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Kidney stones consist largely of calcium oxalate (CaOx), and induce inflammation and damage to renal tubular epithelial (RTE) cells, leading to CaOx nephrocalcinosis. Sirtuin 6 (SIRT6), a sirtuin family member, is an NAD-dependent deacetylase that has been associated with cell damage and inflammation in various diseases. This study evaluated the efficacy of the novel SIRT6 allosteric agonist MDL-800 in treating CaOx nephrocalcinosis. The data revealed that MDL-800 preconditioning alleviated CaOx crystal-mediated damage in RTE cells by suppressing inflammation, as shown in both cell and animal studies. Furthermore, MDL-800 enhanced SIRT6 deacetylation at H3K9AC. However, MDL-800 pretreatment of SIRT6-knockdown (KD) RTE cells did not protect against CaOx crystal-induced cell damage and inflammation. Mechanistically, MDL-800 markedly downregulated the expression of IL-1β, TNF-α, MCP-1, and IL-6 in mouse kidneys via the TRL4/NF-κB pathway. These data indicated that MDL-800 reduces inflammation and inhibits the TLR4/NF-κB axis by increasing SIRT6-modulated histone deacetylation, thus inhibiting and protecting against inflammatory responses. In summary, MDL-800 modulation of SIRT6-mediated inflammation and renal damage represents a novel strategy for treating CaOx-mediated nephrocalcinosis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Calcium oxalate (CaOx) crystals are the main constituents of renal crystals in humans and induce tubular lumen damage in renal tubules, leading to renal calcium deposition and kidney stone formation. Oxidative stress and inflammation play important roles in regulating calcium oxalate-induced injury. Here, we evaluated the efficacy in inhibiting oxidation and inflammation of pectinolinarigenin, a biologically active natural metabolite, in CaOx nephrocalcinosis and further explored its targets of action. First, we developed cellular and mouse models of calcium oxalate renal nephrocalcinosis and identified the onset of oxidative stress and inflammation according to experimental data. We found that pectolinarigenin inhibited this onset while reducing renal crystal deposition. Network pharmacology was subsequently utilized to screen for hypoxia-inducible factor-1α (HIF-1α), a regulator involved in the body's release and over-oxidation of inflammatory factors. Finally, molecular docking, cellular thermal shift assay, and other experiments to detect HIF-1α expression showed that pectolinarigenin directly combined with HIF-1α and prevented downstream reactive oxygen species activation and release. Our results indicate that pectolinarigenin can target and inhibit HIF-1α-mediated inflammatory responses and oxidative stress damage and be a novel drug for CaOx nephrocalcinosis treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Aim: Perturbed calcium homeostasis limits life expectancy in familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC). This rare disease occurs by loss-of-function mutations in CLDN16 or CLDN19 genes, causing impaired paracellular reabsorption of divalent cations along the cortical thick ascending limb (cTAL). Only partial compensation takes place in the ensuing late distal convoluted tubule, connecting tubule, and collecting duct, where the luminal transient receptor potential channel V5 (TRPV5), as well as basolateral plasma membrane calcium ATPase (PMCA) and sodium-potassium exchanger (NCX1) mediate transcellular Ca 2+ reabsorption. The loop diuretic furosemide induces compensatory activation in these distal segments. Normally, furosemide enhances urinary calcium excretion via inhibition of the aforementioned cTAL. As Ca 2+ reabsorption in the cTAL is already severely impaired in FHHNC patients, furosemide may alleviate hypercalciuria in this disease by activation of the distal transcellular Ca 2+ transport proteins., Methods: Cldn16-deficient mice (Cldn16 -/- ) served as a FHHNC model. Wild-type (WT) and Cldn16 -/- mice were treated with furosemide (7 days of 40 mg/kg bw) or vehicle. We assessed renal electrolyte handling (metabolic cages) and key divalent transport proteins., Results: Cldn16 -/- mice show higher Ca 2+ excretion than WT and compensatory stimulation of Cldn2, TRPV5, and NCX1 at baseline. Furosemide reduced hypercalciuria in Cldn16 -/- mice and enhanced TRPV5 and PMCA levels in Cldn16 -/- but not in WT mice., Conclusions: Furosemide significantly reduces hypercalciuria, likely via upregulation of luminal and basolateral Ca 2+ transport systems in the distal nephron and collecting duct in this model for FHHNC., (© 2023 The Authors. Acta Physiologica published by John Wiley & Sons Ltd on behalf of Scandinavian Physiological Society.)

Background: Pharmacological therapy may be useful in the treatment of moderate to severe hypercalcemia in patients with infantile hypercalcemia-1 (HCINF1) due to pathogenic variants in the cytochrome P450 24 subfamily A member 1 (CYP24A1). Rifampin is an antituberculosis drug that is a potent inducer of cytochrome P450 3 subfamily A member 4, which is involved in an alternative catabolic pathway of vitamin D. The efficacy of rifampin in improving hypercalcemia was previously reported, but many questions remain on the long-term efficacy and safety. The aim of the study is to test the long-term efficacy and safety of rifampin in a patient with HCINF1., Methods: We report clinical, biochemical, and imaging features of a 23-year-old man affected by HCINF1 with moderate hypercalcemia (12.9 mg/dL), symptomatic nephrolithiasis, nephrocalcinosis, and impaired kidney function [estimated glomerular filtration rate (eGFR) 60 mL/min/1.73 m2] treated with rifampin for an overall period of 24 months. Kidney, liver, and adrenal function were evaluated at every follow-up visit., Results: In 2 months, rifampin induced a normalization of serum calcium (9.6 mg/dL) associated with an improvement of kidney function (eGFR 92 mL/min/1.73 m2) stable during the treatment. After 15 months, rifampin was temporally withdrawn because of asthenia, unrelated to impairment of adrenal function. After 3 months, the timing of drug administration was shifted from the morning to the evening, obtaining the remission of asthenia. At the end of follow-up, the nephrolithiasis disappeared and the nephrocalcinosis was stable., Conclusions: Rifampin could represent an effective choice to induce a stable reduction of calcium levels in patients with HCINF1, with a good safety profile., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The present study was the first prospective cohort evaluated the efficacy and safety of different doses of calcitriol in XLH children. The results suggested that a dose of 40 ng/kg/day calcitriol, compared with 20 ng/kg/day, was more effective in relieving the rickets, with similar safety outcomes. Further investigations were expected to set more dose groups., Introduction: Dose recommended for calcitriol in X-linked hypophosphatemia (XLH) varies in different studies. Therefore, we aimed to compare the efficacy as well as the safety of 20 ng/kg/d and 40 ng/kg/d calcitriol in Chinese XLH pediatrics population., Methods: A 2-year, randomized, open-label, prospective study recruited 68 XLH children, which were randomized to receive either 40 ng/kg/day or 20 ng/kg/day calcitriol. Efficacy endpoints were the total Thacher ricket severity score (RSS) change from baseline to month 12 and 24, the difference in serum TALP level, fasting serum phosphate level, body height Z-score, and frequency of dental abscess. Safety assessments were done using renal ultrasound nephrocalcinosis grades (0-4), fasting serum and 24 h urine calcium level, and the occurrence of hyperparathyroidism., Results: The decrease in the total RSS from baseline was more significant in the high-dose group at 12 (difference 0.87, p = 0.049) and 24 month (difference 1.23, p = 0.011). The serum TALP level was significantly lower in the high-dose group at 6 months. Pi level, height Z-score change, frequency of dental abscess and ratio of de novo nephrocalcinosis were comparable. A lower incidence of secondary hyperparathyroidism was seen in the high-dose group (p < 0.0001)., Conclusion: For the first time in this prospective cohort, 40 ng/kg/d calcitriol was shown to be the more effective therapy in XLH children than the 20 ng/kg/d. Moreover, 40 ng/kg/d calcitriol was not associated with increasing adverse events., Trial Registration: ClinicalTrials.gov Identifier: NCT 03,820,518., (© 2022. The Author(s).)

Background: Lumasiran, a sub-cutaneous RNA-interference therapy, has been recently approved for primary hyperoxaluria type 1 (PH1), with doses and intervals according to body weight. Little is known as to its use in infants; the aim of this study was to describe treatment outcome in 3 infants who received lumasiran therapy before 2 years of age., Case-Diagnosis/treatment: Patient 1 was diagnosed antenatally and received lumasiran from day 9. According to the product information template (PIT), he received monthly lumasiran (3 times at 6 mg/kg, then 3 mg/kg), with hyperhydration and potassium citrate. Despite decreased plasma oxalate levels, persistent normal kidney function, and good tolerance, kidney ultrasound performed after 2 months found nephrocalcinosis, without normalization of urinary oxalate (UOx). The dose was increased back to 6 mg/kg, inducing a normalization in UOx. Nephrocalcinosis started to improve at month 10. Patient 2 was diagnosed at 2.5 months (acute kidney failure); nephrocalcinosis was present from diagnosis. She received monthly lumasiran (6 mg/kg), with progressive decrease in UOx and substantial improvement in kidney function but stable nephrocalcinosis after 9 injections. Patient 3 was diagnosed fortuitously (nephrocalcinosis) at 3.5 months and received lumasiran before genetic diagnosis, leading to decreased UOx and maintenance of normal kidney function. Nephrocalcinosis improved after 5 injections., Conclusions: This report presents the youngest children treated with lumasiran worldwide. Lumasiran seems effective without side effects in infants but does not completely prevent the onset of nephrocalcinosis in the most severe forms. Higher doses than those proposed in the PIT might be required because of hepatic immaturity., (© 2022. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Intrarenal calcium oxalate (CaOx) crystals induce renal tubular epithelial cell (TEC) inflammatory and oxidative injury. This study is aimed at exploring potential therapeutic lipid components in kidney stones because lipids are involved in the development of several diseases and indicate the risk of kidney stones. Serum specimens were collected from 35 kidney stone patients and 35 normal controls. The lipid components in serum were measured, and differences were analyzed. The documented biological importance was comprehensively reviewed to identify lipids that differed significantly between the two groups to find potential agents associated with kidney stones. CaOx nephrocalcinosis mouse model was established to examine the therapeutic effects of specific lipids on CaOx deposition and CaOx-induced oxidative renal injury. Several lipids with significantly different levels were present in the serum of patients with stones and normal controls. Resolvin D1 (RvD1) (4.93-fold change, P < 0.001) and protectin D1 (PD1) (5.06-fold change, P < 0.001) were significantly decreased in the serum of patients with kidney stones, and an integrative review suggested that these factors might be associated with inflammatory responses, which is a crucial mechanism associated with stone damage. The administration of RvD1 and PD1 significantly inhibited kidney CaOx deposition and suppressed CaOx-induced renal tubular cell inflammatory injury and necrosis in a CaOx nephrocalcinosis mouse model. Furthermore, RvD1 and PD1 facilitated the expression of the oxidative indicator superoxide dismutase 2 (SOD2), inhibited NADPH oxidase 2 (NOX2) expression, and diminished intracellular reactive oxygen species (ROS) levels. This study preliminarily elucidated the role of lipids in kidney stones. The inhibitory effects of RvD1 and PD1 on oxidative damage induced by CaOx deposition provide a promising perspective for kidney stone treatment strategies., Competing Interests: The authors have declared that no conflicts of interest exist., (Copyright © 2022 Bohan Wang et al.)

Introduction: Chronic hypoparathyroidism is a relatively rare disease associated with multicomponent medical therapy and various complications. The analysis of large databases of patients with chronic hypoparathyroidism is a necessary tool to enhance quality of medical care, as well as to determine the optimal clinical and therapeutic approaches, and prognostic markers of the disease., The Aim: of this study is to estimate the clinical and biochemical profile, long-term complications, medical therapy and disease control of the patients with chronic postsurgical and non-surgical hypoparathyroidism., Materials and Methods: the cross-sectional, observational, continuous study was based on the Russian Registry of patients with hypoparathyroidism. 544 patients from 63 regions of the Russian Federation were included in this study., Results: The majority of cases had postsurgical etiology (88.4%). Postsurgical hypoparathyroidism prevailed in females (р<0.001). About a half of patients had blood calcium and phosphorus targets, 56 and 52% respectively. Nephrolithiasis was confirmed in 32.5%, nephrocalcinosis - in 12.3% of cases. The risk of nephrocalcinosis/nephrolithiasis increased by 1.85 times with disease duration more than 4.5 years. The cataract was found in 9.4%. The cut-off point for the development of cataracts was 9.5 years, with a 6.96-fold increased risk. The longer duration of hypoparathyroidism of any etiology was associated with more frequent cataract (p=0.0018).We found brain calcification in 4%, arrhythmias in 7.2% and neuropsychiatric symptoms in 5.15% of cases. Generally, the BMD in the studied group corresponded to age values, and there was no evidence for the phenomenon of high bone density. TBS was consistent with normal bone microarchitectonics. In our study, the majority of patients (83.5%) was treated with standard therapy of calcium and vitamin D supplements. 5 patients with severe disease course were treated with rhPTH (1-34)., Conclusions: Analysis of the presented database indicates insufficient diagnosis of the complications associated with chronic hypoparathyroidism. Overall, hypoparathyroidism is associated with higher risks of renal stone formation, decreased GFR, cataract especially in patients with longer duration of disease., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Kovaleva, Eremkina, Elfimova, Krupinova, Bibik, Maganeva, Gorbacheva, Dobreva, Melnichenko and Mokrysheva.)

The roles of the lncRNA X inactive specific transcript (XIST) in many diseases, including cancers and inflammatory sickness, have been previously elucidated. However, renal calculus remained poorly understood. In this study, we revealed the potential effects of XIST on kidney stones that were exerted via inflammatory response and oxidative stress mechanisms. We established a glyoxylate-induced calcium oxalate (CaOx) stone mouse model and exposed HK-2 cells to calcium oxalate monohydrate (COM). The interactions among XIST, miR-223-3p, and NOD-like receptor protein 3 (NLRP3) and their respective effects were determined by RNAs and protein expression, luciferase activity, and immunohistochemistry (IHC) assays. Cell necrosis, reactive oxygen species (ROS) generation, and inflammatory responses were detected after silencing XIST, activating and inhibiting miR-223-3p, and both knocking down XIST and activating miR-223-3p in vitro and in vivo. The XIST, NLRP3, caspase-1, and IL-1 β levels were notably increased in kidney samples from glyoxylate-induced CaOx stone model mice. XIST knockdown significantly suppressed the inflammatory damage and ROS production and further attenuated oxalate crystal deposition. miRNA-223-3p mimics also exerted the same effects. Moreover, we verified the interactions among XIST, miRNA-223-3p and NLRP3, and the subsequent effects. Our results suggest that the lncRNA XIST participates in the formation and progression of renal calculus by interacting with miR-223-3p and the NLRP3/Caspase-1/IL-1 β pathway to mediate the inflammatory response and ROS production., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Peng Lv et al.)

SHORT syndrome is a rare developmental disorder frequently associated with growth failure and insulin resistant diabetes mellitus (IRDM). Since GH has a diabetogenic effect, GH therapy has been regarded as a contraindication. We observed a Brazilian girl with SHORT syndrome who received GH therapy from 4 6/12 years of age for SGA short stature. GH dosage was increased from 0.23 to 0.36 mg/kg/week, but statural response to GH therapy remained poor. Her blood HbA1c level, though it remained 5.5-6.0% in childhood, began to elevate with puberty and increased to 9.2% at 10 6/12 years of age, despite the discontinuation of GH therapy at 9 11/12 years of age. Laboratory studies indicated antibody-negative IRDM. She was treated with metformin and canagliflozin (a sodium glucose co-transporter 2 (SGLT2) inhibitor), which ameliorated overt diurnal hyperglycemia and mild nocturnal hypoglycemia and reduced her blood HbA1c around 7%. Whole exome sequencing revealed a de novo heterozygous pathogenic variant (c.1945C>T:p.(Arg649Trp)) in PIK3R1 known as the sole causative gene for SHORT syndrome. Subsequent literature review for patients with molecularly confirmed SHORT syndrome revealed the development of IRDM in 10 of 15 GH-untreated patients aged ≥12 years but in none of three GH-treated and six GH-untreated patients aged ≤10 years. These findings imply a critical role of pubertal development and/or advanced age rather than GH therapy in the development of IRDM, and a usefulness of SGLT2 inhibitor in the treatment of IRDM.

Aim: To clarify the differences in overall survival (OS) depending on the presence or absence of hypomagnesemia and the type of epidermal growth factor receptor antibody as first-line therapy for metastatic colorectal cancer (mCRC)., Patients and Methods: We retrospectively compared the OS in 68 patients who received cetuximab or panitumumab for mCRC at Ogaki Municipal Hospital (Ogaki, Japan) between January 2010 and December 2019., Results: The complete and partial response rates in the cetuximab and panitumumab groups were 60.0% and 72.0%, respectively (p=0.470). The OS was significantly longer in the panitumumab group (median=1,007 days, range=208-1,433 days) than in the cetuximab group (median=735 days, range=181-2,391 days; p=0.047). Hypomagnesemia did not contribute to differences in OS in the two groups., Conclusion: Panitumumab may lead to a longer OS than cetuximab as first-line treatment of mCRC. The presence or absence of hypomagnesemia in cetuximab- or panitumumab-treated patients did not affect OS., (Copyright © 2020 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: SHORT syndrome is a rare inherited multisystem disease that includes characteristic facial features, growth retardation, and metabolic anomalies and is related to heterozygous mutations in the PIK3R1 gene. However, it is difficult to ascertain the relationship between the phenotype and the genotype quickly and efficiently., Methods: We report two Chinese girls with SHORT syndrome who presented with growth retardation, dysmorphic features, insulin resistance, and diabetes. Comprehensive medical evaluations were collected, including anthropometric measurements, laboratory measurements, and imaging examinations. Whole exome and Sanger sequencing was performed to detect and confirm the underlying genetic mutations in these patients. We prescribed metformin for the patients., Results: The patients both presented diabetes, insulin resistance, short stature, lipodystrophy, and characteristic facial dysmorphic features. A heterozygous mutation was detected in the PIK3R1 gene (c.1615&#95;1617del) of Patient 1. The analysis of patient 2 revealed another PIK3R1 mutation (c.1945C>T). After family validation, neither their parents nor their brothers had similar clinical presentations or carried the same mutation., Conclusion: We identified two de novo heterozygous mutations in PIK3R1 as the cause of SHORT syndrome in two Chinese girls. Additionally, in terms of diabetes control, metformin works well in the early treatment stage., (© 2020 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Intrarenal calcium oxalate (CaOx) crystals induce renal tubular epithelial cells (TECs) injury and inflammation, which involve Toll-like receptor 4 (TLR4)/interferon regulatory factor 1 (IRF1) signaling. Additionally, infiltrating macrophages (Mϕs) might influence intrarenal CaOx crystals and CaOx-induced renal injury. Although the roles of nuclear factor erythroid 2-related factor 2 (Nrf2) in regulating inflammation and macrophage polarization are well characterized, its potential mechanisms in regulating CaOx nephrocalcinosis remain undefined. Methods: We used a Gene Expression Omnibus dataset to analyze gene-expression profiles. Luciferase reporter, western blot, quantitative polymerase chain reaction, immunofluorescence staining, fluorescence in situ hybridization, positron emission tomography computed tomography imaging, flow cytometry, and chromatin immunoprecipitation assays were employed to study the mechanism of miR-93-TLR4/IRF1 regulation by Nrf2. Anti-inflammatory activity and regulation of macrophage polarization by Nrf2 were investigated in vitro and in vivo . Results: We found that stone-mediated kidney inflammation significantly affected stone growth, and that sulforaphane attenuated CaOx nephrocalcinosis-induced kidney injury and renal CaOx crystals deposition. Additionally, Nrf2 levels significantly increased and negatively correlated with TLR4 and IRF1 levels in a mouse model of CaOx nephrocalcinosis following sulforaphane treatment. Moreover, Nrf2 suppressed TLR4 and IRF1 levels and decreased M1-macrophage polarization which induced by supernatants from COM-stimulated TECs in vitro . In terms of mechanism, transcription factor analyses, microRNA microarray, and chromatin immunoprecipitation assays showed that Nrf2 exhibited positive transcriptional activation of miR-93-5p. In addition, Luciferase reporter, qRT-PCR, and western blot validated that miR-93-5p targets TLR4 and IRF1 mRNA. Furthermore, suppressed miR-93-5p expression partially reversed Nrf2-dependent TLR4/IRF1 downregulation. Conclusions: The results suggested that sulforaphane might promote M2Mϕ polarization and inhibit CaOx nephrocalcinosis-induced inflammatory injury to renal tubular epithelial cells via the Nrf2-miR-93-TLR4/IRF1 pathway in vitro and in vivo., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Burosumab (KRN23) is an FGF23 neutralizing antibody that has been the subject of several recent clinical trials principally focused on the treatment of hypophosphatemic rickets in patients with X-linked hypophosphatemia (XLH). Since the first publications in 2014, these trials have demonstrated efficacy with minimal safety concerns in both adult and pediatric cohorts. These studies have used dose-escalation to establish a dosing regimen that is well-tolerated in clinical use. This review summarizes the clinical trial data with respect to burosumab treatment in adults and children as well as noting several clinical trials currently underway. While burosumab appears transformative for the treatment of XLH, long term follow-up studies would be required to allay concerns over the potential for nephrocalcinosis and cardiac calcification. While these do not appear to be problematic in current trials, the effects of chronic or lifelong treatment have yet to be established., (Copyright © 2020 Schindeler, Biggin and Munns.)

Loss-of-function mutations in CYP24A1 (MIM 126065 20q13.2), the gene encoding the 24-hydroxylase responsible for 25-OH-D and 1,25-(OH) 2 D degradation, are identified in about 20% of patients presenting Idiopathic Infantile Hypercalcemia (IIH) (MIM 143880). Common features of this autosomal recessive condition included hypercalcemia with hypercalciuria, suppressed PTH and a high 25-OH-D 3 :24,25-(OH) 2 D 3 ratio. Medical care mainly relies on sun protection and life-long contraindication of vitamin D to avoid complications such as early nephrocalcinosis and renal failure. Molecular diagnosis therefore keeps a crucial place in the diagnosis of IIH, and genetic counseling should be systematically recommended to prevent vitamin D administration in affected siblings. In this report is described the molecular characterization of a CYP24A1 deletion identified in two unrelated families. This highlights the potential role of CYP24A1 copy number variations (CNV) in IIH. Considering the presence of CNV affecting CYP24A1 in public databases, CNV analysis should be systematically added to the sequencing studies in IIH. Targeted Massively Parallel Sequencing (MPS) study coupled with a CNV detection tool called CovCop is a powerful method to detect genic rearrangement and improve genetic analysis., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Mutations in the SLC34A3 gene, encoding the sodium/phosphate cotransporter 2C (NPTIIc), induce decreased renal phosphate reabsorption, hypophosphatemia, decreased fibroblast growth factor 23 and parathyroid hormone, and increased 1,25-dihydroxyvitamin D (1,25[OH] 2 D) levels. The complete phenotype is characterized by hypophosphatemia, hypercalciuria, and nephrolithiasis/nephrocalcinosis, leading to chronic kidney disease and osteoporosis in adults. We report a 15-year-old boy referred for nephrocalcinosis. The patient demonstrated hypercalcemia, hypercalciuria, normal serum phosphate level, normal tubular phosphate reabsorption, and increased serum 1,25(OH) 2 D level with suppressed serum parathyroid hormone. Compound heterozygous mutations in SLC34A3 were found. Hydrochlorothiazide failed to decrease calciuria. Fluconazole, an inhibitor of 1α-hydroxylase, was effective in normalizing calciuria without decreasing glomerular filtration rate. We conclude that children with SLC334A3 mutations can present with a less-typical phenotype, having normal serum phosphate levels and normal renal phosphate reabsorption. Genetic abnormalities of NPTIIc should be considered in cases of increased 1,25(OH) 2 D levels without mutations in CYP24A1. The utility of fluconazole to decrease 1,25(OH) 2 D levels requires confirmation in larger studies., (Copyright © 2019 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Background: Under physiological conditions, proximal tubular phosphate reabsorption via NaPi-IIa (and NaPi-IIc) ensures the maintenance of phosphate homeostasis. Impairment of NaPi-IIa, encoded by SLC34A1, is associated with various overlapping clinical syndromes, including hypophosphatemic nephrolithiasis with osteoporosis, renal Fanconi's syndrome with chronic kidney disease, and idiopathic infantile hypercalcemia and nephrocalcinosis., Methods: A patient was referred to our hospital due to hyponatremia, hyperkalemia, and hypophosphatemia, as well as persistent hypercalcemia after fluid therapy and sodium replacement. At admission to our hospital, potassium and sodium values were normal. After initiation of phosphorus therapy, hypokalemia and metabolic alkalosis were observed. Renal sonography showed bilateral medullary nephrocalcinosis. Analyses of the SLC34A1 gene were performed due to hypercalcemia and hypophosphatemia., Results: Gene analyses identified a novel homozygous c.682T>C (p.W228R) (p.Trp228Arg) mutation. There are no previous reports of patients with SLC34A1 gene mutations presenting with hypokalemia and metabolic alkalosis., Conclusion: Herein, we present a case of infantile hypercalcemia 2 with a very different phenotype from that of previously described patients. Our findings provide further evidence for the wide range of phenotypic heterogeneity associated with NaPi-IIa impairment., (© 2018 S. Karger AG, Basel.)

Baştuğ F, Nalçacıoğlu H, Baş VN, Tekatlı-Çelik B, Çetinkaya H, Yel S. Acute renal failure due to severe hypercalcemia and nephrocalcinosis treated with two doses of pamidronate in an infant with Williams-Beuren syndrome. Turk J Pediatr 2018; 60: 210-215. Infantile hypercalcemia has been reported in 15% of infants and children with Williams-Beuren syndrome (WBS) and has generally mild clinical symptoms. However, the need for pamidronate treatment in a few infants with severe hypercalcemia associated with WBS has been reported in literature. Many disorders, such as primary hyperoxaluria, associated with nephrocalcinosis can lead to renal failure, but there are only a few reports in infants with WBS who have decreased renal function and nephrocalsinosis. We present a 23-month-old girl with WBS (confirmed with fluorescent in situ hybridization probes) who presented with acute renal failure with severe symptomatic hypercalcemia and nephrocalcinosis, which responded to two infusions of pamidronate.

Magnesium is essential to the proper functioning of numerous cellular processes. Magnesium ion (Mg 2+ ) deficits, as reflected in hypomagnesemia, can cause neuromuscular irritability, seizures and cardiac arrhythmias. With normal Mg 2+ intake, homeostasis is maintained primarily through the regulated reabsorption of Mg 2+ by the thick ascending limb of Henle's loop and distal convoluted tubule of the kidney. Inadequate reabsorption results in renal Mg 2+ wasting, as evidenced by an inappropriately high fractional Mg 2+ excretion. Familial renal Mg 2+ wasting is suggestive of a genetic cause, and subsequent studies in these hypomagnesemic families have revealed over a dozen genes directly or indirectly involved in Mg 2+ transport. Those can be classified into four groups: hypercalciuric hypomagnesemias (encompassing mutations in CLDN16, CLDN19, CASR, CLCNKB), Gitelman-like hypomagnesemias (CLCNKB, SLC12A3, BSND, KCNJ10, FYXD2, HNF1B, PCBD1), mitochondrial hypomagnesemias (SARS2, MT-TI, Kearns-Sayre syndrome) and other hypomagnesemias (TRPM6, CNMM2, EGF, EGFR, KCNA1, FAM111A). Although identification of these genes has not yet changed treatment, which remains Mg 2+ supplementation, it has contributed enormously to our understanding of Mg 2+ transport and renal function. In this review, we discuss general mechanisms and symptoms of genetic causes of hypomagnesemia as well as the specific molecular mechanisms and clinical phenotypes associated with each syndrome.

Objectives: Recent studies have demonstrated that minerals play a role in glucose metabolism disorders in humans. Magnesium, in particular, is an extensively studied mineral that has been shown to function in the management of hyperglycemia, hyperinsulinemia, and insulin resistance (IR) action. The aim of this study was to investigate the effect of magnesium supplementation on IR in humans via systematic review of the available clinical trials., Methods: This review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. A survey was conducted to select clinical trials related to the effects of this mineral in insulin sensitivity using the following databases: PubMed, SciVerse Scopus, ScienceDirect, and SciVerse Cochrane., Results: After the selection process, 12 articles were identified as eligible, representing different clinical conditions and being free of restriction with regard to sex, age, ethnicity, and differential dosing/shape of magnesium. The results of eight clinical trials showed that supplementation with magnesium influences serum fasting glucose concentrations, and five trials determined an effect on fasting insulin levels. The results of seven studies demonstrated that mineral supplementation reduced homeostasis model assessment for IR values., Conclusions: The data of this systematic review provide evidence as to the benefits of magnesium supplementation in reducing IR in patients with hypomagnesemia presenting IR. However, new intervention studies are needed to elucidate the role of the nutrient in protection against this metabolic disorder, as well as the standardization of the type, dose, and time of magnesium supplementation., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Hyperparathyroidism is common in patients undergoing kidney transplantation. Occasionally, this condition can cause early allograft dysfunction by inducing calcium phosphate deposition in the allograft, which results in nephrocalcinosis. Although nephrocalcinosis occurs occasionally in kidney allografts, it has only rarely been reported in the literature., Case Presentation: Here, we present the case of a 58-year-old Thai woman with severe hyperparathyroidism who received a living-related kidney transplant from her 35-year-old son. Our patient developed allograft dysfunction on day 2 post-transplantation despite good functioning graft on day 1. Allograft biopsy showed extensive calcium phosphate deposition in distal tubules. She was treated with cinacalcet (a calcimimetic agent) and aluminum hydroxide. Allograft function was restored to normal within 1 week after transplantation with greatly reduced intact parathyroid hormone level., Conclusion: Hyperparathyroidism in early functioning allograft causes elevated calcium and phosphate concentration in distal tubules resulting in nephrocalcinosis. The massive calcium phosphate precipitation obstructs tubular lumens, which leads to acute tubular dysfunction. Treatment of nephrocalcinosis with cinacalcet is safe and may improve this condition by increasing serum phosphate and reducing serum calcium and intact parathyroid hormone.

Objective: Hereditary hypophosphatemias (HH) are rare monogenic conditions characterized by decreased renal tubular phosphate reabsorption. The aim of this study was to explore the prevalence, genotypes, phenotypic spectrum, treatment response, and complications of treatment in the Norwegian population of children with HH., Design: Retrospective national cohort study., Methods: Sanger sequencing and multiplex ligand-dependent probe amplification analysis of PHEX and Sanger sequencing of FGF23, DMP1, ENPP1KL, and FAM20C were performed to assess genotype in patients with HH with or without rickets in all pediatric hospital departments across Norway. Patients with hypercalcuria were screened for SLC34A3 mutations. In one family, exome sequencing was performed. Information from the patients' medical records was collected for the evaluation of phenotype., Results: Twety-eight patients with HH (18 females and ten males) from 19 different families were identified. X-linked dominant hypophosphatemic rickets (XLHR) was confirmed in 21 children from 13 families. The total number of inhabitants in Norway aged 18 or below by 1st January 2010 was 1,109,156, giving an XLHR prevalence of ∼1 in 60,000 Norwegian children. FAM20C mutations were found in two brothers and SLC34A3 mutations in one patient. In XLHR, growth was compromised in spite of treatment with oral phosphate and active vitamin D compounds, with males tending to be more affected than females. Nephrocalcinosis tended to be slightly more common in patients starting treatment before 1 year of age, and was associated with higher average treatment doses of phosphate. However, none of these differences reached statistical significance., Conclusions: We present the first national cohort of HH in children. The prevalence of XLHR seems to be lower in Norwegian children than reported earlier., (© 2016 The authors.)

Aim: The present study aimed to assess the efficacy of 15 mEq magnesium supplied as part of a prehydration regimen in preventing cisplatin-induced nephrotoxicity in patients undergoing therapy with cisplatin-alone (40 mg/m(2)/week) for cervical cancer., Patients and Methods: We studied 28 patients with cervical cancer. This prospective cohort study compared nephrotoxicity in patients who received hydration with and without magnesium sulfate (Mg-hydration group, n=14; non-Mg-hydration group, n=14)., Results: Baseline characteristics, stage of cervical cancer, cisplatin dose and renal function did not differ significantly between the two groups. The serum creatinine level significantly increased from 0.58 to 0.75 mg/dl, and the estimated glomerular filtration rate significantly decreased from 85.1 to 66.5 ml/min by chemotherapy in the non-Mg-hydration group. In contrast, these levels did not change significantly in the Mg-hydration group., Conclusion: A magnesium dose of 15 mEq was found to provide nephroprotective effects among patients with cervical cancer undergoing chemotherapy with cisplatin alone., (Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Cetuximab, a monoclonal antibody specific for epidermal growth factor receptor, is increasingly used off-label and in early-phase trials for pediatric malignancies. Here, we report a patient with metastatic medulloblastoma receiving therapy with cyclophosphamide, vinblastine, and cetuximab. During evaluation for possible seizures, he was noted to be severely hypocalcemic, hypokalemic, and hypomagnesemic, a consequence of the blockade of renal epidermal growth factor receptor expression. His symptoms rapidly abated with intravenous electrolyte repletion. This case highlights the clinical heterogeneity of tetany and the importance of careful laboratory screening for known adverse effects of chemotherapy, particularly when newer biological agents are used off-study in combination chemotherapeutic regimens.

Background and Aims: It has been suggested that magnesium deficiency is associated with the triggering of acute phase response, which may contribute to type 2 diabetes and cardiovascular disease risk. We undertook this study to determine whether oral magnesium supplementation modifies serum levels of high-sensitivity C-reactive protein (hsCRP) in apparently healthy subjects with prediabetes and hypomagnesemia., Methods: A total of 62 men and non-pregnant women aged 18-65 year, with new diagnosis of prediabetes (glucose 5.6 <7.0 mmol/L and/or post-load glucose ≥7.7 <11.1 mmol/L) and hypomagnesemia (serum magnesium levels <0.74 mmol/L) were enrolled in a clinical double-blind placebo-controlled trial and randomly allocated to receive either magnesium chloride (30 mL of MgCl2 5% solution) or NaHCO3 0.1% solution, once daily for 3 months., Results: At basal conditions, anthropometric and biochemical variables were similarly distributed in both groups. At the end of follow-up, participants who received magnesium chloride showed higher serum magnesium levels (0.86 ± 0.08 vs. 0.69 ± 0.16 mmol/L, p = 0.002) and lower hsCRP levels (4.8 ± 15.2 vs. 17.1 ± 21.0 nmol/L, p = 0.01) compared with participants in the control group., Conclusions: Oral magnesium supplementation decreases hsCRP levels in apparently healthy subjects with prediabetes and hypomagnesemia., (Copyright © 2014 IMSS. Published by Elsevier Inc. All rights reserved.)

Background: Mutations in SLC34A3 have been shown to cause hereditary hypophosphatemic rickets with hypercalciuria (HHRH). Patients with compound heterozygous or homozygous mutations develop skeletal lesions in addition to hypercalciuria, hypophosphatemia and/or elevated 1,25-dihydroxy vitamin D [1,25-(OH)2D] levels. Here, we report a case of hypercalciuria without skeletal lesions in a patient with compound heterozygous mutations of SLC34A3., Case Presentation: A 3-year-old girl presented with microscopic hematuria. Laboratory data revealed elevated 1,25-(OH)2D levels and serum calcium, reduced serum inorganic phosphorus and hypercalciuria. In addition, the ratio of maximal rate of renal tubular reabsorption of phosphate to glomerular filtration rate was reduced. Abdominal ultrasound revealed bilateral nephrocalcinosis. These data were consistent with HHRH, but the patient had no clinical features of rickets or any family history of skeletal disease. Genetic analysis revealed compound heterozygous mutations of c.175+1 G>A and c.1234 C>T in SLC34A3., Conclusions: This is the report of a patient with compound heterozygous mutations of SLC34A3 and normal skeletal features. Biallelic mutations in SLC34A3 can thus be associated with hypercalciuria not accompanied by rickets. Orally administered inorganic phosphate is predicted to improve symptoms in these patients, hence screening for SLC34A3 mutations should be considered in patients with hypercalciuria of unknown etiology.

Background: Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis is a rare tubulopathy leading to renal calcification and progressive renal failure., Case Presentation: We report a consanguineous Arab family (of Qatari origin) with 7 affected siblings with variable phenotypes including hypomagnesaemia, hypercalciuria, nephrocalcinosis and renal stones. Presenting features included haematuria and recurrent urinary tract infections. As the biochemical and clinical phenotypes of this family resembled familial hypomagnesaemia with hypercalciuria and nephrocalcinosis, we performed genetic investigation in order to provide a precise molecular diagnosis. We screened all coding regions of the CLDN16 gene and identified a novel mutation (c.G647A, p.R216H) which was found homozygously in the six severely affected cases, who manifested significant nephrocalcinosis, often nephrolithiasis and sometimes reduced GFR. Parents were both heterozygous for the mutation and, together with children carrying the mutation in its heterozygous state, exhibited mild or no biochemical phenotypes., Conclusion: Mutations in CLDN16 underlie familial hypomagnesaemia with hypercalciuria and nephrocalcinosis but remain a rare cause of nephrocalcinosis and nephrolithiasis. Management includes reduction of hypercalciuria with thiazide diuretics, correction of serum magnesium and close monitoring of renal function given the significant risk of end stage renal failure with this inherited form of nephrocalcinosis.

Purpose: Many medicinal plants have been employed during ages to treat urinary stones though the rationale behind their use is not well established. Thus, the present study was proposed to evaluate the effect of coconut water as a prophylactic agent in experimentally induced nephrolithiasis in a rat model., Materials and Methods: The male Wistar rats were divided randomly into three groups. Animals of group I (control) were fed standard rat diet. In group II, the animals were administrated 0.75% ethylene glycol in drinking water for the induction of nephrolithiasis. Group III animals were administrated coconut water in addition to ethylene glycol. All the treatments were continued for a total duration of seven weeks., Results and Conclusion: Treatment with coconut water inhibited crystal deposition in renal tissue as well as reduced the number of crystals in urine. Furthermore, coconut water also protected against impaired renal function and development of oxidative stress in the kidneys. The results indicate that coconut water could be a potential candidate for phytotherapy against urolithiasis.

Hypomagnesemia has been linked with increased morbidity and mortality in critically ill patients. Since the condition is common after cardiopulmonary bypass surgery, the objective of this study was to determine whether magnesium supplementation in the immediate postoperative period may improve outcomes of patients undergoing cardiac surgery with cardiopulmonary bypass. This prospective, randomized, double-blind, placebo-controlled study was conducted in a third-level, cardiac surgery intensive care unit (ICU) at a university hospital. Two hundred and sixteen patients undergoing elective cardiac surgery with cardiopulmonary bypass were randomized to receive either an intravenous bolus of 1.5 g of magnesium sulphate followed by an infusion of 12 g of the same salt in 24 h (105 patients), or placebo (111 patients) administered according to the same schedule as the treatment group. No significant differences were found either in the primary end point (hours of intubation) or in the secondary end points (length of inotropic support, new atrial fibrillation, ventricular tachycardia or ventricular fibrillation, length of intensive care unit stay, or ICU or hospital mortality). Hypomagnesemia was present in 12% of patients on admission to the intensive care unit. The magnesium group had a greater need for pacemaker stimulation. In conclusion, under the conditions of the present study, magnesium supplementation after cardiac surgery with cardiopulmonary bypass does not favourably affect clinical outcomes.

History and Admission Findings: We report two patients with medullary nephrocalcinosis and nephrolithiasis. The first patients had unspecific symptoms of a systemic inflammatory disease, the second patient was asymptomatic., Investigations: Both patients had normocalcemia and normal parathyroid hormone levels, very high 1,25(OH)(2)-vitamin D and normal to low 25-OH-vitamin D levels. On renal ultrasound, both patients displayed nephrocalcinosis and nephrolithiasis., Diagnosis: Both patients showed dysregulation of the 1α-hydroxylase activity. The first patient suffered from a systemic inflammatory disease with consecutive activation of macrophages with extrarenal α-hydroxylase activity. The second patient had a "loss of function" mutation of the calcium sensing receptor with - for the situation - inadequatly high parathyroid hormone levels and consequently a renal dysregulation of the 1α-hydroxylase., Treatment and Course: After immunosuppressive treatment with prednisolone and hydroxychloroquin there was complete remission of the systemic inflammatory disease in the first patient. In consequence the 1,25-(OH)(2)-vitamin D levels regressed and renal function stabilized. The second patient was completely asymptomatic with normal renal function, so far we did not initiate any treatment., Conclusions: Nephrocalcinosis and nephrolithiasis can result from hypercalciuria due to dysregulated hydroxylation of vitamin D. For both renal and extrarenal sources causal treatment is available., (© Georg Thieme Verlag KG Stuttgart · New York.)

To determine whether oral magnesium supplementation modifies serum levels of high-sensitivity C-reactive protein (hsCRP), TNF-alpha, IL-6, and IL-10 in subjects with prediabetes, inflammation, and hypomagnesemia, a total of 26 subjects men and non-pregnant women were included and randomly allocated to receive 30 ml of MgCl(2) 5% solution (equivalent to 382 mg of magnesium) or placebo, daily during three months. At baseline conditions, there were not significant statistical differences between the groups. At end of the study, hsCRP levels were significantly lower in the intervention group (3.3 ± 2.5 vs 8.0 ± 5.9 mg/L, p = 0.03), as compared with the control group. However, the intra-group analysis of the individuals who received magnesium, did not shows significant statistical differences between baseline and final conditions (4.1 ± 3.0 and 3.3 ± 2.5, p = 0.45). In addition, TNF-alpha (1.2 ± 0.3 vs 1.1 ± 0.3 pg/mL, p = 0.69), IL-6 (0.3 ± 0.3 vs 5.0 ± 7.7 pg/mL, p = 0.08), and IL-10 (1.8 ± 0.4 vs 1.8 ± 0.5 pg/mL, p = 0.89) serum levels were not significantly different between the groups. Our results do not show a beneficial effect of oral magnesium supplementation on hsCRP, IL-6, TNF-alpha, and IL-10 levels in prediabetic subjects with hypomagnesemia and inflammation. Further studies with large sample sizes and longer time of follow-up are necessaries to verify the results of our pilot study.

Background: The calcimimetic cinacalcet is approved for treating secondary hyperparathyroidism in patients with chronic kidney disease on dialysis. Biochemical profiles and clinical outcomes in patients discontinuing cinacalcet at the time of transplantation are scarce., Methods: We performed a prospective observational cohort study, including 303 incident renal transplant recipients, of whom 21 were on cinacalcet treatment at the time of transplantation. Parameters of mineral metabolism and incidence of parathyroidectomy and nephrocalcinosis in patients discontinuing cinacalcet at the time of transplantation patients ("cinacalcet +") were compared to cinacalcet-naïve patients ("cinacalcet -"). Mean follow-up was 35.6 ± 15.8 months., Results: At the time of transplantation, parameters of mineral metabolism were similar in both groups. Conversely, at month 3, serum ionized calcium (p = 0.0007), calcitriol (p = 0.02), biointact parathyroid hormone (p = 0.06) levels and urinary fractional excretion of phosphorus (p = 0.06) were higher, while serum phosphorus levels (p = 0.06) were lower in "cinacalcet +." Analysis based on matching at the time of initiation showed that the course of post-transplant mineral metabolism in cinacalcet-treated patients (median treatment period 12.5 months) vs. cinacalcet-naïve patients was identical. "Cinacalcet +" patients are characterized by a high-incidence proportion of both post-transplant nephrocalcinosis (45% at month 3) and parathyroidectomy (28.6%). No difference in renal function was observed between "cinacalcet +" and "cinacalcet-" patients., Conclusion: Cinacalcet does not affect the course of secondary hyperparathyroidism in patients awaiting kidney transplantation. Biochemical profiles and a high parathyroidectomy rate suggest rebound hyperparathyroidism in renal transplant recipients discontinuing cinacalcet at the time of transplantation, which may be related to the short exposure time specific to this population. Risk/benefit studies are urgently required to define the role of continued calcimimetic treatment in renal transplant recipients and to determine the optimal treatment of secondary hyperparathyroidism in patients listed for transplantation., (© 2011 John Wiley & Sons A/S.)

Primary familial hypomagnesemia is a rare genetically determined disorder characterized by a selective defect in magnesium (Mg) absorption. Mutations of the transient receptor potential melastatin 6 (TRPM6) gene, which codes for TRPM6, the basic channel for intestinal Mg absorption and a new member of the transient receptor potential (TRP) family of cation channels, result in primary hypomagnesemia. Here we present a 14-year-old Turkish girl whose first symptoms manifested as neonatal tetany at 17 days old. During her follow-up, she was mainly taking high-dose oral Mg therapy. However, intravenous Mg and calcium (Ca) therapies were given during symptomatic attacks. When her requirements for Ca and Mg were increased during the pubertal growth period, which overlapped with increased loss of Mg during the summer, oral Ca and active vitamin D (calcitriol, Rocaltrol) were added. Calcitriol is needed because hypomagnesemia results in decreased production and resistance to the actions of active vitamin D, which leads to the disturbance of intracellular signal transmission. Although high-dose oral Mg is reported as a sufficient therapy in most of the patients with primary familial hypomagnesemia, addition of active vitamin D to the usual oral Mg and Ca therapy seems very useful, as in this patient.

Diuretics commonly are administered in disorders of sodium balance. Loop diuretics inhibit the Na-K-2Cl transporter and also increase calcium excretion. They are often used in the treatment of hypercalcemia. Thiazide diuretics block the thiazide-sensitive NaCl transporter in the distal convoluted tubule, and can decrease calcium excretion. They are often used in the treatment of nephrolithiasis. Carbonic anhydrase inhibitors decrease bicarbonate absorption and the resultant metabolic acidosis can increase calcium excretion. Their use can promote nephrocalcinosis and nephrolithiasis. This review will address the use of diuretics on disorders of calcium homeostasis., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Introduction: Sodium thiosulfate (STS) is a U.S. Food and Drug Administration (FDA)-approved chelating agent that is used for the treatment of cyanide poisoning and prophylaxis against cisplatin nephropathy. Recently, STS has also been used in the treatment of calciphylaxis, which is a disease characterized by calcification in the soft tissues with vascular calcification and thrombosis causing nonhealing ulcers. We proposed a rat model to evaluate whether STS has any possible beneficial effect on calcium nephrolithiasis or nephrocalcinosis., Methods: Twenty-one male Sprague-Dawley rats were used in the study. All animals received standard rat chow throughout the experiment. The animals were started on special drinking water containing 0.4% ethylene glycol plus 1.0% ammonium chloride for 7 days to induce crystalluria and nephrocalcinosis. The animals were then randomized to two groups. Group 1 served as a control and received daily intraperitoneal injections of normal saline. Group 2 received daily intraperitoneal injections of STS solution. Special drinking water containing 0.8% ethylene glycol was continued during the treatment period., Results: Group 2 gained significantly less weight than group 1 (18.0% v 8.5%, p < 0.05). The amount of crystalluria in group 2 was much less than that in group 1, but did not reach statistical significance (0.7 v 4.2, p = 0.09). Degree of calcification noted in the kidneys was not statistically different between the two groups., Conclusions: The current study did not reveal any significant benefit of STS administration on calcium stone disease. However, many more studies are necessary before the possibility of a beneficial effect is completely disproved.

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC), an autosomal recessive renal tubular disorder is characterized by the impaired tubular reabsorption of magnesium and calcium in the thick ascending limb of the loop of Henle. This disease is caused by mutations in the claudin-16 gene (CLDN16), which encodes the tight junction protein, claudin-16. Claudin-16 belongs to the claudin family and regulates the paracellular transport of magnesium and calcium. Here, we report on three Turkish siblings with typical clinical features of FHHNC in association with the homozygous mutation Leu151Phe.

In recent years, alendronate, an oral biphosphonate, has been added to therapy of hypercalcemia secondary to vitamin D intoxication in children. Alendronate may cause mucosal ulcerations in the mouth and esophagus. We report our experience in two infants with vitamin D intoxication to whom alendronate therapy was administered through nasogastric tube, an alternate route for alendronate administration.

The aim of this study was to test the effect of L: -arginine methyl ester (L-Arg) on indices of free radical involvement in a rat model of experimental nephrocalcinosis. Twenty-eight Sprague-Dawley rats were randomized into four groups of seven. The first group (G1), the sham-control group received pure distilled drinking water. The second group (G2) received drinking water containing 0.7% ethylene glycol (EG) in distilled water for 3 weeks. The third group (G3) received drinking water containing 0.7% EG in distilled water for 3 weeks and L-Arg was administered for 3 weeks. The fourth group (G4) received drinking water containing 0.7% EG in distilled water for 3 weeks and L-NAME was administered for 3 weeks. Urine and aortic blood was collected to determine some parameters. The kidneys were also removed for histological examination. The increase in blood urea nitrogen, serum creatinine, K(+), Mg(2+ )and uric acid were mild in group 3 compared with the groups 2 and 4. The urinary concentrations of Na(+), K(+), Mg(2+) and uric acid were noticed to be similar among the groups. However, Ca(2+ )and oxalate excretion were significantly higher in groups 2, 3 and 4 than in group 1. The mean values of SOD, CAT and GSH-Px values were significantly increased in group 3 when compared to groups 2 and 4. Presence of aggregated urinary crystals was clearer in experimental groups compared to group 1. The tubular dilatation, epithelial degeneration and lymphocytic infiltration were significantly found in groups 2 and 4. Mild tissue damage was observed in L-Arg-pretreated rats. Under polarized light microscope intense crystals in the cortex and medulla were observed in the kidney of group 2 and 4 and moderate crystals were noticed in group 3. In conclusion, L-Arg supplementation may decrease free radicals and tubulary membrane injury in nephrocalcinosis due to infiltrating leukocytes and decreased antioxidant enzyme activities in rats fed with EG diet.

Background: Hydrochlorothiazide (HCT) is applied in the therapy of familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC) caused by claudin-16 (CLDN16) mutation. However, the short-term efficacy of HCT to reduce hypercalciuria in FHHNC has not yet been demonstrated in a clinical trial., Methods: Four male and four female patients with FHHNC and CLDN16 mutation, under long-standing HCT therapy (0.4-1.2 mg/kg, median 0.9 mg/kg, dose according to calciuria), aged 0.7-22.4 years, were included in a clinical study to investigate the effect of HCT on calciuria. The study design consisted of three periods: continued therapy for 4 weeks, HCT withdrawal for 6 weeks and restart of therapy at the same dose for 4 weeks. Calciuria and magnesiuria were assessed weekly as Ca/creat and Mg/creat ratio, every 2 weeks in 24 h urine, and serum Mg, K and kaliuria (s-Mg, s-K and K/creat) at weeks 0, 6, 10 and 14. The data of each study period were averaged and analysed by Friedman and Wilcoxon test., Results: Ca/creat was significantly reduced by HCT (median before/at/after withdrawal 0.76/1.24/0.77 mol/mol creat; n = 8, P<0.05). The reduction of Ca/24 h by HCT was not statistically significant (0.13/0.19/0.13 mmol/kg x 24 h; n = 5). Serum Mg (0.51/0.64/0.56 mmol/l; n = 8, P<0.05) and Serum K (3.65/4.35/3.65 mmol/l; n = 8, P<0.05) were significantly higher during withdrawal. However, Mg/creat (0.98/0.90/0.90 mol/mol creat; n = 8), Mg/24 h (0.14/0.12/0.18 mmol/kg x 24h; n = 5) and K/creat (6.3/8.4/6.2 mol/mol creat; n = 8) remained statistically unchanged during withdrawal., Conclusions: We demonstrated that HCT is effective in reducing hypercalciuria due to CLDN16 mutation on a short-term basis. However, the efficacy of HCT to attenuate disease progression remains to be elucidated.

Vitamin D intoxication is a well-known cause of hypercalcemia in children. We report here the use of oral alendronate for the treatment of hypercalcemia due to vitamin D intoxication in a 7 month-old infant with nephrocalcinosis. The serum calcium levels were normalized without complications. Oral alendronate therapy may be safely used in hypercalcemia due to vitamin. D intoxication in pediatric patients with nephrocalcinosis resistant to hydration, diuretics or corticosteroids.

Multiple myeloma disrupts calcium homeostasis by a variety of mechanisms, including bone destruction and resorption. This causes hypercalcemia. When left untreated, hypercalcemia leads to nephrocalcinosis, impairment of kidney function, and eventually renal failure. Some degree of renal dysfunction is common in myeloma patients. Here, we report case studies showing the efficacy and renal safety of the single-nitrogen bisphosphonate, ibandronate, for the treatment of hypercalcemia and/or nephrocalcinosis in multiple myeloma patients hospitalized with acute renal failure. Patients (n = 7) received either one or two intravenous infusions of ibandronate (2-6 mg). Ibandronate was well tolerated in all patients and returned elevated blood calcium levels to normal. Renal function improved for all patients and normalized in 3/7 patients. We conclude that ibandronate is involved in rapidly improving or restoring acute renal function and calcium levels to within the normal range in this patient population. To clarify the exact value of ibandronate, further investigation is warranted in randomized prospective trials., (Copyright 2006 S. Karger AG, Basel.)

Introduction: Nephrocalcinosis is a rare complication of chronic tubulointerstitial nephritis observed in primary Sjögren's syndrome. It can precede subjective sicca symptoms., Observation: We report the case of a 50-year-old woman who presented with a primary Sjögren's syndrome. The first symptoms appeared 10-years-ago while she was affected with a nephrocalcinosis., Conclusion: Autoimmune investigations for Sjögren's syndrome should be initiated in any patient presenting with nephrocalcinosis and distal renal tubular acidosis.

Vitamin D intoxication in infancy has serious consequences attributable to acute hypercalcemia and subsequent hypercalcuria/nephrocalcinosis. Current treatments of patients with vitamin D intoxication are unsatisfactory and associated with prolonged hypercalcemia. We now report the use of oral alendronate sodium in a 3-month-old infant with vitamin D intoxication. Short-term oral alendronate sodium treatment effectively corrected hypercalcemia/hypercalciuria, decreased the duration of hospitalization, and appears safe in 15 months of observation.

Familial hypomagnesemia, hypercalciuria and nephrocalcinosis (FHHNC) is a rare autosomal recessive inherited disorder that has recently been attributed to a defect in the paracellin-1 ( PCLN-1)gene, encoding for a protein responsible for the tubular reabsorption of magnesium and calcium. Limited information is available on clinical course, therapy and prognosis. We provide information on five patients with FHHNC and their follow-up at our institution. Polyuria, nephrocalcinosis and hyperuricemia were the main clinical findings of a diagnosis at a median age of 4.4 years. The clinical course of PCLN-1 mutations as presented in this study is highly variable, ranging from compensated renal failure to end-stage renal failure - as happened in two of our patients. The progression to renal failure cannot be deduced from the initial presentation. Medical treatment does not appear to influence the progression of the disease. Despite calcium and magnesium substitution, normal values could not be achieved in these patients. Early treatment with vitamin D and calcium was essential to maintain growth. Adequate treatment allows for a normal height and pubertal development.