Prospective Multicenter International Registry of Ultrasound-Facilitated Catheter-Directed Thrombolysis in Intermediate-High and High-Risk Pulmonary Embolism (KNOCOUT PE).

BACKGROUND: Prior clinical trials have demonstrated the efficacy of ultrasound-facilitated catheter-directed thrombolysis (USCDT) for the treatment of acute intermediate-risk pulmonary embolism (PE) using reduced thrombolytic doses and shorter infusion durations. However, utilization and safety of such strategies in broader PE populations remain unclear. The KNOCOUT PE (The EKoSoNic Registry of the Treatment and Clinical Outcomes of Patients With Pulmonary Embolism) registry is a multicenter international registry designed to study the treatment of acute PE with USCDT, with focus on safety outcomes. METHODS: The KNOCOUT PE prospective cohort included 489 patients (64 sites internationally) with acute intermediate-high or high-risk PE treated with USCDT between March 2018 and June 2020. Principal safety outcomes were independently adjudicated International Society on Thrombosis and Haemostasis major bleeding at 72 hours post-treatment and mortality within 12 months of treatment. Additional outcomes included change in right ventricular/left ventricular ratio and quality of life measures over 12 months. RESULTS: Mean alteplase (r-tPA [recombinant tissue-type plasminogen activator]) infusion duration was 10.5 hours. Mean total r-tPA dose was 18.1 mg, with 31.0% of patients receiving ≤12 mg. Major bleeding events within 72 hours occurred in 1.6% (8/489) of patients. One patient experienced worsening of a preexisting subdural hematoma after USCDT and therapeutic anticoagulation, which ultimately required surgery. All-cause mortality at 30 days was 1.0% (5/489). Improvement in PE quality of life score was observed with a 41.1% (243/489, 49.7%) and 44.2% (153/489, 31.3%) mean relative reduction by 3 and 12 months, respectively. CONCLUSIONS: In a prospective observational cohort study of patients with intermediate-high and high-risk PE undergoing USCDT, mean r-tPA dose was 18 mg, and the rates of major bleeding and mortality were low. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03426124.

Effects of immune checkpoint blockade on antigen-specific CD8+ T cells for use in adoptive cellular therapy.

Adoptive T-cell therapies have been successfully used as prophylaxis or treatment for immunocompromised patients at risk of viral infections or advanced cancers. Unfortunately, for some refractory cancers, they have failed. To overcome this, checkpoint inhibitors are used to rescue immune antitumor responses. We hypothesized that in vitro checkpoint blockade during T-cell stimulation and expansion with messenger RNA (mRNA)-pulsed DCs may enhance the activity of antigen-specific T cells and improve the efficacy of adoptive cellular therapy platforms. Human peripheral blood mononuclear cells were isolated from cytomegalovirus (CMV)-seropositive donors to generate DCs. These were pulsed with CMV matrix phosphoprotein 65 (CMVpp65)-mRNA to educate T cells in coculture for 15 days. Three checkpoint blockade conditions were evaluated (anti-PD1, anti-Tim3, and anti-PD1 + Tim3). IL-2 and antibodies blockades were added every 3 days. Immunophenotyping was performed on Day 0 and Day 15. Polyfunctional antigen-specific responses were evaluated upon rechallenge with CMVpp65 peptides. CMVpp65-activated CD8+ T cells upregulate Lag3 and Tim3 (P ≤ 0.0001). Tim3 antibody blockade alone or in combination led to a significant upregulation of Lag3 expression on CD8+ pp65Tetramer+ central memory, effector memory, and terminal effector memory cells re-expressing RA (TEMRA) T cells. This latter T-cell subset uniquely maintains double-positive Tim3/Lag3 expression after checkpoint blockade. By contrast, PD1 blockade had minimal effects on Tim3 or Lag3 expression. In addition, IFN-γ secretion was reduced in T cells treated with Tim3 blockade in a dose-dependent manner (P = 0.004). In this study, we have identified a potential activating component of Tim3 and linkage between Tim3 and Lag3 signaling upon blocking the Tim3 axis during T-cell-antigen-presenting cell interactions that should be considered when targeting immune checkpoints for clinical use.

The impact of pulmonary hypertension on outcomes of transcatheter mitral valve replacement in mitral annular calcification.

OBJECTIVES: To assess the impact of pulmonary hypertension (PH) on outcomes of patients with severe mitral annular calcification (MAC) undergoing transcatheter mitral valve replacement (TMVR). BACKGROUND: PH is associated with poor outcomes after mitral valve surgery. Whether the presence of PH in patients with MAC undergoing (TMVR) is associated with poor outcomes, is unknown. METHODS: Retrospective evaluation of 116 patients from 51 centers in 11 countries who underwent TMVR with valve in mitral annular calcification (ViMAC) using balloon-expandable aortic transcatheter valves (THVs) from September 2012 to March 2017. Pulmonary artery systolic blood pressure (PASP) by echocardiogram was available in 90 patients. The subjects were stratified based on PASP: No PH = PASP ≤35 mmHg (n = 11); mild to moderate PH = PASP 36-49 mmHg (n = 21) and severe PH = PASP ≥50 mmHg (n = 58). Clinical, procedural, and echocardiographic outcomes were assessed. RESULTS: Mean age was 72.7 (±12.8) years, 59 (65.6%) were female, Society of Thoracic Surgeons score was 15.8 + 11.8% and 90.0% where in New York Heart Association (NYHA) class III-IV. There was no significant difference in all-cause mortality at 30 days (no PH = 27.3%, mild-moderate PH = 19.0%, severe PH = 31.6%; p = 0.55) or at 1 year (no PH = 54.5%, mild-moderate PH = 38.1%, severe PH = 56.1%; p = 0.36). No difference in adverse events, NYHA class or amount of residual mitral regurgitation at 1 year were observed between the groups. CONCLUSION: This study suggests that the presence of PH in patients with predominantly mitral stenosis with MAC undergoing TMVR does not impact mortality or adverse events. Further studies are needed to fully understand the effect of PH in this group of patients.

Gene Therapy-Induced Antigen-Specific Tregs Inhibit Neuro-inflammation and Reverse Disease in a Mouse Model of Multiple Sclerosis.

The devastating neurodegenerative disease multiple sclerosis (MS) could substantially benefit from an adeno-associated virus (AAV) immunotherapy designed to restore a robust and durable antigen-specific tolerance. However, developing a sufficiently potent and lasting immune-regulatory therapy that can intervene in ongoing disease is a major challenge and has thus been elusive. We addressed this problem by developing a highly effective and robust tolerance-inducing in vivo gene therapy. Using a pre-clinical animal model, we designed a liver-targeting gene transfer vector that expresses full-length myelin oligodendrocyte glycoprotein (MOG) in hepatocytes. We show that by harnessing the tolerogenic nature of the liver, this powerful gene immunotherapy restores immune tolerance by inducing functional MOG-specific regulatory T cells (Tregs) in vivo, independent of major histocompatibility complex (MHC) restrictions. We demonstrate that mice treated prophylactically are protected from developing disease and neurological deficits. More importantly, we demonstrate that when given to mice with preexisting disease, ranging from mild neurological deficits to severe paralysis, the gene immunotherapy abrogated CNS inflammation and significantly reversed clinical symptoms of disease. This specialized approach for inducing antigen-specific immune tolerance has significant therapeutic potential for treating MS and other autoimmune disorders.

Characteristics of centenarians admitted to a community teaching hospital.

BACKGROUND: The "oldest old" are the most rapidly growing segment of society, and clinicians will increasingly encounter this age group in this century. METHODS: To describe the characteristics of a special subgroup of the oldest old, the centenarians, we conducted a retrospective case series analysis of all patients 100 years of age and above admitted to a large community teaching hospital. RESULTS: Thirty-nine patients with a mean age of 101.3 years were admitted a total of 57 times during the 5-year study period. The main reasons for admission were hip fracture, stroke, and urinary tract infection. Patients admitted from nursing facilities were taking more medications than community dwelling patients, and patients who were confused on admission were more likely to be readmitted. Only 2 patients died. CONCLUSIONS: Polypharmacy is common in centenarians, especially in institutionalized patients, and confusion may be a useful predictor of subsequent readmission. In-hospital mortality, however, is low in this population.