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Falconi CA, Junho CVDC, Fogaça-Ruiz F, Vernier ICS, da Cunha RS, Stinghen AEM, Carneiro-Ramos MS. Uremic Toxins: An Alarming Danger Concerning the Cardiovascular System. Front Physiol 2021; 12:686249. [PMID: 34054588 PMCID: PMC8160254 DOI: 10.3389/fphys.2021.686249] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 04/19/2021] [Indexed: 12/14/2022] Open
Abstract
The kidneys and heart share functions with the common goal of maintaining homeostasis. When kidney injury occurs, many compounds, the so-called “uremic retention solutes” or “uremic toxins,” accumulate in the circulation targeting other tissues. The accumulation of uremic toxins such as p-cresyl sulfate, indoxyl sulfate and inorganic phosphate leads to a loss of a substantial number of body functions. Although the concept of uremic toxins is dated to the 1960s, the molecular mechanisms capable of leading to renal and cardiovascular injuries are not yet known. Besides, the greatest toxic effects appear to be induced by compounds that are difficult to remove by dialysis. Considering the close relationship between renal and cardiovascular functions, an understanding of the mechanisms involved in the production, clearance and overall impact of uremic toxins is extremely relevant for the understanding of pathologies of the cardiovascular system. Thus, the present study has as main focus to present an extensive review on the impact of uremic toxins in the cardiovascular system, bringing the state of the art on the subject as well as clinical implications related to patient’s therapy affected by chronic kidney disease, which represents high mortality of patients with cardiac comorbidities.
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Affiliation(s)
- Carlos Alexandre Falconi
- Laboratory of Cardiovascular Immunology, Center of Natural and Human Sciences (CCNH), Federal University of ABC, Santo André, Brazil
| | - Carolina Victoria da Cruz Junho
- Laboratory of Cardiovascular Immunology, Center of Natural and Human Sciences (CCNH), Federal University of ABC, Santo André, Brazil
| | - Fernanda Fogaça-Ruiz
- Laboratory of Cardiovascular Immunology, Center of Natural and Human Sciences (CCNH), Federal University of ABC, Santo André, Brazil
| | - Imara Caridad Stable Vernier
- Laboratory of Cardiovascular Immunology, Center of Natural and Human Sciences (CCNH), Federal University of ABC, Santo André, Brazil
| | - Regiane Stafim da Cunha
- Experimental Nephrology Laboratory, Basic Pathology Department, Universidade Federal do Paraná, Curitiba, Brazil
| | | | - Marcela Sorelli Carneiro-Ramos
- Laboratory of Cardiovascular Immunology, Center of Natural and Human Sciences (CCNH), Federal University of ABC, Santo André, Brazil
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Chen Y, Zelnick LR, Wang K, Katz R, Hoofnagle AN, Becker JO, Hsu CY, Go AS, Feldman HI, Mehta RC, Lash JP, Waikar SS, Hamm L, Chen J, Shafi T, Kestenbaum BR. Association of tubular solute clearances with the glomerular filtration rate and complications of chronic kidney disease: the Chronic Renal Insufficiency Cohort study. Nephrol Dial Transplant 2020; 36:gfaa057. [PMID: 33330914 PMCID: PMC8237987 DOI: 10.1093/ndt/gfaa057] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 02/25/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The secretion of organic solutes by the proximal tubules is an essential intrinsic kidney function. The degree to which secretory solute clearance corresponds with the glomerular filtration rate (GFR) and potential metabolic implications of net secretory clearance are largely unknown. METHODS We evaluated 1240 participants with chronic kidney disease (CKD) from the multicenter Chronic Renal Insufficiency Cohort (CRIC) Study. We used targeted mass-spectrometry to quantify candidate secretory solutes in paired 24-h urine and plasma samples. CRIC study personnel measured GFR using 125I-iothalamate clearance (iGFR). We used correlation and linear regression to determine cross-sectional associations of secretory clearances with iGFR and common metabolic complications of CKD. RESULTS Correlations between iGFR and secretory solute clearances ranged from ρ = +0.30 for hippurate to ρ = +0.58 for kynurenic acid. Lower net clearances of most secretory solutes were associated with higher serum concentrations of parathyroid hormone (PTH), triglycerides and uric acid. Each 50% lower kynurenic acid clearance was associated with a 21% higher serum PTH concentration [95% confidence interval (CI) 15-26%] and a 10% higher serum triglyceride concentration (95% CI 5-16%) after adjustment for iGFR, albuminuria and other potential confounders. Secretory solute clearances were not associated with statistically or clinically meaningful differences in serum calcium, phosphate, hemoglobin or bicarbonate concentrations. CONCLUSIONS Tubular secretory clearances are modestly correlated with measured GFR among adult patients with CKD. Lower net secretory clearances are associated with selected metabolic complications independent of GFR and albuminuria, suggesting potential clinical and biological relevance.
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Affiliation(s)
- Yan Chen
- Department of Epidemiology, University of Washington, Seattle, WA, USA
- Kidney Research Institute, Seattle, WA, USA
| | - Leila R Zelnick
- Kidney Research Institute, Seattle, WA, USA
- Department of Medicine, Division of Nephrology, University of Washington, Seattle, WA, USA
| | - Ke Wang
- Kidney Research Institute, Seattle, WA, USA
- Department of Medicine, Division of Nephrology, University of Washington, Seattle, WA, USA
| | - Ronit Katz
- Kidney Research Institute, Seattle, WA, USA
- Department of Medicine, Division of Nephrology, University of Washington, Seattle, WA, USA
| | - Andrew N Hoofnagle
- Kidney Research Institute, Seattle, WA, USA
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - Jessica O Becker
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - Chi-Yuan Hsu
- Department of Medicine, Division of Nephrology, University of California San Francisco, San Francisco, CA, USA
| | - Alan S Go
- Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA
| | - Harold I Feldman
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA, USA
- Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, PA, USA
| | - Rupal C Mehta
- Department of Medicine, Division of Nephrology and Hypertension, Jesse Brown Veterans Administration Medical Center & Northwestern University, Chicago, IL, USA
| | - James P Lash
- Department of Medicine, Division of Nephrology, University of Illinois at Chicago, Chicago, IL, USA
| | | | - L Hamm
- Division of Nephrology and Hypertension, Tulane University Department of Medicine, New Orleans, LA, USA
| | - Jing Chen
- Division of Nephrology and Hypertension, Tulane University Department of Medicine, New Orleans, LA, USA
| | - Tariq Shafi
- Department of Medicine, Division of Nephrology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Bryan R Kestenbaum
- Kidney Research Institute, Seattle, WA, USA
- Department of Medicine, Division of Nephrology, University of Washington, Seattle, WA, USA
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Cobo G, Lindholm B, Stenvinkel P. Chronic inflammation in end-stage renal disease and dialysis. Nephrol Dial Transplant 2019; 33:iii35-iii40. [PMID: 30281126 PMCID: PMC6168801 DOI: 10.1093/ndt/gfy175] [Citation(s) in RCA: 231] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Indexed: 12/15/2022] Open
Abstract
Under normal conditions, inflammation is a protective and physiological response to various harmful stimuli. However, in several chronic debilitating disorders, such as chronic kidney disease, inflammation becomes maladaptive, uncontrolled and persistent. Systemic persistent inflammation has, for almost 20 years, been recognized as a major contributor to the uraemic phenotype (such as cardiovascular disease, protein energy wasting, depression, osteoporosis and frailty), and a predictor of cardiovascular and total mortality. Since inflammation is mechanistically related to several ageing processes (inflammageing), it may be a major driver of a progeric phenotype in the uraemic milieu. Inflammation is likely the consequence of a multifactorial aetiology and interacts with a number of factors that emerge when uraemic toxins accumulate. Beside interventions aiming to decrease the production of inflammatory molecules in the uraemic milieu, novel strategies to increase the removal of large middle molecules, such as expanded haemodialysis, may be an opportunity to decrease the inflammatory allostatic load associated with retention of middle molecular weight uraemic toxins.
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Affiliation(s)
- Gabriela Cobo
- Department of Education and Research, Hospital Eugenio Espejo, Quito, Ecuador
| | - Bengt Lindholm
- Division of Renal Medicine and Baxter Novum, Karolinska Institutet, Stockholm, Sweden
| | - Peter Stenvinkel
- Division of Renal Medicine and Baxter Novum, Karolinska Institutet, Stockholm, Sweden
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Snauwaert E, Van Biesen W, Raes A, Glorieux G, Van Bogaert V, Van Hoeck K, Coppens M, Roels S, Vande Walle J, Eloot S. Concentrations of representative uraemic toxins in a healthy versus non-dialysis chronic kidney disease paediatric population. Nephrol Dial Transplant 2019; 33:978-986. [PMID: 28992139 DOI: 10.1093/ndt/gfx224] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 05/24/2017] [Indexed: 12/18/2022] Open
Abstract
Background Chronic kidney disease (CKD) in childhood is poorly explained by routine markers (e.g. urea and creatinine) and is better depicted in adults by other uraemic toxins. This study describes concentrations of representative uraemic toxins in non-dialysis CKD versus healthy children. Methods In 50 healthy children and 57 children with CKD Stages 1-5 [median estimated glomerular filtration rate 48 (25th-75th percentile 24-71) mL/min/1.73 m2; none on dialysis], serum concentrations of small solutes [symmetric and asymmetric dimethyl-arginine (SDMA and ADMA, respectively)], middle molecules [β2-microglobuline (β2M), complement factor D (CfD)] and protein-bound solutes [p-cresylglucuronide (pCG), hippuric acid (HA), indole-acetic acid (IAA), indoxyl sulphate (IxS), p-cresyl sulphate (pCS) and 3-carboxy-4-methyl-5-propyl-furanpropionic acid (CMPF)] were measured. Concentrations in the CKD group were expressed as z-score relative to controls and matched for age and gender. Results SDMA, CfD, β2M, IxS, pCS, IAA, CMPF and HA concentrations were higher in the overall CKD group compared with controls, ranging from 1.7 standard deviations (SD) for IAA and HA to 11.1 SD for SDMA. SDMA, CfD, β2M, IxS and CMPF in CKD Stages 1-2 with concentrations 4.8, 2.8, 4.5, 1.9 and 1.6 SD higher, respectively. In contrast, pCS, pCG and IAA concentrations were only higher than controls from CKD Stages 3-4 onwards, but only in CKD Stage 5 for ADMA and HA (z-score 2.6 and 20.2, respectively). Conclusions This is the first study to establish reference values for a wide range of uraemic toxins in non-dialysis CKD and healthy children. We observed an accumulation of multiple uraemic toxins, each with a particular retention profile according to the different CKD stages.
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Affiliation(s)
- Evelien Snauwaert
- Department of Paediatrics and Medical Genetics, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Wim Van Biesen
- Department of Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Ann Raes
- Department of Paediatric Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Griet Glorieux
- Department of Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Valerie Van Bogaert
- Department of Paediatrics and Medical Genetics, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Koen Van Hoeck
- Department of Paediatric Nephrology, Antwerp University Hospital, Antwerp, Belgium
| | - Marc Coppens
- Department of Anaesthesiology, Ghent University Hospital, Ghent, Belgium
| | - Sanne Roels
- Department of Data Analysis, Faculty of Psychology and Pedagogy, Ghent University, Ghent, Belgium
| | - Johan Vande Walle
- Department of Paediatric Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Sunny Eloot
- Department of Nephrology, Ghent University Hospital, Ghent, Belgium
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Snauwaert E, Van Biesen W, Raes A, Holvoet E, Glorieux G, Van Hoeck K, Van Dyck M, Godefroid N, Vanholder R, Roels S, Walle JV, Eloot S. Accumulation of uraemic toxins is reflected only partially by estimated GFR in paediatric patients with chronic kidney disease. Pediatr Nephrol 2018; 33:315-323. [PMID: 28939943 DOI: 10.1007/s00467-017-3802-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 08/07/2017] [Accepted: 08/25/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Chronic kidney disease (CKD) in childhood is characterised by the accumulation of uraemic toxins resulting in a multisystem disorder that has a negative impact on quality of life. Childhood CKD is predominantly defined by a decrease in glomerular filtration rate, estimated (eGFR) by a single serum measurement of endogenous biomarkers, e.g. creatinine. The objective of this study was to evaluate how accurately eGFR predicts the concentration of uraemic toxins in a paediatric CKD cohort. METHODS In 65 children (10.8 [5.1; 14.7] years) with CKD (eGFR 44 [20; 64] mL/min/1.73 m2), serum concentrations were determined of small solutes (uric acid [UA], urea, symmetric dimethylarginine [SDMA], asymmetric dimethylarginine [ADMA]), middle molecules (β2-microglobulin [β2M], complement factor D [CfD]) and protein-bound solutes (p-cresylglucuronide [pCG], hippuric acid, indole acetic acid, indoxyl sulphate [IxS], p-cresylsulfate [pCS] and 3-carboxy-4-methyl-5-propyl-furanpropionic acid [CMPF]). Spearman's correlation coefficients (r) were calculated to correlate uraemic toxin concentrations with three different eGFR equations, based on either serum creatinine or β2M. RESULTS Updated Schwartz eGFR was correlated reasonably well with concentrations of creatinine (r = -0.98), urea (rs = -0.84), SDMA (r = -0.82) and middle molecules CfD and β2M (both rs = -0.90). In contrast, poor correlation coefficients were found for CMPF (rs = -0.32), UA (rs = -0.45), ADMA (rs = -0.47) and pCG (rs = -0.48). The other toxins, all protein-bound, had rs between -0.75 and -0.57. Comparable correlations were found between the three evaluated eGFR equations and uraemic toxin concentrations. CONCLUSIONS This study demonstrates that eGFR poorly predicts concentrations of protein-bound uraemic toxins, UA and ADMA in childhood CKD. Therefore, eGFR only partially reflects the complexity of the accumulation pattern of uraemic toxins in childhood CKD.
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Affiliation(s)
- Evelien Snauwaert
- Department of Paediatrics and Medical Genetics, Faculty of Medicine and Health Sciences, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Wim Van Biesen
- Department of Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Ann Raes
- Department of Paediatric Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Els Holvoet
- Department of Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Griet Glorieux
- Department of Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Koen Van Hoeck
- Department of Paediatric Nephrology, Antwerp University Hospital, Antwerp, Belgium
| | - Maria Van Dyck
- Department of Paediatric Nephrology, University Hospital Leuven, Leuven, Belgium
| | - Nathalie Godefroid
- Department of Paediatric Nephrology, University Hospital Saint-Luc, Brussels, Belgium
| | | | - Sanne Roels
- Department of Data Analysis, Faculty of Psychology and Pedagogy, Ghent University, Ghent, Belgium
| | - Johan Vande Walle
- Department of Paediatric Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Sunny Eloot
- Department of Nephrology, Ghent University Hospital, Ghent, Belgium
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Vanholder R, Pletinck A, Schepers E, Glorieux G. Biochemical and Clinical Impact of Organic Uremic Retention Solutes: A Comprehensive Update. Toxins (Basel) 2018; 10:toxins10010033. [PMID: 29316724 PMCID: PMC5793120 DOI: 10.3390/toxins10010033] [Citation(s) in RCA: 200] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/21/2017] [Accepted: 12/23/2017] [Indexed: 02/07/2023] Open
Abstract
In this narrative review, the biological/biochemical impact (toxicity) of a large array of known individual uremic retention solutes and groups of solutes is summarized. We classified these compounds along their physico-chemical characteristics as small water-soluble compounds or groups, protein bound compounds and middle molecules. All but one solute (glomerulopressin) affected at least one mechanism with the potential to contribute to the uremic syndrome. In general, several mechanisms were influenced for each individual solute or group of solutes, with some impacting up to 7 different biological systems of the 11 considered. The inflammatory, cardio-vascular and fibrogenic systems were those most frequently affected and they are one by one major actors in the high morbidity and mortality of CKD but also the mechanisms that have most frequently been studied. A scoring system was built with the intention to classify the reviewed compounds according to the experimental evidence of their toxicity (number of systems affected) and overall experimental and clinical evidence. Among the highest globally scoring solutes were 3 small water-soluble compounds [asymmetric dimethylarginine (ADMA); trimethylamine-N-oxide (TMAO); uric acid], 6 protein bound compounds or groups of protein bound compounds [advanced glycation end products (AGEs); p-cresyl sulfate; indoxyl sulfate; indole acetic acid; the kynurenines; phenyl acetic acid;] and 3 middle molecules [β2-microglobulin; ghrelin; parathyroid hormone). In general, more experimental data were provided for the protein bound molecules but for almost half of them clinical evidence was missing in spite of robust experimental data. The picture emanating is one of a complex disorder, where multiple factors contribute to a multisystem complication profile, so that it seems of not much use to pursue a decrease of concentration of a single compound.
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Affiliation(s)
- Raymond Vanholder
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
| | - Anneleen Pletinck
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
| | - Eva Schepers
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
| | - Griet Glorieux
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
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Karras A, Boutouyrie P, Briet M, Bozec E, Haymann JP, Legendre C, McMahon LP, Delahousse M. Reversal of Arterial Stiffness and Maladaptative Arterial Remodeling After Kidney Transplantation. J Am Heart Assoc 2017; 6:e006078. [PMID: 28889098 PMCID: PMC5634273 DOI: 10.1161/jaha.117.006078] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/29/2017] [Indexed: 01/23/2023]
Abstract
BACKGROUND Chronic kidney disease is characterized by stiffening, thinning, dilatation, and increased circumferential wall stress of large arteries, associated with increased cardiovascular risk. Kidney transplantation (KT) reverses many pathological features of chronic kidney disease and improves life expectancy; however, longitudinal studies exploring the impact of KT on recipient large arteries are scarce. METHODS AND RESULTS This study was designed to appraise arterial changes following KT. Carotid-femoral pulse wave velocity, carotid remodeling (circumferential wall stress and carotid internal diameter), and stiffness were measured in 161 consecutive recipients receiving either a living (n=49) or a deceased (n=112) donor allograft, at 3 and 12 months after transplantation. Mean pulse wave velocity decreased from 10.8 m/s (95% confidence interval, 10.5-11.2 m/s) (at month 3) to 10.1 m/s (95% confidence interval, 9.8-10.5 m/s) (at month 12) (P<0.001). After multivariate adjustment, pulse wave velocity reduction from month 3 to month 12 was significantly larger in the living donor allograft KT (P<0.001). Circumferential wall stress decreased, 70 kPa (95% confidence interval, 68-72 kPa) to 64 kPa (95% confidence interval, 62-67 kPa), as well as carotid internal diameter and carotid stiffness (P<0.001 for all). Reductions in circumferential wall stress, diameter, and stiffness were significantly larger in the living donor allograft KT (P<0.001). When deceased donor allograft patients were classified into standard and expanded criteria donors, changes in both pulse wave velocity and circumferential wall stress were blunted in expanded criteria donors. Changes were independent of graft function and blood pressure changes. CONCLUSIONS Large-artery stiffness and maladaptive carotid artery remodeling of chronic kidney disease is partially reversed within 12 months of KT and appears unrelated to renal function. Improvements were independently associated with live organ donation. Our data suggest that expanded criteria donors may hamper vascular recovery.
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Affiliation(s)
- Alexandre Karras
- Nephrology Department, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
- Institut National de la Santé et de la Recherche Médicale U970-PARCC, Paris, France
- Université Paris Descartes, Paris, France
| | - Pierre Boutouyrie
- Pharmacology Department, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
- Institut National de la Santé et de la Recherche Médicale U970-PARCC, Paris, France
- Université Paris Descartes, Paris, France
| | - Marie Briet
- Pharmacology Department, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
- Institut National de la Santé et de la Recherche Médicale U970-PARCC, Paris, France
- Université Paris Descartes, Paris, France
| | - Erwan Bozec
- Pharmacology Department, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
- Institut National de la Santé et de la Recherche Médicale U970-PARCC, Paris, France
| | - Jean-Philippe Haymann
- Physiology Department, Hôpital Tenon, Assistance Publique Hôpitaux de Paris, Paris, France
- Université Pierre et Marie Curie, Paris, France
| | - Christophe Legendre
- Renal Transplantation Department, Hôpital Necker, Assistance Publique Hôpitaux de Paris, Paris, France
| | | | - Michel Delahousse
- Nephrology and Renal Transplantation Department, Hôpital Foch, Suresnes, France
- INSERM U 1018 CESP Team 5, UVSQ, Villejuif, France
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8
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Argyropoulos CP, Chen SS, Ng YH, Roumelioti ME, Shaffi K, Singh PP, Tzamaloukas AH. Rediscovering Beta-2 Microglobulin As a Biomarker across the Spectrum of Kidney Diseases. Front Med (Lausanne) 2017; 4:73. [PMID: 28664159 PMCID: PMC5471312 DOI: 10.3389/fmed.2017.00073] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/26/2017] [Indexed: 12/28/2022] Open
Abstract
There is currently an unmet need for better biomarkers across the spectrum of renal diseases. In this paper, we revisit the role of beta-2 microglobulin (β2M) as a biomarker in patients with chronic kidney disease and end-stage renal disease. Prior to reviewing the numerous clinical studies in the area, we describe the basic biology of β2M, focusing in particular on its role in maintaining the serum albumin levels and reclaiming the albumin in tubular fluid through the actions of the neonatal Fc receptor. Disorders of abnormal β2M function arise as a result of altered binding of β2M to its protein cofactors and the clinical manifestations are exemplified by rare human genetic conditions and mice knockouts. We highlight the utility of β2M as a predictor of renal function and clinical outcomes in recent large database studies against predictions made by recently developed whole body population kinetic models. Furthermore, we discuss recent animal data suggesting that contrary to textbook dogma urinary β2M may be a marker for glomerular rather than tubular pathology. We review the existing literature about β2M as a biomarker in patients receiving renal replacement therapy, with particular emphasis on large outcome trials. We note emerging proteomic data suggesting that β2M is a promising marker of chronic allograft nephropathy. Finally, we present data about the role of β2M as a biomarker in a number of non-renal diseases. The goal of this comprehensive review is to direct attention to the multifaceted role of β2M as a biomarker, and its exciting biology in order to propose the next steps required to bring this recently rediscovered biomarker into the twenty-first century.
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Affiliation(s)
- Christos P Argyropoulos
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Shan Shan Chen
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Yue-Harn Ng
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Maria-Eleni Roumelioti
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Kamran Shaffi
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Pooja P Singh
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Antonios H Tzamaloukas
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States.,Raymond G. Murphy VA Medical Center Albuquerque, Albuquerque, NM, United States
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9
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Załęska-Kocięcka M, Jezierski P, Grabowski M, Kuśmierski K, Dąbrowski M, Piotrowska K, Banaszewski M, Imiela J, Stępińska J. Role of β2-microglobulin in postoperative cognitive decline. Biomark Med 2017; 11:245-253. [DOI: 10.2217/bmm-2016-0274] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Aim: β2-microglobulin (β2M) was proved to affect hippocampal functions in mice. Materials & methods: Seventy-one patients undergoing aortic valve replacement were analyzed in prospective observational study. Kidney biomarkers and Mini Mental State Examinations (MMSEs) were performed before procedure, at discharge and after 6 months. Results: Patients with β2M increase over the median change (>0.42 mg/l) experienced a significant in-hospital drop in MMSE (p = 0.005). Patients with β2M increase over the median change also failed to improve a delayed-word-recall domain of the test (p = 0.826) while patients with a lower increase improved results in the domain (p = 0.004). After 6 months, MMSE improvement was associated with a significant decrease in β2M (p = 0.042). Conclusion: These are the first in man data demonstrating relation between changes in cognition and β2M. The phenomenon was reversible which indicates its therapeutic potential.
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Affiliation(s)
| | - Paweł Jezierski
- Neurology Clinic, Institute of Psychiatry & Neurology, Warsaw, Poland
| | - Maciej Grabowski
- Acquired Valve Disease Clinic, Institute of Cardiology, Warsaw, Poland
| | - Krzysztof Kuśmierski
- Cardiac Surgery & Transplantology Clinic, Institute of Cardiology, Warsaw, Poland
| | - Maciej Dąbrowski
- Interventional Cardiology & Angiology Clinic, Institute of Cardiology, Warsaw, Poland
| | - Katarzyna Piotrowska
- Department of Quantitative Methods & Information Technology, Kozminski University, Warsaw, Poland
| | - Marek Banaszewski
- Cardiac Intensive Therapy Clinic, Institute of Cardiology, Warsaw, Poland
| | - Jacek Imiela
- Department of Internal Medicine & Nephrology, Miedzyleski Hospital, Warsaw, Poland
| | - Janina Stępińska
- Cardiac Intensive Therapy Clinic, Institute of Cardiology, Warsaw, Poland
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10
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Underwood CF, Hildreth CM, Wyse BF, Boyd R, Goodchild AK, Phillips JK. Uraemia: an unrecognized driver of central neurohumoral dysfunction in chronic kidney disease? Acta Physiol (Oxf) 2017; 219:305-323. [PMID: 27247097 DOI: 10.1111/apha.12727] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 01/21/2016] [Accepted: 05/31/2016] [Indexed: 12/12/2022]
Abstract
Chronic kidney disease (CKD) carries a large cardiovascular burden in part due to hypertension and neurohumoral dysfunction - manifesting as sympathetic overactivity, baroreflex dysfunction and chronically elevated circulating vasopressin. Alterations within the central nervous system (CNS) are necessary for the expression of neurohumoral dysfunction in CKD; however, the underlying mechanisms are poorly defined. Uraemic toxins are a diverse group of compounds that accumulate as a direct result of renal disease and drive dysfunction in multiple organs, including the brain. Intensive haemodialysis improves both sympathetic overactivity and cardiac baroreflex sensitivity in renal failure patients, indicating that uraemic toxins participate in the maintenance of autonomic dysfunction in CKD. In rodents exposed to uraemia, immediate early gene expression analysis suggests upregulated activity of not only pre-sympathetic but also vasopressin-secretory nuclei. We outline several potential mechanisms by which uraemia might drive neurohumoral dysfunction in CKD. These include superoxide-dependent effects on neural activity, depletion of nitric oxide and induction of low-grade systemic inflammation. Recent evidence has highlighted superoxide production as an intermediate for the depolarizing effect of some uraemic toxins on neuronal cells. We provide preliminary data indicating augmented superoxide production within the hypothalamic paraventricular nucleus in the Lewis polycystic kidney rat, which might be important for mediating the neurohumoral dysfunction exhibited in this CKD model. We speculate that the uraemic state might serve to sensitize the central actions of other sympathoexcitatory factors, including renal afferent nerve inputs to the CNS and angiotensin II, by way of recruiting convergent superoxide-dependent and pro-inflammatory pathways.
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Affiliation(s)
- C. F. Underwood
- Department of Biomedical Sciences; Macquarie University; Sydney NSW Australia
| | - C. M. Hildreth
- Department of Biomedical Sciences; Macquarie University; Sydney NSW Australia
| | - B. F. Wyse
- Department of Biomedical Sciences; Macquarie University; Sydney NSW Australia
| | - R. Boyd
- Department of Biomedical Sciences; Macquarie University; Sydney NSW Australia
| | - A. K. Goodchild
- Department of Biomedical Sciences; Macquarie University; Sydney NSW Australia
| | - J. K. Phillips
- Department of Biomedical Sciences; Macquarie University; Sydney NSW Australia
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11
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[Conservative management option in elderly patients]. Nephrol Ther 2016; 12:98-103. [PMID: 26725173 DOI: 10.1016/j.nephro.2015.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 09/08/2015] [Accepted: 09/09/2015] [Indexed: 11/21/2022]
Abstract
"Conservative management" is as an alternative care pathway offered to patients who elect not to start dialysis often because of a heavy burden of comorbid illness and advanced ages. Our research, characterized by a transdisciplinary medical and social investigation and based on a case by case analysis, intends to understand the reasons and the context in which this choice has to be made. On the first hand, the results show that all the studied cases can be explained by two variables, the latter can be combined: when the patient is suffering from important clinical pathologies; when the patient lives with this renal failure as a trouble linked to the age. On the second hand, two important questions are raised: the first one is about the medical practices and stems from the influence of criteria always present in the decisions to take (the paramedical exams and the clinical information from the interview, the patient's examination and the discussion with his/her close family member). The second one is about the patient's autonomy and can be analyzed regarding to his/her capacity to express his/her choices and share it with his close family. But also, to live in according to his age, that is to say the relation he/she has with his/her edged body and to the limits of his/her existence. The key notion of shared decision-making renewed is to refer in the consultation and the choices to take to the question of the advantages/drawbacks for the patient's life and not only to the question of the connection between the results and the medical risks, in order to exchange view with the patient on his/her future life and not only on the condition of his failed organ.
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Vanholder RC, Eloot S, Glorieux GLRL. Future Avenues to Decrease Uremic Toxin Concentration. Am J Kidney Dis 2015; 67:664-76. [PMID: 26500179 DOI: 10.1053/j.ajkd.2015.08.029] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 08/19/2015] [Indexed: 01/13/2023]
Abstract
In this article, we review approaches for decreasing uremic solute concentrations in chronic kidney disease and in particular, in end-stage renal disease (ESRD). The rationale to do so is the straightforward relation between concentration and biological (toxic) effect for most toxins. The first section is devoted to extracorporeal strategies (kidney replacement therapy). In the context of high-flux hemodialysis and hemodiafiltration, we discuss increasing dialyzer blood and dialysate flows, frequent and/or extended dialysis, adsorption, bioartificial kidney, and changing physical conditions within the dialyzer (especially for protein-bound toxins). The next section focuses on the intestinal generation of uremic toxins, which in return is stimulated by uremic conditions. Therapeutic options are probiotics, prebiotics, synbiotics, and intestinal sorbents. Current data are conflicting, and these issues need further study before useful therapeutic concepts are developed. The following section is devoted to preservation of (residual) kidney function. Although many therapeutic options may overlap with therapies provided before ESRD, we focus on specific aspects of ESRD treatment, such as the risks of too-strict blood pressure and glycemic regulation and hemodynamic changes during dialysis. Finally, some recommendations are given on how research might be organized with regard to uremic toxins and their effects, removal, and impact on outcomes of uremic patients.
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Affiliation(s)
| | - Sunny Eloot
- Nephrology Department, University Hospital, Gent, Belgium
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13
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Effect of High-Flux Dialysis on Circulating FGF-23 Levels in End-Stage Renal Disease Patients: Results from a Randomized Trial. PLoS One 2015; 10:e0128079. [PMID: 26024521 PMCID: PMC4449206 DOI: 10.1371/journal.pone.0128079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 04/21/2015] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND In patients undergoing maintenance hemodialysis (HD), increased levels of circulating fibroblast growth factor-23 (FGF-23) are independently associated with cardiovascular events and mortality. Interventional strategies aiming to reduce levels of FGF-23 in HD patients are of particular interest. The purpose of the current study was to compare the impact of high-flux versus low-flux HD on circulating FGF-23 levels. METHODS We conducted a post-hoc analysis of the MINOXIS study, including 127 dialysis patients randomized to low-flux (n = 62) and high-flux (n = 65) HD for 52 weeks. Patients with valid measures for FGF-23 investigated baseline and after 52 weeks were included. RESULTS Compared to baseline, a significant increase in FGF-23 levels after one year of low-flux HD was observed (Delta plasma FGF-23: +4026 RU/ml; p < 0.001). In contrast, FGF-23 levels remained stable in the high flux group (Delta plasma FGF-23: +373 RU/ml, p = 0.70). The adjusted difference of the absolute change in FGF-23 levels between the two treatment groups was statistically significant (p < 0.01). CONCLUSIONS Over a period of 12 months, high-flux HD was associated with stable FGF-23 levels, whereas the low-flux HD group showed an increase of FGF-23. However, the implications of the different FGF 23 time-trends in patients on high flux dialysis, as compared to the control group, remain to be explored in specifically designed clinical trials. TRIAL REGISTRATION German Clinical Trials Register (DRKS) DRKS00007612.
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Rroji M, Eloot S, Dhondt A, Van Biesen W, Glorieux G, Neirynck N, Vandennoortgate N, Liabeuf S, Massy Z, Vanholder R. Association of advanced age with concentrations of uraemic toxins in CKD. J Nephrol 2015; 29:81-91. [DOI: 10.1007/s40620-015-0195-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/27/2015] [Indexed: 11/28/2022]
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Vanholder R, Boelaert J, Glorieux G, Eloot S. New methods and technologies for measuring uremic toxins and quantifying dialysis adequacy. Semin Dial 2014; 28:114-24. [PMID: 25441338 DOI: 10.1111/sdi.12331] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This publication reviews the currently available methods to identify uremic retention solutes, to determine their biological relevance and to quantify their removal. The analytical methods for the detection of uremic solutes have improved continuously, allowing the identification of several previously unknown solutes. Progress has been accelerated by the development of comprehensive strategies such as genomics, proteomics and the latest "omics" area, metabolomics. Those methodologies will be further refined in future. Once the concentration of solutes of interest is known based on targeted analysis, their biological relevance can be studied by means of in vitro, ex vivo, or animal models, provided those are representative for the key complications of the uremic syndrome. For this to come to pass, rigid protocols should be applied, e.g., aiming at free solute concentrations conform those found in uremia. Subsequently, the decrease in concentration of relevant solutes should be pursued by nondialysis (e.g., by influencing nutritional intake or intestinal generation, using sorbents, modifying metabolism, or preserving renal function) and dialysis methods. Optimal dialysis strategies can be sought by studying solute kinetics during dialysis. Clinical studies are necessary to assess the correct impact of those optimized strategies on outcomes. Although longitudinal studies of solute concentration and surrogate outcome studies are first steps in suggesting the usefulness of a given approach, ultimately hard outcome randomized controlled trials are needed to endorse evidence-based therapeutic choices. The nonspecificity of dialysis removal is however a handicap limiting the chances to provide proof of concept that a given solute or group of solutes has definite biological impact.
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Affiliation(s)
- Raymond Vanholder
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, Gent, Belgium
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Beta2-microglobulin as a diagnostic marker in cerebrospinal fluid: a follow-up study. DISEASE MARKERS 2014; 2014:495402. [PMID: 24895473 PMCID: PMC4034398 DOI: 10.1155/2014/495402] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 03/17/2014] [Accepted: 03/30/2014] [Indexed: 02/07/2023]
Abstract
Beta2-Microglobulin (β2-m) is a low molecular weight protein occurring in all body fluids. Its concentration increases in various pathologies. Increased values in cerebrospinal fluid (CSF) are ascribed to an activation of immune system. Using immunoturbidimetry, we examined concentrations of beta2-microglobulin in cerebrospinal fluid in a large group of 6274 patients with defined neurological diseases. Cell counts, total protein, albumin, glucose, lactic acid, immunoglobulins concentrations, and isofocusing (IEF) were also evaluated. We found substantial changes of CSF β2-m concentrations in purulent meningitis, leptomeningeal metastasis, viral meningitis/encephalitis, and neuroborreliosis, while in multiple sclerosis these changes were not significant. Intrathecal synthesis and immune activation were present in these clinical entities. A new normative study enables better understanding of beta2-microglobulin behavior in CSF.
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Chmielewski M, Cohen G, Wiecek A, Jesús Carrero J. The peptidic middle molecules: is molecular weight doing the trick? Semin Nephrol 2014; 34:118-34. [PMID: 24780468 DOI: 10.1016/j.semnephrol.2014.02.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Chronic kidney disease (CKD) is characterized by a gradual endogenous intoxication caused by the progressive accumulation of bioactive compounds that in normal conditions would be excreted and/or metabolized by the kidney. Uremic toxicity now is understood as one of the potential causes for the excess of cardiovascular disease and mortality observed in CKD. An important family of uremic toxins is that of the peptidic middle molecules, with a molecular weight ranging between 500 and 60,000 Da, which makes them, as a consequence, difficult to remove in the process of dialysis unless the dialyzer pore size is large enough. This review provides an overview of the main and best-characterized peptidic middle molecules and their role as potential culprits of the cardiometabolic complications inherent to CKD patients.
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Affiliation(s)
- Michal Chmielewski
- Department of Nephrology, Transplantology and Internal Medicine, Medical University of Gdansk, Gdansk, Poland
| | - Gerald Cohen
- Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Andrzej Wiecek
- Department of Nephrology, Endocrinology and Metabolic Diseases, Medical University of Silesia, Katowice, Poland
| | - Juan Jesús Carrero
- Division of Nephrology and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
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Eloot S, Van Biesen W, Glorieux G, Neirynck N, Dhondt A, Vanholder R. Does the adequacy parameter Kt/V(urea) reflect uremic toxin concentrations in hemodialysis patients? PLoS One 2013; 8:e76838. [PMID: 24236005 PMCID: PMC3827207 DOI: 10.1371/journal.pone.0076838] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 08/31/2013] [Indexed: 11/18/2022] Open
Abstract
Hemodialysis aims at removing uremic toxins thus decreasing their concentrations. The present study investigated whether Kt/Vurea, used as marker of dialysis adequacy, is correlated with these concentrations. Predialysis blood samples were taken before a midweek session in 71 chronic HD patients. Samples were analyzed by colorimetry, HPLC, or ELISA for a broad range of uremic solutes. Solute concentrations were divided into four groups according to quartiles of Kt/Vurea, and also of different other parameters with potential impact, such as age, body weight (BW), Protein equivalent of Nitrogen Appearance (PNA), Residual Renal Function (RRF), and dialysis vintage. Dichotomic concentration comparisons were performed for gender and Diabetes Mellitus (DM). Analysis of Variance in quartiles of Kt/Vurea did not show significant differences for any of the solute concentrations. For PNA, however, concentrations showed significant differences for urea (P<0.001), uric acid (UA), p-cresylsulfate (PCS), and free PCS (all P<0.01), and for creatinine (Crea) and hippuric acid (HA) (both P<0.05). For RRF, concentrations varied for β2-microglobulin (P<0.001), HA, free HA, free indoxyl sulfate, and free indole acetic acid (all P<0.01), and for p-cresylglucuronide (PCG), 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF), free PCS, and free PCG (all P<0.05). Gender and body weight only showed differences for Crea and UA, while age, vintage, and diabetes mellitus only showed differences for one solute concentration (UA, UA, and free PCS, respectively). Multifactor analyses indicated a predominant association of concentration with protein intake and residual renal function. In conclusion, predialysis concentrations of uremic toxins seem to be dependent on protein equivalent of nitrogen appearance and residual renal function, and not on dialysis adequacy as assessed by Kt/Vurea. Efforts to control intestinal load of uremic toxin precursors by dietary or other interventions, and preserving RRF seem important approaches to decrease uremic solute concentration and by extension their toxicity.
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Affiliation(s)
- Sunny Eloot
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, Gent, Belgium
- * E-mail:
| | - Wim Van Biesen
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, Gent, Belgium
| | - Griet Glorieux
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, Gent, Belgium
| | - Nathalie Neirynck
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, Gent, Belgium
| | - Annemieke Dhondt
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, Gent, Belgium
| | - Raymond Vanholder
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, Gent, Belgium
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Li M, Qureshi AR, Ellis E, Axelsson J. Impaired postprandial fibroblast growth factor (FGF)-19 response in patients with stage 5 chronic kidney diseases is ameliorated following antioxidative therapy. Nephrol Dial Transplant 2013; 28 Suppl 4:iv212-9. [DOI: 10.1093/ndt/gft337] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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Neirynck N, Glorieux G, Boelaert J, Schepers E, Liabeuf S, Dhondt A, Massy Z, Vanholder R. Uremia-related oxidative stress in leukocytes is not triggered by β2-microglobulin. J Ren Nutr 2013; 23:456-63. [PMID: 24016624 DOI: 10.1053/j.jrn.2013.07.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 07/04/2013] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Chronic kidney disease (CKD) is characterized by low-grade inflammation and increased risk for cardiovascular disease. The interest in β2-microglobulin (B2M) as a marker for cardiovascular outcome with and without CKD has grown. Clinical studies suggested that B2M could be involved in the pathogenesis of vascular disease, for which chronic leukocyte activation is a pathogenic factor. We investigated whether B2M is proinflammatory by inducing oxidative burst in leukocytes. METHODS Oxidative burst was measured at baseline and after stimulation with N-formyl-methionine-leucine-phenylalanine (fMLP), Escherichia coli, or phorbol-12-myristate-acetate (PMA) in the whole blood of healthy volunteers in the absence (saline) and presence of human B2M (hB2M; 10 and 50 mg/L) versus uremic whole blood. Because of suspicion of contamination, hB2M was dialyzed for purification and purified B2M (dB2M) and dialysates were tested in the burst test. As a comparator, reactive oxygen species (ROS) in response to lipopolysaccharide (LPS) was measured. RESULTS Unpurified hB2M strongly enhanced ROS in monocytes and granulocytes after E. coli and PMA and moderately after fMLP stimulation compared with control (P < .01) and uremia (P < .01) whereas at baseline hB2M only induced ROS in granulocytes (P < .05). After purification, dB2M no longer increased burst activity, suggesting that contamination was responsible for the initial effect. An endotoxin concentration of less than 1.5 EU/mL, as observed in hB2M, could not induce oxidative stress. CONCLUSION This study suggests that B2M, a traditional marker for middle molecule retention and a novel marker for cardiovascular outcome, may not by itself cause vascular damage by influencing inflammatory response due to induction of leukocyte free radical production. However, an effect on other cell types involved cannot be excluded. Our data further reveal that this type of research might be skewed by non-LPS contaminants, and that care should be taken to exclude this bias.
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Affiliation(s)
- Nathalie Neirynck
- Nephrology Division, Department of Internal Medicine, Ghent University Hospital, Gent, Belgium.
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Mutsaers HAM, Engelke UFH, Wilmer MJG, Wetzels JFM, Wevers RA, van den Heuvel LP, Hoenderop JG, Masereeuw R. Optimized metabolomic approach to identify uremic solutes in plasma of stage 3-4 chronic kidney disease patients. PLoS One 2013; 8:e71199. [PMID: 23936492 PMCID: PMC3732267 DOI: 10.1371/journal.pone.0071199] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 06/28/2013] [Indexed: 11/18/2022] Open
Abstract
Background Chronic kidney disease (CKD) is characterized by the progressive accumulation of various potential toxic solutes. Furthermore, uremic plasma is a complex mixture hampering accurate determination of uremic toxin levels and the identification of novel uremic solutes. Methods In this study, we applied 1H-nuclear magnetic resonance (NMR) spectroscopy, following three distinct deproteinization strategies, to determine differences in the plasma metabolic status of stage 3–4 CKD patients and healthy controls. Moreover, the human renal proximal tubule cell line (ciPTEC) was used to study the influence of newly indentified uremic solutes on renal phenotype and functionality. Results Protein removal via ultrafiltration and acetonitrile precipitation are complementary techniques and both are required to obtain a clear metabolome profile. This new approach, revealed that a total of 14 metabolites were elevated in uremic plasma. In addition to confirming the retention of several previously identified uremic toxins, including p-cresyl sulphate, two novel uremic retentions solutes were detected, namely dimethyl sulphone (DMSO2) and 2-hydroxyisobutyric acid (2-HIBA). Our results show that these metabolites accumulate in non-dialysis CKD patients from 9±7 µM (control) to 51±29 µM and from 7 (0–9) µM (control) to 32±15 µM, respectively. Furthermore, exposure of ciPTEC to clinically relevant concentrations of both solutes resulted in an increased protein expression of the mesenchymal marker vimentin with more than 10% (p<0.05). Moreover, the loss of epithelial characteristics significantly correlated with a loss of glucuronidation activity (Pearson r = −0.63; p<0.05). In addition, both solutes did not affect cell viability nor mitochondrial activity. Conclusions This study demonstrates the importance of sample preparation techniques in the identification of uremic retention solutes using 1H-NMR spectroscopy, and provide insight into the negative impact of DMSO2 and 2-HIBA on ciPTEC, which could aid in understanding the progressive nature of renal disease.
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Affiliation(s)
- Henricus A. M. Mutsaers
- Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
- Department of Physiology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Udo F. H. Engelke
- Department of Laboratory Medicine, Laboratory of Genetic, Endocrine and Metabolic Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Martijn J. G. Wilmer
- Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Jack F. M. Wetzels
- Department of Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Ron A. Wevers
- Department of Laboratory Medicine, Laboratory of Genetic, Endocrine and Metabolic Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Lambertus P. van den Heuvel
- Department of Laboratory Medicine, Laboratory of Genetic, Endocrine and Metabolic Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department of Pediatrics, Catholic University Leuven, Leuven, Belgium
| | - Joost G. Hoenderop
- Department of Physiology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Rosalinde Masereeuw
- Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
- * E-mail:
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Germain MJ, Cohen LM. What determines whether a patient initiates chronic renal replacement therapy? Clin J Am Soc Nephrol 2013; 8:1276-8. [PMID: 23833314 DOI: 10.2215/cjn.06200613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Bonato FOB, Lemos MM, Cassiolato JL, Canziani MEF. Prevalence of ventricular arrhythmia and its associated factors in nondialyzed chronic kidney disease patients. PLoS One 2013; 8:e66036. [PMID: 23762460 PMCID: PMC3676379 DOI: 10.1371/journal.pone.0066036] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 05/01/2013] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Sudden cardiac death is the most common cause of mortality in chronic kidney disease patients, and it occurs mostly due to ventricular arrhythmias. In this study, we aimed at investigating the prevalence of ventricular arrhythmia and the factors associated with its occurrence in nondialyzed chronic kidney disease patients. DESIGN SETTING PARTICIPANTS AND MEASUREMENTS This cross-sectional study evaluated 111 chronic kidney disease patients (estimated glomerular filtration rate 34.7±16.1 mL/min/1.73 m(2), 57±11.4 years, 60% male, 24% diabetics). Ventricular arrhythmia was assessed by 24-hour electrocardiogram. Left ventricular hypertrophy (echocardiogram), 24-hour ambulatory blood pressure monitoring, and coronary artery calcification (multi-slice computed tomography) and laboratory parameters were also evaluated. RESULTS Ventricular arrhythmia was found in 35% of the patients. Non-controlled hypertension was observed in 21%, absence of systolic decency in 29%, left ventricular hypertrophy in 27%, systolic dysfunction in 10%, and coronary artery calcification in 49%. Patients with ventricular arrhythmia were older (p<0.001), predominantly men (p = 0.009), had higher estimated glomerular filtration rate (p = 0.03) and hemoglobin (p = 0.005), and lower intact parathyroid hormone (p = 0.024) and triglycerides (p = 0.011) when compared to patients without ventricular arrhythmia. In addition, a higher left ventricular mass index (p = 0.002) and coronary calcium score (p = 0.002), and a lower ejection fraction (p = 0.001) were observed among patients with ventricular arrhythmia. In the multiple logistic regression analysis, aging, increased hemoglobin levels and reduced ejection fraction were independently related to the presence of ventricular arrhythmia. CONCLUSIONS Ventricular arrhythmia is prevalent in nondialyzed chronic kidney disease patients. Age, hemoglobin levels and ejection fraction were the factors associated with ventricular arrhythmia in these patients.
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Affiliation(s)
| | - Marcelo Montebello Lemos
- Division of Nephrology, Department of Internal Medicine, Federal University of São Paulo, São Paulo, Brazil
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Foster MC, Inker LA, Levey AS, Selvin E, Eckfeldt J, Juraschek SP, Coresh J. Novel filtration markers as predictors of all-cause and cardiovascular mortality in US adults. Am J Kidney Dis 2013; 62:42-51. [PMID: 23518194 DOI: 10.1053/j.ajkd.2013.01.016] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 01/14/2013] [Indexed: 12/17/2022]
Abstract
BACKGROUND New filtration markers, including β-trace protein (BTP) and β₂-microglobulin (B2M), may, similar to cystatin C, enable a stronger prediction of mortality compared to serum creatinine-based estimated glomerular filtration rate (eGFRcr). We sought to evaluate these mortality associations in a representative sample of US adults. STUDY DESIGN Prospective cohort study. SETTING & PARTICIPANTS 6,445 adults 20 years or older from the Third National Health and Nutrition Examination Survey (1988-1994) with mortality linkage through December 31, 2006. PREDICTORS Serum cystatin C, BTP, and B2M levels and eGFRcr categorized into quintiles, with the highest quintile (lowest for eGFRcr) split into tertiles (subquintiles Q5a-Q5c). OUTCOMES All-cause, cardiovascular disease, and coronary heart disease mortality. MEASUREMENTS Demographic- and multivariable-adjusted Cox proportional hazard models. RESULTS During follow-up, 2,392 deaths (cardiovascular, 1,079; coronary heart disease, 605) occurred. Levels of all 4 filtration markers were associated with mortality risk after adjusting for demographics (P trend<0.02). Adjusted for mortality risk factors, compared to the middle quintile, the highest subquintiles for cystatin C (Q5c: HR, 1.94; 95% CI, 1.43-2.62), BTP (Q5c: HR, 2.14; 95% CI, 1.56-2.94), and B2M (Q5c: HR, 2.58; 95% CI, 1.96-3.41) were associated with increased all-cause mortality risk, whereas the association was weaker for eGFRcr (Q5c: HR, 1.31; 95% CI, 0.84-2.04). Associations persisted for the novel markers and not for eGFRcr at eGFRcr ≥60 mL/min/1.73 m². Trends were similar for cardiovascular disease and coronary heart disease mortality. LIMITATIONS Single measurements of markers from long-term stored samples. CONCLUSIONS The strong association of cystatin C level with mortality compared with serum creatinine estimates is shared by BTP and B2M. This supports the utility of alternative filtration markers beyond creatinine when improved risk prediction related to decreased GFR is needed.
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Affiliation(s)
- Meredith C Foster
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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