Publications by authors named "Kar-Hui Ng"

Introduction The early diagnosis and appropriate treatment of monogenic glomerular diseases can reduce kidney failure, avoid unnecessary investigations such as kidney biopsies and ineffective treatment with immunosuppressants, guide transplant decisions, and inform the genetic risks of their family members. Yet, genetic testing for kidney disease is under-utilized in Singapore. We aimed to implement a nephrologist-led genetic service and evaluate the acceptance, adoption, utility and cost-effectiveness of genetic testing for monogenic glomerular disease in Singapore.

View Article and Find Full Text PDF

Introduction: Health-related quality of life (HRQoL) studies demonstrate the impact of end-stage renal disease (ESRD) on the physical and psychosocial development of children. While several instruments are used to measure HRQoL, few have standardized domains specific to pediatric ESRD. This review examines current evidence on self and proxy-reported HRQoL among pediatric patients with ESRD, based on the Pediatric Quality of Life Inventory (PedsQL) questionnaires.

View Article and Find Full Text PDF

Long-term humoral immunity is mediated by short-lived plasma cells (replenished by memory B cells) and long-lived plasma cells. Their relative contributions are uncertain for immunity to SARS-CoV-2, especially given the widespread use of novel mRNA vaccines. Yet, this has far-reaching implications in terms of the need for regular booster doses in the general population and perhaps even revaccination in patients receiving B cell-depleting therapy.

View Article and Find Full Text PDF

Advances in kidney genomics in the past 20 years has opened the door for more precise diagnosis of kidney disease and identification of new and specific therapeutic agents. Despite these advances, an imbalance exists between low-resource and affluent regions of the world. Individuals of European ancestry from the United States, United Kingdom, and Iceland account for 16% of the world's population, but represent more than 80% of all genome-wide association studies.

View Article and Find Full Text PDF

Background: Nephrotic syndrome (NS) is a common pediatric kidney disease, yet current treatments for complicated NS are only partially effective and have significant toxicity. There is no Food and Drug Administration (FDA)- or European Medicines Agency (EMA)-approved safe and effective treatment for NS. Thiazolidinediones (TZDs) have been shown to reduce proteinuria in both diabetic and non-diabetic kidney disease and in preclinical studies to directly protect podocytes from injury and reduce proteinuria.

View Article and Find Full Text PDF
Article Synopsis
  • Primary Coenzyme Q10 (CoQ) deficiency is an ultra-rare genetic disorder that often results in nephrotic syndrome and is linked to mutations in specific genes.
  • A global study of 116 patients showed that oral CoQ supplementation can lead to a significant reduction in proteinuria (by 88% at 12 months) and better preservation of kidney function over time.
  • The findings suggest that all patients with primary CoQ deficiency should receive early and long-term CoQ supplementation to slow kidney disease progression and protect other organs from damage, with few mild side effects reported.
View Article and Find Full Text PDF

Primary Coenzyme Q10 deficiency is a rare mitochondriopathy with a wide spectrum of organ involvement, including steroid-resistant nephrotic syndrome mainly associated with disease-causing variants in the genes COQ2, COQ6 or COQ8B. We performed a systematic literature review, PodoNet, mitoNET, and CCGKDD registries queries and an online survey, collecting comprehensive clinical and genetic data of 251 patients spanning 173 published (47 updated) and 78 new cases. Kidney disease was first diagnosed at median age 1.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Rituximab is an important second line therapy in difficult nephrotic syndrome (NS), especially given toxicity of long-term glucocorticoid or calcineurin inhibitor (CNI) use. However, clinical response to rituximab is heterogenous. We hypothesized that this was underpinned by immunological differences amongst patients with NS.

View Article and Find Full Text PDF

Background: Decline in skills and knowledge among patients and/or caregivers contributes to peritoneal-dialysis (PD)-related peritonitis. Re-training is important, but no guidelines exist. We describe the implementation of a structured re-training program to decrease peritonitis rates.

View Article and Find Full Text PDF

Peritonitis- and catheter-related infections due to nontuberculous mycobacteria (NTM) including have been reported among adults on peritoneal dialysis (PD). There is no recommended antimicrobial regimen for the treatment of peritonitis. Clofazimine has emerged as an important adjuvant antimicrobial treatment of lung infection.

View Article and Find Full Text PDF

Circulating factors have been implicated in the pathogenesis of minimal change disease (MCD), and may have direct effects on cholesterol metabolism. This study investigated the pathogenesis of hypercholesterolemia in an IL-13 overexpression rat model of MCD prior to the onset of proteinuria, so as to establish the direct contribution of IL-13, especially with regard to hepatic cholesterol handling. In this model of MCD, the temporal relationship between hypercholesterolemia and proteinuria was first identified.

View Article and Find Full Text PDF

Detailed understanding of the roles of humoral and cellular immune responses in sterilizing dengue virus (DENV) infection in humans is required to inform effective vaccine development. We report an unusual case of persistent DENV infection in a lymphopenic renal transplant recipient who was therapeutically immunosuppressed to prevent organ rejection. Following resolution of symptomatic dengue, this patient remained positive for DENV3 RNA in the blood for 4 months and viruric up to 9 months post-infection despite demonstrable levels of serum neutralizing antibodies throughout this period.

View Article and Find Full Text PDF

Background: A lack of consensus exists as to the timing of kidney biopsy in children with steroid-dependent nephrotic syndrome (SDNS) where minimal change disease (MCD) predominates. This study aimed at examining the applicability of a biomarker-assisted risk score model to select SDNS patients at high risk of focal segmental glomerulosclerosis (FSGS) for biopsy.

Methods: Fifty-five patients with SDNS and biopsy-proven MCD (n = 40) or FSGS (n = 15) were studied.

View Article and Find Full Text PDF

Epigenetic regulation of gene expression has a crucial role allowing for the self-renewal and differentiation of stem and progenitor populations during organogenesis. The mammalian kidney maintains a population of self-renewing stem cells that differentiate to give rise to thousands of nephrons, which are the functional units that carry out filtration to maintain physiological homeostasis. The polycomb repressive complex 2 (PRC2) epigenetically represses gene expression during development by placing the H3K27me3 mark on histone H3 at promoter and enhancer sites, resulting in gene silencing.

View Article and Find Full Text PDF

Our established interleukin-13 () overexpression rat model of minimal change-like nephropathy provided a platform to study the molecular signalling pathways in T-helper 2 (Th2) cytokine associated minimal change nephrotic syndrome (MCNS). We hypothesized that IL-13 may act directly on podocytes, causing podocyte foot process effacement and hence proteinuria in our rat model of minimal change-like nephropathy. The present study aimed firstly to delineate the glomerular 'gene signature' associated with IL-13-mediated dysregulation of podocyte-related proteins, and subsequently to investigate the role of the differentially regulated genes (DEGs) in IL-13-mediated podocyte injury.

View Article and Find Full Text PDF

Failure to thrive in a child is defined as 'lack of expected normal physical growth' or 'failure to gain weight'. Diagnosis requires repeated growth measurements over time using local, age-appropriate growth centile charts. Premature babies with appropriate growth velocity and children with 'catch-down' growth, constitutional growth delay or familial short stature show normal growth variants, and usually do not require further evaluation.

View Article and Find Full Text PDF

Background And Objectives: Rituximab is used with variable success in difficult FSGS. Because B cell depletion significantly affects T cell function, we characterized T cell subsets in patients with FSGS to determine if an immunologic signature predictive of favorable response to rituximab could be identified.

Design, Setting, Participants, & Measurements: Twenty-two consecutive patients with FSGS (median age =14.

View Article and Find Full Text PDF

The risk of acute kidney injury (AKI) in hospitalized critically ill neonatal populations without primary renal disease continues to be high, in both term and premature infants. Observational studies have revealed high rates of chronic kidney disease (CKD) in survivors of neonatal AKI. Proposed mechanisms underlying the progression of CKD following AKI include nephron loss and hyperfiltration, vascular insufficiency and maladaptive repair mechanisms.

View Article and Find Full Text PDF

Background: While the appearance of red clots in the dialyzer is a common phenomenon in every hemodialysis unit, the occurrence of white thrombi in the tubing is relatively rare.

Case Presentation: We describe an adolescent male with recurrent white thrombi formation in the hemodialysis tubing. This patient had chronic renal failure from focal segmental glomerulosclerosis, but was no longer nephrotic at the time of the thrombi formation.

View Article and Find Full Text PDF

Background: Initiating continuous renal replacement therapy (CRRT) in infants exposes them to the dual hemodynamic challenges of high circuit extracorporeal volumes and potential membrane reactions, in the case of acrylonitrile AN69 membranes. The use of the new Prismaflex HF20 membrane in hemodynamically unstable low-body-weight infants on inotropic support has not been reported.

Treatment: We describe the use of the HF20 (Gambro Lundia AB, Lund, Sweden) membrane in four low-body-weight infants (2.

View Article and Find Full Text PDF