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Oxalate Nephropathy (ON) represents a serious condition characterized by a decline in renal function associated with calcium oxalate crystal deposition within renal tubules. It can arise from Primary Hyperoxaluria (PH) due to genetic defects or secondary causes such as increased dietary oxalate intake. We present a case of a 46-year-old male with facial puffiness, abdominal pain, and pedal oedema, diagnosed with acute kidney injury superimposed on probable chronic kidney disease. Diagnostic investigations revealed bilateral renal echogenicity and severe acute tubular injury with calcium oxalate crystal deposition on renal biopsy. A24-hour urinary oxalate analysis confirmed ON. Despite the absence of identifiable risk factors, the patient was categorized as probable primary oxalate nephropathy, pending genetic testing results. Management included thrice-weekly haemodialysis and assessment for liver-kidney transplant. Early identification and intervention are crucial in ON to prevent progression to renal failure, emphasizing the need for heightened clinical suspicion and timely management strategies.

Primary hyperoxaluria (PH) is a rare genetic disorder characterized by excessive oxalate production because of specific gene defects. PH1 is the most prevalent type, causing recurrent kidney stone disease and often leading to chronic kidney disease and kidney failure. Our previous study suggested that pregnancy did not adversely affect kidney function in female patients with PH. In this study, we identified 4 PH1 cases with urinary oxalate (UOx) measurements during pregnancy from the Rare Kidney Stone Consortium and Oxalosis and Hyperoxaluria Foundation PH registry to investigate UOx levels during pregnancy in patients with PH1. The PH Registry is approved by the Institutional Review Board of Mayo Clinic (Rochester, MN). All 4 showed a decrease in UOx during pregnancy when compared with before pregnancy and after delivery. These findings contrast with those of the general population, in which the UOx tends to increase during pregnancy because of a simultaneous physiological increase in the glomerular filtration rate. Elucidating the mechanism underlying reduced UOx during pregnancy in PH1 could suggest novel PH therapies. These findings could also affect the clinical management and have implications regarding the safety of withholding novel PH1-directed molecular therapies that currently have uncertain safety profiles during pregnancy. We highlight the need for additional data on urinary changes in patients with PH and other populations while pregnant to clarify changes in UOx throughout pregnancy.

Primary hyperoxaluria is a rare congenital autosomal recessive disorder disrupting the glyoxylate metabolism pathway in the liver. Type1 primary hyperoxaluria is caused by a deficiency in a specific liver enzyme namely, alanine glyoxylate-aminotransferase which catalyzes the conversion of glyoxylate to glycine. By the absence of this enzyme, glyoxylate is converted to oxalate and high oxalate level causes deposition of insoluble calcium oxalate crystals in different organs specifically kidneys. The disease usually manifested by recurrent nephrolithiasis and/or nephrocalcinosis leads to renal failure. This report describes an end-stage renal disease case of a 36-year-old Iranian woman without any history of nephrolithiasis who underwent kidney transplantation. She developed an early onset transplant kidney failure. The patient underwent kidney biopsy, which revealed oxalate nephropathy, accordingly the genetic study confirmed diagnosis of primary hyperoxaluria. This rare case shows how type 1 primary hyperoxaluria can develop after kidney transplantation without having any manifestation prior to transplantation

Abstract Background Primary hyperoxaluria (PH) is a rare genetic disorder characterized by the excessive production and accumulation of oxalate. We present five cases of PH, each exhibiting varying manifestations of the disorder including a case presenting as postpartum kidney failure. Notably, three of these cases involve a previously unreported mutation. Case presentations We evaluated five Indian patients who presented with varying manifestations of PH. The first case, a 30 year old woman, presented as post-partum kidney failure and was found to be having oxalate nephropathy precipitated by dietary oxalate overload in the setting of previously undiagnosed PH. Genetic analysis revealed a previously unreported mutation in the alanine-glyoxylate aminotransferase gene. The patient underwent simultaneous kidney liver transplant. The second and third cases, 26 and 28 year old women respectively, were asymptomatic siblings of the first patient, who were diagnosed through screening. The fourth case is a 12 year boy with PH type 1 presenting as nephrolithiasis and rapidly worsening kidney function requiring combined kidney liver kidney transplant. Case 5 is a 6 year old male child with type 2 PH presenting with nephrolithiasis, nephrocalcinosis and normal kidney function. All the patients were born to consanguineous parents. Conclusions Due to limited clinical suspicion and inadequate diagnostic resources in certain countries with limited resources, it is possible for PH to go undiagnosed. The manifestations of the disease can range from no noticeable symptoms to severe disease. Interestingly, in some individuals with primary hyperoxaluria, the disease may not exhibit any symptoms until it is triggered by a high intake of dietary oxalate.

Key Clinical Message Cutaneous oxalosis is a rare manifestation of systemic oxalosis, typically associated with primary or secondary hyperoxaluria. We present a rare case of a 23‐year‐old female diagnosed with primary hyperoxaluria and end‐stage renal disease, who presented with papules on the palms without any vascular complications. The skin can be affected by oxalate deposition, resulting in various manifestations such as vascular complications or calcified nodules. In our case, the patient had primary hyperoxaluria and end‐stage renal disease but exhibited atypical features of cutaneous oxalosis. Histopathology confirmed the presence of oxalate crystals in the dermis, subcutis, and medium‐sized arteries. The mechanism of oxalate deposition in this case remains unclear. This case underscores the importance of considering cutaneous oxalosis in the differential diagnosis of patients with renal failure and skin lesions, and highlights the variability of clinical presentations in primary hyperoxaluria.

Primary hyperoxalurias (PHs) are inherited metabolic disorders marked by enzymatic cascade disruption, leading to excessive oxalate production that is subsequently excreted in the urine. Calcium oxalate deposition in the renal tubules and interstitium triggers renal injury, precipitating systemic oxalate build-up and subsequent secondary organ impairment. Recent explorations of novel therapeutic strategies have challenged and necessitated the reassessment of established management frameworks. The execution of diverse clinical trials across various medication classes has provided new insights and knowledge. With the evolution of PH treatments reaching a new milestone, prompt and accurate diagnosis is increasingly critical. Developing early, effective management and treatment plans is essential to improve the long-term quality of life for PH patients.

Background: Primary hyperoxaluria (PH) is a rare genetic disorder characterized by excessive accumulation of oxalate in plasma and urine, resulting in various phenotypes due to allelic and clinical heterogeneity. This study aimed to analyze the genotype of 21 Chinese patients with primary hyperoxaluria (PH) and explore their correlations between genotype and phenotype.Methods: Combined with clinical phenotypic and genetic analysis, we identified 21 PH patients from highly suspected Chinese patients. The clinical, biochemical, and genetic data of the 21 patients were subsequently reviewed.Results: We reported 21 cases of PH in China, including 12 cases of PH1, 3 cases of PH2 and 6 cases of PH3, and identified 2 novel variants (c.632T > G and c.823_824del) in AGXT gene and 2 novel variants (c.258_272del and c.866-34_866-8del) in GRHPR gene, respectively. A possible PH3 hotspot variant c.769T > G was identified for the first time. In addition, patients with PH1 showed higher levels of creatinine and lower eGFR than those with PH2 and PH3. In PH1, patients with severe variants in both alleles had significantly higher creatinine and lower eGFR than other patients. Delayed diagnosis still existed in some late-onset patients. Of all cases, 6 had reached to end-stage kidney disease (ESKD) at diagnosis with systemic oxalosis. Five patients were on dialysis and three had undergone kidney or liver transplants. Notably, four patients showed a favorable therapeutic response to vitamin B6, and c.823_824dup and c.145A > C may be identified as potentially vitamin B6-sensitive genotypes.Conclusion: In brief, our study identified 4 novel variants and extended the variant spectrum of PH in the Chinese population. The clinical phenotype was characterized by large heterogeneity, which may be determined by genotype and a variety of other factors. We first reported two variants that may be sensitive to vitamin B6 therapy in Chinese population, providing valuable references for clinical treatment. In addition, early screening and prognosis of PH should be given more attention. We propose to establish a large-scale registration system for rare genetic diseases in China and call for more attention on rare kidney genetic diseases.

Viola D’Ambrosio,1,2 Pietro Manuel Ferraro1,2 1U.O.S. Terapia Conservativa della Malattia Renale Cronica, U.O.C. Nefrologia, Dipartimento di Scienze Mediche e Chirurgiche, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italia; 2Dipartimento Universitario di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Roma, ItaliaCorrespondence: Pietro Manuel Ferraro, U.O.S. Terapia Conservativa della Malattia Renale Cronica, U.O.C. Nefrologia, Dipartimento di Scienze Mediche e Chirurgiche, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo Agostino Gemelli 8, Roma, 00168, Italia, Tel +39-06-3015-7819, Fax +39-06-3015-942, Email pietromanuel.ferraro@unicatt.itAbstract: Primary hyperoxaluria (PH) is a rare genetic disease caused by excessive hepatic production and elevated urinary excretion of oxalate that leads to recurrent nephrolithiasis, nephrocalcinosis and, eventually, kidney failure. As glomerular filtration rate declines, oxalate accumulates leading to systemic oxalosis, a debilitating condition with high morbidity and mortality. Although PH is usually diagnosed during infancy, it can present at any age with different phenotypes, ranging from mild symptoms to extremely debilitating manifestations. PH is an autosomal recessive disorder and, to date, three types have been identified: PH1, PH2 and PH3. PH1 is the most common and most aggressive type, accounting for almost 80% of primary hyperoxaluria diagnoses. Until 2020, general treatment for PH1 consisted mainly in high fluid intake, urine alkalization, surgical management of recurrent nephrolithiasis and eventually, if and when kidney failure occurred, intensive dialysis regimens and transplantation strategies (simultaneous or sequential liver-kidney transplant or isolated liver/kidney transplant in carefully selected patients). Specific treatment did and still consists in administration of pyridoxine hydrochloride, although it is only effective in a subset of PH1 patients. Lumasiran, a novel biological drug based on mRNA interference that has been recently approved in the US and European Union, showed promising results and is set to be a turning point in the management of PH1. This literature review aims to summarize the available evidence on PH1 treatment with lumasiran, in order to provide both pediatric and adult nephrologists and clinicians with the knowledge for the identification and management of PH1 patients suitable for treatment.Keywords: primary hyperoxaluria, oxalate, lumasiran, iRNA, nephrolithiasis

Genome-editing strategies, especially CRISPR-Cas9 systems, have substantially increased the efficiency of innovative therapeutic approaches for monogenic diseases such as primary hyperoxalurias (PHs). We have previously demonstrated that inhibition of glycolate oxidase using CRISPR-Cas9 systems represents a promising therapeutic option for PH type I (PH1). Here, we extended our work evaluating the efficacy of liver-specific inhibition of lactate dehydrogenase (LDH), a key enzyme responsible for converting glyoxylate to oxalate; this strategy would not be limited to PH1, being applicable to other PH subtypes. In this work, we demonstrate a liver-specific inhibition of LDH that resulted in a drastic reduction of LDH levels in the liver of PH1 and PH3 mice after a single-dose delivery of AAV8 vectors expressing the CRISPR-Cas9 system, resulting in reduced urine oxalate levels and kidney damage without signs of toxicity. Deep sequencing analysis revealed that this approach was safe and specific, with no off-targets detected in the liver of treated animals and no on-target/off-tissue events. Altogether, our data provide evidence that in vivo genome editing using CRISPR-Cas9 systems would represent a valuable tool for improved therapeutic approaches for PH.

Primary hyperoxaluria is the most severe stone disease responsible for multiple stone recurrence and impairment of kidney function. It is a rare inherited disease with an autosomal transmission. Due to the high proportion of consanguineous marriages by comparison to other areas in the world, this pathology is more frequent in North Africa. Stones are made of calcium oxalate monohydrate, which is not unique to the disease and cannot help physicians for the diagnosis. By contrast, stone morphology may be a useful marker of the pathology. We report our experience based on 614 stones from Moroccan children analyzed by infrared spectroscopy and examined by stereomicroscopy for the determination of their morphological type. Our results show that 85 stones (13.8%) exhibit a type Ic morphology, strongly suggestive of the disease in children patients. It was confirmed in all subjects of a subgroup of 43 patients who benefited from urinary biochemical explorations revealing whewellite crystalluria and a very high oxalate to creatinine ratio.

Introduction: In primary hyperoxaluria type 1 (PH1), oxalate overproduction frequently causes kidney stones, nephrocalcinosis, and kidney failure. As PH1 is caused by a congenital liver enzyme defect, combined liver–kidney transplantation (CLKT) has been recommended in patients with kidney failure. Nevertheless, systematic analyses on long-term transplantation outcomes are scarce. The merits of a sequential over combined procedure regarding kidney graft survival remain unclear as is the place of isolated kidney transplantation (KT) for patients with vitamin B6-responsive genotypes. Methods: We used the OxalEurope registry for retrospective analyses of patients with PH1 who underwent transplantation. Analyses of crude Kaplan–Meier survival curves and adjusted relative hazards from the Cox proportional hazards model were performed. Results: A total of 267 patients with PH1 underwent transplantation between 1978 and 2019. Data of 244 patients (159 CLKTs, 48 isolated KTs, 37 sequential liver–KTs [SLKTs]) were eligible for comparative analyses. Comparing CLKTs with isolated KTs, adjusted mortality was similar in patients with B6-unresponsive genotypes but lower after isolated KT in patients with B6-responsive genotypes (adjusted hazard ratio 0.07, 95% CI: 0.01–0.75, P = 0.028). CLKT yielded higher adjusted event-free survival and death-censored kidney graft survival in patients with B6-unresponsive genotypes (P = 0.025, P < 0.001) but not in patients with B6-responsive genotypes (P = 0.145, P = 0.421). Outcomes for 159 combined procedures versus 37 sequential procedures were comparable. There were 12 patients who underwent pre-emptive liver transplantation (PLT) with poor outcomes. Conclusion: The CLKT or SLKT remains the preferred transplantation modality in patients with PH1 with B6-unresponsive genotypes, but isolated KT could be an alternative approach in patients with B6-responsive genotypes.

Abstract Background: Time-dependent Cox proportional hazards regression is a popular statistical method used in kidney disease research to evaluate associations between biomarkers collected serially over time with progression to kidney failure. Typically, biomarkers of interest are considered time-dependent covariates being updated at each new measurement using last observation carried forward (LOCF). Recently, joint modeling has emerged as a flexible alternative for multivariate longitudinal and time-to-event data. This study describes and demonstrates multivariate joint modeling using as an example the association of serial biomarkers (plasma oxalate [POX] and urinary oxalate [UOX]) and kidney function among patients with primary hyperoxaluria in the Rare Kidney Stone Consortium Registry. Methods: Time-to-kidney failure was regressed on serially measured biomarkers in two ways: time-dependent LOCF Cox proportional hazards regression and multivariate joint models. Results: In time-dependent LOCF Cox regression, higher POX was associated with increased risk of kidney failure (HR = 2.20 per doubling, 95% CI = [1.38-3.51], p < 0.001) whereas UOX was not (HR = 1.08 per doubling, [0.66–1.77], p = 0.77). In multivariate joint models, estimates suggest higher UOX may be associated with lower risk of kidney failure (HR = 0.42 per doubling [0.15–1.04], p = 0.066), though not statistically significant, since impaired urinary excretion of oxalate may reflect worsening kidney function. Conclusions: Multivariate joint modeling is more flexible than LOCF and may better reflect biological plausibility since biomarkers are not steady-state values between measurements. While LOCF is preferred to naïve methods not accounting for changes in biomarkers over time, results may not accurately reflect flexible relationships that can be captured with multivariate joint modeling.

The incidence of chronic kidney diseases (CKDs) by rare etiologies is growing along with other CKDs. This mini-review discusses the epidemiology, pathogenesis, clinical presentation, and diagnosis of rare kidney disease recurrence after kidney transplantation (KTx) including primary hyperoxaluria (PH), adenine phosphoribosyl transferase (APRT), C3 glomerulopathy (C3 GP), and fibrillary glomerulonephritis (FGN). It was shown that PH, like acute rejection, causes delayed graft function, confusing the physicians. Moreover, C3 GP is more prevalent than FGN among kidney transplant patients. Therefore, it is necessary to monitor rare diseases (RDs) before KTx in patients with any history of bilateral nephrocalcinosis or nephrolithiasis.

Cells have evolved sophisticated molecular control systems to maximize the efficiency of the folding process. However, any subtle alteration of the environment or the protein can lead to misfolding or affect the conformational plasticity of the native states. It has been widely demonstrated that misfolding and/or conformational instability are the underlying mechanisms of several rare disorders caused by enzymatic deficits. In fact, disease-causing mutations often lead to the substitution of amino acids that are crucial for the achievement of a folded conformation, or play a role on the equilibrium between native-state conformers. One of the promising approaches to treat conformational disorders is the use of pharmacological chaperones (PCs), small molecules that specifically bind a target protein and stabilize a functional fold, thus increasing the amount of functionally active enzyme. Molecules acting as PCs are usually coenzymes, substrate analogues behaving as competitive inhibitors, or allosteric modulators. In this review, the general features of PCs are described, along with three examples of diseases (Gaucher disease, Phenylketonuria, and Primary Hyperoxaluria) in which this approach is currently under study at preclinical and/or clinical level.

Abstract Background Primary hyperoxaluria (PH) is a rare inherited autosomal recessive disease caused by disturbed glyoxylate metabolism. The disease is characterized by calcium oxalate crystal deposition in various organs, especially in the kidney. Due to the lack of current understanding of PH, nearly all patients are only initially diagnosed with PH when recurrent lithiasis and progressive end-stage renal disease occur. Many cases are not diagnosed in patients until renal allograft insufficiency occurs after renal transplantation. This case report and literature review aim to emphasize the need for careful pre-transplant PH screening of patients with bilateral nephrocalcinosis or nephrolithiasis. Case presentation Renal allograft insufficiency was diagnosed as PH after kidney transplantation. Here, we detail the complete clinical course, including computed tomography images of the original kidney and renal graft, histopathological images of a biopsy of the transplanted kidney, the results of laboratory and molecular genetic tests, and the treatment. In addition, we reviewed the literature from 2000 to 2021 and analyzed 19 reported cases of PH diagnosed after kidney transplantation, and provide a summary of the characteristics, complications, treatment, and prognosis of these cases. Conclusions By reviewing and analyzing these cases, we concluded that patients with a history of nephrocalcinosis or nephrolithiasis in both kidneys need preoperative screening for PH and appropriate treatment before kidney transplantation. Delayed graft function caused by PH is easily misdiagnosed as acute rejection, and needle biopsy should be performed at an early stage.

Abstract Differentiation of hypertrophic cardiomyopathy phenotypes is challenging but crucial for appropriate management. We report a case of myocardial oxalate deposition as an infrequent cause of infiltrative cardiomyopathy.

Introduction: Primary hyperoxaluria (PH) is a family of 3 rare genetic disorders of hepatic glyoxylate metabolism that lead to overproduction and increased renal excretion of oxalate resulting in progressive renal damage. LDHA inhibition of glyoxylate-to-oxalate conversion by RNA interference (RNAi) has emerged as a potential therapeutic option for all types of PH. LDHA is mainly expressed in the liver and muscles. Methods: Nonclinical data in mice and nonhuman primates show that LDHA inhibition by RNAi reduces urinary oxalate excretion and that its effects are liver-specific without an impact on off-target tissues, such as the muscles. To confirm the lack of unintended effects in humans, we analyzed data from the phase I randomized controlled trial of single-dose nedosiran, an RNAi therapy targeting hepatic LDHA. We conducted a review of the literature on LDHA deficiency in humans, which we used as a baseline to assess the effect of hepatic LDHA inhibition. Results: Based on a literature review of human LDHA deficiency, we defined the phenotype as mainly muscle-related with no liver manifestations. Healthy volunteers treated with nedosiran experienced no drug-related musculoskeletal adverse events. There were no significant alterations in plasma lactate, pyruvate, or creatine kinase levels in the nedosiran group compared with the placebo group, signaling the uninterrupted interconversion of lactate and pyruvate and normal muscle function. Conclusion: Phase I clinical data on nedosiran and published nonclinical data together provide substantial evidence that LDHA inhibition is a safe therapeutic mechanism for the treatment of all known types of PH.

The clinical manifestation of primary hyperoxaluria includes hyperoxaluria and recurrent urinary calculi. In this study, an oxidative damage model was constructed based on oxalate damage to the human renal proximal tubular epithelial cells (HK-2), and a comparative study was carried out on four different sulfated levels of Undaria pinnatifida polysaccharides (UPP0, UPP1, UPP2, and UPP3 with sulfate group [–OSO3−] contents of 1.59%, 6.03%, 20.83%, and 36.39%, respectively) on the repair of oxidatively damaged HK-2 cells. The results showed that after repair by UPPs, cell viability was enhanced, healing ability was improved, the intracellular superoxide dismutase level and mitochondrial membrane potential were increased, malondialdehyde, reactive oxygen species, and intracellular Ca2+ levels were reduced, cellular autophagy was reduced; lysosomal integrity was improved, and cytoskeleton and cell morphology were restored. The ability of repaired cells to endocytose nano-calcium oxalate dihydrate crystals (nano−COD) was enhanced. The activity of UPPs was closely related to their –OSO3− content. A too high or too low –OSO3− content was not conducive to polysaccharide activity, and only UPP2 exhibited the best cell repair ability and strongest ability to promote the cell endocytosis of crystals. UPP2 may be used as a potential agent to inhibit CaOx crystal deposition caused by high oxalate concentration.

Abstract Primary hyperoxaluria (PH) is a group of diseases due to mutations in genes coding for enzymes involved in oxalate metabolism. Three types of PH are identified depending on the gene mutated. Type 1 is the most frequent with 80% of the cases, while PH2 and PH3 are rarer. The severity of renal involvement varies between the three types. Indeed, between 60% and 80% of PH1 but only 20% of PH2 patients will reach end‐stage kidney disease. In PH3 patients, dialysis is uncommon. Because oxalate clearance is impaired in CKD patients, oxalate can precipitate in various organs leading to systemic oxalosis. We report an uncommon presentation of bone oxalosis associated with hypercalcemia in a dialyzed patient. This report emphasizes the difficulties to diagnose primary hyperoxaluria and the challenge of treating dialyzed patients.

Primary hyperoxaluria type I (PH1) is caused by AGXT gene mutations that decrease the functional activity of alanine:glyoxylate aminotransferase. A build-up of the enzyme’s substrate, glyoxylate, results in excessive deposition of calcium oxalate crystals in the renal tract, leading to debilitating renal failure. Oxidation of glycolate by glycolate oxidase (or hydroxy acid oxidase 1, HAO1) is a major cellular source of glyoxylate, and siRNA studies have shown phenotypic rescue of PH1 by the knockdown of HAO1, representing a promising inhibitor target. Here, we report the discovery and optimization of six low-molecular-weight fragments, identified by crystallography-based fragment screening, that bind to two different sites on the HAO1 structure: at the active site and an allosteric pocket above the active site. The active site fragments expand known scaffolds for substrate-mimetic inhibitors to include more chemically attractive molecules. The allosteric fragments represent the first report of non-orthosteric inhibition of any hydroxy acid oxidase and hold significant promise for improving inhibitor selectivity. The fragment hits were verified to bind and inhibit HAO1 in solution by fluorescence-based activity assay and surface plasmon resonance. Further optimization cycle by crystallography and biophysical assays have generated two hit compounds of micromolar (44 and 158 µM) potency that do not compete with the substrate and provide attractive starting points for the development of potent and selective HAO1 inhibitors.

Primary hyperoxaluria (PH) is a rare autosomal recessive metabolic disorder where serum oxalate levels rise due to overproduction. The kidney tubule is a main target for oxalate deposition, resulting in damage to the organ. Kidney failure is rare in these patients. We present a 67-year-old female with hemodialysis-dependent end-stage renal disease likely due to PH type 2 or 3. With extremely high levels of serum oxalate (60.4 μmol/L), this patient had minimal treatment options for her rare disease. This report details a unique presentation of a rare disease where kidney biopsy was instrumental.

Abstract Background Primary hyperoxaluria (PH) is an inherited disease lacking of hepatic oxalic acid metabolic enzymes which could lead to irreverisible renal damage. Currently, liver–kidney transplantation is a curative but highly invasive therapy used to treat patients with PH. However, limited studies have focused on combined liver–kidney transplantation (CLKT) and sequential liver and kidney transplantation (SLKT) in patients with PH. Methods The present study included 201 patients with PH who received both liver and kidney transplants and who were listed on the Scientific Registry of Transplant Recipients from 1987 to 2018. According to the liver–kidney transplant procedure, patients were separated into a CLKT group and a SLKT group. Patient demographics and transplant outcomes were assessed in each group. Results Compared with the SLKT group, The CLKT group got a worse pretransplant dialysis condition in both the proportion of patients under pretransplant dialysis (p = 0.048) and the duration of the pretransplant dialysis (p

Abstract Background Patients with primary hyperoxaluria (PH) often develop kidney stones and chronic kidney disease. Noninvasive urine markers reflective of active kidney injury could be useful to gauge the effectiveness of ongoing treatments. Methods A panel of biomarkers that reflect different nephron sites and potential mechanisms of injury (clusterin, neutrophil gelatinase-associated lipocalin (NGAL), 8-isoprostane (8IP), monocyte-chemoattractant protein 1(MCP-1), liver-type fatty acid binding protein (L-FABP), heart-type fatty acid binding protein (H-FABP), and osteopontin (OPN)) were measured in 114 urine specimens from 30 PH patients over multiple visits. Generalized estimating equations were used to assess associations between biomarkers and 24 h urine excretions, calculated proximal tubular oxalate concentration (PTOx), and eGFR. Results Mean (±SD) age at first visit was 19.5 ± 16.6 years with an estimated glomerular filtration rate (eGFR) of 68.4 ± 21.0 ml/min/1.73m2. After adjustment for age, sex, and eGFR, a higher urine MCP-1 concentration and MCP-1/creatinine ratio was positively associated with CaOx supersaturation (SS). Higher urine NGAL and NGAL/creatinine as well as OPN and OPN/creatinine were associated with higher eGFR. 8IP was negatively associated with PTOx and urinary Ox, but positively associated with CaOx SS. Conclusion In PH patients greater urine MCP-1 and 8IP excretion might reflect ongoing collecting tubule crystallization, while greater NGAL and OPN excretion may reflect preservation of kidney mass and function. CaOx crystals, rather than oxalate ion may mediate oxidative stress in hyperoxaluric conditions. Further studies are warranted to determine whether urine MCP-1 excretion predicts long term outcome or is altered in response to treatment.

Background: Primary hyperoxaluria type 1 (PH1) is a rare genetic disease caused by hepatic overproduction of oxalate, ultimately responsible for kidney stones, kidney failure and systemic oxalosis. Lumasiran, is a liver-directed RNA interference therapeutic agent. It has been shown to reduce hepatic oxalate production by targeting glycolate oxidase, and to dramatically reduce oxalate excretion.Care Report: We present the case of a teenager patient affected by PH1, who entered in the lumasiran compassionate use program. The patient had a rapid and sustained decrease in urinary oxalate/creatinine ratio, with a mean reduction after lumasiran administration of about 70%. During the 18 months long follow-up, urinary oxalate remained low, reaching nearly normal values. Plasma oxalate also decreased dramatically. Normal levels were reached immediately after the first dose and remained consistently low thereafter. During the same follow-up period, eGFR remained stable at about 60 ml/min/1.73 m2, but no new kidney stones were observed. Existing kidney stones did not increase in size. The patient did not suffer renal colic events and did not require further urological interventions.Conclusion: In our severely affected PH1 patient, lumasiran proved to be very effective in rapidly and consistently reducing plasma oxalate and urinary excretion to normal and near-normal levels, respectively. In the 18 months long follow-up post-lumasiran, the eGFR remained stable and the patient showed clinical improvements. As far as we know, this report covers the longest observation period after initiation of this novel RNAi therapy.

Primary hyperoxaluria type 1 is a rare genetic condition characterized by oxalate deposition in the kidneys. We report findings of an 8-month old female presenting with failure to thrive, poor oral intake, and kidney stones resulting in the diagnosis of primary hyperoxaluria type 1. The patient exhibits a unique presentation without renal failure at the time of diagnosis suggesting a previously unreported comorbidity in early stages of disease.

Background Primary hyperoxaluria (PH), a rare inborn error of glyoxylate meta bolism causing overproduction of oxalate, is classified into three genetic subgroups: type 1–3 (PH1–PH3) caused by AGXT, GRHPR, and HOGA1 gene mutations, respectively. We performed a retrospective case series study of Korean pediatric patients with PH. Methods In total, 11 unrelated pediatric patients were recruited and their phenotypes and genotypes were analyzed by a retrospective review of their medical records. Results Mutational analyses revealed biallelic AGXT mutations (PH1) in nine patients and a single heterozygous GRHPR and HOGA1 mutation in one patient each. The c.33dupC was the most common AGXT mutation with an allelic frequency of 44%. The median age of onset was 3 months (range, 2 months–3 years), and eight patients with PH1 presented with end stage renal disease (ESRD). Patients with two truncating mutations showed an earlier age of onset and more frequent retinal involvement than patients with one truncating mutation. Among eight PH1 patients presenting with ESRD, five patients were treated with intensive dialysis followed by liver transplantation (n=5) with/without subsequent kidney transplantation (n=3). Conclusion Most patients presented with severe infantile forms of PH. Patients with two truncating mutations displayed more severe phenotypes than those of patients with one truncating mutation. Sequential liver and kidney transplantation was adopted for PH1 patients presenting with ESRD. A larger nation-wide multicenter study is needed to confirm the genotype-phenotype correlations and outcomes of organ transplantation.

Abstract Background Primary hyperoxaluria (PH) is a rare inborn disorder of the metabolism of glyoxylate, which causes the hallmark production oxalate and forms insoluble calcium oxalate crystals that accumulate in the kidney and other organs. Since the manifestation of PH varies from recurrent nephrolithiasis, nephrocalcinosis, and end-stage renal disease with age at onset of symptoms ranging from infancy to the sixth decade, the disease remains undiagnosed until after kidney transplantation in some cases. Case presentation Herein, we report 3 cases of PH diagnosed after kidney transplantation failure, providing the comprehensive clinical course, the ultrasonic image of renal graft and pathologic image of the biopsy, highlighting the relevance of biopsy findings and the results of molecular genetic testing. We also focus on the treatment and the unfavorable outcome of the patients. Meanwhile, we review the literature and show the additional 10 reported cases of PH diagnosed after kidney transplantation. Additionally, we discuss the progressive molecular understanding of the mechanisms involved in PH and molecular therapy. Conclusions Overall, the necessity of preoperative screening of PH in all patients even with a minor history of nephrolithiasis and the importance of proper treatment are the lessons we learn from the 3 cases, which prompt us to avoid tragedies.

Background: Primary hyperoxaluria type 1 (PH1) is a rare monogenic disorder characterized by excessive hepatic production of oxalate leading to recurrent nephrolithiasis, nephrocalcinosis, and progressive kidney damage, often requiring renal replacement therapy (RRT). Though systemic oxalate deposition is well-known, the natural history of PH1 during RRT has not been systematically described. In this study, we describe the clinical, laboratory, and echocardiographic features of a cohort of PH1 patients on RRT.Methods: Patients with PH1 enrolled in the Rare Kidney Stone Consortium PH Registry who progressed to require RRT, had ≥2 plasma oxalate (pOx) measurements 3–36 months after start of RRT, and at least one pair of pOx measurements between 6 and 18 months apart were retrospectively analyzed. Clinical, echocardiographic, and laboratory results were obtained from the Registry.Results: The 17 PH1 patients in our cohort had a mean total HD hours/week of 17.4 (SD 7.9; range 7.5–36) and a range of age of RRT start of 0.2–75.9 years. The average change in plasma oxalate (pOx) over time on RRT was −0.74 [−2.9, 1.4] μmol/L/month with the mean pOx never declining below 50 μmol/L. Over time on RRT, oxalosis progressively developed in multiple organ systems. Echocardiography performed on 13 subjects showed worsening of left ventricular global longitudinal strain correlated with pOx (p < 0.05).Conclusions: Even when a cohort of PH1 patients were treated with intensified RRT, their predialysis pOx remained above target and they developed increasing evidence of oxalosis. Echocardiographic data suggest that cardiac dysfunction could be related to elevated pOx and may worsen over time.

Background: Primary hyperoxaluria type 1 (PH1) is a rare autosomal recessive disease caused by a mutation in the AGXT gene, resulting in deficiency of the alanineglyoxylate:aminotransferase enzyme. It is characterized by accumulation of oxalate in the kidneys and other organs. Case Presentation: A Syrian woman with a history of nephrolithiasis and heterozygosity for factor V Leiden and prothrombin gene mutations presented with postpartum renal failure. She required initiation of renal replacement therapy at 14 weeks postpartum. Kidney biopsy showed severe acute and chronic crystalline deposition consistent with oxalate nephropathy. Genetic testing revealed a Gly170Arg mutation in the AGXT gene, confirming the diagnosis of PH1. Conclusions: The diagnosis of PH should be considered in patients with severe, recurrent calcium oxalate nephrolithiasis. Early treatment with pyridoxine reduces urinary oxalate excretion and can delay progression to end-stage renal disease (ESRD). After ESRD, intensive dialysis is needed to prevent systemic oxalate accumulation and deposition. Combined liver and kidney transplantation is curative. In our patient, we anticipate that liver transplantation will cure both the hyperoxaluria and the hypercoagulable state.

Abstract Background Substrate reduction therapy with analogs reduces the accumulation of substrates by inhibiting the metabolic pathways involved in their biosynthesis, providing new treatment options for patients with primary hyperoxalurias (PHs) that often progress to end-stage renal disease (ESRD). This research aims to evaluate the inhibition efficacy of Hydroxy-L-proline (HYP) analogs against calcium oxalate (CaOx) crystal formation in the Drosophila Melanogaster (D. Melanogaster) by comparing them with Pyridoxine (Vitamin B6). Methods Three stocks of Drosophila Melanogaster (W118, CG3926 RNAi, and Act5C-GAL4/CyO) were utilized. Two stocks (CG3926 RNAi and Act5C-GAL4 /CyO) were crossed to generate the Act5C > dAGXT RNAi recombinant line (F1 generation) of D. Melanogaster which was used to compare the efficacy of Hydroxy-L-proline (HYP) analogs inhibiting CaOx crystal formation with Vitamin B6 as the traditional therapy for primary hyperoxaluria. Results Nephrolithiasis model was successfully constructed by downregulating the function of the dAGXT gene in D. Melanogaster (P-Value = 0.0045). Furthermore, the efficacy of Hydroxy-L-proline (HYP) analogs against CaOx crystal formation was demonstrated in vivo using D. Melanogaster model; the results showed that these L-Proline analogs were better in inhibiting stone formation at very low concentrations than Vitamin B6 (IC50 = 0.6 and 1.8% for standard and dietary salt growth medium respectively) compared to N-acetyl-L-Hydroxyproline (IC50 = 0.1% for both standard and dietary salt growth medium) and Baclofen (IC50 = 0.06 and 0.1% for standard and dietary salt growth medium respectively). Analysis of variance (ANOVA) also showed that Hydroxy-L-proline (HYP) analogs were better alternatives for CaOx inhibition at very low concentration especially when both genetics and environmental factors are intertwined (p

Background and Aims: The perioperative management of patients presenting for simultaneous liver and kidney transplantation (SLKT) is a complex process. We analysed SLKTs performed in our institution to identify preoperative,intraoperative and post-operative challenges encountered in the management. Methods: We retrospectively studied the case records of 12 patients who underwent SLKT between 2009 and 2014 and analysed details of pre-operative evaluation and optimisation, intraoperative anaesthetic management and the implications of use of perioperative continuous renal replacement therapy (CRRT) and the post-operative course of these patients. Results: Of the total 12 cases, 4 were under 16 years of age. The indications for SLKT were primary hyperoxaluria (5), congenital hepatic fibrosis with polycystic kidney disease (2), ethanol-related end-stage liver disease (ESLD) with hepatorenal syndrome type 1 (1). Four patients had ESLD with end-stage renal disease due to other causes. Six recipients received live donor grafts and 6 patients received cadaveric grafts. Seven patients received intraoperative CRRT. Mean duration of surgery was 12.5 h. Cardiac output monitors used were trans-oesophageal echocardiogram (2), pulmonary artery catheter (1) and pulse contour cardiac output monitor (3). There was 1 sepsis-related mortality on 7th post-operative day. Conclusion: A thorough pre-operative evaluation and optimisation, knowledge and anticipation of potential problems, and meticulous intraoperative fluid management guided by appropriate monitoring and use of CRRT when needed can help in achieving successful outcomes.

Calcium oxalate (CaOx) crystal deposition is a common finding immediately after kidney transplantation. However, small depositions of CaOx could be benign while extensive depositions lead to poor graft outcome. Here we report three cases with end-stage renal disease (ESRD), bilateral nephrolithiasis, and unknown diagnosis of primary hyperoxaluria (PH) who underwent a renal transplant and experienced an early-onset graft failure. Although an acute rejection was suspected, renal allograft biopsies and subsequent allograft nephrectomies showed extensive CaOx deposition, which raised a suspicion of PH. Even though increased urinary excretion of CaOx was found in all patients, this diagnosis could be confirmed with further tests including genetic study and metabolic assay. In conclusion, massive CaOx deposition in kidney allograft is an important cause of poor allograft survival and needs special management. Furthermore, our cases suggest patients with ESRD and a history of nephrolithiasis should be screened for elevated urinary oxalate excretion and rule out of PH.

Background: Primary hyperoxaluria is a rare disease characterized by the excessive production and accumulation of oxalate in the body. Methods: We described the case of an infant with primary hyperoxaluria type who had end-stage renal failure in the second month of life, family history of deaths due to renal disease, renal biopsy showing intense deposition of oxalate crystals 111 the lumen, tubular cells, and kidney interstitium, with secondary glomerular disorder. Conclusions: primary hyperoxaluria type I should be regarded as one of the differential diagnoses of renal failure in the first months of life, especially when no suggestive history of other diseases is present

Primary hyperoxaluria type-1 (PH1) is a rare inherited autosomal recessive disorder in which a deficiency of the hepatic enzyme alanine-glyoxylate aminotransferase leads to endogenous oxalate overproduction, renal failure, systemic oxalate deposition and death. As hemodialysis provides insufficient oxalate clearance, patients ultimately require both liver and kidney transplantation for correction of the metabolic abnormality and oxalate excretion. Herein, we describe a young adult male with end-stage renal disease and systemic oxalosis causing progressive disabling multi-organ dysfunction while awaiting transplantation. We review the literature regarding liver-kidney transplantation and suggest that for patients with PH1, a standardized assessment of organ dysfunction and functional impairment may improve identification of patients requiring urgent transplantation thereby reducing the morbidity and mortality that can occur with delayed transplantation.

RESUMEN La hiperoxaluria primaria es un trastorno del metabolismo autosómico recesivo que origina una hiperproducción hepática de oxalato, que no puede ser metabolizado por el hígado y se elimina por vía renal formando litiasis, nefrocalcinosis y ocasionando un deterioro progresivo y precoz de la función renal que, generalmente, a pesar del tratamiento médico precisará de una terapia renal sustitutiva. La hiperoxaluria primaria (HOP) tipo 1 es el trastorno más frecuente, se debe a un déficit de la enzima alanina-glicolato aminotransferasa que se encuentra en los peroxisomas hepáticos. Por tanto, el trasplante hepatorrenal simultáneo (THRS) es el tratamiento definitivo para los pacientes con enfermedad renal crónica terminal. Sin embargo, algunos resultados sugieren que la morbimortalidad es mayor al realizar este procedimiento frente al trasplante renal aislado. Se presentan cinco pacientes adultos con hiperoxaluria primaria y un filtrado glomerular medio de 20,2 ± 1,3 ml/min/1,73 m2 a los que se les realizó un THRS entre 1999 y 2015 en el Hospital Universitario 12 de Octubre. No se observó recurrencia de la enfermedad ni pérdida del injerto hepático o renal durante el postoperatorio y únicamente un episodio de rechazo agudo tardío sin pérdida del injerto renal. La supervivencia de los receptores fue del 100% con una mediana de seguimiento de 84 meses. Debido a que el THRS permite la curación de la enfermedad y constituye una técnica segura, con una baja morbimortalidad y elevada supervivencia, debe considerarse como el tratamiento de elección en la hiperoxaluria primaria con enfermedad renal terminal.