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Cejka D, Thiem U, Blinzler E, Machacek J, Voelkl J, Smith ER, Pasch A, Haller MC. Citrate-Buffered, Magnesium-Enriched Dialysate on Calcification Propensity in Hemodialysis Patients - The CitMag Study. Kidney Int Rep 2024; 9:1765-1773. [PMID: 38899177 PMCID: PMC11184245 DOI: 10.1016/j.ekir.2024.03.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 03/07/2024] [Accepted: 03/18/2024] [Indexed: 06/21/2024] Open
Abstract
Introduction Serum calcification propensity (T50 time) is associated with mortality in patients on dialysis. Several solitary interventions improve T50. However, whether a combination of interventions yields further increases in T50 is unknown. We hypothesized that a combination of 2 interventions, namely increasing magnesium concentration while simultaneously substituting acetate for citrate in the dialysis fluid, leads to increases in T50 values. Methods In a randomized controlled trial, 60 patients on chronic hemodialysis were allocated to either continue on standard (S) dialysate (3 mmol/l acetate, 0.5 mmol/l magnesium) or a sequence of magnesium-enriched (Mg0.75) dialysate (3 mmol/l acetate, 0.75 mmol/l magnesium) for 2 weeks followed by combination treatment using citrate-buffered, magnesium-enriched (Cit+Mg0.75) dialysate (1 mmol/l citrate, 0.75 mmol/l magnesium) for 3 weeks. The primary end point was the difference in T50 times between the S group and the Cit+Mg0.75 group. Results There was no significant difference in T50 time between the S group and the Cit+Mg0.75 group (236 ± 77 vs. 265 ± 97 min, P = 0.23). The size (hydrodynamic radius) of secondary calciprotein particles did not differ between the S group and the Cit+Mg0.75 group (294 ± 95 vs. 309 ± 91 nm, P = 0.56). In longitudinal analyses, serum magnesium concentrations increased from 1.07 ± 0.17 to 1.24 ± 0.17 mmol/l with the Mg0.75 dialysate (P < 0.0001) but decreased again to 1.19 ± 0.16 mmol/l with the Cit+Mg0.75 dialysate (P < 0.0001). Conclusion The combination of citrate buffer with increased magnesium concentration in dialysate does not improve T50.
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Affiliation(s)
- Daniel Cejka
- Department of Medicine III – Nephrology, Hypertension, Transplantation, Rheumatology, Geriatrics, Ordensklinikum Linz - Elisabethinen Hospital, Linz, Austria
| | - Ursula Thiem
- Department of Medicine III – Nephrology, Hypertension, Transplantation, Rheumatology, Geriatrics, Ordensklinikum Linz - Elisabethinen Hospital, Linz, Austria
- Faculty of Medicine, Johannes Kepler University Linz, Austria
| | - Eric Blinzler
- Department of Medicine III – Nephrology, Hypertension, Transplantation, Rheumatology, Geriatrics, Ordensklinikum Linz - Elisabethinen Hospital, Linz, Austria
| | - Jennifer Machacek
- Department of Medicine III – Nephrology, Hypertension, Transplantation, Rheumatology, Geriatrics, Ordensklinikum Linz - Elisabethinen Hospital, Linz, Austria
| | - Jakob Voelkl
- Institute for Physiology and Pathophysiology, Johannes Kepler University Linz, Austria
- Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
| | - Edward R. Smith
- Department of Nephrology, Royal Melbourne Hospital, Parkville, Victoria, Australia
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - Andreas Pasch
- Institute for Physiology and Pathophysiology, Johannes Kepler University Linz, Austria
- Calciscon AG, Biel, Switzerland
| | - Maria C. Haller
- Department of Medicine III – Nephrology, Hypertension, Transplantation, Rheumatology, Geriatrics, Ordensklinikum Linz - Elisabethinen Hospital, Linz, Austria
- Center for Medical Statistics, Informatics, and Intelligent Systems, Medical University, Vienna, Austria
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Zeper LW, Bos C, Leermakers PA, Franssen GM, Raavé R, Hoenderop JGJ, de Baaij JHF. Liver and spleen predominantly mediate calciprotein particle clearance in a rat model of chronic kidney disease. Am J Physiol Renal Physiol 2024; 326:F622-F634. [PMID: 38420675 DOI: 10.1152/ajprenal.00239.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 02/13/2024] [Accepted: 02/15/2024] [Indexed: 03/02/2024] Open
Abstract
Calciprotein particles (CPPs) provide an efficient mineral buffering system to prevent the complexation of phosphate and calcium in the circulation. However, in chronic kidney disease (CKD), the phosphate load exceeds the mineral buffering capacity, resulting in the formation of crystalline CPP2 particles. CPP2 have been associated with cardiovascular events and mortality. Moreover, CPP2 have been demonstrated to induce calcification in vitro. In this study, we examined the fate of CPP2 in a rat model of CKD. Calcification was induced in Sprague-Dawley rats by 5/6 nephrectomy (5/6-Nx) combined with a high-phosphate diet. Control rats received sham surgery and high-phosphate diet. Twelve weeks after surgery, kidney failure was significantly induced in 5/6-Nx rats as determined by enhanced creatinine and urea plasma levels and abnormal kidney histological architecture. Subsequently, radioactive and fluorescent (FITC)-labeled CPP2 ([89Zr]Zr-CPP2-FITC) were injected intravenously to determine clearance in vivo. Using positron emission tomography scans and radioactive biodistribution measurements, it was demonstrated that [89Zr]Zr-CPP2-FITC are mainly present in the liver and spleen in both 5/6-Nx and sham rats. Immunohistochemistry showed that [89Zr]Zr-CPP2-FITC are predominantly taken up by Kupffer cells and macrophages. However, [89Zr]Zr-CPP2-FITC could also be detected in hepatocytes. In the different parts of the aorta and in the blood, low values of [89Zr]Zr-CPP2-FITC were detectable, independent of the presence of calcification. CPP2 are cleared rapidly from the circulation by the liver and spleen in a rat model of CKD. In the liver, Kupffer cells, macrophages, and hepatocytes contribute to CPP2 clearance.NEW & NOTEWORTHY Calciprotein particles (CPPs) buffer calcium and phosphate in the blood to prevent formation of crystals. In CKD, increased phosphate levels may exceed the buffering capacity of CPPs, resulting in crystalline CPPs that induce calcification. This study demonstrates that labeled CPPs are predominantly cleared from the circulation in the liver by Kupffer cells, macrophages, and hepatocytes. Our results suggest that targeting liver CPP clearance may reduce the burden of crystalline CPP in the development of vascular calcification.
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Affiliation(s)
- Lara W Zeper
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Caro Bos
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Pieter A Leermakers
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gerben M Franssen
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - René Raavé
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jeroen H F de Baaij
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, The Netherlands
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Abstract
Patients with chronic kidney disease (CKD) exhibit tremendously elevated risk for cardiovascular disease, particularly ischemic heart disease, due to premature vascular and cardiac aging and accelerated ectopic calcification. The presence of cardiovascular calcification associates with increased risk in patients with CKD. Disturbed mineral homeostasis and diverse comorbidities in these patients drive increased systemic cardiovascular calcification in different manifestations with diverse clinical consequences, like plaque instability, vessel stiffening, and aortic stenosis. This review outlines the heterogeneity in calcification patterning, including mineral type and location and potential implications on clinical outcomes. The advent of therapeutics currently in clinical trials may reduce CKD-associated morbidity. Development of therapeutics for cardiovascular calcification begins with the premise that less mineral is better. While restoring diseased tissues to a noncalcified homeostasis remains the ultimate goal, in some cases, calcific mineral may play a protective role, such as in atherosclerotic plaques. Therefore, developing treatments for ectopic calcification may require a nuanced approach that considers individual patient risk factors. Here, we discuss the most common cardiac and vascular calcification pathologies observed in CKD, how mineral in these tissues affects function, and the potential outcomes and considerations for therapeutic strategies that seek to disrupt the nucleation and growth of mineral. Finally, we discuss future patient-specific considerations for treating cardiac and vascular calcification in patients with CKD-a population in need of anticalcification therapies.
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Affiliation(s)
- Joshua D Hutcheson
- Department of Biomedical Engineering, Florida International University, Miami, FL (J.D.H.)
| | - Claudia Goettsch
- Department of Internal Medicine I, Division of Cardiology, Medical Faculty, RWTH Aachen University, Germany (C.G.)
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4
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Bojic M, Cejka D, Bielesz B, Schernthaner GH, Höbaus C. Secondary calciprotein particle size is associated with patient mortality in peripheral artery disease. Atherosclerosis 2023; 370:12-17. [PMID: 36898866 DOI: 10.1016/j.atherosclerosis.2023.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 01/26/2023] [Accepted: 02/21/2023] [Indexed: 03/12/2023]
Abstract
BACKGROUND AND AIMS Secondary calciprotein particles (CPP-II) induce inflammation and contribute to vascular calcification. CPP-II size is associated with vascular calcification in patients with chronic kidney disease (CKD) and all-cause mortality in hemodialysis patients. Here, we investigate for the first time a possible role of CPP-II size in patients with peripheral artery disease (PAD) without severe CKD. METHODS We measured the hydrodynamic radius (Rh) of CPP-II by using dynamic light scattering in a cohort of 281 PAD patients. Mortality was evaluated over a period of ten years by central death registry queries. 35% of patients died during the observation period (median of 8.8 (6.2-9.0) years). Cox-regression analyses were performed to estimate hazard ratios (HR) and 95% confidence intervals (CI) and to allow for multivariable adjustment. RESULTS The mean CPP-II size was 188 (162-218) nm. Older patients, patients with reduced kidney function, and those with media sclerosis had larger CPP-II (p < 0.001, p = 0.008, and p = 0.043, retrospectively). There was no association between CPP-II size and overall atherosclerotic disease burden (p = 0.551). CPP-II size was independently significantly associated with all-cause (HR 1.33 (CI 1.01-1.74), p = 0.039) and cardiovascular mortality (HR 1.52 (CI 1.05-2.20), p = 0.026) in multivariable regression analyses. CONCLUSIONS Large CPP-II size is associated with mortality in PAD patients and might be a new feasible biomarker for the presence of media sclerosis in this patient population.
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Affiliation(s)
- Marija Bojic
- Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
| | - Daniel Cejka
- Internal Medicine III - Nephrology, Transplantation Medicine, Rheumatology, Ordensklinikum Linz, Fadingerstraße 1, 4020, Linz, Austria
| | - Bernhard Bielesz
- Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
| | - Gerit-Holger Schernthaner
- Division of Angiology, Department of Medicine II, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
| | - Clemens Höbaus
- Division of Angiology, Department of Medicine II, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
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Zawada AM, Wolf M, Rincon Bello A, Ramos-Sanchez R, Hurtado Munoz S, Ribera Tello L, Mora-Macia J, Fernández-Robres MA, Soler-Garcia J, Aguilera Jover J, Moreso F, Stuard S, Stauss-Grabo M, Winter A, Canaud B. Assessment of a serum calcification propensity test for the prediction of all-cause mortality among hemodialysis patients. BMC Nephrol 2023; 24:35. [PMID: 36792998 PMCID: PMC9933331 DOI: 10.1186/s12882-023-03069-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 01/20/2023] [Indexed: 02/17/2023] Open
Abstract
BACKGROUND Vascular calcification is a major contributor to the high cardiac burden among hemodialysis patients. A novel in vitro T50-test, which determines calcification propensity of human serum, may identify patients at high risk for cardiovascular (CV) disease and mortality. We evaluated whether T50 predicts mortality and hospitalizations among an unselected cohort of hemodialysis patients. METHODS This prospective clinical study included 776 incident and prevalent hemodialysis patients from 8 dialysis centers in Spain. T50 and fetuin-A were determined at Calciscon AG, all other clinical data were retrieved from the European Clinical Database. After their baseline T50 measurement, patients were followed for two years for the occurrence of all-cause mortality, CV-related mortality, all-cause and CV-related hospitalizations. Outcome assessment was performed with proportional subdistribution hazards regression modelling. RESULTS Patients who died during follow-up had a significantly lower T50 at baseline as compared to those who survived (269.6 vs. 287.7 min, p = 0.001). A cross-validated model (mean c statistic: 0.5767) identified T50 as a linear predictor of all-cause-mortality (subdistribution hazard ratio (per min): 0.9957, 95% CI [0.9933;0.9981]). T50 remained significant after inclusion of known predictors. There was no evidence for prediction of CV-related outcomes, but for all-cause hospitalizations (mean c statistic: 0.5284). CONCLUSION T50 was identified as an independent predictor of all-cause mortality among an unselected cohort of hemodialysis patients. However, the additional predictive value of T50 added to known mortality predictors was limited. Future studies are needed to assess the predictive value of T50 for CV-related events in unselected hemodialysis patients.
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Affiliation(s)
- Adam M Zawada
- grid.415062.4Fresenius Medical Care Deutschland GmbH, Else-Kroener-Str. 1, 61352 Bad Homburg, Germany
| | - Melanie Wolf
- Fresenius Medical Care Deutschland GmbH, Else-Kroener-Str. 1, 61352, Bad Homburg, Germany.
| | | | | | | | | | | | | | | | | | - Francesc Moreso
- Fresenius Medical Care Services Cataluña, S.L, Barcelona, Spain
| | - Stefano Stuard
- grid.415062.4Fresenius Medical Care Deutschland GmbH, Else-Kroener-Str. 1, 61352 Bad Homburg, Germany
| | - Manuela Stauss-Grabo
- grid.415062.4Fresenius Medical Care Deutschland GmbH, Else-Kroener-Str. 1, 61352 Bad Homburg, Germany
| | - Anke Winter
- grid.415062.4Fresenius Medical Care Deutschland GmbH, Else-Kroener-Str. 1, 61352 Bad Homburg, Germany
| | - Bernard Canaud
- grid.415062.4Fresenius Medical Care Deutschland GmbH, Else-Kroener-Str. 1, 61352 Bad Homburg, Germany ,grid.121334.60000 0001 2097 0141School of Medicine, University of Montpellier, Montpellier, France
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Huang QX, Pang J, Shi CK, Huang XW, Chen XF, Luo YF, An HW, Jian JL, Liu L, Li YL. Impact of parathyroidectomy among nondiabetic hemodialysis patients with severe hyperparathyroidism. Ren Fail 2022; 44:1160-1168. [PMID: 35880645 PMCID: PMC9331203 DOI: 10.1080/0886022x.2022.2098768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Background Parathyroidectomy (PTX) is a treatment for hyperparathyroidism (HPT) and has uncertain risks and benefits. The aim of this study was to evaluate the effect of PTX versus nonoperative treatment among nondiabetic hemodialysis patients. Methods A retrospective matched cohort study was performed. Each PTX patient was matched with one patient who had severe HPT but rejected PTX. The patients were matched by sex, birth date, date of first dialysis, nondiabetic status, and left ventricular ejection fraction. The serum markers, survival, main adverse cardiovascular and cerebrovascular event (MACCE) rates, and hospitalization were compared between the PTX patients and matched non-PTX patients. Results There were 1143 patients at our center in the Chinese National Renal Data System (CNRDS) between 2010 and 2020. Of these, 75 PTX patients were matched with 75 non-PTX patients. Rapid decreases in the mean intact parathyroid hormone, calcium and phosphorus concentrations, and a gradual increase in hemoglobin concentration were observed in the PTX group. The mortality was 2.9 per 100 patient-years in the PTX group and 10.9 per 100 patient-years in the non-PTX group (p < 0.001). Compared with non-PTX patients, PTX patients had an adjusted HR for death of 0.236 (95% CI 0.108–0.518). The cumulative MACCE rates were 6.7 per 100 patient-years in the PTX group and 15.2 per 100 patient-years in the non-PTX group (p < 0.001). The adjusted HR of the occurrence of first MACCE for PTX patients compared with non-PTX patients was 0.524 (95% CI 0.279-0.982). The cumulative hospitalization rates were 50.3 per 100 patient-years in the PTX group and 66.5 per 100 patient-years in the matched non-PTX group (p < 0.001). Conclusions Compared with non-PTX patients, PTX was associated with an improvement in the biochemical measures and patient-level outcomes in nondiabetic hemodialysis patients with severe HPT.
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Affiliation(s)
- Qing-Xiu Huang
- Department of Nephrology, Zhongshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Zhongshan, China
| | - Jie Pang
- Department of Nephrology, Zhongshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Zhongshan, China
| | - Chuan-Ke Shi
- Department of Surgery, Zhongshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Zhongshan, China
| | - Xiao-Wen Huang
- Department of Ultrasonography, Zhongshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Zhongshan, China
| | - Xiao-Fang Chen
- Department of Nephrology, Zhongshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Zhongshan, China
| | - Yan-Feng Luo
- Department of Nephrology, Zhongshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Zhongshan, China
| | - Hai-Wen An
- Department of Nephrology, Zhongshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Zhongshan, China
| | - Jian-Lin Jian
- Department of Nephrology, Zhongshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Zhongshan, China
| | - Linna Liu
- Department of Nephrology, Zhongshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Zhongshan, China
| | - Yan-Lin Li
- Department of Nephrology, Zhongshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Zhongshan, China
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Pluquet M, Kamel S, Choukroun G, Liabeuf S, Laville SM. Serum Calcification Propensity Represents a Good Biomarker of Vascular Calcification: A Systematic Review. Toxins (Basel) 2022; 14:toxins14090637. [PMID: 36136575 PMCID: PMC9501050 DOI: 10.3390/toxins14090637] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/05/2022] [Accepted: 09/09/2022] [Indexed: 11/16/2022] Open
Abstract
Vascular calcification contributes to cardiovascular morbidity and mortality. A recently developed serum calcification propensity assay is based on the half-transformation time (T50) from primary calciprotein particles (CPPs) to secondary CPPs, reflecting the serum’s endogenous capacity to prevent calcium phosphate precipitation. We sought to identify and review the results of all published studies since the development of the T50-test by Pasch et al. in 2012 (whether performed in vitro, in animals or in the clinic) of serum calcification propensity. To this end, we searched PubMed, Elsevier EMBASE, the Cochrane Library and Google Scholar databases from 2012 onwards. At the end of the selection process, 57 studies were analyzed with regard to the study design, sample size, characteristics of the study population, the intervention and the main results concerning T50. In patients with primary aldosteronism, T50 is associated with the extent of vascular calcification in the abdominal aorta. In chronic kidney disease (CKD), T50 is associated with the severity and progression of coronary artery calcification. T50 is also associated with cardiovascular events and all-cause mortality in CKD patients, patients on dialysis and kidney transplant recipients and with cardiovascular mortality in patients on dialysis, kidney transplant recipients, patients with ischemic heart failure and reduced ejection fraction, and in the general population. Switching from acetate-acidified dialysate to citrate-acidified dialysate led to a longer T50, as did a higher dialysate magnesium concentration. Oral administration of magnesium (in CKD patients), phosphate binders, etelcalcetide and spironolactone (in hemodialysis patients) was associated with a lower serum calcification propensity. Serum calcification propensity is an overall marker of calcification associated with hard outcomes but is currently used in research projects only. This assay might be a valuable tool for screening serum calcification propensity in at-risk populations (such as CKD patients and hemodialyzed patients) and, in particular, for monitoring changes over time in T50.
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Affiliation(s)
- Maxime Pluquet
- MP3CV Laboratory, EA7517, Jules Verne University of Picardie, F-80000 Amiens, France
| | - Said Kamel
- MP3CV Laboratory, EA7517, Jules Verne University of Picardie, F-80000 Amiens, France
- Department of Biochemistry, Amiens University Medical Center, F-80000 Amiens, France
| | - Gabriel Choukroun
- MP3CV Laboratory, EA7517, Jules Verne University of Picardie, F-80000 Amiens, France
- Department of Nephrology, Amiens University Medical Center, F-80000 Amiens, France
| | - Sophie Liabeuf
- MP3CV Laboratory, EA7517, Jules Verne University of Picardie, F-80000 Amiens, France
- Pharmacoepidemiology Unit, Department of Clinical Pharmacology, Amiens University Medical Center, F-80000 Amiens, France
- Correspondence:
| | - Solène M. Laville
- MP3CV Laboratory, EA7517, Jules Verne University of Picardie, F-80000 Amiens, France
- Pharmacoepidemiology Unit, Department of Clinical Pharmacology, Amiens University Medical Center, F-80000 Amiens, France
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Elliott J, Geddes RF. New concepts in phosphorus homeostasis and its impact on renal health with particular reference to the cat. Vet J 2022; 283-284:105842. [PMID: 35577278 DOI: 10.1016/j.tvjl.2022.105842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 05/08/2022] [Accepted: 05/10/2022] [Indexed: 11/17/2022]
Abstract
New discoveries relating to phosphorus homeostasis include the hormones fibroblast growth factor-23 and klotho produced by bone and kidney. These hormones, together with novel understanding of how calcium and phosphate ions are carried in colloidal form as calciprotein particles, have changed our view of how phosphorus is regulated. Recognition that high dietary intake of inorganic forms of phosphorus in humans is a risk factor for both cardiovascular and renal diseases have led to re-examination of the impact of inorganic sources of phosphorus in prepared cat foods on renal health. Data suggest that when homeostatic mechanisms lead to proximal tubular (S3 segment) phosphate concentrations exceeding 3.25mmol/L for a significant part of the day, tubular stress and structural kidney damage ensues. Recent experimental rodent studies support the concept that calciprotein particles form in the proximal tubule at these prevailing phosphate concentrations and trigger proximal tubular damage. Long-term feeding studies in cats suggest that carefully formulated prepared diets containing 1g/Mcal of inorganic phosphorus (in the form of sodium tripolyphosphate or potassium monophosphate and pyrophosphate), resulting in estimated tubular phosphate concentrations <2.5mmol/L can be fed to healthy adult cats without detectable adverse effects on renal health.
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Affiliation(s)
- Jonathan Elliott
- Department of Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
| | - Rebecca F Geddes
- Department of Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire AL9 7TA, UK
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9
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Tiong MK, Cai MMX, Toussaint ND, Tan SJ, Pasch A, Smith ER. Effect of nutritional calcium and phosphate loading on calciprotein particle kinetics in adults with normal and impaired kidney function. Sci Rep 2022; 12:7358. [PMID: 35513558 PMCID: PMC9072391 DOI: 10.1038/s41598-022-11065-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/31/2022] [Indexed: 12/20/2022] Open
Abstract
Plasma approaches metastability with respect to its calcium and phosphate content, with only minor perturbations in ionic activity needed to sustain crystal growth once nucleated. Physiologically, calcium and phosphate are intermittently absorbed from the diet each day, yet plasma concentrations of these ions deviate minimally post-prandially. This implies the existence of a blood-borne mineral buffer system to sequester calcium phosphates and minimise the risk of deposition in the soft tissues. Calciprotein particles (CPP), endogenous mineral-protein colloids containing the plasma protein fetuin-A, may fulfill this function but definitive evidence linking dietary mineral loading with their formation is lacking. Here we demonstrate that CPP are formed as a normal physiological response to feeding in healthy adults and that this occurs despite minimal change in conventional serum mineral markers. Further, in individuals with Chronic Kidney Disease (CKD), in whom mineral handling is impaired, we show that both fasting and post-prandial levels of CPP precursors are markedly augmented and strongly inversely correlated with kidney function. This study highlights the important, but often neglected, contribution of colloidal biochemistry to mineral homeostasis and provides novel insight into the dysregulation of mineral metabolism in CKD.
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Affiliation(s)
- Mark K Tiong
- Department of Nephrology, The Royal Melbourne Hospital, Grattan Street, Parkville, VIC, 3052, Australia. .,Department of Medicine (RMH), University of Melbourne, Parkville, Australia.
| | - Michael M X Cai
- Department of Nephrology, The Royal Melbourne Hospital, Grattan Street, Parkville, VIC, 3052, Australia
| | - Nigel D Toussaint
- Department of Nephrology, The Royal Melbourne Hospital, Grattan Street, Parkville, VIC, 3052, Australia.,Department of Medicine (RMH), University of Melbourne, Parkville, Australia
| | - Sven-Jean Tan
- Department of Nephrology, The Royal Melbourne Hospital, Grattan Street, Parkville, VIC, 3052, Australia.,Department of Medicine (RMH), University of Melbourne, Parkville, Australia
| | - Andreas Pasch
- Calciscon AG, Biel, Switzerland.,Lindenhofspital Bern, Bern, Switzerland.,Department of Physiology and Pathophysiology, Johannes Kepler University, Linz, Austria
| | - Edward R Smith
- Department of Nephrology, The Royal Melbourne Hospital, Grattan Street, Parkville, VIC, 3052, Australia. .,Department of Medicine (RMH), University of Melbourne, Parkville, Australia.
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10
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Lin X, Zhu T, Xu F, Zhong JY, Li F, Shan SK, Wu F, Guo B, Zheng MH, Wang Y, Xu QS, Liao XB, Lu HY, Xie XB, Yuan LQ. Plasma Exosomes Derived From Patients With End-Stage Renal Disease and Renal Transplant Recipients Have Different Effects on Vascular Calcification. Front Cell Dev Biol 2021; 8:618228. [PMID: 33585452 PMCID: PMC7876285 DOI: 10.3389/fcell.2020.618228] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/18/2020] [Indexed: 01/12/2023] Open
Abstract
End-stage renal disease (ESRD) patients usually develop extensive and progressive vascular calcification, and lots of calcification inhibitors as well as procalcifying factors are involved in the process. However, the mechanisms of vascular calcification in ESRD patients are still ill-defined. In the present study, we found that the plasma exosomes derived from ESRD patients (ESRD-Ex) promoted calcification of vascular smooth muscle cells (VSMCs) significantly, while plasma exosomes from renal transplant recipients (RTR-Ex) could partially attenuate VSMCs calcification. Moreover, the protein concentration of ESRD-Ex was significantly higher than plasma exosomes from the normal health control group (Nor-Ex) and RTR-Ex, and the content of both matrix gla protein (MGP) and Fetuin-A, the calcification inhibitors, were prominently lower in ESRD-Ex than those in Nor-Ex. The content of Annexin-A2, one of the calcification promoters, was significantly higher in ESRD-Ex and RTR-Ex than that in Nor-Ex. However, bone morphogenetic protein (BMP-2) and receptor activator for nuclear factor-κB ligand (Rankl) had no significant difference among the three groups. In addition, the content of Fetuin-A in RTR-Ex was higher than that in ESRD-Ex, although it was still lower than that in Nor-Ex. Furthermore, the levels of both Fetuin-A and MGP in plasma exosomes were negatively while the levels of Annexin-A2 in plasma exosomes was positively correlated to coronary artery calcification scores (CACS). These results indicated that ESRD-Ex significantly promoted VSMCs calcification, while renal transplantation could partially attenuate the procalcification effect of exosomes. Fetuin-A and MGP were decreased, but Annexin-A2 was increased in ESRD-Ex, and renal transplantation could increase the level of Fetuin-A rather than MGP.
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Affiliation(s)
- Xiao Lin
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
- Department of Endocrinology and Metabolism, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Ting Zhu
- Department of Endocrinology and Metabolism, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
- Department of Endocrinology, Central Hospital of Yiyang, Yiyang, China
| | - Feng Xu
- Department of Endocrinology and Metabolism, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jia-Yu Zhong
- Department of Geriatrics, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Fuxingzi Li
- Department of Endocrinology and Metabolism, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Su-Kang Shan
- Department of Endocrinology and Metabolism, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Feng Wu
- Department of Pathology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Bei Guo
- Department of Endocrinology and Metabolism, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Ming-Hui Zheng
- Department of Endocrinology and Metabolism, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Yi Wang
- Department of Endocrinology and Metabolism, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Qiu-Shuang Xu
- Department of Endocrinology and Metabolism, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Xiao-Bo Liao
- Department of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Hong-Yu Lu
- Xiangya Medical College, Central South University, Changsha, China
| | - Xu-Biao Xie
- Department of Kidney Transplantation, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Ling-Qing Yuan
- Department of Endocrinology and Metabolism, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
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