveness in acute gastrointestinal GVHD.

Severe acute graft-versus-host disease (aGVHD) is associated with significant mortality and morbidity, especially in steroid-resistant (SR) cases. Spatial transcriptomic technology can elucidate tissue-based interactions in vivo and possibly identify predictors of treatment response. Tissue sections from 32 treatment-naïve patients with biopsy-confirmed lower gastrointestinal (GI) aGVHD were obtained. The GeoMx digital spatial profiler was used to capture transcriptome profiles of >18 000 genes from different foci of immune infiltrates, colonic epithelium, and vascular endothelium. Each tissue compartment sampled showed 2 distinct clusters that were analyzed for differential expression and spatially resolved correlation of gene signatures. Classic cell-mediated immunity signatures, normal differentiated epithelial cells, and inflamed vasculature dominated foci sampled from steroid-sensitive cases. In contrast, a neutrophil predominant noncanonical inflammation with regenerative epithelial cells and some indication of angiogenic endothelial response was overrepresented in areas from SR cases. Evaluation of potential prognostic biomarkers identified ubiquitin specific peptidase 17-like (USP17L) family of genes as being differentially expressed in immune cells from patients with worsened survival. In summary, we demonstrate distinct tissue niches with unique gene expression signatures within lower GI tissue from patients with aGVHD and provide evidence of a potential prognostic biomarker.

Satellite repeat RNA expression in epithelial ovarian cancer associates with a tumor-immunosuppressive phenotype.

Aberrant expression of viral-like repeat elements is a common feature of epithelial cancers, and the substantial diversity of repeat species provides a distinct view of the cancer transcriptome. Repeatome profiling across ovarian, pancreatic, and colorectal cell lines identifies distinct clustering independent of tissue origin that is seen with coding gene analysis. Deeper analysis of ovarian cancer cell lines demonstrated that human satellite II (HSATII) satellite repeat expression was highly associated with epithelial-mesenchymal transition (EMT) and anticorrelated with IFN-response genes indicative of a more aggressive phenotype. SATII expression - and its correlation with EMT and anticorrelation with IFN-response genes - was also found in ovarian cancer RNA-Seq data and was associated with significantly shorter survival in a second independent cohort of patients with ovarian cancer. Repeat RNAs were enriched in tumor-derived extracellular vesicles capable of stimulating monocyte-derived macrophages, demonstrating a mechanism that alters the tumor microenvironment with these viral-like sequences. Targeting of HSATII with antisense locked nucleic acids stimulated IFN response and induced MHC I expression in ovarian cancer cell lines, highlighting a potential strategy of modulating the repeatome to reestablish antitumor cell immune surveillance.

Reverse Transcriptase Inhibition Disrupts Repeat Element Life Cycle in Colorectal Cancer.

Altered RNA expression of repetitive sequences and retrotransposition are frequently seen in colorectal cancer, implicating a functional importance of repeat activity in cancer progression. We show the nucleoside reverse transcriptase inhibitor 3TC targets activities of these repeat elements in colorectal cancer preclinical models with a preferential effect in p53-mutant cell lines linked with direct binding of p53 to repeat elements. We translate these findings to a human phase II trial of single-agent 3TC treatment in metastatic colorectal cancer with demonstration of clinical benefit in 9 of 32 patients. Analysis of 3TC effects on colorectal cancer tumorspheres demonstrates accumulation of immunogenic RNA:DNA hybrids linked with induction of interferon response genes and DNA damage response. Epigenetic and DNA-damaging agents induce repeat RNAs and have enhanced cytotoxicity with 3TC. These findings identify a vulnerability in colorectal cancer by targeting the viral mimicry of repeat elements. SIGNIFICANCE: Colorectal cancers express abundant repeat elements that have a viral-like life cycle that can be therapeutically targeted with nucleoside reverse transcriptase inhibitors (NRTI) commonly used for viral diseases. NRTIs induce DNA damage and interferon response that provide a new anticancer therapeutic strategy. This article is highlighted in the In This Issue feature, p. 1397.

Radiation therapy enhances immunotherapy response in microsatellite stable colorectal and pancreatic adenocarcinoma in a phase II trial.

Overcoming intrinsic resistance to immune checkpoint blockade for microsatellite stable (MSS) colorectal cancer (CRC) and pancreatic ductal adenocarcinoma (PDAC) remains challenging. We conducted a single-arm, non-randomized, phase II trial (NCT03104439) combining radiation, ipilimumab and nivolumab to treat patients with metastatic MSS CRC (n = 40) and PDAC (n = 25) with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. The primary endpoint was disease control rate (DCR) by intention to treat. DCRs were 25% for CRC (ten of 40; 95% confidence interval (CI), 13-41%) and 20% for PDAC (five of 25; 95% CI, 7-41%). In the per-protocol analysis, defined as receipt of radiation, DCR was 37% (ten of 27; 95% CI, 19-58%) in CRC and 29% (five of 17; 95% CI, 10-56%) in PDAC. Pretreatment biopsies revealed low tumor mutational burden for all samples but higher numbers of natural killer (NK) cells and expression of the HERVK repeat RNA in patients with disease control. This study provides proof of concept of combining radiation with immune checkpoint blockade in immunotherapy-resistant cancers.

Temporal and spatial heterogeneity of host response to SARS-CoV-2 pulmonary infection.

The relationship of SARS-CoV-2 pulmonary infection and severity of disease is not fully understood. Here we show analysis of autopsy specimens from 24 patients who succumbed to SARS-CoV-2 infection using a combination of different RNA and protein analytical platforms to characterize inter-patient and intra-patient heterogeneity of pulmonary virus infection. There is a spectrum of high and low virus cases associated with duration of disease. High viral cases have high activation of interferon pathway genes and a predominant M1-like macrophage infiltrate. Low viral cases are more heterogeneous likely reflecting inherent patient differences in the evolution of host response, but there is consistent indication of pulmonary epithelial cell recovery based on napsin A immunohistochemistry and RNA expression of surfactant and mucin genes. Using a digital spatial profiling platform, we find the virus corresponds to distinct spatial expression of interferon response genes demonstrating the intra-pulmonary heterogeneity of SARS-CoV-2 infection.

Metabolomic Signature of Human Aortic Valve Stenosis.

This study outlines the first step toward creating the metabolite atlas of human calcified aortic valves by identifying the expression of metabolites and metabolic pathways involved at various stages of calcific aortic valve stenosis progression. Untargeted analysis identified 72 metabolites and lipids that were significantly altered (p < 0.01) across different stages of disease progression. Of these metabolites and lipids, the levels of lysophosphatidic acid were shown to correlate with faster hemodynamic progression and could select patients at risk for faster progression rate.

Progression of low-pressure to acute classic cardiac tamponade-a diagnostic dilemma in the setting of spontaneous left ventricular rupture.

Cardiac tamponade (CT) is a pathophysiologic continuum where hemodynamic embarrassment occurs as a result of progressive, decreased venous return that impairs diastolic ventricular filling, which in turn, when uncorrected, severely compromises cardiac output. While CT is classically associated with high intrapericardial pressures due to rapidly accumulating large pericardial effusions, low-pressure CT is a recognized entity in which a comparatively low intrapericardial pressure could result in cardiac chamber compression and subsequent cardiovascular collapse. In this article, we highlight a previously unreported scenario of rapidly re-accumulating, acute CT in the setting of left ventricular rupture in a patient who had presumably presented with low-pressure CT due to hemoperiardium.

Efficacy, tolerability and safety of propiverine hydrochloride in comparison to oxybutynin in children with urge incontinence due to overactive bladder: Results of a multicentre observational cohort study.

OBJECTIVE: To compare, in a retrospective observational cohort study, the efficacy, tolerability and safety of propiverine and oxybutynin in children with urge incontinence (UI) due to overactive bladder. PATIENTS AND METHODS: Medical records were scrutinized for children with UI. As a primary efficacy outcome variable the achievement of continence after treatment with variable doses of propiverine or oxybutynin was assessed. Weekly UI episodes and daily voiding frequency were evaluated as secondary efficacy outcomes. Tolerability was evaluated by the rate of adverse events, adverse drug reactions caused by antimuscarinics and premature treatment termination. RESULTS: At 16 study centres, 621 children aged 5-14 years with UI due to overactive bladder were enrolled. After anticholinergic treatment (437 propiverine, 184 oxybutynin) continence was achieved in 61.6% and 58.7% of the patients after 186 and 259 days, respectively. There were clinically relevant improvements in voiding frequency across treatment groups. Daily doses of propiverine were markedly below the recommendations (0.54 vs 0.8 mg/kg body weight), daily doses of oxybutynin were according to the recommendations (0.31 vs 0.2-0.4 mg/kg body weight) at treatment initiation. There was a significantly more favourable tolerability to propiverine than oxybutynin for the overall rate of adverse events (3.9% vs 16.3%, odds ratio 4.813), adverse drug reactions caused by propiverine or oxybutynin (2.8% vs 9.2%) and premature treatment termination due to adverse drug reactions (1.6% vs 4.4%). CONCLUSION: Propiverine and oxybutynin are effective in children with UI due to overactive bladder. Sufficient treatment periods of at least 2, preferably 3-4, months are the crucial factors for a successful treatment. The tolerability profile of propiverine is better than for oxybutynin.

Pseudo cardiac tamponade in the setting of excess pericardial fat.

Cardiac tamponade is the phenomenon of hemodynamic compromise caused by a pericardial effusion. Following a myocardial infarction, the most common causes of pericardial fluid include early pericarditis, Dressler's syndrome, and hemopericardium secondary to a free wall rupture. On transthoracic echocardiography, pericardial fluid appears as an echo-free space in between the visceral and parietal layers of the pericardium. Pericardial fat has a similar appearance on echocardiography and it may be difficult to discern the two entities. We present a case of a post-MI patient demonstrating pseudo tamponade physiology in the setting of excessive pericardial fat.

Aortic dissection and hypothermic arrest in a Jehovah's Witness patient: a case for recombinant factor VIIa?

PURPOSE: To present a case of survival of a cognitively intact Jehovah's Witness patient with an aortic dissection who underwent hypothermic arrest. Recombinant factor VIIa, but no blood products were administered. CLINICAL FEATURES: An 83-yr-old female with an acute type A aortic dissection underwent emergent surgical repair. Proximal extension of the dissection necessitated prolonged cardiopulmonary bypass (CPB) and hypothermic circulatory arrest. Despite this, perioperative hemostatis was adequate. Recombinant factor VIIa 90 microg x kg(-1) i.v. was administered post-CPB. The patient had an uneventful postoperative course, and was discharged home neurologically intact. CONCLUSIONS: Patients who conscientiously object to the transfusion of blood products may present a considerable anesthetic challenge, especially those at risk from coagulopathy associated with CPB and hypothermic circulatory arrest. Recombinant factor VIIa may play a role in hemostasis management of these individuals, however, well-designed randomized controlled trials need to be undertaken to establish the efficacy and risks related to this potential indication.

Cardiac perforation after device closure of atrial septal defects with the Amplatzer septal occluder.

OBJECTIVES: Amplatzer septal occluder (ASO)-associated cardiac perforation (CP) at our institution prompted this retrospective review. BACKGROUND: Cardiac perforation is a rare complication after transcatheter atrial septal defect (ASD) closure. METHODS: To identify CP after transcatheter ASD closure with ASO, cardiac events (CE) describing definite CP, hemopericardium, pericardial effusion, cardiovascular collapse, or sudden death were analyzed. Cardiac events were identified from published literature (MEDLINE), medical device regulating agencies in North America and the European Commission, and AGA Medical Corporation (Golden Valley, Minnesota). Institutional cases were reviewed. Cardiac events were defined as early (pre-discharge) or late (post-discharge). RESULTS: Twenty-nine CEs were identified. Five were excluded because findings were inconclusive for device-related CP. Ten patients were <18 years of age. Late CEs occurred in 66.6%; 25% presented weeks later (longest, three years). Three deaths were reported. Cardiac perforation occurred predominantly in the anterosuperior atrial walls and/or adjacent aorta. CONCLUSIONS: Amplatzer septal occluder-associated CP uniquely involves the anterosuperior atrial walls and adjacent aorta. Pathophysiology remains poorly understood.