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Urolithiasis Dec 2020Measurement of oxalate in the blood is essential for monitoring primary hyperoxaluria patients with progressive renal impairment and on dialysis prior to... (Comparative Study)
Comparative Study
Measurement of oxalate in the blood is essential for monitoring primary hyperoxaluria patients with progressive renal impairment and on dialysis prior to transplantation. As no external quality assurance scheme is available for this analyte, we conducted a sample exchange scheme between six laboratories specifically involved with the investigation of primary hyperoxaluria to compare results. The methodologies compared were gas chromatography/mass spectrometry (GCMS), ion chromatography with mass spectrometry (ICMS), and enzymatic methods using oxalate oxidase and spectrophotometry. Although individual laboratories performed well in terms of reproducibility and linearity, there was poor agreement (absolute values) between centres as illustrated by a longer-term comparison of patient results from two of the participating laboratories. This situation was only partly related to differences in calibration and mainly reflected the lower recoveries seen with the ultrafiltration of samples. These findings lead us to conclude that longitudinal monitoring of primary hyperoxaluria patients with deteriorating kidney function should be performed by a single consistent laboratory and the methodology used should always be defined. In addition, plasma oxalate concentrations reported in registry studies and those associated with the risk of systemic oxalosis in published studies need to be interpreted in light of the methodology used. A reference method and external quality assurance scheme for plasma oxalate analysis would be beneficial.
Topics: Hematologic Tests; Humans; Hyperoxaluria, Primary; Oxalates
PubMed: 32472220
DOI: 10.1007/s00240-020-01197-4 -
Journal of Managed Care & Specialty... Mar 2022Primary hyperoxaluria (PH) is a family of rare, life-threatening genetic liver disorders characterized by elevated production and excretion of oxalate. To date, the...
Primary hyperoxaluria (PH) is a family of rare, life-threatening genetic liver disorders characterized by elevated production and excretion of oxalate. To date, the clinical and economic burden associated with PH has not been well characterized due to the rarity of the disease and previous challenges with diagnostic coding that prevented proper identification of patients with PH in claims data. To characterize the clinical and economic costs, as well as health care resource utilization (HCRU), associated with PH relative to a matched cohort of patients without PH. Data from the IQVIA PharMetrics Plus Database were used to conduct a retrospective matched-cohort study to compare differences in clinical characteristics, HCRU, and pharmacy and medical costs in patients with PH compared with a matched cohort of patients without PH from January 2014 to December 2019. Overall, 324 patients were included in the PH cohort and 1,620 patients were in the non-PH cohort. The mean age of PH patients was 48.1 years, and approximately 58% of the sample were male. Significantly more patients in the PH cohort than the non-PH cohort were diagnosed with stage 2 chronic kidney disease (CKD; 3.1% vs 0.4%, respectively; < 0.001), stage 3 CKD (4.6% vs 0.5%; < 0.001), stage 4 CKD (2.5% vs 0.1%; < 0.001), and stage 5 CKD or end-stage renal disease (ESRD; 2.2% vs 0.1%; < 0.001). PH patients had a significantly higher mean Charlson Comorbidity Index composite score than patients in the non-PH cohort (0.79 vs 0.37; < 0.001). HCRU was significantly higher in patients with PH. The PH cohort had a significantly higher proportion of patients with at least 1 visit to clinicians specializing in nephrology (19% vs 0.4%, respectively; < 0.001), cardiology (22% vs 12%; < 0.001), ophthalmology (16% vs 7%; < 0.001), general surgery (9% vs 6%; = 0.011), and urology (65% vs 6%; < 0.001) compared with patients without PH. Mean total annual health care costs in the PH cohort were 65% higher than in the non-PH cohort ($22,549 vs $7,852, respectively; < 0.001). Similar results were found for total prescription drug costs ($4,125 vs $2,464; = 0.012). Despite the rarity of PH, patients with this disease incur substantial clinical and economic burden and may cause financial strain on the health care system. Additional research is warranted to understand the economic and clinical burden of PH stratified by the 3 subtypes of the disease. Funding for this research was provided by Dicerna Pharmaceuticals. Mucha and Hoppe are employed by Dicerna Pharmaceuticals. Silber Miyasoto, Skaar, and Wang are employed by Trinity Life Sciences, which was contracted by Dicerna Pharmaceuticals to conduct the study analysis. Langman is consultant to Dicerna Pharmaceuticals. This study was presented as a poster at the AMCP Nexus 2020 (virtual), October 19-23, 2020, and American Society of Nephrology 2020 (virtual), October 19-25, 2020.
Topics: Cohort Studies; Health Care Costs; Humans; Hyperoxaluria, Primary; Insurance Claim Review; Male; Middle Aged; Patient Acceptance of Health Care; Retrospective Studies; United States
PubMed: 35199581
DOI: 10.18553/jmcp.2022.28.3.316 -
EMBO Molecular Medicine Jan 2024The therapeutic use of adeno-associated viral vector (AAV)-mediated gene disruption using CRISPR-Cas9 is limited by potential off-target modifications and the risk of...
The therapeutic use of adeno-associated viral vector (AAV)-mediated gene disruption using CRISPR-Cas9 is limited by potential off-target modifications and the risk of uncontrolled integration of vector genomes into CRISPR-mediated double-strand breaks. To address these concerns, we explored the use of AAV-delivered paired Staphylococcus aureus nickases (D10ASaCas9) to target the Hao1 gene for the treatment of primary hyperoxaluria type 1 (PH1). Our study demonstrated effective Hao1 gene disruption, a significant decrease in glycolate oxidase expression, and a therapeutic effect in PH1 mice. The assessment of undesired genetic modifications through CIRCLE-seq and CAST-Seq analyses revealed neither off-target activity nor chromosomal translocations. Importantly, the use of paired-D10ASaCas9 resulted in a significant reduction in AAV integration at the target site compared to SaCas9 nuclease. In addition, our study highlights the limitations of current analytical tools in characterizing modifications introduced by paired D10ASaCas9, necessitating the development of a custom pipeline for more accurate characterization. These results describe a positive advance towards a safe and effective potential long-term treatment for PH1 patients.
Topics: Humans; Animals; Mice; CRISPR-Cas Systems; Deoxyribonuclease I; Gene Editing; Hyperoxaluria, Primary
PubMed: 38182795
DOI: 10.1038/s44321-023-00008-8 -
Scientific Reports Sep 2022Primary hyperoxaluria (PH) is an autosomal recessive disorder of oxalate metabolism caused by pathogenic variants in either of three genes (AGXT, GRHPR or HOGA1). The...
Primary hyperoxaluria (PH) is an autosomal recessive disorder of oxalate metabolism caused by pathogenic variants in either of three genes (AGXT, GRHPR or HOGA1). The study aimed at characterizing the clinical phenotypes as well as the genotypic spectrum of PH in Egypt. We screened 25 Egyptian patients suspected of PH for the three responsible genes by Sanger sequencing. We diagnosed 20 patients from 18 unrelated families, in which the natural history, family history, clinical features and genotypes were evaluated. PH patients were 15 males and 5 females ranging in age from 4 months to 31 years (median 8 years). Fifteen families were consanguineous (83%) and familial clustering was reported in six families (33%). Pathogenic variants in all 40 alleles were in AGXT, with none detected in GRHPR or HOGA1. We detected two novel pathogenic variants c.166-1_172dupGATCATGG (p.Asp58Glyfs*65) and c.766delC (p.Gln256fs*16) and seven previously reported variants in our cohort. This is the first study reporting the genotype of a considerable number of PH1 patients from Egypt. Our detected variants in the AGXT gene could form the basis for future genetic counseling and prenatal diagnosis in Egypt and surrounding populations.
Topics: Adolescent; Adult; Child; Child, Preschool; Egypt; Female; Humans; Hyperoxaluria, Primary; Infant; Male; Mutation; Oxalates; Phenotype; Transaminases; Young Adult
PubMed: 36151119
DOI: 10.1038/s41598-022-17980-9 -
Urologiia (Moscow, Russia : 1999) Dec 2019Primary hyperoxaluria is a group of inherited metabolic diseases characterized by increased formation of calcium-oxalate stones in kidneys with development of... (Review)
Review
Primary hyperoxaluria is a group of inherited metabolic diseases characterized by increased formation of calcium-oxalate stones in kidneys with development of nephrolithiasis and chronic kidney disease. The article summarizes the modern information on the diagnostics and treatment of the disorder depending on genotype of the patient (AGXT, GRHPR, HOGA1 genes). The evaluation of the molecular genetic aetiology of the kidney stone disease contributes to the personalized treatment and prevention of the pathology in the patients and their relatives.
Topics: Genetic Predisposition to Disease; Genotype; Humans; Hyperoxaluria, Primary; Kidney; Kidney Calculi; Molecular Biology; Phenotype
PubMed: 31808650
DOI: No ID Found -
Progres En Urologie : Journal de... Nov 2023The morphological-compositional analysis of urinary stones allows distinguishing schematically several situations: dietary, digestive, metabolic/hormonal, infectious and... (Review)
Review
The morphological-compositional analysis of urinary stones allows distinguishing schematically several situations: dietary, digestive, metabolic/hormonal, infectious and genetic problems. Blood and urine testing are recommended in the first instance to identify risk factors of urinary stone disease in order to avoid recurrence or progression. The other objective is to detect a potential underlying pathology associated with high risk of urinary stone disease (e.g. primary hyperparathyroidism, primary or enteric hyperoxaluria, cystinuria, distal renal tubular acidosis) that may require specific management. Lifestyle-diet measures are the basis of the management of all stone types, but pharmacological treatments may be required. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendation (CPR) method and the ADAPTE method, depending on whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis) [EAU 2022] and their adaptability to the French context.
Topics: Humans; Lithiasis; Urolithiasis; Urinary Calculi; Urology; Risk Factors
PubMed: 37918992
DOI: 10.1016/j.purol.2023.08.004 -
Kidney International Reports Oct 2023Primary hyperoxaluria type 1 (PH1) has a highly heterogeneous disease course. Apart from the c.508G>A (p.Gly170Arg) variant, which imparts a relatively favorable...
INTRODUCTION
Primary hyperoxaluria type 1 (PH1) has a highly heterogeneous disease course. Apart from the c.508G>A (p.Gly170Arg) variant, which imparts a relatively favorable outcome, little is known about determinants of kidney failure. Identifying these is crucial for disease management, especially in this era of new therapies.
METHODS
In this retrospective study of 932 patients with PH1 included in the OxalEurope registry, we analyzed genotype-phenotype correlations as well as the impact of nephrocalcinosis, urolithiasis, and urinary oxalate and glycolate excretion on the development of kidney failure, using survival and mixed model analyses.
RESULTS
The risk of developing kidney failure was the highest for 175 vitamin-B6 unresponsive ("null") homozygotes and lowest for 155 patients with c.508G>A and c.454T>A (p.Phe152Ile) variants, with a median age of onset of kidney failure of 7.8 and 31.8 years, respectively. Fifty patients with c.731T>C (p.Ile244Thr) homozygote variants had better kidney survival than null homozygotes ( = 0.003). Poor outcomes were found in patients with other potentially vitamin B6-responsive variants. Nephrocalcinosis increased the risk of kidney failure significantly (hazard ratio [HR] 3.17 [2.03-4.94], < 0.001). Urinary oxalate and glycolate measurements were available in 620 and 579 twenty-four-hour urine collections from 117 and 87 patients, respectively. Urinary oxalate excretion, unlike glycolate, was higher in patients who subsequently developed kidney failure ( = 0.034). However, the 41% intraindividual variation of urinary oxalate resulted in wide confidence intervals.
CONCLUSION
In conclusion, homozygosity for null variants and nephrocalcinosis were the strongest determinants for kidney failure in PH1.
PubMed: 37849991
DOI: 10.1016/j.ekir.2023.07.025 -
Frontiers in Medicine 2021Primary hyperoxaluria type 1 (PH1) is a rare genetic disease that can result in irreversible damage to the kidneys and, eventually, extrarenal organs. While kidney...
Primary hyperoxaluria type 1 (PH1) is a rare genetic disease that can result in irreversible damage to the kidneys and, eventually, extrarenal organs. While kidney failure is a known consequence of PH1, few studies to date have characterized clinical consequences of PH1 prior to kidney failure, and data on healthcare resource use outcomes across different stages of disease severity in PH1 are also limited. To help fill this knowledge gap, this study characterized the clinical and healthcare resource use (HRU) burden in patients with PH1 with varying stages of kidney disease. Nephrologists in the United States, Canada, United Kingdom, France, Germany, and Italy abstracted chart data from patients with PH1 under their care via an online questionnaire. Eligible patients had confirmed PH1 and ≥2 office visits from 2016 to 2019. A total of 120 patients were analyzed (median age at diagnosis, 17.4 years old, median age at index 19.5 years old, median eGFR at index 45 ml/min/1.73 m; median follow-up 1.7 years). During follow-up, the most common PH1 manifestations were kidney stones and urinary tract infections (UTIs, both 56.8%), and the most common symptoms were fatigue/weakness (71.7%) and pain (64.6%). With regard to HRU during follow-up, 37.4% required lithotripsy, 31.3% required ureteroscopy, and 9.6% required nephrolithotomy. PH1-related hospitalizations and emergency/urgent care visits were noted for 84.0 and 81.6% of patients, respectively. The current study demonstrated that patients with PH1 across various stages of kidney disease exhibited a substantial clinical burden, including kidney stones, UTIs, fatigue/weakness, and pain, and required frequent HRU, including kidney stone procedures, hospitalizations, and emergency visits. These findings highlight the significant morbidity and HRU burden in patients with PH1.
PubMed: 34616753
DOI: 10.3389/fmed.2021.703305 -
Pediatric Nephrology (Berlin, Germany) Mar 2023Accurate diagnosis of primary hyperoxaluria (PH) has important therapeutic consequences. Since biochemical assessment can be unreliable, genetic testing is a crucial... (Review)
Review
Accurate diagnosis of primary hyperoxaluria (PH) has important therapeutic consequences. Since biochemical assessment can be unreliable, genetic testing is a crucial diagnostic tool for patients with PH to define the disease type. Patients with PH type 1 (PH1) have a worse prognosis than those with other PH types, despite the same extent of oxalate excretion. The relation between genotype and clinical phenotype in PH1 is extremely heterogeneous with respect to age of first symptoms and development of kidney failure. Some mutations are significantly linked to pyridoxine-sensitivity in PH1, such as homozygosity for p.G170R and p.F152I combined with a common polymorphism. Although patients with these mutations display on average better outcomes, they may also present with CKD stage 5 in infancy. In vitro studies suggest pyridoxine-sensitivity for some other mutations, but confirmatory clinical data are lacking (p.G47R, p.G161R, p.I56N/major allele) or scarce (p.I244T). These studies also suggest that other vitamin B6 derivatives than pyridoxine may be more effective and should be a focus for clinical testing. PH patients displaying the same mutation, even within one family, may have completely different clinical outcomes. This discordance may be caused by environmental or genetic factors that are unrelated to the effect of the causative mutation(s). No relation between genotype and clinical or biochemical phenotypes have been found so far in PH types 2 and 3. This manuscript reviews the current knowledge on the genetic background of the three types of primary hyperoxaluria and its impact on clinical management, including prenatal diagnosis.
Topics: Humans; Hyperoxaluria, Primary; Pyridoxine; Mutation; Genetic Testing; Genotype; Transaminases
PubMed: 35695965
DOI: 10.1007/s00467-022-05613-2 -
Urolithiasis Feb 2021The aim of our study is to explore the relationship between genotype and phenotype in Chinese PH1 patients and determine the putative mutation hotspot regions. This was... (Observational Study)
Observational Study
The aim of our study is to explore the relationship between genotype and phenotype in Chinese PH1 patients and determine the putative mutation hotspot regions. This was a retrospective study regarding 13 Chinese PH1 patients. And all sporadic published researches of Chinese PH1 populations were searched and enrolled based on the inclusive standard. All patients presented with multiple urolithiasis or nephrolithiasis. Urinary oxalate values demonstrated an obvious and extensive variability, ranging from 1.01 to 3.85 mmol/1.73 m. Molecular diagnosis showed that 13 mutant types were detected. Infantile form patient (pt.) 10 and five patients (pts. 5, 7, 8, 9, 12) carrying c.815_816insGA or c.33_34insC demonstrated a worse prognosis, of whom pt. 5 progressed into ESRD 4 years later and died of chronic kidney failure. Based on the integrated Chinese mutation data, two variants (c.815_816insGA and c.33_34insC) were determined as the most common mutations. Besides, c.1049G>A was initially identified in a Chinese patient. Conclusions: heterogeneity between genotype and phenotype was observed and described in Chinese PH1 patients. c.815_816insGA and c.33_34insC which were recognized as AGXT mutation hotspot regions in China implied a poor prognosis. And c.1049G>A was not determined as the race-specific mutation of Pakistani.
Topics: Adolescent; Age of Onset; Asian People; Calcium Oxalate; Child; Child, Preschool; China; Disease Progression; Female; Follow-Up Studies; Genotype; Humans; Hyperoxaluria, Primary; Infant; Kidney Failure, Chronic; Male; Mutation; Prognosis; Retrospective Studies; Transaminases; Urolithiasis
PubMed: 32556641
DOI: 10.1007/s00240-020-01201-x