A de novo dominant-negative variant is associated with OTULIN-related autoinflammatory syndrome

OTULIN-related autoinflammatory syndrome (ORAS), a severe autoinflammatory disease, is caused by biallelic pathogenic variants of OTULIN, a linear ubiquitin-specific deubiquitinating enzyme. Loss of OTULIN attenuates linear ubiquitination by inhibiting the linear ubiquitin chain assembly complex (LUBAC). Here, we report a patient who harbors two rare heterozygous variants of OTULIN (p.P152L and p.R306Q). We demonstrated accumulation of linear ubiquitin chains upon TNF stimulation and augmented TNF-induced cell death in mesenchymal stem cells differentiated from patient-derived iPS cells, which confirms that the patient has ORAS. However, although the de novo p.R306Q variant exhibits attenuated deubiquitination activity without reducing the amount of OTULIN, the deubiquitination activity of the p.P152L variant inherited from the mother was equivalent to that of the wild-type. Patient-derived MSCs in which the p.P152L variant was replaced with wild-type also exhibited augmented TNF-induced cell death and accumulation of linear chains. The finding that ORAS can be caused by a dominant-negative p.R306Q variant of OTULIN furthers our understanding of disease pathogenesis.

Do attentional focus cues affect the type or number of explicit rules? Proof of concepts of the self-invoking trigger or explicit knowledge hypotheses

Internal focus has been shown to be detrimental to performance by disrupting the motor system, whereas external focus enhances performance by promoting automaticity. One hypothesis, which explains the underlying mechanism of the disruption of the motor system, proposes that internal focus affects the type of thoughts (explicit rules) by invoking self-conscious, evaluative thoughts (McKay et al., 2015). In contrast, another hypothesis proposes that internal focus increases the number of explicit rules, loading working memory (Poolton et al., 2006). To examine the competing hypotheses, neurotypical young adults (22.98 ± 4.46 years old, n = 20 males, n = 40 females) were assigned to one of three groups: external focus (n = 20), internal focus (n = 20), and control (n = 20) groups, and practiced a reciprocal aiming task for two days with retention/transfer tests. Between trials, participant's thoughts were evaluated by an open-ended questionnaire. The type of explicit rules was analyzed using a chi-square test, and the number of explicit rules was analyzed using a mixed-effect Poisson regression. The results showed that external focus resulted in a greater proportion of explicit rules about the task and a lesser proportion of self-evaluative thoughts. The number of explicit rules did not differ between groups. Our results suggest that external focus may strengthen focus on task-relevant features, while internal focus moves people's attention away from important features, potentially explaining why the motor system is disrupted by internal focus.

Laboratory Study of Collisionless Magnetic Reconnection

A concise review is given on the past two decades' results from laboratory experiments on collisionless magnetic reconnection in direct relation with space measurements, especially by the Magnetospheric Multiscale (MMS) mission. Highlights include spatial structures of electromagnetic fields in ion and electron diffusion regions as a function of upstream symmetry and guide field strength, energy conversion and partitioning from magnetic field to ions and electrons including particle acceleration, electrostatic and electromagnetic kinetic plasma waves with various wavelengths, and plasmoid-mediated multiscale reconnection. Combined with the progress in theoretical, numerical, and observational studies, the physics foundation of fast reconnection in collisionless plasmas has been largely established, at least within the parameter ranges and spatial scales that were studied. Immediate and long-term future opportunities based on multiscale experiments and space missions supported by exascale computation are discussed, including dissipation by kinetic plasma waves, particle heating and acceleration, and multiscale physics across fluid and kinetic scales.

Safety and efficacy of elapegademase in patients with adenosine deaminase deficiency: A multicenter, open-label, single-arm, phase 3, and postmarketing clinical study

INTRODUCTION

Adenosine deaminase (ADA) deficiency is an ultrarare inherited purine metabolism disorder characterized by severe combined immunodeficiency. Elapegademase-lvlr is a new pegylated recombinant bovine ADA used in enzyme-replacement therapy (ERT) for ADA deficiency. Therefore, replacement with the new drug may eliminate the infectious risks associated with the currently used bovine intestinal-derived product, pegademase.

METHODS

We conducted a multicenter, single-arm, open-label, phase 3, and postmarketing clinical study of elapegademase for patients with ADA deficiency. The following biochemical markers were monitored to determine an appropriate dose of elapegademase: the trough deoxyadenosine nucleotide (dAXP) level ≤0.02 μmol/mL in erythrocytes or whole blood and the trough serum ADA activity ≥1100 U/L (equivalent to plasma levels ≥15 μmol/h/mL) indicated sufficient enzyme activity and detoxification as efficacy endpoints and monitored adverse events during the study as safety endpoints.

RESULTS

A total of four patients (aged 0-25 years) were enrolled. One infant patient died of pneumonia caused by cytomegalovirus infection whereas the other three completed the study and have been observed in the study period over 3 years. The infant patient had received elapegademase at 0.4 mg/kg/week until decease and the others received elapegademase at maximum doses of 0.3 mg/kg/week for 164-169 weeks. As a result, all four patients achieved undetectable levels of dAXPs together with sufficient enzyme activity, increased T and B cell numbers, and slightly elevated and maintained IgM and IgA immunoglobulin levels. Serious adverse events occurred in three patients, all of which were assessed as unrelated to elapegademase.

CONCLUSIONS

This study showed that elapegademase had comparable safety and efficacy to pegademase as ERT for ADA deficiency by demonstrating stable maintenance of sufficient ADA activity and lowering dAXP to undetectable levels, while no drug-related adverse events were reported (Trial registration: JapicCTI-163204).

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Rheumatologic manifestations with elevated levels of IL-6, IL-17A, and IL-23 in a patient with scurvy

Symptomatic vitamin C deficiency, scurvy, is a relatively rare disease in developed countries, but it has been reported in patients with autism spectrum disorder or developmental delay who tend to have selective diets. Patients with scurvy often demonstrate musculoskeletal manifestations with unknown pathophysiology. Herein, we report a case of scurvy in an 11-year-old boy who presented with iron-deficiency anaemia, systemic osteomyelitis, myositis predominantly in the lower extremities, and right ventricular volume overload with mild pulmonary hypertension and was diagnosed with scurvy. He had a mild developmental disorder and a selective diet, which resulted in severe vitamin C deficiency. He received intravenous and oral vitamin C supplementation, which relieved his arthralgia and muscle pain in a week. Following 4 months of vitamin C supplementation, he demonstrated no abnormal manifestations on laboratory or imaging examination and recovered without sequelae. Inflammatory cytokine and chemokine evaluations demonstrated elevated levels of interleukin (IL)-6, IL-17A, and IL-23, which are associated with T-helper (Th) 17 cell activation. This study is the first to suggest the association between the inflammation seen in scurvy, rheumatic manifestations in the patient, and Th17 cell activation. Further analysis of the association between the inflammation and vitamin C supplementation may contribute to new insights for the comprehension and treatment of other inflammatory diseases, such as rheumatic diseases.

Therapeutic Drug Monitoring of Oral Voriconazole in an Infant Less than Six Months of Age and Pharmacokinetics Changes Induced by Development of CYP2C19 in the Growth Process: A Novel Case Report

Therapeutic drug monitoring (TDM) is recommended for voriconazole (VRCZ) to avoid adverse events and maximize antifungal efficacy. Currently, the appropriate dose for patients under the age of 2 years is unknown. Here, we report the case of a 1.5-month-old infant with inborn errors of immunity who was orally administered VRCZ. This patient's plasma concentration decreased significantly from 3.8 µg/mL (day 6) to 0.09 µg/mL (day 21), leading to repeated dose escalations to achieve the target concentration (1.38 µg/mL, day 58). The signal intensity ratio of VRCZ to its main metabolite, N-oxide VRCZ, in LC/MS/MS also decreased from 5.30 (day 6) to 0.57 (day 64). Consequently, we suspected that VRCZ metabolism may be enhanced during infant growth. To our knowledge, this is the first report of remarkable changes in VRCZ pharmacokinetics with metabolic activity enhanced by the growth process. In conclusion, we propose that frequent TDM helped to maintain adequate VRCZ plasma concentration in a infants less than 6 months of age.

Educational Approaches That Enhance Online Clinical Clerkship during the COVID-19 Pandemic

Objective This cross-sectional national study determined which educational approaches are associated with the effectiveness of online clerkship for medical students. Method A survey was conducted for medical students at 78 medical schools in Japan from May 29 to June 14, 2020. It comprised the following aspects: (a) participants' profiles, (b) number of opportunities to learn from each educational approach (lecture, medical quiz, assignment, oral presentation, observation of a physician's practice, clinical skill practice, participation in interprofessional meetings, and interactive discussions with physicians) in online clerkship, (c) frequency of technical problems, and (d) educational outcome measurement (satisfaction, motivation, knowledge acquisition, skill acquisition, change in self-study time, and understanding of the importance of medical care team). Results Of the 2,640 respondents, 2,594 (98.3%) agreed to cooperate. Ultimately, 1,711 matched our inclusion criteria. All educational approaches but assignments were positively associated with satisfaction and motivation. All educational approaches excluding assignment submission and interprofessional meeting were positively associated with knowledge acquisition. Observation, practice, and interprofessional meeting were positively associated with skill acquisition. Only assignment submission was positively associated with the change in self-study time. Educational approaches excluding medical quizzes were positively associated with understanding the importance of the medical care team. Technical problems were negatively associated with motivation, knowledge acquisition, and skill acquisition. Conclusions Educators should implement various educational approaches, especially observation and practice, even in online clinical clerkship. They also need to minimize the technical problems associated with the Internet, as they reduce the effectiveness of online clerkship.

Prevalence of Hoarseness and Its Association with Severity of Dysphagia in Patients with Sarcopenic Dysphagia

OBJECTIVES

To investigate the prevalence of hoarseness and its association with the severity of dysphagia in patients with sarcopenic dysphagia.

DESIGN

Cross-sectional study using the Japanese sarcopenic dysphagia database.

SETTING

19 hospitals including 9 acute care hospitals, 8 rehabilitation hospitals, 2 long-term care hospitals, and 1 home visit rehabilitation team.

PARTICIPANTS

287 patients with sarcopenic dysphagia, aged 20 years and older.

MEASUREMENTS

Sarcopenic dysphagia was diagnosed using a reliable and validated diagnostic algorithm for the condition. The presence and characteristics of hoarseness classified as breathy, rough, asthenic, and strained were assessed. The prevalence of hoarseness and the relationship between hoarseness and Food Intake LEVEL Scale (FILS) were examined. Order logistic regression analysis adjusted for age, sex, naso-gastric tube, and handgrip strength was used to examine the relationship between hoarseness and FILS at baseline and at follow-up.

RESULTS

The mean age was 83 ± 10 years. Seventy-four (26%) patients had hoarseness, while 32 (11%), 20 (7%), 22 (8%), and 0 (0%) patients had breathy, rough, asthenic, and strained hoarseness, respectively. Median FILS at the initial evaluation was 7 (interquartile range, 5-8). Hoarseness (β=0.747, 95% confidence intervals= 0.229, 1.265, p=0.005), age, sex, naso-gastric tube, and handgrip strength were associated independently with baseline FILS, while hoarseness (β=0.213, 95% confidence intervals= -0.324, 0.750, p=0.438) was not associated independently with the FILS at follow-up.

CONCLUSIONS

Hoarseness was associated with the severity of dysphagia at baseline, however not a prognostic factor for sarcopenic dysphagia. Resistance training of swallowing and respiratory muscles and voice training as part of rehabilitation nutrition might be useful for treating sarcopenic dysphagia.

Case Report: Rotavirus Vaccination and Severe Combined Immunodeficiency in Japan

Severe combined immunodeficiency (SCID) is an inborn error of immunity that occurs in approximately 1 in 50,000 births, mainly due to impaired lymphocyte differentiation. Without curative treatment, such as hematopoietic cell transplantation (HCT) or gene therapy, severe infection in the first year of life could make this condition fatal. The results of HCT are poor when patients have active infections, thus requiring early diagnosis before onset of infection. In five cases of SCID diagnosed in Japan, the oral rotavirus vaccine had been administered before diagnosis. In this study, we demonstrated that the rotavirus from their stools was a vaccine-derived strain. In some cases, severe gastroenteritis triggered the diagnosis of SCID. However, newborn screening for SCID is available before the first rotavirus vaccination using assays for the detection of T-cell receptor excision circles (TRECs). Therefore, to improve the prognosis of patients with SCID in Japan, we should establish a screening system of TRECs for newborns throughout Japan.

Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

Altered Rheological Properties of Saliva with Aging in Mouse Sublingual Gland

Mucin in saliva plays a critical role in the hydration and lubrication of the oral mucosa by retaining water molecules, and its impaired function may be associated with hyposalivation-independent xerostomia. Age-dependent effects on salivary gland function and rheological properties of secreted saliva are not fully understood as aging is a complex and multifactorial process. We aimed to evaluate age-related changes in the rheological properties of saliva and elucidate the underlying mechanism. We performed ex vivo submandibular gland (SMG) and sublingual gland (SLG) perfusion experiments to collect saliva from isolated glands of young (12 wk old) and aged (27 mo old) female C57BL/6J mice and investigate the rheological properties by determining the spinnbarkeit (viscoelasticity). While fluid secretion was comparable in SMG and SLG of both mice, spinnbarkeit showed a significant decrease in SLG saliva of aged mice than that of young mice. There were no significant differences in GalNAc concentration between young and aged SLG saliva. Liquid chromatography/tandem mass spectrometry analysis of SLG saliva revealed that (Hex)₁ (HexNAc)₁ (NeuAc)₁ at m/z 793.31 was the most abundant O-glycan structure in SLG saliva commonly detected in both mice. Lectin staining of salivary gland tissue showed that SLG stained strongly with Maackia amurensis lectin II (MAL II) while Sambucus nigra agglutinin (SNA) stained little, if any, SLG. The messenger RNA expression of St3gal1 that encodes an α-2,3 sialic acid sialyltransferase SIAT4-A showed a decrease in SLG of aged mice, confirmed by a Western blot analysis. Lectin blot analysis in SLG saliva revealed that the relative signal intensity detected by MAL II was significantly lower in aged SLG. Our results suggest that spinnbarkeit decreases in SLG of aging mice due to downregulation of sialic acid linked to α-2,3 sialic acid sialyltransferase expression.

Predicting the effectiveness of the online clinical clerkship curriculum: Development of a multivariate prediction model and validation study

Given scientific and technological advancements, expectations of online medical education are increasing. However, there is no way to predict the effectiveness of online clinical clerkship curricula. To develop a prediction model, we conducted cross-sectional national surveys in Japan. Social media surveys were conducted among medical students in Japan during the periods May–June 2020 and February–March 2021. We used the former for the derivation dataset and the latter for the validation dataset. We asked students questions in three areas: 1) opportunities to learn from each educational approach (lectures, medical quizzes, assignments, oral presentations, observation of physicians’ practice, clinical skills practice, participation in interprofessional meetings, and interactive discussions with physicians) in online clinical clerkships compared to face-to-face, 2) frequency of technical problems on online platforms, and 3) satisfaction and motivation as outcome measurements. We developed a scoring system based on a multivariate prediction model for satisfaction and motivation in a cross-sectional study of 1,671 medical students during the period May–June 2020. We externally validated this scoring with a cross-sectional study of 106 medical students during February–March 2021 and assessed its predictive performance. The final prediction models in the derivation dataset included eight variables (frequency of lectures, medical quizzes, oral presentations, observation of physicians’ practice, clinical skills practice, participation in interprofessional meetings, interactive discussions with physicians, and technical problems). We applied the prediction models created using the derivation dataset to a validation dataset. The prediction performance values, based on the area under the receiver operating characteristic curve, were 0.69 for satisfaction (sensitivity, 0.50; specificity, 0.89) and 0.75 for motivation (sensitivity, 0.71; specificity, 0.85). We developed a prediction model for the effectiveness of the online clinical clerkship curriculum, based on students’ satisfaction and motivation. Our model will accurately predict and improve the online clinical clerkship curriculum effectiveness.

Identification of Germline Non-coding Deletions in XIAP Gene Causing XIAP Deficiency Reveals a Key Promoter Sequence

PURPOSE

X-linked inhibitor of apoptosis protein (XIAP) deficiency, also known as the X-linked lymphoproliferative syndrome of type 2 (XLP-2), is a rare immunodeficiency characterized by recurrent hemophagocytic lymphohistiocytosis, splenomegaly, and inflammatory bowel disease. Variants in XIAP including missense, non-sense, frameshift, and deletions of coding exons have been reported to cause XIAP deficiency. We studied three young boys with immunodeficiency displaying XLP-2-like clinical features. No genetic variation in the coding exons of XIAP was identified by whole-exome sequencing (WES), although the patients exhibited a complete loss of XIAP expression.

METHODS

Targeted next-generation sequencing (NGS) of the entire locus of XIAP was performed on DNA samples from the three patients. Molecular investigations were assessed by gene reporter expression assays in HEK cells and CRISPR-Cas9 genome editing in primary T cells.

RESULTS

NGS of XIAP identified three distinct non-coding deletions in the patients that were predicted to be driven by repetitive DNA sequences. These deletions share a common region of 839 bp that encompassed the first non-coding exon of XIAP and contained regulatory elements and marks specific of an active promoter. Moreover, we showed that among the 839 bp, the exon was transcriptionally active. Finally, deletion of the exon by CRISPR-Cas9 in primary cells reduced XIAP protein expression.

CONCLUSIONS

These results identify a key promoter sequence contained in the first non-coding exon of XIAP. Importantly, this study highlights that sequencing of the non-coding exons that are not currently captured by WES should be considered in the genetic diagnosis when no variation is found in coding exons.

Development of Graves' disease during drug-free remission of juvenile dermatomyositis

We report a Japanese boy with Graves' disease (GD) which developed during drug-free remission of juvenile dermatomyositis (JDM). He had been diagnosed with JDM at the age of 6 years by typical skin rashes, muscle weakness, elevated serum transaminase levels, and typical findings of both magnetic resonance imaging and muscle biopsy. Although anti-melanoma differentiation antigen 5 autoantibody was positive, there was no complication of interstitial lung disease. He showed good response to methylprednisolone pulse therapy followed by oral prednisolone in combination with weekly methotrexate (MTX) and achieved drug-free remission after 3.5 years of treatment. Nevertheless, serum levels of soluble interleukin-2 receptor (sIL-2R) gradually elevated to 3185 U/ml despite no signs of relapse or malignancy. Hyperactivity and attention deficit was also noted. One year and 3 months after the cessation of MTX, he presented with abdominal pain, tachycardia, and apparent goitre. Laboratory tests showed elevated free triiodothyronine, undetectable thyroid stimulating hormone (TSH), and positive anti-TSH receptor antibodies. 99mTc scintigraphy showed high levels of thyroid uptake. He was diagnosed with GD and treated with 15 mg/day of thiamazole. Although transient drug eruption was observed, his thyroid functions are currently well-controlled on 5 mg/day of thiamazole. In conclusion, to our knowledge, this is the first report in English literature describing complication of GD with JDM. Unexpected elevation of sIL-2R could be a clue to the diagnosis of GD during the follow-up of JDM.

Hematopoietic Cell Transplantation for Inborn Errors of Immunity Other than Severe Combined Immunodeficiency in Japan: Retrospective Analysis for 1985-2016

PURPOSE

Hematopoietic cell transplantation (HCT) is a curative therapy for most patients with inborn errors of immunity (IEI). We conducted a nationwide study on HCT for patients with IEI other than severe combined immunodeficiency (non-SCID) in Japan.

METHODS

Data from the Japanese national database (Transplant Registry Unified Management Program, TRUMP) for 566 patients with non-SCID IEI, who underwent their first HCT between 1985 and 2016, were retrospectively analyzed.

RESULTS

The 10-year overall survival (OS) and event-free survival (EFS) were 74% and 64%, respectively. The 10-year OS for HCT from unrelated bone marrow (URBM), accounting for 39% of HCTs, was comparable to that for HCT from matched sibling donor (MSD), 79% and 81%, respectively. HCT from unrelated cord blood (URCB), accounting for 28% of HCTs, was also common, with a 10-year OS of 69% but less robust engraftment. The intensity of conditioning was not associated with OS or neutrophil recovery; however, myeloablative conditioning was more frequently associated with infection-related death. Patients who received myeloablative irradiation showed poor OS. Multivariate analyses revealed that HCT in 1985-1995 (hazard ratio [HR], 2.0; P = 0.03), URCB (HR, 2.0; P = 0.01), and related donor other than MSD (ORD) (HR, 2.9; P < 0.001) were associated with poor OS, and URCB (HR, 3.6; P < 0.001) and ORD (HR, 2.7; P = 0.02) showed a higher incidence of retransplantation.

CONCLUSIONS

We present the 1985-2016 status of HCT for non-SCID IEI in Japan with sufficient statistical power, highlighting the potential of URBM as an alternative donor and the feasibility of reduced intensity conditioning.

Absent X-linked inhibitor of apoptosis protein expression in T cell blasts and causal mutations including non-coding deletion

BACKGROUND

X-linked inhibitor of apoptosis protein (XIAP) deficiency is one of inborn errors of immunity characterized by recurrent hemophagocytic lymphohistiocytosis and refractory inflammatory bowel disease (IBD), mimicking Crohn's disease. The aim of this study is to make an accurate diagnosis of XIAP deficiency based on genetic and XIAP expression studies and to investigate endoscopic findings shared by patients with this disease.

METHODS

Four male patients with recurrent hemophagocytic lymphohistiocytosis and long-term refractory IBD were studied for the diagnosis of XIAP deficiency. Endoscopic findings of the four patients were also studied in parallel.

RESULTS

These four patients were diagnosed with XIAP deficiency based on the absent XIAP expression in cultured T-cell blasts. Sequence analysis of the responsible gene, XIAP, demonstrated two novel nonsense mutations of p.Gln114X and p.Glu25X, and a previously reported nonsense mutation of p.Arg381X. Although no mutations in the coding region were detected in the fourth patient, further studies demonstrated a novel 2,199 bp deletion encompassing non-coding exon 1, presumably affecting transcription and stability of XIAP mRNA. All of the patients eventually underwent hematopoietic stem cell transplantation, leading to a complete or partial remission of IBD. These four patients shared an endoscopic finding of multiple wide and longitudinal ulcers with straight and non-raised edge in the colon.

CONCLUSIONS

X-linked inhibitor of apoptosis protein expression in T-cell blasts could facilitate the diagnosis of this disease, especially with causal mutations in non-coding regions.

Factors Associated with Increased Caregiver Burden of Informal Caregivers during the COVID-19 Pandemic in Japan

This study's objective was to explore the association between various factors and the increased caregiver burden of informal caregivers during the COVID-19 pandemic. On February, 2021, 700 informal caregivers completed an online survey. We assessed the change in caregiver burden during the COVID-19 pandemic. Among all caregiver participants, 287 (41.0%) complained of an increased caregiver burden due to the COVID-19 pandemic. The factors associated with increased caregiver burden were depressive symptoms in caregivers [odds ratio (OR), 2.20; 95% confidence interval (CI), 1.50-3.23], dementia (OR, 2.48; 95%CI, 1.07-5.73) and low Barthel Index scores (OR, 2.01; 95%CI, 1.39-2.90) in care receivers, care days (OR, 1.09; 95%CI, 1.01-1.17) and times (OR, 1.06; 95%CI, 1.01-1.10), and use of home care service (OR, 1.46; 95%CI, 1.01-2.10) and visiting care service (OR, 1.71; 95%CI, 1.20-2.45). These findings suggest we need to pay attention to the physical and mental health of both the care receivers and caregivers.

Association between Inflammation and Functional Outcome in Patients with Sarcopenic Dysphagia

OBJECTIVES

This study aimed to investigate whether inflammation affects the outcome of swallowing ability to improve treatment for sarcopenic dysphagia.

DESIGN

A retrospective observational cohort study was performed using data from the Japanese sarcopenic dysphagia database.

SETTING

The database was constructed using data from 19 hospitals and one home visiting rehabilitation team.

PARTICIPANTS

Patients with sarcopenic dysphagia with measurements of C-reactive protein (CRP) and serum albumin (Alb) were included.

MEASUREMENTS

Patients were assigned to two groups using CRP, Alb, and the Japanese modified Glasgow Prognostic Score (mGPS). The Food Intake LEVEL Scale (FILS) was measured at the times of admission and follow-up (FILS follow-up) to assess swallowing function.

RESULTS

A total of 197 patients were included. Mean or median values of each parameter were as follows: age: 83.8±8.7, Alb: 3.2 ± 0.6 g/dL, CRP: 8.0 [3.0, 29.0] mg/L, mGPS: 1 [1-2], FILS: 7 [6-8], FILS follow-up: 8 [7-8], and duration of follow-up: 57.0 [27.0, 85.0] days. The FILS score at follow-up was significantly lower in the high CRP group (≥ 5.0 mg/L) than in the low CRP group (< 5.0 mg/L) (p = 0.01). Further, the FILS score at follow-up was significantly lower in the high mGPS group (class; 2) than in the low mGPS group (class; 0 and 1) (p = 0.03). In the multiple linear regression analyses without FILS at baseline, CRP and mGPS were independent risk factors for FILS follow-up. When FILS at baseline was entered, CRP and mGPS were not an independent risk factors for FILS follow-up.

CONCLUSIONS

Inflammation could modify the outcome of the patients with sarcopenic dysphagia. Inflammation may be an important risk factor in evaluating patients with sarcopenic dysphagia.

Progressive multifocal leukoencephalopathy with mild clinical conditions and detection of archetype-like JC virus in cerebrospinal fluid

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system with a poor prognosis and is primarily caused by JC virus (JCV) with a mutation called prototype. We encountered a case of PML with moderate progression and analyzed the mutational patterns of JCV in the cerebrospinal fluid (CSF). A 19-year-old Japanese woman with mild neurological symptoms was diagnosed with combined immunodeficiency following pneumocystis pneumonia. Brain magnetic resonance imaging scan showed multiple brain lesions, and real-time polymerase chain reaction testing detected JCV in the CSF, leading to the diagnosis of PML. The disease course of PML was stable after administration of mefloquine and mirtazapine with immunoglobulin replacement therapy. In the JCV genome cloned from the patient CSF, DNA sequences of the gene encoding the capsid protein (VP1) and the non-coding control region exhibited small mutations. However, they were quite similar to those of the archetype JCV, which persists asymptomatically in healthy individuals. These findings provide insight into the mutational characteristics of JCV in PML with mild symptoms and progression.

Diagnostic Accuracy of Diastolic Fractional Flow Reserve for Functional Evaluation of Coronary Stenosis

Background

In the resting conditions, narrowing the window of coronary pressure measurements from the whole cardiac cycle to diastole improves diagnostic performance of coronary pressure–derived physiological index. However, whether this also applies to the hyperemic conditions has not yet been thoroughly evaluated.

Objectives

The purpose of this study was to assess whether diastolic fractional flow reserve (diastolic FFR) has better diagnostic performance in identifying ischemia-causing coronary lesions than conventional FFR in a prospective, multicenter, and independent core laboratory–based environment.

Methods

In this prospective multicenter registry at 29 Japanese centers, we compared the diagnostic performance of FFR, diastolic FFR, resting distal to aortic coronary pressure (Pd/Pa), and diastolic pressure ratio (dPR) using myocardial perfusion scintigraphy (MPS) as the reference standard in 378 patients with single-vessel coronary disease.

Results

Inducible myocardial ischemia was found on MPS in the relevant myocardial territory of the target vessel in 85 patients (22%). In the receiver-operating curve analyses, diastolic FFR had comparable area under the curve (AUC) compared with FFR (AUC_{diastolic FFR}: 0.66; 95% confidence interval [CI]: 0.58-0.73, vs AUC_FFR: 0.66; 95% CI: 0.58-0.74, P = 0.624). FFR and diastolic FFR showed significantly larger AUCs than resting Pd/Pa (0.62; 95% CI: 0.54-0.70; P = 0.033 and P = 0.046) but did not show significantly larger AUCs than dPR (0.62; 95% CI: 0.55-0.70; P = 0.102 and P = 0.113).

Conclusions

Diastolic FFR showed a similar diagnostic performance to FFR as compared with MPS. This result reaffirms the use of FFR as the most accurate invasive physiological lesion assessment. (Diagnostic accuracy of diastolic fractional flow reserve (d-FFR) for functional evaluation of coronary stenosis; UMIN000015906)

TRENDS IN THE PREVALENCE OF FRAILTY IN JAPAN: A META-ANALYSIS FROM THE ILSA-J

OBJECTIVE

To examine whether age-specific prevalence of frailty in Japan changed between 2012 and 2017.

DESIGN

This study performed meta-analyses of data collected from 2012 to 2017 using the Integrated Longitudinal Studies on Aging in Japan (ILSA-J), a collection of representative Japanese cohort studies.

SETTING

The ILSA-J studies were conducted on community-living older adults.

PARTICIPANTS

ILSA-J studies were considered eligible for analysis if they assessed physical frailty status and presence of frailty in the sample. Seven studies were analyzed for 2012 (±1 year; n = 10312) and eight studies were analyzed for 2017 (±1 year; n = 7010). Five studies were analyzed for both 2012 and 2017.

MEASUREMENTS

The study assessed the prevalence of frailty and frailty status according to 5 criteria: slowness, weakness, low activity, exhaustion, and weight loss.

RESULTS

The overall prevalence of physical frailty was 7.0% in 2012 and 5.3% in 2017. The prevalence of frailty, especially in people 70 years and older, tended to decrease in 2017 compared to 2012. Slight decreases were found in the prevalence of frailty subitems including weight loss, slowness, exhaustion, and low activity between 2012 and 2017, but change in the prevalence of weakness was weaker than other components.

CONCLUSIONS

The prevalence of physical frailty decreased from 2012 to 2017. There are age- and gender-related variations in the decrease of each component of frailty.

The Influence of the COVID-19 Pandemic on Physical Activity and New Incidence of Frailty among Initially Non-Frail Older Adults in Japan: A Follow-Up Online Survey

OBJECTIVES

The objective of this study was to investigate the influence of the COVID-19 pandemic on physical activity (PA) and the incidence of frailty among initially non-frail older adults in Japan.

DESIGN

A follow-up online survey.

SETTING AND SUBJECTS

Among the 1,600 baseline online survey participants, 388 adults were already frail, and 275 older adults did not respond to the follow-up survey. Thus, the final number of participants in this study was 937 (follow-up rate: 77.3%).

METHODS

We assessed the total PA time at four time points according to the COVID-19 waves in Japan: January 2020 (before the pandemic), April 2020 (during the first wave), August 2020 (during the second wave), and January 2021 (during the third wave). We then investigated the incidence of frailty during a one-year follow-up period (during the pandemic).

RESULTS

The total PA time during the first, second, and third waves of the pandemic decreased from the pre-pandemic PA time by 33.3%, 28.3%, and 40.0%, respectively. In particular, the total PA time of older adults who were living alone and socially inactive decreased significantly: 42.9% (first wave), 50.0% (second wave), and 61.9% (third wave) less than before the pandemic, respectively. Additionally, they were at a significantly higher risk of incident frailty than those who were not living alone and were socially active (adjusted odds ratio: 2.04 [95% confidence interval: 1.01-4.10]).

CONCLUSION

Our findings suggest that older adults who live alone and are socially inactive are more likely to experience incident frailty/disability due to decreased PA during the pandemic. Understanding this mechanism may be crucial for maintaining the health status of older adults.

The Mass of Geniohyoid Muscle Is Associated with Maximum Tongue Pressure and Tongue Area in Patients with Sarcopenic Dysphagia

OBJECTIVES

We investigated the associations about the mass of geniohyoid and tongue muscle and the maximum tongue pressure in patients with sarcopenic dysphagia using ultrasonography.

DESIGN

Cross sectional study.

SETTING

5 hospitals including 3 acute and 2 rehabilitation hospitals and 1 older facility.

PARTICIPANTS

36 inpatients with sarcopenic dysphagia.

MEASUREMENTS

Ultrasonography was performed for geniohyoid muscle and tongue. The area for geniohyoid and tongue muscles in sagittal plane and the mean brightness level (0-255) in the muscle area were calculated. Maximum tongue pressure as strength of swallowing muscle were investigated. Partial correlation coefficient and multiple regression analysis adjusting for age and sex were performed.

RESULTS

The mean age was 81.1 ± 7.9. Men were 23. The mean BMI was 19.0 ± 4.1. The mean maximum tongue pressure was 21.3 ± 9.3 kPa. The mean cross sectional area for geniohyoid muscles was 140 ± 47 mm2. The mean brightness for geniohyoid muscle was 18.6 ± 9.0. The mean cross sectional area for tongue muscles was 1664.1 ± 386.0 mm2. The mean brightness for tongue muscles was 34.1 ± 10.6. There was a significant positive correlation between area of geniohyoid muscle and maximum tongue pressure (r = 0.38, p = 0.04). Geniohyoid muscle area was an explanatory factor for maximum tongue pressure (p = 0.012) and tongue muscle area (p = 0.031) in multivariate analysis.

CONCLUSIONS

Geniohyoid muscle mass was an independent explanatory factor for maximum tongue pressure and tongue muscle mass.

Brightness modulations of our nearest terrestrial planet Venus reveal atmospheric super-rotation rather than surface features

Terrestrial exoplanets orbiting within or near their host stars’ habitable zone are potentially apt for life. It has been proposed that time-series measurements of reflected starlight from such planets will reveal their rotational period, main surface features and some atmospheric information. From imagery obtained with the Akatsuki spacecraft, here we show that Venus’ brightness at 283, 365, and 2020 nm is modulated by one or both of two periods of 3.7 and 4.6 days, and typical amplitudes  <10% but occasional events of 20–40%. The modulations are unrelated to the solid-body rotation; they are caused by planetary-scale waves superimposed on the super-rotating winds. Here we propose that two modulation periods whose ratio of large-to-small values is not an integer number imply the existence of an atmosphere if detected at an exoplanet, but it remains ambiguous whether the atmosphere is optically thin or thick, as for Earth or Venus respectively. Multi-wavelength and long temporal baseline observations may be required to decide between these scenarios. Ultimately, Venus represents a false positive for interpretations of brightness modulations of terrestrial exoplanets in terms of surface features.

Establishing diagnostics for terrestrial exoplanets are crucial for their characterization. Here, the authors show brightness modulations of Venus are caused by planetary-scale waves superimposed on the super-rotating winds can be used to detect existence of an atmosphere if detected at an exoplanet.

Impact of body mass index on the clinical outcomes in heart failure patients undergoing cardiac rehabilitation

Background

Increased body mass index (BMI) has recently shown to have a favorable effect on the prognosis in heart failure (HF) patients. However, the impact of BMI on clinical events and mortality in HF patients who underwent cardiac rehabilitation (CR) remains unclear.

Purpose

This study aimed to investigate whether the obesity paradox is present in HF patients who have undergone CR.

Methods

This study enrolled 238 consecutive HF patients who had undergone CR at our university hospital between November 2015 and October 2017. The clinical characteristics and anthropometric data of these patients, including BMI, were collected at the beginning of the CR. The major adverse cardiovascular event (MACE) was defined as a composite of all-cause mortality and unplanned hospitalization for HF. Follow-up data regarding the primary endpoints were collected until November 2018.

Results

Patients (mean age 68.7 years, male 61%) were divided into four groups as per BMI quartiles. More patients in the highest BMI group were women, were significantly younger, and had a higher prevalence of hypertension, dyslipidemia, and diabetes mellitus; however, no significant differences were observed in the prevalence of chronic kidney disease, left ventricular ejection fraction, and brain natriuretic peptide levels of the four groups. During a median follow-up duration of 583 days, 28 patients experienced all-cause mortality, and 42 were hospitalized for HF. Kaplan–Meier analysis showed that patients in the highest BMI quartiles had lower rates of MACE (Log-rank P&lt;0.05) (Figure 1). After adjusting for confounding factors, Cox regression multivariate analysis revealed that BMI was negatively and independently associated with the incidence of MACE (hazard ratio: 0.89, 95% confidence interval: 0.83–0.96, P&lt;0.05).

Conclusion

Increased BMI was associated with better clinical prognosis even in HF patients who have undergone CR Therefore, BMI assessment may be useful for risk stratification in HF patients who have undergone CR.

Figure 1. Kaplan-Meier survival curve

Funding Acknowledgement

Type of funding source: None

NRSF-GNAO1-CaMK2 axis exacerbates cardiac remodeling and progresses heart failure by impairing Ca2+ homeostasis

Background

In the development of heart failure, pathological intracellular signaling reactivates fetal cardiac genes, which leads to maladaptive remodeling and cardiac dysfunction. We previously reported that a transcriptional repressor, neuron restrictive silencer factor (NRSF) represses fetal cardiac genes and maintains normal cardiac function under normal conditions, while hypertrophic stimuli de-repress this NRSF mediated repression via activation of CaMKII. Molecular mechanisms by which NRSF maintains cardiac systolic function remains to be determined, however.

Purpose

To elucidate how NRSF maintains normal cardiac homeostasis and identify the novel therapeutic targets for heart failure.

Methods and results

We generated cardiac-specific NRSF knockout mice (NRSF cKO), and found that these NRSF cKO showed cardiac dysfunction and premature deaths accompanied with lethal arrhythmias, as was observed in our previously reported cardiac-specific dominant-negative mutant of NRSF transgenic mice (dnNRSF-Tg).

By cDNA microarray analysis of dnNRSF-Tg and NRSF-cKO, we identified that expression of Gnao1 gene encoding Gαo, a member of inhibitory G proteins, was commonly increased in ventricles of both types of mice.

ChIP-seq analysis, reporter assay and electrophoretic mobility shift assay identified that NRSF transcriptionally regulates Gnao1 gene expression.

Genetic Knockdown of Gαo in dnNRSF-Tg and NRSF-cKO by crossing these mice with Gnao1 knockout mice ameliorated the reduced systolic function, increased arrhythmogenicity and reduced survival rates.

Transgenic mice expressing a human GNAO1 in their hearts (GNAO1-Tg) showed progressive cardiac dysfunction with cardiac dilation. Ventricles obtained from GNAO1-Tg have increased phosphorylation level of CaMKII and increased expression level of endogenous mouse Gnao1 gene. These data suggest that increased cardiac expression of Gαo is sufficient to induce pathological Ca2+-dependent signaling and cardiac dysfunction, and that Gαo forms a positive regulatory circuit with CaMKII and NRSF.

Electrophysiological analysis in ventricular myocytes of dnNRSF-Tg revealed that impaired Ca2+ handling via alterations in localized L-type calcium channel (LTCC) activities; decreased T-tubular and increased surface sarcolemmal LTCC activities, underlies Gαo-mediated cardiac dysfunction.

Furthermore, we also identified increased expression of Gαo in ventricles of two different heart failure mice models, mice with transverse aortic constriction and mice carrying a mutant cardiac troponin T, and confirmed that genetic reduction of Gαo prevented the progression of cardiac dysfunction in both types of mice.

Conclusions

Increased expression of Gαo, induced by attenuation of NRSF-mediated repression forms a pathological circuit via activation of CaMKII. This circuit exacerbates cardiac remodeling and progresses heart failure by impairing Ca2+ homeostasis. Gαo is a potential therapeutic target for heart failure.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grants-in –Aid for Scientific Research from the Japan Society for the Promotion of Science

Coexistence of acute poststreptococcal glomerulonephritis and acute rheumatic fever in a Japanese girl with primary Sjögren's syndrome

Although acute poststreptococcal glomerulonephritis (APSGN) and acute rheumatic fever (ARF) are well-known complications of group A streptococcus infection, concomitant occurrence of both diseases is rare. We report an 11-year-old Japanese girl with primary Sjögren's syndrome complicated by acute renal failure about 2 weeks after the onset of pharyngitis. Although histopathological findings of the kidney were not confirmative, APSGN was suggested by the spontaneous recovery of her renal function, typical latent period with high levels of antistreptolysin O and low serum levels of C3 but not of C4. In addition, cardiac hypomotility and regurgitation of the 4 valves progressed in the convalescent phase of APSGN, which was accompanied by elevation of serum C-reactive protein and plasma brain natriuretic peptide (BNP) levels. Myocarditis was suggested by delayed gadolinium-enhancement of cardiac walls on cardiac magnetic resonance imaging. She was diagnosed with APSGN and ARF and was treated with a combination of short course prednisolone and prophylactic penicillin G. There is no relapse of renal or cardiac symptoms during 6 years follow-up. Unexpected elevation of plasma BNP in a convalescent stage of APSGN suggests the development of ARF. Underlying Sjögren's syndrome (SS) may modify the histopathological findings and make it difficult to differentiate APSGN from CTD-associated nephritis such as lupus nephritis (LN) even by renal biopsy.

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

P1357 Left atrial function decreases with age in patients with repaired tetralogy of Fallot decrease

BACKGROUND

Left ventricular function has been shown to be an important prognostic indicator in patients with repaired tetralogy of Fallot (rTOF) and tends to decrease with age. In recent years, left atrial (LA) function was reported to be a useful prognostic indicator more than or equal to left ventricular function in acquired heart diseases. However, atrial function in rTOF has not yet been sufficiently examined.

PURPOSE

The aim of this study was to investigate the relationship between LA dysfunction and age in rTOF using strain analysis.

METHODS

In order to assess the relationship between LA function and age, we recruited 59 patients with rTOF ranging in age from 5-40 years. We stratified the patients into 3 groups (T1: 5-10 years, T2: 11-20 years, T3: 21-40 years) and divided 54 controls of similar age into 3 corresponding groups (N1, N2, and N3). Two-dimensional speckle tracking images (2D-STI) obtained from four- and two-chamber views were used to assess LA functions by measuring reservoir, conduit, and pump strain. Additionally, we measured the strain rate (SR) in the systole, early diastole, and late diastole.

RESULTS

LA reservoir strain (37.4 ± 2.2% vs. 47.9 ± 1.7%, P= 0.004), LA pump strain (8.3 ± 1.4% vs. 14.1 ± 2.7%, p &lt;.001), atrial systolic LA-SR (1.5 ± 0.4% vs. 2.4 ± 0.6%, p &lt;.001), and systolic LA-SR (1.5 ± 0.3% vs. 2.1 ± 0.4%, p = 0.003) were significantly decreased in T3 compared with N3. Although only LA conduit strain decreased with aging (r = -0.3204, p = 0011) in controls, all of the LA reservoir (r = -0.325, p = 0.020), conduit (r = -0.314, p = 0.025), and pump strain (r = -0.481, p &lt; 0.001) in rTOF decreased with aging.

Early diastole SR was significantly decreased in the T1 and T3 groups compared with the N1 and N3 groups (T1 vs N1, 3.00 ± 0.63% vs. 4.03 ± 0.0.80%, p &lt;.0.001, T3 vs N3, 2.31 ± 0.57% vs.3.31 ± 0.47%, p &lt; 0.001). Both systolic SR and late diastole SR decreased in T3 group compared with the N3 (1.54 ± 0.32% vs. 2.08 ± 0.42%, p = 0.003, 1.42 ± 0.32% vs.2.42 ± 0.61%, p &lt; 0.001), respectively. Although only early diastole SR decreased with aging (r = -0.415, p &lt; 0.001) in controls, all of the systole (r = -0.287, p = 0.041), early diastole (r = -0.337, p = 0.019), and late diastole SR (r = -0.407, p = 0.003) in rTOF decreased with aging.

CONCLUSIONS

In rTOF, most of the LA functions assessed by strain analysis decreased compared to normal controls in over 20 years old age. Furthermore, all measured functions decreased with age in rTOF while only two parameters decreased with age in normal controls. These results suggest that LA function may be an important indicator in long-term rTOF follow-up. These are new insights into LA function in patients with rTOF.

P5410Combination assessment of renal and hepatic dysfunction improves the predictability of prognosis in patients with acute decompensated heart failure

Background

Renal dysfunction is associated with poor mortality in patients with heart failure (HF). Hepatic dysfunction, assessed by Fibrosis-4 (FIB4) index, has also prediction ability in acute decompensated HF (ADHF) patients. We investigated whether the assessment of the combination of FIB4 index and renal dysfunction improves predictability in patients with ADHF.

Methods

We retrospectively enrolled consecutive 758 patients who admitted due to ADHF from January 2011 to February 2018 and followed up for one year. FIB4 index on admission was calculated by the formula: age (yrs) × AST[U/L] / (platelets [103/μL] × (ALT[U/L])1/2). Study subjects were divided into high FIB4 index (>3.25) and low FIB4 index (≤3.25), furthermore each group were classified by the presence/absence of CKD (estimated glomerular filtration rate <60 ml/min/1.73m). We have generated four groups; low FIB4/without CKD (n=154), low FIB4/with CKD (n=294), high FIB4/without CKD (n=56), and high FIB4/with CKD (n=254). The primary outcome was defined as all-cause mortality in one year. We performed Kaplan-Meyer analysis and multivariable Cox regression models. Furthermore, we evaluated the incremental value with C-index, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) when FIB4 index and renal dysfunction added to a baseline model.

Results

In total, 106 patients died in one year. High FIB4 index and CKD showed significantly higher 1-year mortality (high FIB4 index: 19.7% vs 10.3%, p<0.001, CKD: 17.0% vs 6.7%, p<0.001, respectively). Kaplan-Meyer analysis shows that high FIB4 index with CKD showed statistically higher mortality than the others (vs low FIB4/without CKD, p<0.001, vs high FIB4/without CKD, p=0.031, vs low FIB4/with CKD, p<0.001, respectively).

Multivariate Cox regression model revealed that both high FIB4 index and CKD were an independent risk predictor of 1-year mortality (FIB4 index: p<0.001, HR 1.06, 95% CI 1.035–1.087, CKD: p=0.004, HR 1.834, 95% CI 1.213–2.773, respectively) in patients with ADHF.

A baseline model for prediction of 1-year mortality was determined by multivariable logistic regression including age, body mass index, systolic blood pressure, and serum albumin (C-index: 0.688). Adding high FIB4 index and CKD to the baseline model, all of C-index (0.738, p=0.04), NRI (0.122, p=0.067), and IDI (0.024, p=0.004) were improved.

Receiver operating characteristic curves

Conclusions

Combination assessment of renal and hepatic dysfunction could improve the predictability of prognosis in patients with ADHF.

Acknowledgement/Funding

None

P4551Prognostic utility of Palliative Prognostic Index for prediction of 30-day and 1-year outcome in patients with acute decompensated heart failure

Background

The prognosis of heart failure remains poor similar to the terminal cancer patients, although recent progress in medical treatment. Palliative Prognostic Index (PPI) is a widely used prognostic index for terminal cancer patients (PPI includes: Palliative Performance Scale, oral intake, oedema, dyspnea at rest and delirium), suggesting the short-term prognostic marker of terminal cancer patients.

Purpose

The purpose of this study was to evaluate the impact of PPI on 30-day mortality, 1-year mortality and 1-year events (including all-cause mortality, readmission due to heart failure and new onset of cerebral infarction after hospital discharge) among acute decompensated heart failure (ADHF) patients.

Method

Study subjects comprised of consecutive 764 patients who admitted due to ADHF and followed up for 1-year. PPI were calculated at the time of hospital admission. Study subjects were divided into two groups based on the PPI: L-PPI (PPI<6) and H-PPI (6≤PPI). We calculated the C-index, net reclassification improvement (NRI) and the integrated discrimination improvement (IDI) to evaluate the improvement of prediction ability on 30-day mortality.

Result

H-PPI showed significantly higher 30-day mortality than L-PPI [7.9% vs 2.0%, log rank p<0.001, Hazard retio (HR): 1.26, 95% confidential interval(CI): 1.14–1.37, p<0.001], 1-year mortality [20.0% vs 12.7%, log rank p=0.022, HR 1.15, 95% CI 1.09–1.21, p<0.001]and 1-year events [45.5% vs 31.1%, log rank p<0.001, HR 1.13, 95% CI 1.09–1.17, p<0.001]. Multivariate cox proportional hazard models adjusted with several covariates revealed that PPI was an independent predictor of 30-day mortality (HR: 1.23, 95% CI: 1.10–1.36, p<0.001), 1-year mortality (HR: 1.10, 95% CI: 1.04–1.16, p<0.001) and 1-year events (HR: 1.11, 95% CI: 1.07–1.15, p<0.001), respectively.

A reference model for prediction of 30-day mortality was determined including left ventricular ejection fraction and serum albumin concentration by multivariable logistic regression analysis. (P<0.05) (C-index: 0.720) Adding PPI to the reference model (C-index: 0.773) significantly improved both NRI (0.458, p=0.038) and IDI (0.046, p=0.007), respectively.

Conclusion

We suggest that assessment of PPI showed good prognostic ability for 30-day and 1-year outcome, while PPI provided additional prognostic information in patients with ADHF.

4968Increased Gao expression underlies cardiac dysfunction and lethal arrhythmias accompanied with abnormal Ca2+ handling

Background

We previously demonstrated that a transcriptional repressor, neuron restrictive silencer factor (NRSF), maintains normal cardiac function and electrical stability. Transgenic mice expressing a dominant-negative mutant of NRSF in their hearts (dnNRSF-Tg) exhibit systolic dysfunction with cardiac dilation and premature death due to lethal arrhythmias like human dilated cardiomyopathy (DCM). Underlining mechanisms remain to be elucidated, however.

Purpose

We studied underling mechanisms by which NRSF maintains normal cardiac function to identify novel therapeutic targets for heart failure.

Methods and results

We generated cardiac-specific NRSF knockout mice (NRSFcKO) and confirmed that cardiac phenotypes of NRSFcKO are similar to those of dnNRSF-Tg.

cDNA microarray analysis revealed that cardiac gene expression of GNAO1 that encodes Gαo, a member of inhibitory G protein Gαi family, is increased in both dnNRSF-Tg and NRSFcKO ventricles.

We confirmed that GNAO1 is a direct target of NRSF through ChIP-seq analysis, reporter assay and electrophoretic mobility shift assay.

In dnNRSF-Tg, pharmacological inhibition of Gαo with pertussis toxin improved systolic dysfunction and knockdown of Gαo by crossing with GNAO1 knockout mice improved not only systolic function but also frequency of ventricular arrhythmias and survival rates.

Electrophysiological and biochemical analysis in ventricular myocytes obtained from dnNRSF-Tg demonstrated that genetic reduction of Gαo ameliorated abnormalities in Ca2+ handling, which include increased current density in surface sarcolemmal L-type Ca2+ channel, reduced content of sarcoplasmic reticulum Ca2+ and lowered peak of Ca2+ transient. Furthermore, genetic reduction of Gαo attenuated increased phosphorylation levels of CAMKII in dnNRSF-Tg ventricles, which presumably underlies the improvement in Ca2+ handling. In addition, we identified increased Gαo expression in ventricles of heart failure model mice induced by transverse aortic constriction and cardiac troponin T mutant DCM model mice, in both of which, genetic reduction of Gαo ameliorated cardiac dysfunction.

Figure 1

Conclusions

We found that increased expression of Gαo, induced by attenuation of NRSF-mediated repression, plays a crucial role in the progression of cardiac dysfunction and lethal arrhythmias by evoking Ca2+ handling abnormality. These data demonstrate that Gαo is a potential therapeutic target for heart failure.