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Wu S, Li C, Li Y, Liu J, Rong C, Pei H, Li X, Zeng X, Mao W. SLC2A9 rs16890979 reduces uric acid absorption by kidney organoids. Front Cell Dev Biol 2024; 11:1268226. [PMID: 38269090 PMCID: PMC10806012 DOI: 10.3389/fcell.2023.1268226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 12/14/2023] [Indexed: 01/26/2024] Open
Abstract
Introduction: The excretion and absorption of uric acid (UA) by the kidneys helps regulate serum UA levels. GLUT9, encoded by SLC2A9, is mainly expressed in the renal tubules responsible for UA absorption. SLC2A9 polymorphisms are associated with different serum UA levels. However, the lack of proper in vitro models has stalled research on the mechanisms of single nucleotide polymorphisms (SNPs) that affect UA metabolism in human urate transporters. Methods: In this study, we constructed a gene-edited human embryonic stem cells-9 (ESC-H9) derived kidney organoid bearing rs16890979, an SLC2A9 missense mutation with undetermined associations with hyperuricemia or hypouricemia. Kidney organoids derived from ESC-H9 with genetical overexpression (OE) and low expression (shRNA) of SLC2A9 to serve as controls to study the function of SLC2A9. The function of rs16890979 on UA metabolism was evaluated after placing the organoids to urate-containing medium and following histopathological analysis. Results: The kidney organoids with heterozygous or homozygous rs16890979 mutations showed normal SLC2A9 expression levels and histological distribution, phenotypically similar to the wild-type controls. However, reduced absorption of UA by the kidney organoids with rs16890979 mutants was observed. This finding together with the observation that UA absorption is increased in organoids with SLC2A9 overexpression and decreased in those with SLC2A9 knockdown, suggest that GLUT9 is responsible for UA absorption, and the rs16890979 SNP may compromise this functionality. Moreover, epithelial-mesenchymal transition (EMT) was detected in organoids after UA treatment, especially in the kidney organoid carrying GLUT9OE, suggesting the cytobiological mechanism explaining the pathological features in hyperuricosuria-related renal injury. Discussion: This study showing the transitional value of kidney organoid modeling the function of SNPs on UA metabolism. With a defined genetic background and a confirmed UA absorption function should be useful for studies on renal histological, cellular, and molecular mechanisms with this organoid model.
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Affiliation(s)
- Shouhai Wu
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Chuang Li
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
- Guangdong Provincial Key Laboratory of Chinese Medicine for Prevention and Treatment of Refractory Chronic Diseases, Guangzhou, China
| | - Yizhen Li
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Junyi Liu
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Cuiping Rong
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Hongfei Pei
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Xiong Li
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiang Zeng
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Lab of Stem Cell Biology and Innovative Research of Chinese Medicine, Guangdong Provincial Hospital of Chinese Medicine/Guangdong Academy of Chinese Medicine, Guangzhou, China
- National Institute for Stem Cell Clinical Research, Guangdong Provincial Hospital of Chinese Medicine/The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Wei Mao
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
- Guangdong Provincial Key Laboratory of Chinese Medicine for Prevention and Treatment of Refractory Chronic Diseases, Guangzhou, China
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
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Kuhara T, Tetsuo M, Ohse M, Shirakawa T, Nakashima Y, Yoshiura K, Tanaka N, Taya T. Three cases of xanthinuria identified by gas chromatography/mass spectrometry-based urine metabolomics. IJU Case Rep 2023; 6:436-439. [PMID: 37928284 PMCID: PMC10622199 DOI: 10.1002/iju5.12642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 09/06/2023] [Indexed: 11/07/2023] Open
Abstract
Introduction Early diagnosis of patients with urolithiasis or hypouricemia owing to inborn errors of hypoxanthine metabolism is important in preventing renal failure or drug-induced toxicity. Case presentation We identified three patients with xanthinuria using gas chromatography/mass spectrometry-based urine metabolomics: a 72-year-old male with bladder stone, a severe hypouricemic 59-year-old female with type 2 diabetes mellitus, and an 8-year and 9-month-old female who was first discovered to harbor a mutation in the xanthine dehydrogenase gene using whole-exome sequencing, but had a normal molybdenum cofactor sulfurase gene. Hydantoin-5-propionate was detected in the first and third patients but not in the second, suggesting that the first and second patients had type I and II xanthinuria, respectively. Conclusion Gas chromatography/mass spectrometry-based metabolomics can be used for undiagnosed patients with xanthinuria, identification of the type of xanthinuria without allopurinol loading, and the quick functional evaluation of mutations in the xanthinuria-related genes.
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Affiliation(s)
- Tomiko Kuhara
- Japan Clinical Metabolomics InstituteKahokuIshikawaJapan
| | | | - Morimasa Ohse
- Japan Clinical Metabolomics InstituteKahokuIshikawaJapan
| | | | - Yumiko Nakashima
- Department of PediatricsNagasaki University HospitalNagasakiJapan
| | - Koh‐ichiro Yoshiura
- Department of Human GeneticsAtomic Bomb Disease Institute, Nagasaki UniversityNagasakiJapan
| | - Nagaaki Tanaka
- Center for Diabetes, Endocrinology and MetabolismKansai Electric Power HospitalOsakaJapan
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Miake J, Hisatome I, Tomita K, Isoyama T, Sugihara S, Kuwabara M, Ogino K, Ninomiya H. Impact of Hyper- and Hypo-Uricemia on Kidney Function. Biomedicines 2023; 11:biomedicines11051258. [PMID: 37238929 DOI: 10.3390/biomedicines11051258] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 04/18/2023] [Accepted: 04/19/2023] [Indexed: 05/28/2023] Open
Abstract
Uric acid (UA) forms monosodium urate (MSU) crystals to exert proinflammatory actions, thus causing gout arthritis, urolithiasis, kidney disease, and cardiovascular disease. UA is also one of the most potent antioxidants that suppresses oxidative stress. Hyper andhypouricemia are caused by genetic mutations or polymorphism. Hyperuricemia increases urinary UA concentration and is frequently associated with urolithiasis, which is augmented by low urinary pH. Renal hypouricemia (RHU) is associated with renal stones by increased level of urinary UA, which correlates with the impaired tubular reabsorption of UA. Hyperuricemia causes gout nephropathy, characterized by renal interstitium and tubular damage because MSU precipitates in the tubules. RHU is also frequently associated with tubular damage with elevated urinary beta2-microglobulin due to increased urinary UA concentration, which is related to impaired tubular UA reabsorption through URAT1. Hyperuricemia could induce renal arteriopathy and reduce renal blood flow, while increasing urinary albumin excretion, which is correlated with plasma xanthine oxidoreductase (XOR) activity. RHU is associated with exercise-induced kidney injury, since low levels of SUA could induce the vasoconstriction of the kidney and the enhanced urinary UA excretion could form intratubular precipitation. A U-shaped association of SUA with organ damage is observed in patients with kidney diseases related to impaired endothelial function. Under hyperuricemia, intracellular UA, MSU crystals, and XOR could reduce NO and activate several proinflammatory signals, impairing endothelial functions. Under hypouricemia, the genetic and pharmacological depletion of UA could impair the NO-dependent and independent endothelial functions, suggesting that RHU and secondary hypouricemia might be a risk factor for the loss of kidney functions. In order to protect kidney functions in hyperuricemic patients, the use of urate lowering agents could be recommended to target SUA below 6 mg/dL. In order to protect the kidney functions in RHU patients, hydration and urinary alkalization may be recommended, and in some cases an XOR inhibitor might be recommended in order to reduce oxidative stress.
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Affiliation(s)
- Junichiro Miake
- Division of Pharmacology, Department of Pathophysiological and Therapeutic Science, Tottori University Faculty of Medicine, Tottori 683-8503, Japan
| | - Ichiro Hisatome
- Department of Cardiology, Yonago Medical Center, Tottori 683-0006, Japan
| | - Katsuyuki Tomita
- Department of Respiratory Disease, Yonago Medical Center, Tottori 683-0006, Japan
| | - Tadahiro Isoyama
- Department of Urology, Yonago Medical Center, Tottori 683-0006, Japan
| | - Shinobu Sugihara
- Health Service Center, Shimane University, Matsue 690-0823, Japan
| | - Masanari Kuwabara
- Intensive Care Unit and Department of Cardiology, Toranomon Hospital, Tokyo 105-8470, Japan
| | - Kazuhide Ogino
- Department of Cardiology, Tottori Red Cross Hospital, Tottori 680-0017, Japan
| | - Haruaki Ninomiya
- Department of Biological Regulation, Tottori University Faculty of Medicine, Tottori 683-8503, Japan
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Otani N, Ouchi M, Mizuta E, Morita A, Fujita T, Anzai N, Hisatome I. Dysuricemia-A New Concept Encompassing Hyperuricemia and Hypouricemia. Biomedicines 2023; 11:biomedicines11051255. [PMID: 37238926 DOI: 10.3390/biomedicines11051255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
The importance of uric acid, the final metabolite of purines excreted by the kidneys and intestines, was not previously recognized, except for its role in forming crystals in the joints and causing gout. However, recent evidence implies that uric acid is not a biologically inactive substance and may exert a wide range of effects, including antioxidant, neurostimulatory, proinflammatory, and innate immune activities. Notably, uric acid has two contradictory properties: antioxidant and oxidative ones. In this review, we present the concept of "dysuricemia", a condition in which deviation from the appropriate range of uric acid in the living body results in disease. This concept encompasses both hyperuricemia and hypouricemia. This review draws comparisons between the biologically biphasic positive and negative effects of uric acid and discusses the impact of such effects on various diseases.
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Affiliation(s)
- Naoyuki Otani
- Department of Cardiology, Dokkyo Medical University Nikkyo Medical Center, Nikko 321-1298, Tochigi, Japan
| | - Motoshi Ouchi
- Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Mibu 321-0293, Tochigi, Japan
| | - Einosuke Mizuta
- Department of Cardiology, Sanin Rosai Hospital, Yonago 683-8605, Tottori, Japan
| | - Asuka Morita
- Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Mibu 321-0293, Tochigi, Japan
| | - Tomoe Fujita
- Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Mibu 321-0293, Tochigi, Japan
| | - Naohiko Anzai
- Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Mibu 321-0293, Tochigi, Japan
- Department of Pharmacology, Chiba University Graduate School of Medicine, Chiba 260-8670, Chiba, Japan
| | - Ichiro Hisatome
- Yonago Medical Center, National Hospital Organization, Yonago 683-0006, Tottori, Japan
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Kim GH, Jun JB. Altered Serum Uric Acid Levels in Kidney Disorders. Life (Basel) 2022; 12:life12111891. [PMID: 36431026 PMCID: PMC9692609 DOI: 10.3390/life12111891] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/07/2022] [Accepted: 11/13/2022] [Indexed: 11/17/2022]
Abstract
Serum uric acid levels are altered by kidney disorders because the kidneys play a dominant role in uric acid excretion. Here, major kidney disorders which accompany hyperuricemia or hypouricemia, including their pathophysiology, are discussed. Chronic kidney disease (CKD) and hyperuricemia are frequently associated, but recent clinical trials have not supported the pathogenic roles of hyperuricemia in CKD incidence and progression. Diabetes mellitus (DM) is often associated with hyperuricemia, and hyperuricemia may be associated with an increased risk of diabetic kidney disease in patients with type 2 DM. Sodium-glucose cotransporter 2 inhibitors have a uricosuric effect and can relieve hyperuricemia in DM. Autosomal dominant tubulointerstitial kidney disease (ADTKD) is an important hereditary kidney disease, mainly caused by mutations of uromodulin (UMOD) or mucin-1 (MUC-1). Hyperuricemia and gout are the major clinical manifestations of ADTKD-UMOD and ADTKD-MUC1. Renal hypouricemia is caused by URAT1 or GLUT9 loss-of-function mutations and renders patients susceptible to exercise-induced acute kidney injury, probably because of excessive urinary uric acid excretion. Hypouricemia derived from renal uric acid wasting is a component of Fanconi syndrome, which can be hereditary or acquired. During treatment for human immunodeficiency virus, hepatitis B or cytomegalovirus, tenofovir, adefovir, and cidofovir may cause drug-induced renal Fanconi syndrome. In coronavirus disease 2019, hypouricemia due to proximal tubular injury is related to disease severity, including respiratory failure. Finally, serum uric acid and the fractional excretion of uric acid are indicative of plasma volume status; hyperuricemia caused by the enhanced uric acid reabsorption can be induced by volume depletion, and hypouricemia caused by an increased fractional excretion of uric acid is the characteristic finding in syndromes of inappropriate anti-diuresis, cerebral/renal salt wasting, and thiazide-induced hyponatremia. Molecular mechanisms by which uric acid transport is dysregulated in volume or water balance disorders need to be investigated.
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Affiliation(s)
- Gheun-Ho Kim
- Department of Internal Medicine, Hanyang University College of Medicine, Seoul 04763, Republic of Korea
- Correspondence: ; Tel.: +82-2-2290-8318
| | - Jae-Bum Jun
- Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul 04763, Republic of Korea
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Löffler W, Fairbanks L, Gibson T. Treating gout - can hypouricemia produced by moderate doses of combined oral treatment give early treatment success? Preliminary observations. Nucleosides Nucleotides Nucleic Acids 2022; 41:1267-1278. [PMID: 35257638 DOI: 10.1080/15257770.2022.2039394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Six male patients with gout were treated with combined oral medication (febuxostat, 120 mg/d, and benzbromarone, 50 or 100 mg/d), aiming at a more rapid success of uric acid lowering treatment (ULT) compared to guideline suggestions. By combined oral medication in moderate dosage, the sUA was reduced to <2 mg/dl in all cases. We conclude that, by the treatment schedule outlined, the majority of patients with gout can be cured within 1 - 2 years, with uricase treatment being necessary very rarely only.
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Affiliation(s)
| | | | - Terry Gibson
- Acute Admission Ward, St. Thomas Hospital, London, UK
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Collazo Abal C, Romero Santos S, González Mao C, Pazos Lago EC, Barros Angueira F, Castiñeiras Ramos D. Identification of a new mutation in the human xanthine dehydrogenase responsible for xanthinuria type I. Adv Lab Med 2021; 2:567-574. [PMID: 37360896 PMCID: PMC10197278 DOI: 10.1515/almed-2021-0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 06/17/2021] [Indexed: 06/28/2023]
Abstract
Objectives Hereditary xanthinuria is a rare, autosomal and recessive disorder characterized by severe hypouricemia and increased xanthine excretion, caused by a deficiency of xanthine dehydrogenase/oxidase (XDH/XO, EC: 1.17.1.4/1.17.3.2) in type I, or by a deficiency of XDH/XO and aldehyde oxidase (AOX, EC: 1.2.3.1) in type II. Methods We describe a novel point mutation in the XDH gene in homozygosis found in a patient with very low serum and urine levels of uric acid, together with xanthinuria. He was asymptomatic but renal calculi were discovered during imaging. Results Additional cases were found in his family and dietary recommendations were made in order to prevent further complications. Conclusions Hereditary xanthinuria is an underdiagnosed pathology, often found in a routine analysis that shows hypouricemia. It is important for Laboratory Medicine to acknowledge how to guide clinicians in the diagnosis.
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Affiliation(s)
| | | | | | | | - Francisco Barros Angueira
- Galician Public Foundation for Genomic Medicine, University Hospital of Santiago de Compostela, Santiago de Compostela, Spain
| | - Daisy Castiñeiras Ramos
- Laboratory of Metabolic Pathologies, University Hospital of Santiago de Compostela, Santiago de Compostela, Spain
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Yoon J, Cachau R, David VA, Thompson M, Jung W, Jee SH, Daar IO, Winkler CA, Cho SK. Characterization of a Compound Heterozygous SLC2A9 Mutation That Causes Hypouricemia. Biomedicines 2021; 9:biomedicines9091172. [PMID: 34572357 PMCID: PMC8471325 DOI: 10.3390/biomedicines9091172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/26/2021] [Accepted: 08/28/2021] [Indexed: 11/17/2022] Open
Abstract
Renal hypouricemia is a rare genetic disorder. Hypouricemia can present as renal stones or exercise-induced acute renal failure, but most cases are asymptomatic. Our previous study showed that two recessive variants of SLC22A12 (p.Trp258*, pArg90His) were identified in 90% of the hypouricemia patients from two independent cohorts: the Korean genome and epidemiology study (KoGES) and the Korean Cancer Prevention Study (KCPS-II). In this work, we investigate the genetic causes of hypouricemia in the rest of the 10% of unsolved cases. We found a novel non-synonymous mutation of SLC2A9 (voltage-sensitive uric acid transporter) in the whole-exome sequencing (WES) results. Molecular dynamics prediction suggests that the novel mutation p.Met126Val in SLCA9b (p.Met155Val in SLC2A9a) hinders uric acid transport through a defect of the outward open geometry. Molecular analysis using Xenopus oocytes confirmed that the p.Met126Val mutation significantly reduced uric acid transport but does not affect the SLC2A9 protein expression level. Our results will shed light on a better understanding of SLC2A9-mediated uric acid transport and the development of a uric acid-lowering agent.
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Affiliation(s)
- Jaeho Yoon
- Cancer & Developmental Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21701, USA; (J.Y.); (I.O.D.)
| | - Raul Cachau
- Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21701, USA;
| | - Victor A. David
- Molecular Genetic Epidemiology Section, Basic Research Laboratory, National Cancer Institute, Frederick, MD 21701, USA; (V.A.D.); (C.A.W.)
| | - Mary Thompson
- Center for Cancer Research, National Cancer Institute, Frederick, MD 21701, USA;
| | - Wooram Jung
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA;
| | - Sun-Ha Jee
- Department of Epidemiology and Health Promotion, Institute for Health Promotion, Graduate School of Public Health, Yonsei University College of Medicine, Seoul 03722, Korea;
| | - Ira O. Daar
- Cancer & Developmental Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21701, USA; (J.Y.); (I.O.D.)
| | - Cheryl A. Winkler
- Molecular Genetic Epidemiology Section, Basic Research Laboratory, National Cancer Institute, Frederick, MD 21701, USA; (V.A.D.); (C.A.W.)
| | - Sung-Kweon Cho
- Molecular Genetic Epidemiology Section, Basic Research Laboratory, National Cancer Institute, Frederick, MD 21701, USA; (V.A.D.); (C.A.W.)
- Department of Pharmacology, Ajou University School of Medicine, 164, Worldcup-ro, Yeongtong-gu, Suwon 16499, Korea
- Correspondence: or ; Tel.: +82-31-219-4506; Fax: +82-31-219-5069
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Abstract
Background Glycosuria is one of the manifestations of acute tubulointerstitial nephritis (ATIN), but may also be observed in other renal diseases. In this study, we investigated the value of non-diabetic glycosuria as a diagnostic clue for ATIN. Methods We retrospectively reviewed the medical records of adult patients who underwent a kidney biopsy as an evaluation for serum creatinine > 1.4 mg/dL. Patients with proteinuria in the nephrotic range, diabetes mellitus, or transplanted kidney were excluded. The laboratory abnormalities suggestive of tubular injury were compared between 28 patients (14 men and 14 women, mean age 48.5 ± 14.1 years) with ATIN and 116 patients (76 men and 40 women, mean age 53.1 ± 15.0 years) with other diagnoses. Results In ATIN, glycosuria (≥ 1+ on dipstick; 68%) was more frequent than hypophosphatemia (18%), hypouricemia (18%), hypokalemia (18%), and tubular proteinuria (40%). In other diagnoses, glycosuria (≥ 1+) was detected in 7 (6%) patients; 6 of them had the histological diagnosis of antineutrophil cytoplasmic antibody-associated glomerulonephritis. The presence of glycosuria (≥ 1+) had 68% sensitivity and 94% specificity for ATIN, with the positive likelihood ratio of 11.24 and the negative likelihood ratio of 0.34. Pyuria and low total CO2 were equally and more sensitive (68% and 71%, respectively) than glycosuria (≥ 1+), but had no diagnostic value due to low specificities (58% and 60%, respectively). Conclusion In non-diabetic, non-nephrotic patients undergoing a kidney biopsy for azotemia, 1+ or higher glycosuria, if present, was a good predictor of the diagnosis of ATIN.
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Affiliation(s)
- Taeyeon Lee
- Division of Nephrology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Won Seok Yang
- Division of Nephrology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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Tátrai P, Erdő F, Dörnyei G, Krajcsi P. Modulation of Urate Transport by Drugs. Pharmaceutics 2021; 13:pharmaceutics13060899. [PMID: 34204277 PMCID: PMC8235739 DOI: 10.3390/pharmaceutics13060899] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Serum urate (SU) levels in primates are extraordinarily high among mammals. Urate is a Janus-faced molecule that acts physiologically as a protective antioxidant but provokes inflammation and gout when it precipitates at high concentrations. Transporters play crucial roles in urate disposition, and drugs that interact with urate transporters either by intention or by accident may modulate SU levels. We examined whether in vitro transporter interaction studies may clarify and predict such effects. METHODS Transporter interaction profiles of clinically proven urate-lowering (uricosuric) and hyperuricemic drugs were compiled from the literature, and the predictive value of in vitro-derived cut-offs like Cmax/IC50 on the in vivo outcome (clinically relevant decrease or increase of SU) was assessed. RESULTS Interaction with the major reabsorptive urate transporter URAT1 appears to be dominant over interactions with secretory transporters in determining the net effect of a drug on SU levels. In vitro inhibition interpreted using the recommended cut-offs is useful at predicting the clinical outcome. CONCLUSIONS In vitro safety assessments regarding urate transport should be done early in drug development to identify candidates at risk of causing major imbalances. Attention should be paid both to the inhibition of secretory transporters and inhibition or trans-stimulation of reabsorptive transporters, especially URAT1.
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Affiliation(s)
- Péter Tátrai
- Solvo Biotechnology, Science Park, Building B2, 4-20 Irinyi József utca, H-1117 Budapest, Hungary;
| | - Franciska Erdő
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, H-1083 Budapest, Hungary;
| | - Gabriella Dörnyei
- Department of Morphology and Physiology, Faculty of Health Sciences, Semmelweis University, H-1088 Budapest, Hungary;
| | - Péter Krajcsi
- Solvo Biotechnology, Science Park, Building B2, 4-20 Irinyi József utca, H-1117 Budapest, Hungary;
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, H-1083 Budapest, Hungary;
- Department of Morphology and Physiology, Faculty of Health Sciences, Semmelweis University, H-1088 Budapest, Hungary;
- Correspondence:
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Sebesta I, Miyamoto D, Stiburkova B, Blahova S, Sato N, Nagata K, Okamoto K, Tsuruoka S, Ichida K. Modified forearm ischemic test in hypouricemic patients. Nucleosides Nucleotides Nucleic Acids 2020; 39:1432-1439. [PMID: 32312155 DOI: 10.1080/15257770.2020.1750636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Renal hypouricemia sometimes leads to exercise-induced acute kidney injury (EIAKI) of unknown pathogenesis. In order to elucidate the various pathological conditions associated with hypouricemia, we analyzed the effects of low uric acid level on energy metabolism. We have modified semi-ischemic forearm exercise test and performed this test in one Japanese healthy volunteer, three patients with hereditary renal hypouricemia and one patient with hereditary xanthinuria of Czech origin. Forearm exercise was performed by squeezing a hand dynamometer with the sphygmomanometer cuff pressure kept at the mean arterial pressure. Venous blood was drawn five times (before exercise, 3, 10, 30, 45 minutes after the start of exercise) in each tests. The mean plasma lactate concentration increased from a baseline of 1.3 (range 0.7-1.8 mmol/L) to 4.0 (range 2.0-5.5 mmol/L) at 3 minutes after the start of exercise. The plasma hypoxanthine concentrations were quite low before exercise (0-2.9 μmol/L), but increased markedly to a range of 13.6-28.8 μmol/L after 10 minute forearm ischemia. Our protocol allowed us to conclude that the load was sufficient for observing metabolic changes in temporally hypoxia and in following recovery phase. The test was well tolerated and safe, we did not observe any adverse reactions including EIAKI.
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Affiliation(s)
- Ivan Sebesta
- Department of Pediatrics and Adolescent Medicine, Institute of Medical Biochemistry and Laboratory Diagnostics, Charles University First Faculty of Medicine, Prague, Czech Republic
| | - Daisuke Miyamoto
- Department of Nephrology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Blanka Stiburkova
- Department of Pediatrics and Adolescent Medicine, Institute of Rheumatology, Charles University First Faculty of Medicine, Prague, Czech Republic
| | - Sarka Blahova
- Department of Pediatrics and Adolescent Medicine, Charles University First Faculty of Medicine, Prague, Czech Republic
| | - Nana Sato
- Department of Applied Biological Chemistry, The University of Tokyo Graduate School of Agricultural and Life Sciences Faculty of Agriculture, Bunkyo-ku, Japan
| | - Koji Nagata
- Department of Applied Biological Chemistry, The University of Tokyo Graduate School of Agricultural and Life Sciences Faculty of Agriculture, Bunkyo-ku, Japan
| | - Ken Okamoto
- Department of Applied Biological Chemistry, The University of Tokyo Graduate School of Agricultural and Life Sciences Faculty of Agriculture, Bunkyo-ku, Japan
| | - Shuichi Tsuruoka
- Department of Nephrology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Kimiyoshi Ichida
- Division of Kidney and Hypertension, Department of Pathophysiology, Jikei University School of Medicine, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
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12
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Abstract
Recently, research has redirected its interests in uric acid (UA) from gout, an inflammatory disease in joints, to groups of closely interrelated pathologies associated with cardiovascular and kidney dysfunction. Many epidemiological, clinical, and experimental studies have shown that UA may play a role in the pathophysiology of the cardiorenal syndrome continuum; however, it is still unclear if it is a risk factor or a causal role. Hyperuricemia has been well studied in the past two decades, revealing mechanistic insights into UA homeostasis. Likewise, some epidemiological and experimental evidence suggests that hypouricemia can lead to cardiorenal pathologies. The goal of this review is to highlight why studying both hyperuricemia and hypouricemia is warranted as well as to summarize the relevance of UA to kidney function.
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Affiliation(s)
| | - Denisha R Spires
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
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13
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Kingsmore SF, Ramchandar N, James K, Niemi AK, Feigenbaum A, Ding Y, Benson W, Hobbs C, Nahas S, Chowdhury S, Dimmock D. Mortality in a neonate with molybdenum cofactor deficiency illustrates the need for a comprehensive rapid precision medicine system. Cold Spring Harb Mol Case Stud 2020; 6:a004705. [PMID: 32014857 PMCID: PMC6996516 DOI: 10.1101/mcs.a004705] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 10/30/2019] [Indexed: 12/31/2022] Open
Abstract
Neonatal encephalopathy with seizures is a presentation in which rapid whole-genome sequencing (rWGS) has shown clinical utility and improved outcomes. We report a neonate who presented on the third day of life with seizures refractory to antiepileptic medications and neurologic and computerized tomographic findings consistent with severe generalized brain swelling. rWGS revealed compound heterozygous variants in the molybdenum cofactor synthesis gene, type 1A (MOCS1 c.*7 + 5G > A and c.377G > A); a provisional diagnosis of molybdenum cofactor deficiency on day of life 4. An emergency investigational new drug application for intravenous replacement of the MOCS1 product, cyclic pyranopterin monophosphate, was considered, but felt unsuitable in light of the severity of disease and delay in the start of treatment. The patient died on day of life 9 despite having a precise molecular diagnosis within the first week of life. This case illustrates that an rWGS-based molecular diagnosis within the first week of life may be insufficient to improve outcomes. However, it did inform clinical decision-making with regard to resuscitation and predicted long-term outcome. We suggest that to achieve optimal reductions in morbidity and mortality, rWGS must be implemented within a comprehensive rapid precision medicine system (CRPM). Akin to newborn screening (NBS), CRPM will have onboarding, diagnosis, and precision medicine implementation components developed in response to patient and parental needs. Education of health-care providers in a learning model in which ongoing data analyses informs system improvement will be essential for optimal effectiveness of CRPM.
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Affiliation(s)
- Stephen F Kingsmore
- Rady Children's Institute for Genomic Medicine, San Diego, California 92123, USA
| | - Nanda Ramchandar
- Rady Children's Institute for Genomic Medicine, San Diego, California 92123, USA
- Department of Pediatrics, Rady Children's Hospital, University of California, San Diego, California 92123, USA
| | - Kiely James
- Rady Children's Institute for Genomic Medicine, San Diego, California 92123, USA
| | - Anna-Kaisa Niemi
- Department of Pediatrics, Rady Children's Hospital, University of California, San Diego, California 92123, USA
| | - Annette Feigenbaum
- Department of Pediatrics, Rady Children's Hospital, University of California, San Diego, California 92123, USA
| | - Yan Ding
- Rady Children's Institute for Genomic Medicine, San Diego, California 92123, USA
| | - Wendy Benson
- Rady Children's Institute for Genomic Medicine, San Diego, California 92123, USA
| | - Charlotte Hobbs
- Rady Children's Institute for Genomic Medicine, San Diego, California 92123, USA
| | - Shareef Nahas
- Rady Children's Institute for Genomic Medicine, San Diego, California 92123, USA
| | - Shimul Chowdhury
- Rady Children's Institute for Genomic Medicine, San Diego, California 92123, USA
| | - David Dimmock
- Rady Children's Institute for Genomic Medicine, San Diego, California 92123, USA
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14
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Ino A, Yamaguchi K, Taneda S, Makabe S, Wakayama Y, Kataoka H, Tanaka J, Nitta K, Mochizuki T. Proximal Tubulopathy With Fibrillary Inclusions: A Rare Manifestation of Lymphoma-Associated Monoclonal Gammopathy of Renal Significance (MGRS). Kidney Med 2019; 1:397-401. [PMID: 32734220 DOI: 10.1016/j.xkme.2019.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Light chain proximal tubulopathy is a rare M-proteinemia-related nephropathy. The inclusions, composed of light chains in light chain proximal tubulopathy, are generally crystalline, and most exhibit a rhombic shape. Noncrystalline structures, such as rods or needle shapes, may also be present. In our patient, one of the noncrystalline structures, fibrillary inclusions in the cytoplasm, were observed, as previously reported in only 4 patients whose primary disease was either multiple myeloma or monoclonal gammopathy of renal significance. This is the first report involving lymphoma. Early diagnosis of light chain proximal tubulopathy is important because those who undergo chemotherapy have an improved kidney prognosis. However, in cases of kidney involvement with blood disorders, thrombocytopenia is often present. Therefore, in our case, open kidney biopsy was selected. Noncrystalline light chain proximal tubulopathy is believed to be less likely to cause Fanconi syndrome. However, Fanconi syndrome was observed in 3 of the 4 patients with fibrillary inclusions. In our case, hypouricemia was improved by chemotherapy, suggesting that the patient presented with Fanconi syndrome. Noncrystalline light chain proximal tubulopathy with fibrillary inclusions may cause Fanconi syndrome, similar to crystalline light chain proximal tubulopathy. We report a case of light chain proximal tubulopathy with fibrillary inclusions complicated by low-grade B-cell lymphoma in which early treatment was successful.
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15
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Zhou Z, Wang K, Zhou J, Wang C, Li X, Cui L, Han L, Liu Z, Ren W, Wang X, Zhang K, Li Z, Pan D, Li C, Shi Y. Amplicon targeted resequencing for SLC2A9 and SLC22A12 identified novel mutations in hypouricemia subjects. Mol Genet Genomic Med 2019; 7:e00722. [PMID: 31131560 PMCID: PMC6625124 DOI: 10.1002/mgg3.722] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/19/2019] [Accepted: 04/15/2019] [Indexed: 01/05/2023] Open
Abstract
Background To identify potential causative mutations in SLC2A9 and SLC22A12 that lead to hypouricemia or hyperuricemia (HUA). Methods Targeted resequencing of whole exon regions of SLC2A9 and SLC22A12 was performed in three cohorts of 31 hypouricemia, 288 HUA and 280 normal controls. Results A total of 84 high‐quality variants were identified in these three cohorts. Eighteen variants were nonsynonymous or in splicing region, and then included in the following association analysis. For common variants, no significant effects on hypouricemia or HUA were identified. For rare variants, six single nucleotide variations (SNVs) p.T21I and p.G13D in SLC2A9, p.W50fs, p.Q382L, p.V547L and p.E458K in SLC22A12, occurred in totally six hypouricemia subjects and were absent in HUA and normal controls. Allelic and genotypic frequency distributions of the six SNVs differed significantly between the hypouricemia and normal controls even after multiple testing correction, and p.G13D in SLC2A9 and p.V547L in SLC22A12 were newly reported. All these mutations had no significant effects on HUA susceptibility, while the gene‐based analyses substantiated the significant results on hypouricemia. Conclusion Our study first presents a comprehensive mutation spectrum of hypouricemia in a large Chinese cohort.
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Affiliation(s)
- Zhaowei Zhou
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiaric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, P.R. China
| | - Ke Wang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiaric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, P.R. China
| | - Juan Zhou
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiaric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, P.R. China
| | - Can Wang
- Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Shandong Provincial Key Laboratory of Metabolic Disease, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Metabolic Disease Institute, Qingdao University, Qingdao, P.R. China
| | - Xinde Li
- Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Shandong Provincial Key Laboratory of Metabolic Disease, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Metabolic Disease Institute, Qingdao University, Qingdao, P.R. China
| | - Lingling Cui
- Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Shandong Provincial Key Laboratory of Metabolic Disease, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Metabolic Disease Institute, Qingdao University, Qingdao, P.R. China
| | - Lin Han
- Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Shandong Provincial Key Laboratory of Metabolic Disease, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Metabolic Disease Institute, Qingdao University, Qingdao, P.R. China
| | - Zhen Liu
- Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Shandong Provincial Key Laboratory of Metabolic Disease, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Metabolic Disease Institute, Qingdao University, Qingdao, P.R. China
| | - Wei Ren
- Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Shandong Provincial Key Laboratory of Metabolic Disease, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Metabolic Disease Institute, Qingdao University, Qingdao, P.R. China
| | - Xuefeng Wang
- Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Shandong Provincial Key Laboratory of Metabolic Disease, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Metabolic Disease Institute, Qingdao University, Qingdao, P.R. China
| | - Keke Zhang
- Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Shandong Provincial Key Laboratory of Metabolic Disease, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Metabolic Disease Institute, Qingdao University, Qingdao, P.R. China.,The Department of Endocrinology and Metabolism, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China
| | - Zhiqiang Li
- Biomedical Sciences Institute, the Qingdao Branch of SJTU Bio-X Institutes, Qingdao University, Qingdao, P.R. China
| | - Dun Pan
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiaric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, P.R. China
| | - Changgui Li
- Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Shandong Provincial Key Laboratory of Metabolic Disease, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Metabolic Disease Institute, Qingdao University, Qingdao, P.R. China.,The Department of Endocrinology and Metabolism, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China
| | - Yongyong Shi
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiaric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, P.R. China.,Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Shandong Provincial Key Laboratory of Metabolic Disease, The Affiliated Hospital of Qingdao University, Qingdao, P.R. China.,Biomedical Sciences Institute, the Qingdao Branch of SJTU Bio-X Institutes, Qingdao University, Qingdao, P.R. China
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16
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Shah N, Lingappa L, Konanki R, Rani S, Vedam R, Murugan S. Immunodeficiency, Motor Delay, and Hypouricemia Caused by a Novel Mutation of Purine Nucleoside Phosphorylase Gene in an Indian Infant. Ann Indian Acad Neurol 2019; 22:231-233. [PMID: 31007444 PMCID: PMC6472228 DOI: 10.4103/aian.aian_430_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
We describe an 11-month-old boy who presented with recurrent respiratory infections from 6 months of age. His elder sister died at 10 months with severe septicemia and meningitis. The boy had a mild motor delay. Investigations revealed T cell deficiency and very low serum uric acid suggestive of purine nucleoside phosphorylase (PNP) deficiency - a rare variant of severe combined immunodeficiency disease. A novel homozygous missense mutation of c.597C>G(p. S199R) of exon 5 on PNP gene confirmed the diagnosis. We suggest that uric acid should be a part of investigation profile for unidentified motor delay, as recurrent infections can be late presentation.
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Affiliation(s)
- Nikit Shah
- Department of Pediatric Neurology, Rainbow Children's Hospital, Hyderabad, Telangana, India
| | - Lokesh Lingappa
- Department of Pediatric Neurology, Rainbow Children's Hospital, Hyderabad, Telangana, India
| | - Ramesh Konanki
- Department of Pediatric Neurology, Rainbow Children's Hospital, Hyderabad, Telangana, India
| | - Sirisha Rani
- Department of Pediatric Hemato-Oncology, Rainbow Children's Hospital, Hyderabad, Telangana, India
| | - Ramprasad Vedam
- Department of Clinical Genetics, MedGenome Laboratory, Bengaluru, Karnataka, India
| | - Sakthivel Murugan
- Department of Clinical Genetics, MedGenome Laboratory, Bengaluru, Karnataka, India
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17
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Sebesta I, Stiburkova B, Krijt J. Hereditary xanthinuria is not so rare disorder of purine metabolism. Nucleosides Nucleotides Nucleic Acids 2018; 37:324-328. [PMID: 29723117 DOI: 10.1080/15257770.2018.1460478] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Hereditary xanthinuria (type I) is caused by an inherited deficiency of the xanthine oxidorectase (XDH/XO), and is characterized by very low concentration of uric acid in blood and urine and high concentration of urinary xanthine, leading to urolithiasis. Type II results from a combined deficiency of XDH/XO and aldehyde oxidase. Patients present with hematuria, renal colic, urolithiasis or even acute renal failure. Clinical symptoms are the same for both types. In a third type, clinically distinct, sulfite oxidase activity is missing as well as XDH/XO and aldehyde oxidase. The prevalence is not known, but about 150 cases have been described so far. Hypouricemia is sometimes overlooked, that´s why we have set up the diagnostic flowchart. This consists of a) evaluation of uric acid concentrations in serum and urine with exclusion of primary renal hypouricemia, b) estimation of urinary xanthine, c) allopurinol loading test, which enables to distinguish type I and II; and finally assay of xanthine oxidoreductase activity in plasma with molecular genetic analysis. Following this diagnostic procedure we were able to find first patients with hereditary xanthinuria in our Czech population. We have detected nine cases, which is one of the largest group worldwide. Four patients were asymptomatic. All had profound hypouricemia, which was the first sign and led to referral to our department. Urinary concentrations of xanthine were in the range of 170-598 mmol/mol creatinine (normal < 30 mmol/mol creatinine). Hereditary xanthinuria is still unrecognized disorder and subjects with unexplained hypouricemia need detailed purine metabolic investigation.
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Affiliation(s)
- I Sebesta
- a Institute of Inherited Metabolic Disorders, First Faculty of Medicine , Charles University , Prague , Czech Republic.,b Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine , Charles University , Prague , Czech Republic
| | - B Stiburkova
- a Institute of Inherited Metabolic Disorders, First Faculty of Medicine , Charles University , Prague , Czech Republic.,c Institute of Rheumatology, First Faculty of Medicine , Charles University , Prague , Czech Republic
| | - J Krijt
- a Institute of Inherited Metabolic Disorders, First Faculty of Medicine , Charles University , Prague , Czech Republic
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18
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Wang F, Zhao M, Han Z, Li D, Zhang S, Zhang Y, Kong X, Zhang Q, Lei P. Long-Term Subclinical Hyperglycemia and Hypoglycemia as Independent Risk Factors for Mild Cognitive Impairment in Elderly People. TOHOKU J EXP MED 2018; 242:121-128. [PMID: 28592718 DOI: 10.1620/tjem.242.121] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Dementia is one of the most common geriatric diseases, and mild cognitive impairment (MCI) is considered to be incipient dementia. MCI patients have elevated risk of progressing to dementia. Multiple metabolic abnormalities have an unconfirmed effect on MCI risk, and taking adequate measures against metabolic abnormalities might prevent the developing of MCI. Thus, the present study explored the association of MCI risk with common metabolic abnormalities, such as hyperglycemia, hypoglycemia, hyperlipidemia and hypouricemia, and to provide the basis for MCI prevention. A total of 1,262 elderly outpatients with normal cognitive function and without confirmed diabetes mellitus, hyperlipoidemia and gout were enrolled. During the five-year follow-up period, 142 subjects were diagnosed with MCI according to Mini Mental State Examination and Montreal Cognitive Assessment. Furthermore, annual blood glucose, glycated hemoglobin, lipids and uric acid values were obtained, and mean of each indicator was calculated. Only mean values were included in the study to reflect long-term effect of metabolic abnormalities on MCI risk. Thus, the increased risk of MCI was associated with the mean values of blood glucose < 4.7 mmol/L (RR: 1.57, 95% CI: 1.14-2.32), blood glucose ≥ 6.3 mmol/L (RR: 1.49, 95% CI: 1.03-2.39), glycated hemoglobin ≥ 5.9% (RR: 2.28, 95% CI: 1.59-3.91), triglycerides ≥ 2.0 mmol/L (RR: 2.79, 95% CI: 2.14-3.79), total cholesterol ≥ 5.5 mmol/L (RR: 2.37, 95% CI: 1.69-3.39) and uric acid ≤ 380 μmol/L (RR: 1.62, 95% CI: 1.08-2.51). In conclusion, long-term subclinical hyperglycemia, hypoglycemia, hyperlipidemia, and hypouricemia are independent risk factors for MCI in elderly people.
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Affiliation(s)
- Feng Wang
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute
| | - Minghui Zhao
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute
| | - Zhaoli Han
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute
| | - Dai Li
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute
| | - Shishuang Zhang
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute
| | - Yongqiang Zhang
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute
| | - Xiaodong Kong
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute
| | - Qiang Zhang
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute
| | - Ping Lei
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute
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19
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Amin R, Eid L, Edvardsson VO, Fairbanks L, Moudgil A. An unusual cause of "pink diaper" in an infant: Answers. Pediatr Nephrol 2016; 31:577-80. [PMID: 25823988 PMCID: PMC4591240 DOI: 10.1007/s00467-015-3073-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 02/11/2015] [Accepted: 02/12/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Rasheda Amin
- Division of Pediatric Nephrology, Children's National Health System, 111 Michigan Avenue NW, Washington, DC, 20010, USA
| | - Loai Eid
- Division of Pediatrics, Latifa Hospital, Dubai, United Arab Emirates
| | - Vidar O Edvardsson
- Children's Medical Center, Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland
- School of Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Lynette Fairbanks
- Purine Research Laboratory, Viapath, St Thomas' Hospital, London, UK
| | - Asha Moudgil
- Division of Pediatric Nephrology, Children's National Health System, 111 Michigan Avenue NW, Washington, DC, 20010, USA.
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20
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Abstract
In addition to its role as a metabolic waste product, uric acid has been proposed to be an important molecule with multiple functions in human physiologic and pathophysiologic processes and may be linked to human diseases beyond nephrolithiasis and gout. Uric acid homeostasis is determined by the balance between production, intestinal secretion, and renal excretion. The kidney is an important regulator of circulating uric acid levels by reabsorbing about 90% of filtered urate and being responsible for 60% to 70% of total body uric acid excretion. Defective renal handling of urate is a frequent pathophysiologic factor underpinning hyperuricemia and gout. Despite tremendous advances over the past decade, the molecular mechanisms of renal urate transport are still incompletely understood. Many transport proteins are candidate participants in urate handling, with URAT1 and GLUT9 being the best characterized to date. Understanding these transporters is increasingly important for the practicing clinician as new research unveils their physiologic characteristics, importance in drug action, and genetic association with uric acid levels in human populations. The future may see the introduction of new drugs that act specifically on individual renal urate transporters for the treatment of hyperuricemia and gout.
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Affiliation(s)
- Ion Alexandru Bobulescu
- Departments of Internal Medicine and Physiology and the Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-8856, USA.
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