Genetic analysis of Korean non-ischemic dilated cardiomyopathy using next generation sequencing

Background

Non-ischemic dilated cardiomyopathy (NIDCM) is a genetic disorder that causes heart failure and life-threatening arrhythmia. However, there has been no study about the up-to-date genetic analysis for NIDCM in Korean. Therefore, we performed the genetic analysis of Korean NIDCM patients (pts) using next generation sequencing (NGS).

Methods

We analyzed clinical and echocardiographic data of 203 NIDCM in a single center from July 2017 to May 2020. All pts underwent NGS analysis with customized panel including 369 genes. Genetic variants were classified as pathogenic, likely pathogenic mutations or variants of uncertain significance regarding American College of Medical Genetics guideline.

Results

A total of 203 NIDCM pts (57±15 years old, 32.0% male, LVEF 28%) had NGS analysis. Thirty-seven (18.2%) pts had pathogenic or likely pathogenic mutations. The most prevalent mutated genes were TTN (n=16, 43.2%). TNNT2 (n=6, 16.2%), MYBPC3 (n=6, 16.2%) and MYH7 (n=3, 8.1%) mutated genes were common in the following order. The patients with positive panel mutation had no significant difference in initial LVEF (27% vs. 28%, p=0.216) and prevalence of atrial fibrillation (37.8% vs. 44.6%, p=0.454) compared with patients with negative panel mutation. During the median follow-up period of 40 months, there was no significant difference in composite outcome (all-cause death, heart transplantation, LVAD, heart failure re-admission, fatal arrhythmia) (35.3% vs. 32.2%, p=0.729) or presence of improved EF (≥10 points increase from baseline LVEF, and a second measurement of LVEF >40%) (41.2% vs. 50.0%, p=0.354) between the two groups.

Conclusion

This is the first study of NGS analysis in Korean NIDCM pts. We could find disease-related pathogenic or likely pathogenic mutations in 18.2% NIDCM patients. Further prospective, large study should be warranted to elucidate the effect of genetic mutation in clinical manifestation and prognosis of NIDCM in Korean population.

Funding Acknowledgement

Type of funding sources: None.

In-hospital glycemic variability and all-cause mortality in patients hospitalized with acute heart failure: analysis of the KorAHF registry

Introduction

Glycemic variability (GV) is known to be a poor prognostic marker in various diseases including cardiovascular disease.

Purpose

We investigated the association of GV with all-cause mortality in patients with acute heart failure (HF).

Methods

The Korean Acute Heart Failure registry enrolled patients hospitalized for acute HF from 2011 to 2014. Among survivors of the index hospitalization, we analyzed those who had ≥3 blood glucose measurements before discharge. Patients were divided into two groups based on their coefficient of variation (%CV) as an indicator of GV. We investigated all-cause mortality at 6 month and 1 year after discharge.

Results

The study analyzed 2,617 patients (median age 72 years, 53% male). During the median follow-up period of 11 months, 583 (22%) patients died. Compared to alive patients, patients who died had a significantly higher diabetes prevalence (46% vs. 41%, P=0.035) and higher %CV (31.0% vs. 27.5%, P<0.001). Kaplan-Meier curve analysis revealed that a high GV (%CV >21%) was associated with lower cumulative survival to all-cause death compared with a low GV (%CV ≤21%) (log-rank P<0.001). Multivariate Cox proportional analysis showed that a high GV was associated with an increased risk of 6-month mortality (hazard ratio [HR] 2.02, 95% CI 1.58–2.59, P<0.001) and one-year mortality (HR 1.57, 95% CI 1.29–1.91, P<0.001). The risk of high GV for one-year mortality was significant in non-diabetic patients (HR 1.98, 95% CI 1.55–2.53, P<0.001), but not in diabetic patients (HR 1.24, 95% CI 0.91–1.69, P=0.176; P-for-interaction=0.030).

Conclusion

A high GV (%CV >21%) before discharge was associated with all-cause mortality within 1 year, especially in non-diabetic acute HF patients.

Funding Acknowledgement

Type of funding sources: None.

Impact of proportionate versus disproportionate mitral regurgitation on acute procedural changes and clinical outcomes following transcatheter mitral valve repair

Background

Transcatheter mitral edge-to-edge repair (TEER) with MitraClip offers a less invasive alternative for patients with severe, symptomatic mitral regurgitation (MR) who are considered high risk for surgery. However, patient selection for TEER remains challenging given the variability in underlying MR pathology and current discordance among studies regarding predictors of procedural efficacy and clinical outcomes.

Purpose

This study aimed to assess acute procedural changes and long-term outcomes in patients who underwent TEER according to the proportionality of MR, defined as the ratio of the effective regurgitant orifice area (EROA) and left ventricular end-diastolic volume (LVEDV).

Methods

We analyzed patients who underwent TEER at our institution between 2014 and 2020 with available biplane left ventricular volume measurement. Relevant clinical comorbidities, demographics, and anthropometrics, along with pertinent pre- and post-procedural echocardiogram measurements, were obtained by review of the electronic medical record. The EROA to LVEDV index was calculated for all patients who were then stratified by quartiles. Patients with an EROA/LVEDV index in the lowest quartile were defined as having the most proportionate MR and those with an index in the highest quartile were defined as the most disproportionate MR. Baseline and post-TEER parameters were used to assess acute procedural and longitudinal outcomes.

Results

Baseline clinical and echocardiographic parameters of the 230 subjects according to quartile are shown in the table. Following TEER, there was a larger reduction in the left ventricular end-diastolic diameter and increased MR reduction with increasingly disproportionate MR (p=0.03 and p=0.05, respectively). The change in ejection fraction pre- versus post-TEER did not significantly differ across groups (p=0.64). Median follow up time was 1.7 (0.7–3.5) years; mortality occurred in 77 patients (33.5%) and heart failure hospitalizations occurred in 20 patients (8.7%) during follow up. No significant difference in all-cause mortality or post-procedural heart failure hospitalizations was identified across groups.

Conclusions

In our series, patients with proportionate MR were similarly symptomatic to those with disproportionate MR but had less severe MR with increased comorbidities. Post-TEER MR grade was similar between groups. Longer-term follow up in larger groups of patients is needed to determine the clinical implications.

Funding Acknowledgement

Type of funding sources: None.

The association between frailty and physical performance in elderly patients with heart failure

Background

Frailty is known to be an important prognostic indicator in heart failure (HF). The Korean version of the frail scale for Koreans (K-FRAIL) has been developed and verified. The purpose of this study is to analyze the relationship between the K-FRAIL scale and physical performance, including muscular fitness and aerobic capacity in patients with HF.

Methods

This study included 143 HF patients aged over 65 years from a single tertiary hospital. In these subjects, muscular fitness was assessed using the handgrip test and knee extensor strength measurement, and aerobic capacity was assessed by cardiopulmonary exercise test and 6-minute walk test. Frailty status was measured using the K-FRAIL questionnaire and was classified as robust (K-FRAIL scale: 0), prefrail (1–2), and frail (3–5).

Results

Mean age of participants with robust (N=37), prefrail (N=75), and frail (N=31) were 72.5, 73.5, and 76.3 years, respectively. There was no difference in sex and left ventricular ejection fraction (LVEF) among groups, but the estimated glomerular filtration rate (eGFR) was significantly lower as frailty status increased (75.6±17.2 vs. 70.0±20.5 vs. 56.1±23.7 mL/min/1.73 m2; P<0.001). Hand-grip strength and knee extensor muscle strength did not differ among groups. However, peak oxygen consumption (peak VO2; 22.8±5.0 vs. 19.3±4.6 vs. 16.9±4.7 mL/kg/min, P<0.001) and 6-min walk distance (458.4±68.2 vs. 404.5±92.3 vs. 311.2±120.5 m; p<0.001) significantly decreased according to frailty severity. In multivariate regression analysis adjusted for age, sex, haemoglobin, eGFR and LVEF, peak VO2 (β=−0.311; P=0.002) and 6-min walk distance (β=−0.384; P<0.001) showed a significant inverse association with the K-FRAIL scale. With the cut-off value from receiver-operating characteristic curve analysis, peak VO2 (hazard ratio, 5.08; p=0.023) and 6MWT (hazard ratio, 3.99; p=0.020) were independent predictor of frailty according to K-FRAIL scale.

Conclusion

In elderly HF patients, physical performance differs according to frailty status, peak VO2 and 6-min walk distance correlates with the K-FRAIL scale better than muscular fitness.

Funding Acknowledgement

Type of funding sources: None.

4 year outcomes in a prospective evaluation of transcatheter mitral valve-in-valve, valve-in-ring and valve-in-mitral annular calcification: results from the MITRAL trial

Background

The MITRAL Trial (Mitral Implantation of TRAnscatheter vaLves) evaluates the safety and feasibility of balloon-expandable aortic transcatheter heart valves in patients with severe mitral valve disease with mitral annular calcification (MAC), failed surgical rings or failed bioprostheses.

Purpose

We sought to evaluate 4-year outcomes of patients enrolled in the MITRAL trial.

Methods

This is a prospective study that enrolled 91 high surgical risk patients at 13 sites in the U.S. 30 patients underwent Mitral Valve-in-Valve (MViV), 30 Valve-in-Ring (MViR) and 31 Valve-in-MAC (ViMAC). 4-year outcomes of these patients were evaluated in this analysis. Primary endpoints and key serious adverse events including deaths were adjudicated by an independent Clinical Events Committee. Cardiac computed tomography (CT) and echocardiographic images were evaluated by independent CT and Echocardiographic Core Laboratories.

Results

Mean age was 74.3±8.9 years. Most patients undergoing MViV and ViMAC were female (MVIV=63.3%, MViR=36.7% and ViMAC=71%). Mean STS score was 9.2±6.6% (MViV 10.2±6.5%, MViR 8.7±4.7%, ViMAC=8.6±8.2%). All-cause mortality at 4 years was higher for ViMAC and MViR: MViV=6.9% (cardiovascular 3.4%), MViR=48.1% (cardiovascular 18.5%), ViMAC=51.9% (cardiovascular 29.6%), p=0.002 (Figure 1). At 4 years, all survivors had ≤1+ mitral regurgitation and most had none or trace mitral regurgitation (MViV=87.5, MViR=33.3% and ViMAC=100%). Mean mitral valve gradients remained stable (MViV=5.9±2.2 mmHg, MViR= 6.6±5.1 mmHg, ViMAC=5.1±1.0 mmHg), Figure 2. Most survivors experienced significant improvement of symptoms and were in NYHA class I-II at 4-year follow-up (MViV=78.9%, MViR=66.7% and ViMAC=66.7%).

Conclusions

MViV is associated with excellent outcomes at 4 years. MViR and ViMAC were associated with higher mortality at 4 years. However, most survivors in all groups experienced sustained improvement of symptoms and stable THV performance at 4 years. Whether survival bias had an impact on THV performance and improved symptoms at follow-up is not known and deserves further evaluation.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Unrestricted Research Grant from Edwards Lifesciences.

Impact of metformin on the all-cause mortality in diabetic patients hospitalized with acute heart failure

Introduction

Although the hypothesis that metformin is beneficial for diabetic patients with heart failure (HF) has been steadily raised, there have been no solid data on the efficacy of metformin in acute HF patients.

Purpose

We investigated the impact of metformin on all-cause mortality in hospitalized acute HF patients with type 2 diabetes.

Methods

The Korean Acute Heart Failure registry enrolled patients hospitalized for acute HF from 2011 to 2014. Among this cohort, we analyzed patients with diabetes. We investigated all-cause mortality at 1 year after discharge. Propensity score matching (1:1 matching) and Cox proportional hazard models were used to assess difference in all-cause mortality.

Results

The study analyzed 1,976 diabetic patients (median age 72 years, mean left ventricular ejection fraction (LVEF) 34%, 54.5% male). Among them, 712 (36%) patients were on metformin. After 1:1 propensity score matching, 1,424 patients (712 metformin users vs. 712 non-users) were analyzed. During the median follow-up period of 11 months, 146 (21%) metformin non-users died and 108 (15%) metformin users died. Kaplan-Meier curves showed a higher all-cause mortality rate in non-users than in metformin users (Log-rank P=0.0025). After adjustment for clinically relevant variables, metformin was associated with lower risk for all-cause mortality (HR 0.713, 95% CI 0.551–0.922, P=0.01). In subgroup analyses, metformin use was significantly associated with a lower all-cause mortality in higher eGFR group (≥60 ml/min/1.73 m2, HR 0.531, 95% CI 0.357–0.790, P=0.002), but not in lower eGFR group (<60 ml/min/1.73 m2, HR 0.905, 95% CI 0.643–1.275, P=0.569, P-for-interaction=0.033). There was no significant interaction of metformin use for all-cause mortality between the subgroups with LVEF ≤40% and LVEF >40% (P-for-interaction=0.906).

Conclusion

Metformin use was associated with a lower risk for 1-year all-cause mortality in diabetic acute HF patients, especially in high eGFR group.

Funding Acknowledgement

Type of funding sources: None.

Timing of reconstruction of the lower urinary tract in pediatric kidney transplant recipients: A CERTAIN multicenter analysis of current practice

BACKGROUND

Preexistent LUTD are considered a hostile environment, which might negatively impact KTx survival. In such cases, surgical reconstruction of the bladder is required. However, there is still disagreement on the optimal timing of the reconstruction procedure.

METHODS

This is a multicenter analysis of data from the CERTAIN Registry. Included were 62 children aged 8.18 ± 4.90 years, with LUTD. Study endpoints were the duration of initial posttransplant hospitalization, febrile UTIs, and a composite failure endpoint comprising decline of eGFR, graft loss, or death up to 5 years posttransplant. Outcome was compared to matched controls without bladder dysfunction.

RESULTS

Forty-one patients (66.1%) underwent pretransplant and 14 patients (22.6%) posttransplant reconstruction. Bladder augmentation was performed more frequently in the pretransplant (61%) than in the posttransplant group (21%, p = .013). Outcome in the pre- and posttransplant groups and in the subgroups of patients on pretransplant PD with major bladder surgery either pre- (n = 14) or posttransplant (n = 7) was comparable. Outcomes of the main study cohort and the matched control cohort (n = 119) were comparable during the first 4 years posttransplant; at year 5, there were more events of transplant dysfunction in the study cohort with LUTD than in controls (p = .03).

CONCLUSIONS

This multicenter analysis of the current practice of LUTD reconstruction in pediatric KTx recipients shows that pre- or posttransplant surgical reconstruction of the lower urinary tract is associated with a comparable 5-year outcome.

Relationship between age at initiation of cysteamine treatment, adherence with therapy, and glomerular kidney function in infantile nephropathic cystinosis

Infantile nephropathic cystinosis, due to impaired transport of cystine out of lysosomes, occurs with an incidence of 1 in 100-200,000 live births. It is characterized by renal Fanconi syndrome in the first year of life and glomerular dysfunction progression to end-stage kidney disease by approximately 10 years of age. Treatment with oral cysteamine therapy helps preserve glomerular function, but affected individuals eventually require kidney replacement therapy. This is because glomerular damage had already occurred by the time a child is diagnosed with cystinosis, typically in the second year of life. We performed a retrospective multicenter study to investigate the impact of initiating cysteamine treatment within the first 2 months of life in some infants and comparing two different levels of adherence in patients diagnosed at the typical age. We collected 3983 data points from 55 patients born between 1997 and 2020; 52 patients with 1592 data points could be further evaluated. These data were first analyzed by dividing the patient cohort into three groups: (i) standard treatment start with good adherence, (ii) standard treatment start with less good adherence, and (iii) early treatment start. At every age, mean estimated glomerular filtration rate (eGFR) was higher in early-treated patients than in later-treated patients. Second, a generalized additive mixed model (GAMM) was applied showing that patients with initiation of treatment before 2 months of age are expected to have a 34 ml/min/1.73 m² higher eGFR than patients with later treatment start while controlling for adherence and patients' age. These data strongly suggest that oral cysteamine treatment initiated within 2 months of birth preserves kidney function in infantile nephropathic cystinosis and provide evidence of the utility of newborn screening for this disease.

Beneficial effects of starting oral cysteamine treatment in the first 2 months of life on glomerular and tubular kidney function in infantile nephropathic cystinosis

Nephropathic cystinosis is a rare lysosomal storage disease whose basic defect, impaired transport of cystine out of lysosomes, results in intracellular cystine storage. Affected individuals exhibit renal Fanconi Syndrome in infancy, end-stage kidney disease at approximately 10 years of age, and many other systemic complications. Oral cysteamine therapy mitigates the detrimental effects on glomerular function and prevents most of the late complications of the disease but has not shown benefit with respect to the early tubular damage of cystinosis. This is because cystinosis is generally diagnosed in the second year of life, after the damage to kidney tubular function has already occurred. We longitudinally evaluated 6 infants diagnosed and treated with cysteamine from before 2 months of age. The 4 infants with good compliance with cysteamine and consistently low leucocyte cystine levels maintained normal eGFR values, exhibited only minor degrees of renal Fanconi Syndrome, and maintained normal serum levels of potassium, bicarbonate, phosphate, and calcium without electrolyte or mineral supplementation through 2, 4, 10 and 16 years of age. Thus, renal Fanconi syndrome can be attenuated by early administration of cysteamine and renew the call for molecular-based newborn screening for cystinosis.

Effects of an exogenous enzyme preparation extracted from a mixed culture of Aspergillus spp. on lactational performance, metabolism, and digestibility in primiparous and multiparous cows

The objective of this study was to investigate the effects of an exogenous enzyme preparation from Aspergillus oryzae and Aspergillus niger on lactational performance of dairy cows. Forty-eight Holstein cows (32 primiparous and 16 multiparous) averaging (± SD) 36.3 ± 8.7 kg/d milk yield and 141 ± 52 d in milk were enrolled in a 10-wk randomized complete block design experiment (total of 24 blocks) and assigned to 1 of 2 treatments: basal diet, no enzyme supplementation (CON) or the basal diet supplemented with 4.2 g/kg dry matter intake (DMI) of an exogenous enzyme preparation containing amylolytic and fibrolytic activities (ENZ). After a 2-wk covariate period, premixes with the enzyme preparation or control were top-dressed daily by mixing with approximately 500 g of total mixed ration. Production data were collected daily and averaged by week. Milk samples were collected every other week, and milk composition was averaged by week. Blood, fecal, and urine samples were collected over 2 consecutive days at 0, 4, 8, 12, and 36 h after feeding during the last week of the experiment. Compared with CON, cows fed ENZ tended to increase DMI and had increased milk concentrations of true protein, lactose, and other solids. Milk fat content tended to be higher in CON cows. A treatment × parity interaction was found for some of the production variables. Primiparous cows receiving ENZ had greater yields of milk, energy-corrected milk, milk true protein, and lactose compared with CON primiparous cows; these production variables did not differ between treatments for multiparous cows. Intake and total-tract digestibility of nutrients did not differ between treatments. Concentrations of blood glucose and total fatty acids were not affected by ENZ supplementation, but β-hydroxybutyrate concentration tended to be greater in ENZ cows. Overall, the exogenous enzyme preparation used in this study increased milk protein and lactose concentrations in all cows, and milk production in primiparous but not multiparous cows. The differential production response between primiparous and multiparous cows was likely a result of a greater increase in DMI with ENZ supplementation in the younger animals.

Specific CD4+ T Cell Responses to Ancestral SARS-CoV-2 in Children Increase With Age and Show Cross-Reactivity to Beta Variant

SARS-CoV-2 is still a major burden for global health despite effective vaccines. With the reduction of social distancing measures, infection rates are increasing in children, while data on the pediatric immune response to SARS-CoV-2 infection is still lacking. Although the typical disease course in children has been mild, emerging variants may present new challenges in this age group. Peripheral blood mononuclear cells (PBMC) from 51 convalescent children, 24 seronegative siblings from early 2020, and 51 unexposed controls were stimulated with SARS-CoV-2-derived peptide MegaPools from the ancestral and beta variants. Flow cytometric determination of activation-induced markers and secreted cytokines were used to quantify the CD4+ T cell response. The average time after infection was over 80 days. CD4+ T cell responses were detected in 61% of convalescent children and were markedly reduced in preschool children. Cross-reactive T cells for the SARS-CoV-2 beta variant were identified in 45% of cases after infection with an ancestral SARS-CoV-2 variant. The CD4+ T cell response was accompanied most predominantly by IFN-γ and Granzyme B secretion. An antiviral CD4+ T cell response was present in children after ancestral SARS-CoV-2 infection, which was reduced in the youngest age group. We detected significant cross-reactivity of CD4+ T cell responses to the more recently evolved immune-escaping beta variant. Our findings have epidemiologic relevance for children regarding novel viral variants of concern and vaccination efforts.

ScoMorphoFISH: A deep learning enabled toolbox for single-cell single-mRNA quantification and correlative (ultra-)morphometry

Increasing the information depth of single kidney biopsies can improve diagnostic precision, personalized medicine and accelerate basic kidney research. Until now, information on mRNA abundance and morphologic analysis has been obtained from different samples, missing out on the spatial context and single‐cell correlation of findings. Herein, we present scoMorphoFISH, a modular toolbox to obtain spatial single‐cell single‐mRNA expression data from routinely generated kidney biopsies. Deep learning was used to virtually dissect tissue sections in tissue compartments and cell types to which single‐cell expression data were assigned. Furthermore, we show correlative and spatial single‐cell expression quantification with super‐resolved podocyte foot process morphometry. In contrast to bulk analysis methods, this approach will help to identify local transcription changes even in less frequent kidney cell types on a spatial single‐cell level with single‐mRNA resolution. Using this method, we demonstrate that ACE2 can be locally upregulated in podocytes upon injury. In a patient suffering from COVID‐19‐associated collapsing FSGS, ACE2 expression levels were correlated with intracellular SARS‐CoV‐2 abundance. As this method performs well with standard formalin‐fixed paraffin‐embedded samples and we provide pretrained deep learning networks embedded in a comprehensive image analysis workflow, this method can be applied immediately in a variety of settings.

Patients With Infantile Nephropathic Cystinosis in Germany and Austria: A Retrospective Cohort Study

Background

Infantile nephropathic cystinosis (INC) is a rare lysosomal storage disorder resulting in progressive chronic kidney disease (CKD) and a variety of extrarenal manifestations. This orphan disease remains a challenge for patients, their families and health care providers. There is currently no comprehensive study on patients' clinical course in Germany and Austria.

Methods

A retrospective cohort study including 74 patients at eleven centers of care was conducted. Data on time of diagnosis, CKD stage, leukocyte cystine levels (LCL), extrarenal manifestations, and treatment was collected from medical charts and subsequently analyzed using explorative statistics. Age at initiation of kidney replacement therapy (KRT) was evaluated by Kaplan-Meier analyses for different groups of patients.

Results

Patients were diagnosed at a median age of 15 months (IQR: 10-29, range: 0-110), more recent year of birth was not associated with earlier diagnosis. Oral cystine-depleting therapy (i.e., cysteamine) was prescribed at a median dose of 1.26 g/m² per day (IQR: 1.03-1.48, range: 0.22-1.99). 69.2% of all 198 LCL measurements of 67 patients were within the desired target range (≤ 1 nmol cystine/mg protein). Median time-averaged LCLs per patient (n = 65) amounted to 0.57 nmol cystine/mg protein (IQR: 0.33-0.98, range: 0.07-3.13) when considering only values at least 1 year after initiation of therapy. The overall median height of 242 measurements of 68 patients was at the 7^th percentile (IQR: 1-25, range: 1-99). 40.5% of the values were ≤ the 3^rd percentile. Patient sex and year of birth were not associated with age at initiation of KRT, but patients diagnosed before the age of 18 months required KRT significantly later than those patients diagnosed at the age of ≥ 18 months (p = 0.033): median renal survival was 21 years (95% CI: 16, -) vs. 13 years (95% CI, 10, -), respectively.

Conclusion

Early diagnosis and initiation of cystine depleting therapy is important for renal survival in children with INC. Cysteamine doses and LCL showed that treatment in this cohort met international standards although there is great interindividual variety. Patient growth and other aspects of the disease should be managed more effectively in the future.

FC088: Molecular and Functional Characterization of the Mesothelial and Endothelial Cell Barrier in Health, Ckd and Peritoneal Dialysis

BACKGROUND AND AIMS

Tight junctions (TJ) and transcellular ion channels and transporters define solute transport characteristics across cellular barriers, which is of particular interest in patients on peritoneal dialysis (PD). Little is known about their cell specific expression, and regulation in PD. We studied their expression in human endothelial and mesothelial cell lines and in paediatric peritoneal tissues.

METHOD

In vitro, polarized primary human peritoneal mesothelial cells (HPMC), immortalized mesothelial cells (MeT-5A), human umbilical vein endothelial cells (HUVEC) and human capillary microvascular endothelial cells (HCMEC) underwent RNA sequencing, and gene enrichment analysis (GSEA, ClueGO/Cluepedia) for functional annotation. Key findings were reconfirmed by western blotting and confocal laser scanning immunofluorescence microscopy. Transepithelial electrical resistance (TER) and permeability fluxes of fluorescent 4-, 10- and 70-kDa dextran were measured in Transwells. Ex vivo, whole transcriptome and proteome data from microdissected omental arterioles were used for targeted pathway analysis in non-CKD children, chronic kidney disease (CKD5) and on PD with low and high glucose degradation product (GDP) content (n = 6/group). Mesothelial and endothelial peritoneal solute transporting proteins were quantified in parietal peritoneum of independent paediatric non-CKD, CKD5 and PD cohorts by digital immunohistochemistry.

RESULTS

A total of 9853 of 12 760 transcripts were common between all four cell lines. A total of 631 transcripts were MeT-5A, 366 HPMC, 99 HUVEC and 87 HCMEC specific. Next to the tissue origin and transformation status, the transcripts reflected major differences in extracellular matrix, glycocalyx and adhesion organization between HCMEC and HUVEC, and extracellular matrix, migration, growth factor and immune response between HPMC and MeT-5A cells. While total counts of cell junction, transmembrane and endocytosis related transcripts were similar among cell lines, the specific TJ, transmembrane and endocytosis related transcript patterns, differed substantially between endothelial and mesothelial cells. Of the functionally well described sealing TJs, claudin (CLDN)1 was expressed in mesothelial cells, and CLDN5 in endothelial cells. Findings were reconfirmed by western blotting and immunofluorescence staining. Functionally, transepithelial resistance (TER) was 50% lower for HCMEC compared to HPMC, MeT-5A and HUVEC; 4-, 10- and 70-kDa dextran permeability was increased in HCMEC.

Ex vivo, human arteriolar pathway analysis demonstrated upregulation of paracellular transport-related pathways in CKD5 versus non-CKD patients on protein level. Compared to CKD5, low GDP PD upregulated and high GDP PD downregulated these pathways on the transcriptome and protein levels. Transcellular transporter pathway regulation was variable.

In the parietal peritoneum the endothelial surface area for transport was age dependently 1.5–2-fold higher than the mesothelial surface area and the ratio markedly increased with low GDP PD. Validation in parietal peritoneal tissues, reconfirmed arteriolar sealing TJ regulation. Arteriolar CLDN2, a paracellular pore forming cation and water transporter, correlated with D/PCreatinine (r = 0.58) and D/D0Glucose (r = –0.62), mesothelial pore forming cation transporter CLDN15 with D/PCreatinine (r = 0.57) and D/D0Glucose (–0.66). Transcellular transporters for sodium, glucose and phosphate were hardly affected by PD; phosphate transporter PIT1 abundance correlated with serum phosphate (r = –0.48).

CONCLUSION

We provide the first comprehensive analysis of the peritoneal paracellular and transcellular determinants of solute transporters and its regulation by CKD and PD. Mesothelial and endothelial cell barrier sealing and transporter abundance differed substantially, and associated with PD membrane function, with functional data suggesting a key role of both the mesothelial and endothelial cell barrier.

Characterization of interlimb interaction via transcutaneous spinal stimulation of cervical and lumbar spinal enlargements

The use of transcutaneous electrical spinal stimulation (TSS) to modulate sensorimotor networks after neurological insult has garnered much attention from both researchers and clinicians in recent years. Although many different stimulation paradigms have been reported, the interlimb effects of these neuromodulation techniques have been little studied. The effects of multisite TSS on interlimb sensorimotor function are of particular interest in the context of neurorehabilitation, as these networks have been shown to be important for functional recovery after neurological insult. The present study utilized a condition-test paradigm to investigate the effects of interenlargement TSS on spinal motor excitability in both cervical and lumbosacral motor pools. Additionally, comparison was made between the conditioning effects of lumbosacral and cervical TSS and peripheral stimulation of the fibular nerve and ulnar nerve, respectively. In 16/16 supine, relaxed participants, facilitation of spinally evoked motor responses (sEMRs) in arm muscles was seen in response to lumbosacral TSS or fibular nerve stimulation, whereas facilitation of sEMRs in leg muscles was seen in response to cervical TSS or ulnar nerve stimulation. The decreased latency between TSS- and peripheral nerve-evoked conditioning implicates interlimb networks in the observed facilitation of motor output. The results demonstrate the ability of multisite TSS to engage interlimb networks, resulting in the bidirectional influence of cervical and lumbosacral motor output. The engagement of interlimb networks via TSS of the cervical and lumbosacral enlargements represents a feasible method for engaging spinal sensorimotor networks in clinical populations with compromised motor function.NEW & NOTEWORTHY Bidirectional interlimb modulation of spinal motor excitability can be evoked by transcutaneous spinal stimulation over the cervical and lumbosacral enlargements. Multisite transcutaneous spinal stimulation engages spinal sensorimotor networks thought to be important in the recovery of function after spinal cord injury.

Body growth, upper arm fat area, and clinical parameters in children with nephropathic cystinosis compared with other pediatric chronic kidney disease entities

Children with infantile nephropathic cystinosis (INC), an inherited lysosomal storage disease resulting in cystine accumulation in all body cells, are prone to progressive chronic kidney disease (CKD), impaired growth and reduced weight gain; however, systematic anthropometric analyses are lacking. In this prospective multicenter study we investigated linear growth, body proportion, body mass index (BMI), upper arm fat area (UFA) and biochemical parameters in 43 pediatric INC patients with CKD stages 1 to 5 and 49 age-matched CKD controls, with 193 annual measurements. INC patients showed more impaired height than CKD controls (-1.8 vs -0.7 z-score; P < .001), despite adequate cysteamine therapy, treatment for Fanconi syndrome and more frequent use of growth hormone. Only the youngest INC patients shared the same body pattern with CKD controls characterized by preferential impairment of leg length and rather preserved trunk length. In late-prepuberty, body pattern changed only in INC patients due to improved leg growth and more impaired trunk length. Mean UFA z-score in INC patients was slightly reduced in early childhood and progressively decreased thereafter reaching -0.8 z-score in adolescence, while CKD controls showed a steady increase in standardized BMI and UFA especially during adolescent age. Menarche in female INC patients was significantly delayed compared to CKD controls. Our data indicate that with age and progression of disease, pediatric INC patients undergo unique changes of body growth and fat stores that are distinct from those with CKD stemming from other causes, suggesting other factors apart from CKD to contribute to this development. Pediatric patients with infantile nephropathic cystinosis display more severe impaired linear growth than other peer CKD patients, despite of cysteamine treatment, supplementation for Fanconi syndrome, and more frequent use of growth hormone, with a distinct change of body proportions and overall lower body fat.

Maternal versus paternal living kidney transplant donation is associated with lower rejection in young pediatric recipients: A Collaborative Transplant Study report

BACKGROUND

Approximately 1700 children per year with end-stage kidney disease undergo kidney transplantation in Europe and the United States of America; 30%-50% are living donor kidney transplantations. There may be immunological differences between paternal and maternal donors due to transplacental exchange of cells between the mother and fetus during pregnancy leading to microchimerism. We investigated whether the outcome of living-related kidney transplantation in young children is different after maternal compared with paternal organ donation.

METHODS

Using the international Collaborative Transplant Study (CTS) database, we analyzed epidemiological data of 7247 children and adolescents aged <18 years who had received a kidney transplant from either mother or father. Risk of treated rejection episodes and death-censored graft failure were computed using the Kaplan-Meier method and multivariable Cox regression.

RESULTS

In the recipient age group 1-4 years, the rate of treated rejection episodes in recipients of kidneys from maternal donors (N = 195) during the first 2 years post-transplant was significantly lower (hazard ratio HR = 0.47, p = .004) than in patients receiving kidneys from paternal donors (N = 179). This association between donor sex and risk of treated rejections was not observed in children aged 5-9 years. The 5-year death-censored graft survival in children aged 1-4 years with a maternal or paternal donor was comparable.

CONCLUSIONS

Maternal kidney donation in young pediatric renal transplant recipients is associated with an approximately 50% lower rate of treated rejection than paternal kidney donation. Whether this phenomenon is due to maternal microchimerism-induced donor-specific hyporesponsiveness must be evaluated in prospective mechanistic studies.

Factors associated with treatment escalation among MS specialists and general neurologists: Results from an International cojoint study

BACKGROUND

Previous studies in multiple sclerosis (MS) showed that therapeutic inertia (TI) affects 60-90% of neurologists and up to 25% of daily treatment decisions. The objective of this study was to determine the most common factors and attribute levels associated with decisions to treatment escalation in an international study in MS care.

METHODS

300 neurologists with MS expertise from 20 countries were invited to participate. Participants were presented with 12 pairs of simulated MS patient profiles described by 13 clinically relevant factors. We used disaggregated discrete choice experiments to estimate the weight of factors and attributes affecting physicians' decisions when considering treatment selection. Participants were asked to select the ideal candidate for treatment escalation from modest to higher-efficacy therapies.

RESULTS

Overall, 229 neurologists completed the study (completion rate: 76.3%). The top 3 weighted factors associated with treatment escalation were: previous relapses (20%), baseline expanded disability status scale [EDSS] (18%), and MRI activity (13%). Patient demographics and desire for pregnancy had a modest influence (≤ 3%). We observed differences in the weight of factors associated with treatment escalation between MS specialists and non-MS specialists.

CONCLUSIONS

Our results provide critical information on factors influencing neurologists' treatment decisions and should be applied to continuing medical education strategies.

Suspected human intravenous immunoglobulin-induced acute haemolytic anaemia in a dog

A 2-year-old mixed breed dog presented with a 1-year history of crust and erosion on the nasal planum. Because histopathological examination revealed ruptured intraepidermal pustules and superficial dermal inflammation, the dog was diagnosed with pemphigus foliaceus. Human intravenous immunoglobulin was administered in two consecutive doses of 0.5 g/kg/day due to poor therapeutic response to previous immunosuppressive therapy. From Day 3 after the first dose of human intravenous immunoglobulin, tachypnoea, pale mucous membrane, haemoglobinuria and haemoglobinemia were observed, thus confirming haemolytic anaemia. Other drug-induced haemolytic anaemias were excluded because no additional drugs had been administered before the haemolysis occurred. Immune-mediated haemolytic anaemia was also excluded because the direct antiglobulin test was negative. Two transfusions were performed, and haemolysis was not observed from Day 4 of haemolytic anaemia onset. In conclusion, human intravenous immunoglobulin-induced haemolytic anaemia should be considered in dogs that develop haemolysis following the administration of human intravenous immunoglobulin.

Comparing noninvasive sampling techniques with standard cannula sampling method for ruminal microbial analysis

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Ruminal cannula is the gold standard for sampling rumen contents but is limited to few animals.

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Noninvasive methods are needed as proxy for cannula to enable sampling larger numbers of cows.

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Saliva, rumination bolus, tube-derived rumen samples, and feces were compared with cannula samples.

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Microbial community in the solid fraction of tube samples mirrored that of cannula samples.

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Rumination bolus may serve as a proxy for cannula samples under certain conditions.

Rumen microbes play an important role in the conversion of indigestible plant material to energy and protein in dairy cows. Sampling for ruminal contents via cannula is considered the gold standard technique for microbial analysis, but the technique requires ruminally cannulated animals and specialized animal facilities. The purpose of this study was to determine whether other sampling methods and locations along the digestive tract may serve as noninvasive proxies to the cannula method for microbial analysis. Six ruminally cannulated lactating Holstein dairy cows were adapted to a standard total mixed ration for 2 wk and sampled during the third week. Sampling locations and methods included salivary content, rumination bolus (regurgitated digesta collected from the cow's mouth), feces, and rumen contents via stomach tube and cannula. Stomach tube and cannula samples differ in proportions of solid and liquid material and were therefore separated into whole (as collected), liquid, and solid fractions. Samples were collected at 0 (before feeding), 2, 4, 6, 8, and 12 h after feeding over 2 d. All samples were extracted for total genomic DNA and selected samples for metabolically active DNA (RNA), PCR-amplified for the V1-V2 region of the 16S rRNA bacterial gene, and analyzed for bacterial diversity using the QIIME2 pipeline followed by statistical analysis in R (https://www.R-project.org/). In DNA-based analysis, at the community level, saliva, rumination bolus, and fecal samples clustered in separate groups, whereas all fractions of stomach tube and cannula samples clustered together, indicating that microbial communities of stomach tube and cannula samples were homogeneous. Rumination bolus samples at 6, 8, and 12 h after feeding clustered with stomach tube and cannula samples, indicating that rumination bolus samples may be an alternative for cannula samples; however, time of sampling is critical for sampling of bolus digesta. Results of the RNA-based analysis of rumination bolus samples and solid samples from cannula and stomach tube at 0 and 6 h after feeding were similar. We concluded that the solid fraction of samples obtained via the stomach tube method may serve as a proxy for the solid fraction of whole ruminal contents obtained via cannula for DNA-based microbial investigations. Both rumination bolus and stomach tube solid samples may serve as proxies for cannula solid samples for RNA-based microbial analysis.