Complement inhibition for prevention of antibody-mediated rejection in immunologically high-risk heart allograft recipients

Allosensitization represents a major barrier to heart transplantation (HTx). We assessed the efficacy and safety of complement inhibition at transplant in highly sensitized heart transplant recipients. We performed a single-center, single-arm, open-label trial (NCT02013037). Patients with panel reactive antibodies (PRA) ≥70% and pre-formed donor-specific antibodies (DSA) were eligible. In addition to standard of care, patients received nine infusions of eculizumab during the first 2 months posttransplant. The primary composite endpoint was antibody-mediated rejection (AMR) ≥pAMR2 and/or left ventricular dysfunction during the first year. Secondary endpoints included hemodynamic compromise, allograft rejection, and patient survival. Twenty patients were included. Median cPRA and mean fluorescence intensity of immunodominant DSA were 95% (90%-97%) and 6250 (5000-10 000), respectively. Retrospective B cell and T cell flow crossmatches were positive in 14 and 11 patients, respectively. The primary endpoint occurred in four patients (20%). Survival at 1 year was 90% with no deaths resulting from AMR. In a prespecified analysis comparing treated patients to matched control patients, we observed a dramatic reduction in the risk of biopsy-proven AMR in patients treated with eculizumab (HR = 0.36, 95% CI = 0.14-0.95, p = .032). Our findings support the prophylactic use of complement inhibition for heart transplantation at high immunological risk. ClinincalTrials.gov, NCT02013037.

Evaluating the Dynamic Performance of Interfacial Pressure Sensors at a Simulated Body-Device Interface

BACKGROUND

Pressure sensing at the body-device interface can help assess the quality of fit and function of assistive devices during physical activities and movement such as walking and running. However, the dynamic performance of various pressure sensor configurations is not well established.

OBJECTIVES

Two common commercially available thin-film pressure sensors were tested to determine the effects of clinically relevant setup configurations focusing on loading areas, interfacing elements (i.e. 'puck') and calibration methods.

METHODOLOGY

Testing was performed using a customized universal testing machine to simulate dynamic, mobility relevant loads at the body-device interface. Sensor performance was evaluated by analyzing accuracy and hysteresis.

FINDINGS

The results suggest that sensor calibration method has a significant effect on sensor performance although the difference is mitigated by using an elastomeric loading puck. Both sensors exhibited similar performance during dynamic testing that agree with accuracy and hysteresis values reported by manufacturers and in previous studies assessing mainly static and quasi-static conditions.

CONCLUSION

These findings suggest that sensor performance under mobility relevant conditions may be adequately represented via static and quasi-testing testing. This is important since static testing is much easier to apply and reduces the burden on users to verify dynamic performance of sensors prior to clinical application. The authors also recommend using a load puck for dynamic testing conditions to achieve optimal performance.

A novel method for the detection and diagnosis of virus infections in honey bees

In terms of infectious diseases caused by a variety of microorganisms, the ability to promptly and accurately identify the causative agents is the first step on the path to all types of effective management of such infections. Among the various factors that are affecting global bee health, viruses have often been linked to honey bee colony losses and they pose a serious threat to the fraction of agriculture that depends on the service of pollinators. Over the past few decades, PCR-based molecular methods have provided powerful tools for rapid, specific, and sensitive detection and the quantification of difficult-to-grow pathogenic microorganisms such as viruses in honey bees. However, PCR-based methods require nucleic acid extraction and purification, which can be quite laborious and time-consuming and they involve the use of organic solvents and chaotropic agents like phenol and chloroform which are volatile and highly toxic. In response, we developed a novel and non-sacrificial method for detecting viral infections in honey bees. As little as 1 μl of hemolymph was collected from adult workers, larvae, and queens of bee colonies by puncturing the soft inter-tergal integument between the second and third dorsal tergum with a fine glass capillary. The hemolymph was then diluted and subjected to RT-PCR analysis directly. The puncture wound caused by the glass capillary was found to heal automatically and rapidly without any trouble and the lifespan of the experimental workers remained unaffected. Using this method, we detected multiple viruses including Deformed wing virus (DWV), Black queen cell virus (BQCV), and Sacbrood virus (SBV) in infected bees. Furthermore, expressed transcripts that indicate the induction of innate immune response to the virus infections were also detected in the hemolymph of infected bees. The simplicity and cost-effectiveness of this innovative approach will allow it to be a valuable, time-saving, safer, and more environmentally friendly contribution to bee disease management programs.

A53 STUDYING THE ROLE OF ASCL2 IN THE ESOPHAGEAL EPITHELIUM USING ORGANOIDS

Background

The esophagus is lined with a stratified squamous epithelium that assure protection against the austere environment found in the esophageal lumen. The maintenance of this epithelium is ensured by a rare population of cells: stem cells. Those cells have increased capacity of self-renewal and multipotency, which is the capacity to give rise to every cell types of a tissue. The marker Krt15 was used to identify the first stem cell population in the esophagus. Krt15+ cells display an extended lifespan and they are radioresistant, multipotent and capable of self-renewal. Moreover, it was observed by RNA sequencing that the expression of the transcription factor ASCL2 is strongly increased in Krt15+ cells compared to Krt15- cells. Interestingly, ASCL2 is necessary to maintain the stemness of Lgr5+ intestinal stem cells. It is also a target of the Wnt/β-catenin pathway. The overall goal of this project is to determine the role of ACSL2 in the maintenance of esophageal stem cells and to identify its binding partners since ASCL2 needs to dimerize to efficiently bind DNA.

Aims

Confirm that esophageal organoids are adapted to study ASCL2 in the esophagus.

Methods

Esophageal organoids were established from esophageal epithelial cells from wildtype mice. Following this, organoids were treated with an inhibitor of the Notch pathway (DAPT) to induce hyperplasia or infected with lentiviruses to invalidate Ascl2 (CRISPR/Cas9 approach).

Results

To validate that Ascl2 plays an important role in esophageal cell proliferation, Notch pathway was inhibited through DAPT treatment in esophageal organoids to induce hyperplasia, which was confirmed by increased number of proliferative cells (Ki-67+). ASCL2 protein expression was also increased in DAPT-treated organoids supporting its role in proliferation and confirming that organoid is a good model to study ASCL2 role in esophageal epithelial cells. In this optic, organoids lines invalidated for Ascl2 (CRISPR/Cas9 approach) were established. Our preliminary results suggest that Ascl2 loss affects cell proliferation and organoid size under normal conditions.

Conclusions

The expression of ASCL2 correlates with hyperplasia which supports its role in esophageal epithelium homeostasis.

Funding Agencies

Canada research chair et NSERC

Transferrin-mediated iron sequestration suggests a novel therapeutic strategy for controlling Nosema disease in the honey bee, Apis mellifera

Nosemosis C, a Nosema disease caused by microsporidia parasite Nosema ceranae, is a significant disease burden of the European honey bee Apis mellifera which is one of the most economically important insect pollinators. Nevertheless, there is no effective treatment currently available for Nosema disease and the disease mechanisms underlying the pathological effects of N. ceranae infection in honey bees are poorly understood. Iron is an essential nutrient for growth and survival of hosts and pathogens alike. The iron tug-of-war between host and pathogen is a central battlefield at the host-pathogen interface which determines the outcome of an infection, however, has not been explored in honey bees. To fill the gap, we conducted a study to investigate the impact of N. ceranae infection on iron homeostasis in honey bees. The expression of transferrin, an iron binding and transporting protein that is one of the key players of iron homeostasis, in response to N. ceranae infection was analysed. Furthermore, the functional roles of transferrin in iron homeostasis and honey bee host immunity were characterized using an RNA interference (RNAi)-based method. The results showed that N. ceranae infection causes iron deficiency and upregulation of the A. mellifera transferrin (AmTsf) mRNA in honey bees, implying that higher expression of AmTsf allows N. ceranae to scavenge more iron from the host for its proliferation and survival. The suppressed expression levels of AmTsf via RNAi could lead to reduced N. ceranae transcription activity, alleviated iron loss, enhanced immunity, and improved survival of the infected bees. The intriguing multifunctionality of transferrin illustrated in this study is a significant contribution to the existing body of literature concerning iron homeostasis in insects. The uncovered functional role of transferrin on iron homeostasis, pathogen growth and honey bee's ability to mount immune responses may hold the key for the development of novel strategies to treat or prevent diseases in honey bees.

Personalized treatments for depressive symptoms in patients with advanced heart failure: A pragmatic randomized controlled trial

Objectives

Heart Failure is a chronic syndrome affecting over 5.7 million in the US and 26 million adults worldwide with nearly 50% experiencing depressive symptoms. The objective of the study is to compare the effects of two evidence-based treatment options for adult patients with depression and advanced heart failure, on depressive symptom severity, physical and mental health related quality of life (HRQoL), heart-failure specific quality of life, caregiver burden, morbidity, and mortality at 3, 6 and 12-months.

Methods

Trial design. Pragmatic, randomized, comparative effectiveness trial.

Interventions. The treatment interventions are: (1) Behavioral Activation (BA), a patient-centered psychotherapy which emphasizes engagement in enjoyable and valued personalized activities as selected by the patient; or (2) Antidepressant Medication Management administered using the collaborative care model (MEDS).

Participants. Adults aged 18 and over with advanced heart failure (defined as New York Heart Association (NYHA) Class II, III, and IV) and depression (defined as a score of 10 or above on the PHQ-9 and confirmed by the MINI International Neuropsychiatric Interview for the DSM-5) selected from all patients at Cedars-Sinai Medical Center who are admitted with heart failure and all patients presenting to the outpatient programs of the Smidt Heart Institute at Cedars-Sinai Medical Center. We plan to randomize 416 patients to BA or MEDS, with an estimated 28% loss to follow-up/inability to collect follow-up data. Thus, we plan to include 150 in each group for a total of 300 participants from which data after randomization will be collected and analyzed.

Conclusions

The current trial is the first to compare the impact of BA and MEDS on depressive symptoms, quality of life, caregiver burden, morbidity, and mortality in patients with depression and advanced heart failure. The trial will provide novel results that will be disseminated and implemented into a wide range of current practice settings.

Registration

ClinicalTrials.Gov Identifier: NCT03688100.

Heart Transplantation for Giant Cell Myocarditis: A Case Series

BACKGROUND

Giant cell myocarditis (GCM) has a poor prognosis without heart transplant, but post-transplant survival is unknown.

PURPOSE

To describe the post-transplant survival of patients with GCM at a large transplant center.

METHODS

Seven patients underwent heart transplant for histologically confirmed GCM of the explanted heart. The median age was 59 years, and 43% (3 of 7) were female. All patients had cardiogenic shock, multiorgan failure, elevated troponin, and recurrent ventricular tachycardia, and some required mechanical circulatory support. All patients received rabbit antithymocyte globulin (rATG) in the perioperative period at a dose of 1.5 mg/kg daily for 1 to 5 days and 4 received intravenous immunoglobulin 1 g/kg daily for 2 days after rATG. All patients had early initiation of tacrolimus by first to third postoperative day depending on renal function, early mycophenolate, and high dose steroid. All were maintained using tacrolimus, mycophenolate, and prednisone.

RESULTS

One patient had asymptomatic recurrence of GCM at 3 months, managed by up-titration of tacrolimus, and had asymptomatic 2R cellular rejection at 4 months, managed with steroid bolus. No patient had high-grade rejection. One patient died at 267 days, possibly of GCM. Six of 7 (86%) remain alive at a median of 842 days (2.3 years) post transplant.

CONCLUSIONS

Patients with GCM have excellent post-transplant survival with use of rATG and triple drug immunosuppressive therapy; however, some patients remain at risk for GCM recurrence after transplant, which may respond to augmented immunosuppression.

The impact of antidepressants on depressive symptom severity, quality of life, morbidity, and mortality in heart failure: a systematic review

OBJECTIVE

The purpose of this paper is to review the literature on the impact of antidepressants on depressive symptom severity, quality of life (QoL), morbidity, and mortality in patients with heart failure (HF).

METHODS

Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Reporting Items for Systematic Reviews and Meta-Analyses guidelines, studies published from December 1969 to December 2019 that pertain to depression and HF were identified through the use of the PubMed and PsycINFO databases, using the keywords: 'antidepressant*' and 'heart failure.' Two authors independently conducted a focused analysis and reached a final consensus on 17 studies that met the specific selection criteria and passed the study quality checks.

RESULTS

Studies varied in types of antidepressants used as well as in study designs. Ten studies were analyzed for the impact of antidepressant medications on depressive symptom severity. Five of these were randomized controlled trials (RCTs), out of which sertraline and paroxetine showed a significant reduction in depressive symptoms despite the small samples utilized. Four of the 17 studies addressed QoL as part of their outcomes showing no difference for escitalopram (RCT), significantly greater improvements for paroxetine controlled release (RCT), statistical significance for sertraline compared to control (pilot study), and showing significant improvement before and after treatment (open-label trial) for nefazodone. Thirteen of the 17 studies included measures of morbidity and mortality. Although early analyses have pointed to an association of antidepressant use and mortality particularly with fluoxetine, the reviewed studies showed no increase in mortality for antidepressants, and secondary analyses showed improved mortality in patients who achieved remission of depressive symptoms.

CONCLUSION

Out of the various antidepressants studied, which included sertraline, paroxetine, escitalopram, citalopram, bupropion, nefazodone, and nortriptyline, selective serotonin reuptake inhibitors seem to be a safe treatment option for patients with depression and HF. However, due to the variety of study designs as well as the mixed results for each antidepressant, more information for reducing depression severity, morbidity, and mortality and improving quality of life in patients with HF should be examined using robust large sample RCTs.

cBIN1 Score (CS) Identifies Ambulatory HFrEF Patients and Predicts Cardiovascular Events

BACKGROUND

Cardiac Bridging Integrator 1 (cBIN1) is a membrane deformation protein that generates calcium microdomains at cardiomyocyte t-tubules, whose transcription is reduced in heart failure, and is released into blood. cBIN1 score (CS), an inverse index of plasma cBIN1, measures cellular myocardial remodeling. In patients with heart failure with preserved ejection fraction (HFpEF), CS diagnoses ambulatory heart failure and prognosticates hospitalization. The performance of CS has not been tested in patients with heart failure with reduced ejection fraction (HFrEF).

METHODS AND RESULTS

CS was determined from plasma of patients recruited in a prospective study. Two comparative cohorts consisted of 158 ambulatory HFrEF patients (left ventricular ejection fraction (LVEF) ≤ 40%, 57 ± 10 years, 80% men) and 115 age and sex matched volunteers with no known history of HF. N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations were also analyzed for comparison. CS follows a normal distribution with a median of 0 in the controls, which increases to a median of 1.9 (p < 0.0001) in HFrEF patients. CS correlates with clinically assessed New York Heart Association Class (p = 0.007). During 1-year follow-up, a high CS (≥ 1.9) in patients predicts increased cardiovascular events (43% vs. 26%, p = 0.01, hazard ratio 1.9). Compared to a model with demographics, clinical risk factors, and NT-proBNP, adding CS to the model improved the overall continuous net reclassification improvement (NRI 0.64; 95% CI 0.18-1.10; p = 0.006). Although performance for diagnosis and prognosis was similar to CS, NT-proBNP did not prognosticate between patients whose NT-proBNP values were > 400 pg/ml.

CONCLUSION

CS, which is mechanistically distinct from NT-proBNP, successfully differentiates myocardial health between patients with HFrEF and matched controls. A high CS reflects advanced NYHA stage, pathologic cardiac muscle remodeling, and predicts 1-year risk of cardiovascular events in ambulatory HFrEF patients. CS is a marker of myocardial remodeling in HFrEF patients, independent of volume status.

Depression in Heart Failure: A Systematic Review

Objective: This paper sought to identify the instruments used to measure depression in heart failure (HF) and elucidate the impact of treatment interventions on depression in HF. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. Studies published from 1988 to 2018 covering depression and HF were identified through the review of the PubMed and PsycINFO databases using the keywords: "depres*" AND "heart failure." Two authors independently conducted a focused analysis, identifying 27 studies that met the specific selection criteria and passed the study quality checks. Results: Patient-reported questionnaires were more commonly adopted than clinician-rated questionnaires, including the Beck Depression Inventory, the Patient Health Questionnaire (PHQ-9), and the Hospital Anxiety and Depression Scale. Six common interventions were observed: antidepressant medications, collaborative care, psychotherapy, exercise, education, and other nonpharmacological interventions. Except for paroxetine, selective serotonin reuptake inhibitors failed to show a significant difference from placebo. However, the collaborative care model including the use of antidepressants showed a significant decrease in PHQ-9 score after one year. All of the psychotherapy studies included a variation of cognitive behavioral therapy and patients showed significant improvements. The evidence was mixed for exercise, education, and other nonpharmacological interventions. Conclusion: This study suggests which types of interventions are more effective in addressing depression in heart failure patients.

P1502 A clinical case of mitral annulus disjunction syndrome revealed by cardiac MRI

A 39year old female patient with a family history of probable sudden cardiac death/long QT syndrome (sister died aged 36) was referred to our Arrhythmia/inherited cardiac conditions clinic. Patient was fit and well. She described occasional postural presyncope and some chest pain with stress. Not on any medication that could prolong QT. On examination she appeared well with normal heart sounds and no clinical signs of heart failure.

Her ECG in clinic confirmed sinus rhythm with normal QTc at 418msec. There were U waves which may reflect late repolarisation of His Purkinje system.

Diagnostic techniques and findings

A 24-hour ECG tape to look at the average QT interval, an exercise tolerance test to look for appropriate shortening of QT interval with exercise and an echocardiogram to exclude significant structural abnormality were requested.

The 24-hour ECG tape confirmed underlying sinus rhythm with multi-focal aberrant beats &lt;1% of total. One symptom demonstrated short run of ventricular bigeminy.

During the exercise tolerance test, QT interval was not obviously prolonged. There were frequent bifocal ventricular ectopic beats in recovery.

The echocardiogram showed minor abnormality with mild left ventricular dilatation, otherwise normal findings.

Patient referred for cardiac MRI In order to rule out any cardiomyopathy.

Cardiac MRI did not show any prolapse on the 3 chamber cine. In addition, the inferior and inferolateral annulus showed thinning passing into the LV, which is a feature of some patients with mitral annulus disjunction syndrome.

We went through the echocardiogram and in one single frame images are suspicious of focal P2 prolapse.

Learning points:

Mitral annulus disjunction (MAD) is an abnormal atrial displacement of the mitral valve leaflet hinge point. It has been associated with mitral valve prolapse and sudden cardiac death.

MAD is usually revealed with echocardiogram.

In this case report we showed that CMR revealed a MAD previously missed by echo.

Abstract P1502 Figure.

P707 Positive rest and negative adenosine stress perfusion in typical angina

Learning points

Resting perfusion is often considered an integral part of adenosine perfusion imaging in order to overcome dark ring artefact, but it requires an additional contrast injection, prolongs imaging time and adds to cost. Some experts suggest that resting perfusion does not add to clinical interpretation and is not required.

Our case is interesting, showing a previously unreported phenomenon. We cannot explain the reason for it but do not believe that the stress/rest order was reversed (as this would require two radiographers to go off protocol, and they and the supervising physician to be lying) and the physiological response is as expected. It therefore suggests that a rest study may occasionally provide helpful diagnostic information.

Abstract P707 Figure.

Association of a Novel Diagnostic Biomarker, the Plasma Cardiac Bridging Integrator 1 Score, With Heart Failure With Preserved Ejection Fraction and Cardiovascular Hospitalization

Importance

Transverse tubule remodeling is a hallmark of heart failure. Cardiac bridging integrator 1 (cBIN1) is a circulating membrane scaffolding protein that is essential for transverse tubule health, and its plasma level declines with disease.

Objective

To determine if a cBIN1-derived score can serve as a diagnostic biomarker of heart failure with preserved ejection fraction (HFpEF).

Design, Setting, and Participants

In this cohort study, the cBIN1 score (CS) was determined from enzyme-linked immunoabsorbent assay-measured plasma cBIN1 concentrations from study participants in an ambulatory heart failure clinic at Cedars-Sinai Medical Center. Consecutive patients with a confirmed diagnosis of heart failure with preserved ejection fraction (HFpEF; defined by a left ventricular ejection fraction ≥50%) were recruited from July 2014 to November 2015 and compared with age-matched and sex-matched healthy volunteers with no known cardiovascular diagnoses and participants with risk factors for heart failure but no known HFpEF. Baseline characteristics and 1-year longitudinal clinical information were obtained through electronic medical records. Data analysis occurred from November 2016 to November 2017.

Main Outcomes and Measures

The analysis examined the ability of the CS and N-terminal pro-B-type natriuretic peptide (NT-proBNP) results to differentiate among patients with HFpEF, healthy control participants, and control participants with risk factors for heart failure. We further explored the association of the CS with future cardiovascular hospitalizations.

Results

A total of 52 consecutive patients with a confirmed diagnosis of HFpEF were enrolled (mean [SD] age, 57 [15] years; 33 [63%] male). The CS values are significantly higher in the patients with HFpEF (median [interquartile range (IQR)], 1.85 [1.51-2.28]) than in the 2 control cohorts (healthy control participants: median [IQR], -0.03 [-0.48 to 0.41]; control participants with risk factors only: median [IQR], -0.08 [-0.75 to 0.42]; P < .001). For patients with HFpEF, the CS outperforms NT-proBNP when the comparator group was either healthy control participants (CS: area under curve [AUC], 0.98 [95% CI, 0.96-1.00]; NT-proBNP level: AUC, 0.93 [95% CI, 0.88-0.99]; P < .001) or those with risk factors (CS: AUC, 0.98 [95% CI, 0.97-1.00]; NT-proBNP: AUC, 0.93 [95% CI, 0.88-0.99]; P < .001). Kaplan-Meier analysis of 1-year cardiovascular hospitalizations adjusted for age, sex, body mass index, and NT-proBNP levels reveals that patients with HFpEF with CS greater than or equal to 1.80 have a hazard ratio of 3.8 (95% CI, 1.3-11.2; P = .02) for hospitalizations compared with those with scores less than 1.80.

Conclusions and Relevance

If further validated, the plasma CS, a marker of transverse tubule dysfunction, may serve as a biomarker of cardiomyocyte remodeling that has the potential to aide in the diagnosis of HFpEF.

Social-ecological network analysis for sustainability sciences: a systematic review and innovative research agenda for the future

Social-ecological network (SEN) concepts and tools are increasingly used in human-environment and sustainability sciences. We take stock of this budding research area to further show the strength of SEN analysis for complex human-environment settings, identify future synergies between SEN and wider human-environment research, and provide guidance about when to use different kinds of SEN approaches and models. We characterize SEN research along a spectrum specifying the degree of explicit network representation of system components and dynamics. We then systematically review one end of this spectrum, what we term "fully articulated SEN" studies, which specifically model unique social and ecological units and relationships. Results show more focus on methodological advancement and applied ends. While there has been some development and testing of theories, this remains an area for future work and would help develop SENs as a unique field of research, not just a method. Authors have studied diverse systems, while mainly focused on the problem of social-ecological fit alongside a scattering of other topics. There is strong potential, however, to engage other issues central to human-environment studies. Analyzing the simultaneous effects of multiple social, environmental, and coupled processes, change over time, and linking network structures to outcomes are also areas for future advancement. This review provides a comprehensive assessment of (fully articulated) SEN research, a necessary step that can help scholars develop comparable cases and fill research gaps.