Multicenter study on the genetics of glomerular diseases among southeast and south Asians: Deciphering Diversities - Renal Asian Genetics Network (DRAGoN).

Multinational studies have reported monogenic etiologies in 25%-30% of children with steroid-resistant nephrotic syndrome. Such large studies are lacking in Asia. We established Deciphering Diversities: Renal Asian Genetics Network (DRAGoN) and aimed to describe the genetic and clinical spectrums in Asians. We prospectively studied a cohort of 183 probands with suspected genetic glomerulopathies from South and Southeast Asia, of whom 17% had positive family history. Using multi-gene panel sequencing, we detected pathogenic variants in 26 (14%) probands, of whom one-third had COL4A4 or COL4A5 variants (n = 9, 5%). Of those with COL4A5 defects, only 25% had features suggestive of Alport syndrome. Besides traditional predictors for genetic disease (positive family history and extrarenal malformations), we identified novel predictors, namely older age (6.2 vs. 2.4 years; p = 0.001), hematuria (OR 5.6; 95% CI 2.1-14.8; p < 0.001), and proteinuria in the absence of nephrotic syndrome (OR 4.6; 95% CI 1.8-11.8; p = 0.001) at first manifestation. Among patients who first presented with proteinuria without nephrotic syndrome, the genetic diagnostic rates were >60% when a second risk factor (positive family history or extrarenal manifestation) co-existed. The genetic spectrum of glomerulopathies appears different in Asia. Collagen IV genes may be included in sequencing panels even when suggestive clinical features are absent.

Vascular Access Choice, Complications, and Outcomes in Children on Maintenance Hemodialysis: Findings From the International Pediatric Hemodialysis Network (IPHN) Registry.

RATIONALE & OBJECTIVE: Arteriovenous fistulas (AVFs) have been recommended as the preferred vascular access for pediatric patients on maintenance hemodialysis (HD), but data comparing AVFs with other access types are scant. We studied vascular access choice, placement, complications, and outcomes in children. STUDY DESIGN: Prospective observational cohort study. SETTING & PARTICIPANTS: 552 children and adolescents from 27 countries on maintenance HD followed up prospectively by the International Pediatric HD Network (IPHN) Registry between 2012 and 2017. PREDICTOR: Type of vascular access: AVF, central venous catheter (CVC), or arteriovenous graft. OUTCOME: Infectious and noninfectious vascular access complication rates, dialysis performance, biochemical and hematologic parameters, and clinical outcomes. ANALYTICAL APPROACH: Univariate and multivariable linear mixed models, generalized linear mixed models, and proportional hazards models; cumulative incidence functions. RESULTS: During 314 cumulative patient-years, 628 CVCs, 225 AVFs, and 17 arteriovenous grafts were placed. One-third of the children with an AVF required a temporary CVC until fistula maturation. Vascular access choice was associated with age and expectations for early transplantation. There was a 3-fold higher living related transplantation rate and lower median time to transplantation of 14 (IQR, 6-23) versus 20 (IQR, 14-36) months with CVCs compared with AVFs. Higher blood flow rates and Kt/Vurea were achieved with AVFs than with CVCs. Infectious complications were reported only with CVCs (1.3/1,000 catheter-days) and required vascular access replacement in 47%. CVC dysfunction rates were 2.5/1,000 catheter-days compared to 1.2/1,000 fistula-days. CVCs required 82% more revisions and almost 3-fold more vascular access replacements to a different site than AVFs (P<0.001). LIMITATIONS: Clinical rather than population-based data. CONCLUSIONS: CVCs are the predominant vascular access choice in children receiving HD within the IPHN. Age-related anatomical limitations and expected early living related transplantation were associated with CVC use. CVCs were associated with poorer dialysis efficacy, higher complication rates, and more frequent need for vascular access replacement. Such findings call for a re-evaluation of pediatric CVC use and practices.

Neutral pH and low-glucose degradation product dialysis fluids induce major early alterations of the peritoneal membrane in children on peritoneal dialysis.

The effect of peritoneal dialysates with low-glucose degradation products on peritoneal membrane morphology is largely unknown, with functional relevancy predominantly derived from experimental studies. To investigate this, we performed automated quantitative histomorphometry and molecular analyses on 256 standardized peritoneal and 172 omental specimens from 56 children with normal renal function, 90 children with end-stage kidney disease at time of catheter insertion, and 82 children undergoing peritoneal dialysis using dialysates with low-glucose degradation products. Follow-up biopsies were obtained from 24 children after a median peritoneal dialysis of 13 months. Prior to dialysis, mild parietal peritoneal inflammation, epithelial-mesenchymal transition and vasculopathy were present. After up to six and 12 months of peritoneal dialysis, blood microvessel density was 110 and 93% higher, endothelial surface area per peritoneal volume 137 and 95% greater, and submesothelial thickness 23 and 58% greater, respectively. Subsequent peritoneal changes were less pronounced. Mesothelial cell coverage was lower and vasculopathy advanced, whereas lymphatic vessel density was unchanged. Morphological changes were accompanied by early fibroblast activation, leukocyte and macrophage infiltration, diffuse podoplanin presence, epithelial mesenchymal transdifferentiation, and by increased proangiogenic and profibrotic cytokine abundance. These transformative changes were confirmed by intraindividual comparisons. Peritoneal microvascular density correlated with peritoneal small-molecular transport function by uni- and multivariate analysis. Thus, in children on peritoneal dialysis neutral pH dialysates containing low-glucose degradation products induce early peritoneal inflammation, fibroblast activation, epithelial-mesenchymal transition and marked angiogenesis, which determines the PD membrane transport function.

The Cost and Utility of Renal Transplantation in Malaysia.

UNLABELLED: Kidney transplantation is the optimal therapy for the majority of patients with end-stage renal disease. However, the cost and health outcomes of transplantation have not been assessed in a middle-income nation with a low volume of transplantation, such as Malaysia. AIM AND METHODS: This study used microcosting methods to determine the cost and health outcomes of living and deceased donor kidney transplantation in adult and pediatric recipients. The perspective used was from the Ministry of Health Malaysia. Cost-effectiveness measures were cost per life year (LY) and cost per quality-adjusted LYs. The time horizon was the lifetime of the transplant recipient from transplant to death. RESULTS: Records of 206 KT recipients (118 adults and 88 children) were obtained for microcosting. In adults, discounted cost per LY was US $8609(Malaysian Ringgit [RM]29 482) and US $13 209(RM45 234) for living-donor kidney transplant (LKT) and deceased donor kidney transplant (DKT), respectively, whereas in children, it was US $10 485(RM35 905) and US $14 985(RM51 317), respectively. Cost per quality-adjusted LY in adults was US $8826 (RM30 224) for LKT and US $13 592(RM46 546) for DKT. Total lifetime discounted costs of adult transplants were US $119 702 (RM409 921) for LKT, US $147 152 (RM503 922) for DKT. Total costs for pediatric transplants were US $154 841(RM530 252) and US $159 313(RM545 566) for the 2 categories respectively. CONCLUSIONS: Both LKT and DKT are economically favorable for Malaysian adult and pediatric patients with ESRD and result in improvement in quality of life.