Citations

Background and Objectives The genetic basis of adult-onset multiple sclerosis (MS) is well-studied, but less is known about pediatric-onset MS (pedMS), comprising approximately 5% of all MS onsets. Mendelian randomization (MR) studies have demonstrated evidence for a causal association between MS and both 25-hydroxyvitamin D [25(OH)D] serum levels and genetic variation related to vitamin D receptor (VDR) binding. The objective was to identify whether VDR binding variants (VDR-BVs) previously implicated in adult-onset MS were associated with pedMS using genetic instrumental variables (GIVs). Methods Using previously identified VDR-BVs to construct individual GIVs with two-sample MR, we investigated associations with pedMS in 725 cases and 592 controls of European ancestry from the US Network of Pediatric MS Centers. Associations between each VDR-BV and pedMS were estimated using logistic regression adjusting for the first three genome-wide principal components. A significant interaction between a VDR-BV and 25(OH)D GIV provided evidence for a causal association unbiased by pleiotropy. Results One VDR-BV, rs2531804, previously associated with adult-onset MS, was also significantly associated with pedMS after multiple testing correction. Discussion This study is the first to use VDR-BVs from previous MR studies to demonstrate causal differences in VDR binding at a locus contributing to pedMS susceptibility.

Hypoplastic left heart syndrome (HLHS) is the most lethal congenital heart disease (CHD) whose genetic basis remains elusive, likely due to oligogenic complexity. To identify regulators of cardiomyocyte (CM) proliferation relevant to HLHS, we performed a genome-wide siRNA screen in human iPSC-derived CMs, revealing ribosomal protein (RP) genes as the most prominent effectors of CM proliferation. Whole-genome sequencing of 25 HLHS proband–parent trios similarly showed enrichment of rare RP gene variants, including a damaging RPS15A promoter variant shared in a familial CHD case. Cross-species functional analyses demonstrated that perturbation of RP genes impairs cardiac growth: knockdown of RPS15A, RPS17, RPL26L1, RPL39, or RPS15 reduced CM proliferation, caused cardiac malformations in Drosophila , and produced hypoplastic or dysfunctional hearts in zebrafish. Genetic interactions between RP genes and key cardiac transcription factors (TBX5 and NKX2–7) further support their developmental role. Importantly, p53 suppression or Hippo activation partially rescued RP deficiency phenotypes. Together, these findings implicate RP genes as critical regulators of cardiogenesis and candidate contributors to HLHS.

Abstract Hypoplastic left heart syndrome (HLHS) is the most lethal congenital heart disease (CHD). The pathogenesis of HLHS is poorly understood, and due to the likely oligogenic complexity of the disease, definitive HLHS-causing genes have not yet been identified. Postulating impaired cardiomyocyte proliferation as a likely important contributing mechanism to HLHS pathogenesis, and we conducted a genome-wide siRNA screen to identify genes affecting proliferation of human iPSC-derived cardiomyocytes (hPSC-CMs). This yielded ribosomal protein (RP) genes as the most prominent class of effectors of CM proliferation. In parallel, whole genome sequencing and rare variant filtering of a cohort of 25 HLHS proband-parent trios with poor clinical outcome revealed enrichment of rare variants of RP genes. In addition, in a familial CHD case we identified a rare, predicted-damaging promoter variant affecting RPS15A that was shared between the HLHS proband and a distant relative with CHD. Functional testing with an integrated multi-model system approach reinforced the idea that RP genes are major regulators of cardiac growth and proliferation, thus potentially contributing to the hypoplastic phenotype observed in HLHS patients. Cardiac knockdown (KD) of RP genes with promoter or coding variants (RPS15A, RPS17, RPL26L1, RPL39, RPS15) reduced proliferation in generic hPSC-CMs and caused malformed hearts, heart-loss or even lethality in Drosophila. In zebrafish, diminished rps15a function caused reduced CM numbers, heart looping defects, or weakened contractility, while reduced rps17 or rpl39 function caused reduced ventricular size or systolic atrial dysfunction of the atrium, respectively. Importantly, genetic interactions between RPS15A and core cardiac transcription factors TBX5 in CMs, Drosocross, pannier and tinman in flies, and tbx5 and nkx2-7 (nkx2-5 paralog) in fish, support a specific role for RP genes in heart development. Furthermore, RPS15A KD-induced heart/CM proliferation defects were significantly attenuated by p53 KD in both hPSC- CMs and zebrafish, and by Hippo activation (YAP/yorkie overexpression) in developing fly hearts. Based on these findings, we conclude that RP genes play novel critical roles in cardiogenesis and constitute an emerging class of gene candidates likely involved in HLHS and other CHDs.

ABSTRACTBackgroundRenal medullary carcinoma (RMC) is an aggressive tumor associated with sickle cell trait. Despite treatment advances for other rare renal tumors, RMC survival remains poor. We aimed to describe the contemporary management and survival of children and adults with RMC.ProcedureIn this multicenter retrospective cohort study, Pediatric Surgical Oncology Research Collaborative sites searched their databases for patients diagnosed with RMC (2000–2022). Descriptive statistics were calculated and survival analyses performed using Kaplan–Meier and Cox regression.ResultsThirty‐four patients with RMC were identified. Median age was 19 years (IQR: 15–28; range: 7–52). Most were male (24/34; 71%), Black (27/32; 84%), had sickle cell trait or disease (30/33; 91%), presented with metastatic disease (27/34; 79%), and were symptomatic at presentation (32/34; 94%). Median overall survival (OS) was 24 months from diagnosis (16 months for children, 28 months for adults, p = 0.6). Receipt of platinum‐based chemotherapy (23/34; 68%) was associated with significantly higher OS than other regimens (35 vs. 5 months, p < 0.001). Nephrectomy (24/34; 71%) was associated with significantly improved OS compared with non‐operative management (34 vs. 7 months, p = 0.001). Immunotherapy, targeted therapy, or radiation therapy were not associated with significant differences in OS, nor were age, sex, race, sickle cell status, SMARCB1/INI‐1, stage, nephrectomy approach, retroperitoneal lymph node dissection, gross residual disease, margins, or tumor size.ConclusionsRMC survival remains poor despite newer therapies. Nephrectomy and platinum‐based chemotherapy should be considered in locally advanced and metastatic disease. Coordinated international cooperative group studies are needed to meaningfully improve RMC survival.

ABSTRACT Mass spectrometry-based metaproteomics, the identification and quantification of thousands of proteins expressed by complex microbial communities, has become pivotal for unraveling functional interactions within microbiomes. However, metaproteomics data analysis encounters many challenges, including the search of tandem mass spectra against a protein sequence database using proteomics database search algorithms. We used a ground-truth dataset to assess a spectral library searching method against established database searching approaches. Mass spectrometry data collected by data-dependent acquisition (DDA-MS) was analyzed using database searching approaches (MaxQuant and FragPipe), as well as using Scribe with Prosit predicted spectral libraries. We used FASTA databases that included protein sequences from microbial species present in the ground-truth dataset along with background protein sequences, to estimate error rates and assess the effects on detection, peptide-spectral match quality, and quantification. Using the Scribe search engine resulted in more proteins detected at a 1% false discovery rate (FDR) compared to MaxQuant or FragPipe, while FragPipe detected more peptides verified by PepQuery. Scribe was able to detect more low-abundance proteins in the microbiome dataset and was more accurate in quantifying the microbial community composition. This research provides insights and guidance for metaproteomics researchers aiming to optimize results in their analysis of DDA-MS data.

Abstract Background/Introduction Access to timely healthcare in disadvantaged areas remains essential to achieving equitable health outcomes, especially in regions facing structural and social vulnerabilities. Purpose To assess wait times for cardiovascular disease consultations in US-Mexico border regions compared to non-border regions among US Veterans. Methods This cross-sectional analysis included all veteran cardiovascular consultations referred through the Veterans Choice Program to community healthcare centers from 2014 to 2020. We obtained the average wait times in days for consultation approval, scheduling, completion, and total wait time from approval to consultation completion. All consultations were classified by county of residence as either within a US-Mexico border region or a non-border region, as per the La Paz Agreement. Multivariable linear regression analyses were performed to evaluate the impact of border status on average wait times. ARIMA modeling was completed to estimate forecasted wait times during the COVID-19 pandemic. Results A total of 485,158 consultations related to outpatient cardiovascular disease were retrieved from the VA Healthcare System. Amongst these, 461,696 of the consultations were placed in non-border regions whereas 23,462 consultations were placed in US-Mexico border regions. The most common consultation requests were made for general cardiology clinic (n=365,227), echocardiography (n=32,017), cardio-pulmonary rehabilitation (n=40,699), and cardiac stress testing (n=16,258). Wait times for cardiovascular disease consultations were not higher in US-Mexico border counties than in non-border regions. For electrophysiology consultations specifically, border counties exhibited significantly shorter total wait times (coeff = -10.81, p=0.008). Additionally, while the COVID-19 pandemic led to increased total wait times in non-border areas (Figure 1), total wait times in border regions remained stable during this period (Figure 2). Conclusions Our findings suggest that US-Mexico border region status does not result in longer wait times for cardiovascular disease consultations, with the exception of shorter wait times for electrophysiology services. This study provides important insights into the unique dynamics of healthcare access in structurally disadvantaged regions, highlighting that wait times are not a significant barrier to cardiovascular care in border areas, and emphasizes the need to consider regional differences in healthcare delivery policies.

Abstract Background Sodium-glucose cotransporter 2 inhibitors (SGLT2-Is) have emerged as a vital component in the management of heart failure (HF), demonstrating significant improvements in cardiac function. However, their impact on outcomes in patients with acute myocardial infarction (AMI) remains poorly characterized. This study aimed to evaluate the long-term outcomes of SGLT2-Is among patients with AMI. Methods We conducted a retrospective cohort study using data from the TriNetX Banner Health Network platform in the United States, including patients aged ≥18 years with AMI identified through ICD-10 codes. Patients were categorized into two cohorts based on SGLT2-I use. Propensity score matching (PSM) was performed to balance baseline demographics, comorbidities (e.g., hypertension, diabetes, chronic kidney disease, heart failure, and hyperlipidemia), and medication use (e.g., heart failure therapies, antiplatelet agents, anticoagulants). Risk ratios (RRs) and 95% confidence intervals (95% CIs) were estimated for the following cardiovascular outcomes: acute HF hospitalizations, stroke, all-cause hospitalizations, recurrent AMI, cardiac arrest, and new-onset atrial fibrillation (AF). Kaplan-Meier analysis was completed to estimate survival probability from all-cause hospitalizations. Results After PSM, 2,440 patients were analyzed (1,220 SGLT2-I users; 1,220 non-users). Both cohorts had similar characteristics without any residual imbalance: mean age 67.7 years in the SGLT2-I group vs. 67.5 years in non-users, and both groups included 85.2% White and 33.6% female patients. Mean follow-up duration was 608 days for SGLT2-I users and 1,013.5 days for non-users. SGLT2-I use was associated with significantly lower rates of all-cause hospitalizations (RR: 0.712; 95% CI: 0.652–0.777), HF-related hospitalizations (RR: 0.878; 95% CI: 0.781–0.987), recurrent AMI (RR: 0.821; 95% CI: 0.703–0.959), and cardiac arrest (RR: 0.500; 95% CI: 0.345–0.725). No significant differences were observed in stroke (RR: 0.909; 95% CI: 0.702–1.178) or new-onset AF (RR: 0.889; 95% CI: 0.782–1.010) between the cohorts. Conclusions SGLT2-Is are associated with improved cardiovascular outcomes in patients with AMI, including reductions in all-cause and HF-related hospitalizations, recurrent AMI, and cardiac arrest. While these findings are hypothesis-generating, they emphasize the need for prospective clinical trials to confirm these results.Kaplan-Meier Analysis.

Abstract Introduction The SleepImage is an HSAT device (sHSAT) that uses photoplethysmography and oxygen saturation data to generate an apnea hypopnea index (AHI). This sHSAT has been FDA cleared as a software-as-a-medical-device for use in children 2 years and older for diagnosing obstructive sleep apnea (OSA). To our knowledge this sHSAT has not been tested on children concurrent with the gold standard polysomnography (PSG). Methods This study evaluated 50 children 2-6 years of age with tonsillar hypertrophy and OSA symptoms with sHSAT during simultaneous in-lab PSG. Aims were to determine the technical feasibility of using sHSAT in this population and to compare sHSAT results to PSG. The primary endpoint was AHI by sHSAT compared to AHI by PSG and presence of OSA. Sensitivity analysis was performed for presence or absence of OSA diagnosis based on sHSAT versus PSG. Bland-Altman and concordance correlation calculations were used for comparisons. Results 50 patients, median age 4 (IQR 3-5), met criteria; 39 completed PSG and HSAT. The sensitivity with sHSAT for OSA prevalence based on proprietary categorization was 94.1%, specificity 22.7%, LR+ 1.22, and LR- 0.26, with PSG OSA prevalence of 43.6%. There was a 9% sHSAT total failure rate, and the device frequently fell off, resulting in TST difference of -226.9 ±182.8 min between sHSAT and PSG. PSG was trimmed to include only segments where HSAT was confirmed to be on before comparisons. Concordance correlation coefficient between sAHI and AHI-PSG was 0.52. The Bland-Altman analysis comparing sAHI and PSG AHI revealed a mean difference of 0.73 (95% confidence limits: -3.47 to 4.93). Considering only obstructive events, the Bland-Altman the sAHI vs the AHI-PSG shows a mean difference of 1.52 (95%CI -5.40 to 8.44). Conclusion This pilot study demonstrated challenges with feasibility in using the sHSAT in this age group given likelihood of technical difficulties leading to absent or truncated data. When compared with PSG, sHSAT demonstrated a high false-positive rate for diagnosis of OSA, particularly concerning if guiding surgical management. This topic is of considerable importance to the practice of pediatric sleep medicine; further investigation of technological advances in this area is imperative. Support (if any)

Abstract Introduction Despite AASM scoring guidelines encouraging classifying hypopneas as central or obstructive, classification is underutilized in practice. However, without that effort patients may receive an incorrect primary diagnosis and suboptimal treatment. The remedē® System Pivotal Trial studied transvenous phrenic nerve stimulation (TPNS) to treat adult patients with moderate to severe central sleep apnea (CSA). Entry criteria required apnea hypopnea index (AHI)≥20 with the central apnea index (CAI) greater than the obstructive apnea index and obstructive apneas&lt; 20% of AHI but did not consider hypopnea differentiation. This analysis re-examined sleep studies from the trial to assess how hypopnea classification might lead to better patient selection for this therapy. Methods Hypopneas were classified as central versus obstructive by a sleep core laboratory following a modified version of AASM recommended criteria. The AHI composition was assessed at baseline and after 6 months of therapy. Results At baseline, 91% (138/151) of patients had ≥50% of events classified as central when accounting for hypopnea classification. If all hypopneas were assumed to be obstructive, only 63% (95/151) would have had ≥50% central events. Additionally, 95% (144/151) of patients had central AHI ≥15/hour, compared to 73% (110/151) with a central apnea index (CAI) ≥15/hour. The likelihood of achieving a ≥50% AHI reduction increased with the percentage of baseline events that were central: responder rates were 37.5% for patients with &lt; 50% central events at baseline, incrementally increasing to 76.5% for those with ≥90% central events. At 6 months, the residual AHI predominantly consisted of obstructive events. Central events decreased by 89% with treatment, from a baseline median of 32/hour [1st and 3rd quartiles: 22, 50]. Obstructive apneas rose by 2/hour and obstructive hypopneas increased by 2/hour from a baseline median of 5 obstructive events/hour [2, 12]. Conclusion Distinguishing central from obstructive hypopneas is required to accurately determine if a patient has central sleep apnea/Cheyne Stokes respiration, and is crucial for epidemiologic studies, appropriate therapy selection, and managing patient expectations about treatment outcomes. This analysis suggests that accurate hypopnea classification may prevent disqualification of patients who could benefit from TPNS therapy, which effectively treats central sleep apnea syndrome. Support (if any) ZOLL Respicardia, Inc.