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Pediatric Nephrology (Berlin, Germany) Sep 2021Loss-of-function mutations in three genes, involved in the metabolic pathway of glyoxylate, result in increased oxalate production and its crystallization in the form of... (Review)
Review
Loss-of-function mutations in three genes, involved in the metabolic pathway of glyoxylate, result in increased oxalate production and its crystallization in the form of calcium oxalate. This leads to three forms of primary hyperoxaluria-an early-onset inherited kidney disease with wide phenotypic variability ranging from isolated kidney stone events to stage 5 chronic kidney disease in infancy. This review provides a description of metabolic processes resulting in oxalate overproduction and summarizes basic therapeutic approaches. Unfortunately, current treatment of primary hyperoxaluria does not allow the prevention of loss of kidney function or to substantially diminish other symptoms in most patients. However, latest breakthroughs in biotechnology provide new promising directions for drug development. Some of them have already progressed to the level of clinical trials; others are just at the stage of proof of concept. Here we review the most advanced technologies including those that have been harnessed as possible therapeutic modalities.
Topics: Humans; Hyperoxaluria, Primary
PubMed: 33156410
DOI: 10.1007/s00467-020-04817-8 -
Current Opinion in Pediatrics Apr 2020Prevalence of pediatric urolithiasis is increasing, which is definitively visible in increasing numbers of presentations in emergency or outpatient clinics. In pediatric... (Review)
Review
PURPOSE OF REVIEW
Prevalence of pediatric urolithiasis is increasing, which is definitively visible in increasing numbers of presentations in emergency or outpatient clinics. In pediatric patients, a genetic or metabolic disease has to be excluded, so that adequate treatment can be installed as early as possible. Only then either recurrent stone events and chronic or even end-stage kidney disease can be prevented.
RECENT FINDINGS
The genetic background of mostly monogenic kidney stone diseases was unravelled recently. In hypercalcuria, for example, the commonly used definition of idiopathic hypercalciuria was adopted to the genetic background, here three autosomal recessive hereditary forms of CYP24A1, SLC34A1 and SLC34A3 associated nephrocalcinosis/urolithiasis with elevated 1.25-dihydroxy-vitamin D3 (1.25-dihydroxy-vitamin D3) (calcitriol) levels. In addition either activating or inactivating mutations of the calcium-sensing receptor gene lead either to hypocalcemic hypercalciuria or hypercalcemic hypocalciuria. In primary hyperoxaluria, a third gene defect was unravelled explaining most of the so far unclassified patients. In addition, these findings lead to new treatment options, which are currently evaluated in phase III studies.
SUMMARY
Kidney stones are not the disease itself, but only its first symptom. The underlying disease has to be diagnosed in every pediatric patient with the first stone event.
Topics: Child; Humans; Hypercalcemia; Hypercalciuria; Hyperoxaluria; Kidney Calculi; Metabolism, Inborn Errors; Mutation; Nephrocalcinosis; Nephrolithiasis; Receptors, Calcium-Sensing; Urolithiasis; Vitamin D; Vitamin D3 24-Hydroxylase
PubMed: 31789978
DOI: 10.1097/MOP.0000000000000848 -
Pharmaceuticals (Basel, Switzerland) Feb 2024A total of nine TIDES (pepTIDES and oligonucleoTIDES) were approved by the FDA during 2023. The four approved oligonucleotides are indicated for various types of... (Review)
Review
A total of nine TIDES (pepTIDES and oligonucleoTIDES) were approved by the FDA during 2023. The four approved oligonucleotides are indicated for various types of disorders, including amyotrophic lateral sclerosis, geographic atrophy, primary hyperoxaluria type 1, and polyneuropathy of hereditary transthyretin-mediated amyloidosis. All oligonucleotides show chemically modified structures to enhance their stability and therapeutic effectiveness as antisense or aptamer oligomers. Some of them demonstrate various types of conjugation to driving ligands. The approved peptides comprise various structures, including linear, cyclic, and lipopeptides, and have diverse applications. Interestingly, the FDA has granted its first orphan drug designation for a peptide-based drug as a highly selective chemokine antagonist. Furthermore, Rett syndrome has found its first-ever core symptoms treatment, which is also peptide-based. Here, we analyze the TIDES approved in 2023 on the basis of their chemical structure, medical target, mode of action, administration route, and common adverse effects.
PubMed: 38399458
DOI: 10.3390/ph17020243 -
Ophthalmology. Retina Sep 2020
Topics: Humans; Hyperoxaluria, Primary; Infant; Macula Lutea; Macular Degeneration; Oxalates
PubMed: 32896362
DOI: 10.1016/j.oret.2020.04.008 -
Nature Reviews. Urology Mar 2022Primary hyperoxalurias are a devastating family of diseases leading to multisystem oxalate deposition, nephrolithiasis, nephrocalcinosis and end-stage renal disease.... (Review)
Review
Primary hyperoxalurias are a devastating family of diseases leading to multisystem oxalate deposition, nephrolithiasis, nephrocalcinosis and end-stage renal disease. Traditional treatment paradigms are limited to conservative management, dialysis and combined transplantation of the kidney and liver, of which the liver is the primary source of oxalate production. However, transplantation is associated with many potential complications, including operative risks, graft rejection, post-transplant organ failure, as well as lifelong immunosuppressive medications and their adverse effects. New therapeutics being developed for primary hyperoxalurias take advantage of biochemical knowledge about oxalate synthesis and metabolism, and seek to specifically target these pathways with the goal of decreasing the accumulation and deposition of oxalate in the body.
Topics: Female; Humans; Hyperoxaluria, Primary; Kidney Failure, Chronic; Kidney Transplantation; Liver Transplantation; Male; Oxalates
PubMed: 34880452
DOI: 10.1038/s41585-021-00543-4 -
Current Opinion in Nephrology and... Jul 2022Primary hyperoxaluria type 1 (PH1) is a rare genetic disorder that causes hepatic overproduction of oxalate and, often, nephrocalcinosis, nephrolithiasis, chronic kidney... (Review)
Review
PURPOSE OF REVIEW
Primary hyperoxaluria type 1 (PH1) is a rare genetic disorder that causes hepatic overproduction of oxalate and, often, nephrocalcinosis, nephrolithiasis, chronic kidney disease, and kidney failure. The purpose of the review is to provide an update on current emerging therapies for the treatment of PH1.
RECENT FINDINGS
Use of ribonucleic acid interference (RNAi) therapeutics that target the liver to block production of key enzymes along pathways that generate oxalate is a promising approach. Available evidence supports the efficacy of both Lumasiran (targeting glycolate oxidase) and Nedosiran (targeting hepatic lactate dehydrogenase (LDHa)) to reduce urinary oxalate excretion in PH1. The efficacy of alternative approaches including stiripentol (an anticonvulsant drug that also targets LDHa), lanthanum (a potential gastrointestinal oxalate binder), and Oxalobacter formigenes (a bacterium that can degrade oxalate within the gastrointestinal tract and may also increase its secretion from blood) are all also under study. Genetic editing tools including clustered regularly interspaced short palindromic repeats/Cas9 are also in preclinical study as a potential PH1 therapeutic.
SUMMARY
Novel treatments can reduce the plasma oxalate concentration and urinary oxalate excretion in PH1 patients. Thus, it is possible these approaches will reduce the need for combined kidney and liver transplantation to significantly decrease the morbidity and mortality of affected patients.
Topics: Humans; Hyperoxaluria, Primary; Kidney Calculi; L-Lactate Dehydrogenase; Oxalates; RNA, Small Interfering
PubMed: 35266883
DOI: 10.1097/MNH.0000000000000790 -
Genes Aug 2023Oxalate is a metabolic end-product whose systemic concentrations are highly variable among individuals. Genetic (primary hyperoxaluria) and non-genetic (e.g., diet,... (Review)
Review
Oxalate is a metabolic end-product whose systemic concentrations are highly variable among individuals. Genetic (primary hyperoxaluria) and non-genetic (e.g., diet, microbiota, renal and metabolic disease) reasons underlie elevated plasma concentrations and tissue accumulation of oxalate, which is toxic to the body. A classic example is the triad of primary hyperoxaluria, nephrolithiasis, and kidney injury. Lessons learned from this example suggest further investigation of other putative factors associated with oxalate dysmetabolism, namely the identification of precursors (glyoxylate, aromatic amino acids, glyoxal and vitamin C), the regulation of the endogenous pathways that produce oxalate, or the microbiota's contribution to oxalate systemic availability. The association between secondary nephrolithiasis and cardiovascular and metabolic diseases (hypertension, type 2 diabetes, and obesity) inspired the authors to perform this comprehensive review about oxalate dysmetabolism and its relation to cardiometabolic toxicity. This perspective may offer something substantial that helps advance understanding of effective management and draws attention to the novel class of treatments available in clinical practice.
Topics: Humans; Oxalates; Diabetes Mellitus, Type 2; Hyperoxaluria, Primary; Kidney; Nephrolithiasis; Hypertension
PubMed: 37761859
DOI: 10.3390/genes14091719 -
Pediatric Nephrology (Berlin, Germany) Aug 2023Primary hyperoxaluria (PH) results from genetic mutations in different genes of glyoxylate metabolism, which cause significant increases in production of oxalate by the... (Observational Study)
Observational Study
BACKGROUND
Primary hyperoxaluria (PH) results from genetic mutations in different genes of glyoxylate metabolism, which cause significant increases in production of oxalate by the liver. This study aimed to report clinical and laboratory manifestations and outcome of PH type 1 in children in our center.
METHODS
A single-center observational cohort study was conducted at Children's University Hospital in Damascus, and included all patients admitted from 2018 to 2020, with a diagnosis of hyperoxaluria (urinary oxalate excretion > 45 mg/1.73 m/day, or > 0.5 mmol/1.73 m/day). PH type 1 (PH1) diagnosis was established by identification of biallelic pathogenic variants (compound heterozygous or homozygous mutations) in AGXT gene on molecular genetic testing.
RESULTS
The study included 100 patients with hyperoxaluria, with slight male dominance (57%), and median age 1.75 years (range, 1 month-14 years). Initial complaint was urolithiasis or nephrocalcinosis in 47%, kidney failure manifestations in 29%, and recurrent urinary tract infection in 24%. AGXT mutations were detected in 40 patients, and 72.5% of PH1 patients had kidney failure at presentation. Neither gender, age nor urinary oxalate excretion in 24 h had statistical significance in distinguishing PH1 from other forms of hyperoxaluria (P-Value > 0.05). Parental consanguinity, family history of kidney stones, bilateral nephrocalcinosis, presence of oxalate crystals in random urine sample, kidney failure and mortality were statistically significantly higher in PH1 (P-values < 0.05). Mortality was 32.5% among PH1 patients, with 4 PH1 patients (10%) on hemodialysis awaiting combined liver-kidney transplantation.
CONCLUSION
PH1 is still a grave disease with wide variety of clinical presentations which frequent results in delays in diagnosis, thus kidney failure is still a common presentation. In Syria, we face many challenges in diagnosis of PH, especially PH2 and PH3, and in management, with hopes that diagnosis tools and modern therapies will become available in our country. Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information.
Topics: Child; Humans; Male; Infant; Nephrocalcinosis; Hyperoxaluria, Primary; Oxalates; Hyperoxaluria; Kidney Calculi; Renal Insufficiency
PubMed: 36917293
DOI: 10.1007/s00467-023-05917-x -
Clinical Journal of the American... Apr 2024Nephritis is a common manifestation of IgA vasculitis and is morphologically indistinguishable from IgA nephropathy. While MEST-C scores are predictive of kidney...
BACKGROUND
Nephritis is a common manifestation of IgA vasculitis and is morphologically indistinguishable from IgA nephropathy. While MEST-C scores are predictive of kidney outcomes in IgA nephropathy, their value in IgA vasculitis nephritis has not been investigated in large multiethnic cohorts.
METHODS
Biopsies from 262 children and 99 adults with IgA vasculitis nephritis ( N =361) from 23 centers in North America, Europe, and Asia were independently scored by three pathologists. MEST-C scores were assessed for correlation with eGFR/proteinuria at biopsy. Because most patients ( N =309, 86%) received immunosuppression, risk factors for outcomes were evaluated in this group using latent class mixed models to identify classes of eGFR trajectories over a median follow-up of 2.7 years (interquartile range, 1.2-5.1). Clinical and histologic parameters associated with each class were determined using logistic regression.
RESULTS
M, E, T, and C scores were correlated with either eGFR or proteinuria at biopsy. Two classes were identified by latent class mixed model, one with initial improvement in eGFR followed by a late decline (class 1, N =91) and another with stable eGFR (class 2, N =218). Class 1 was associated with a higher risk of an established kidney outcome (time to ≥30% decline in eGFR or kidney failure; hazard ratio, 5.84; 95% confidence interval, 2.37 to 14.4). Among MEST-C scores, only E1 was associated with class 1 by multivariable analysis. Other factors associated with class 1 were age 18 years and younger, male sex, lower eGFR at biopsy, and extrarenal noncutaneous disease. Fibrous crescents without active changes were associated with class 2.
CONCLUSIONS
Kidney outcome in patients with biopsied IgA vasculitis nephritis treated with immunosuppression was determined by clinical risk factors and endocapillary hypercellularity (E1) and fibrous crescents, which are features that are not part of the International Study of Diseases of Children classification.
Topics: Adult; Child; Humans; Male; Adolescent; Glomerulonephritis, IGA; IgA Vasculitis; Glomerular Filtration Rate; Kidney; Nephritis; Proteinuria; Biopsy; Retrospective Studies
PubMed: 38261310
DOI: 10.2215/CJN.0000000000000398 -
Clinical Kidney Journal May 2022The clinical presentation of primary hyperoxaluria in children ranges from mildly symptomatic nephrocalcinosis to very early onset end-stage kidney failure with systemic... (Review)
Review
The clinical presentation of primary hyperoxaluria in children ranges from mildly symptomatic nephrocalcinosis to very early onset end-stage kidney failure with systemic oxalosis, a devastating complication. We review the various manifestations of pediatric hyperoxaluria, treatment options for children with preserved kidney function and appropriate dialysis regimens. Liver or combined liver/kidney transplantation is currently the only definitive treatment for primary hyperoxaluria type 1, but novel RNA interference treatments offer hope for the future. Finally, we address the medical and ethical dilemmas facing pediatricians treating children with hyperoxaluria.
PubMed: 35592624
DOI: 10.1093/ckj/sfab231