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Carrara F, Gaspari F, Trillini M, Peracchi T, Fidone D, Stucchi N, Ferrari S, Cugini D, Perico N, Parvanova A, Remuzzi G, Ruggenenti P. GFR measurement in patients with CKD: Performance and feasibility of simplified iohexol plasma clearance techniques. PLoS One 2024; 19:e0306935. [PMID: 39018289 PMCID: PMC11253958 DOI: 10.1371/journal.pone.0306935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 06/25/2024] [Indexed: 07/19/2024] Open
Abstract
Implementing shortened one-compartment iohexol plasma clearance models for GFR measurement is crucial since the gold standard inulin renal clearance technique and the reference two-compartment, 10-hour, 16-samplings iohexol plasma clearance method are clinically unfeasible. Inulin may precipitate anaphylactic shock. Four-hour and 8-hour one-compartment iohexol plasma clearance models with Bröchner-Mortensen correction provide accurate GFR measurements in patients with estimated GFR (eGFR) > or ≤40 mL/min/1.73m2, respectively. We compared the performance of the simplified 5-hour, 4-samplings, two-compartment population pharmacokinetic model (popPK) with the performance of the reference two-compartment 10-hour iohexol method in 16 patients with GFR 15.2 to 56.5 mL/min/1.73 m2. We also compared the performance of shortened (5, 6 and 7-hour) one-compartment models with the performance of the standard 8-hour one-compartment model in 101 patients with eGFR ≤40 mL/min/1.73 m2. The performance of popPK and shortened methods versus reference methods was evaluated by total deviation index (TDI), concordance correlation coefficient (CCC) and coverage probability (CP). TDI <10%, CCC ≥0.9 and CP >90% indicated adequate performance. TDI, CCC and CP of popPK were 11.11%, 0.809 and 54.10%, respectively. All shortened, one-compartment models overestimated the GFR (p <0.0001 for all) as compared to the 8-hour model. TDI, CCC and CP were 7.02%, 0.815, and 75.80% for the 7-hour model, 7.26%, 0.803, and 74.20% for the 6-hour model, and 8.85%, 0.729 and 64.70% for the 5-hour model. The agreement of popPK model was comparable to that obtained with the Chronic-Kidney-Disease-Collaboration-Epidemiology (CKD-Epi) and the Modification-of-Diet-in-Renal-Disease (MDRD) serum-creatinine based equations for GFR estimation. PopPK model is remarkably unreliable for GFR measurement in stage III-IV CKD patients. In patients with eGFR ≤40 mL/min/1.73m2, shortened one-compartment models, in particular the 5-hour model, are less performant than the reference 8-hour model. For accurate GFR measurements, the iohexol plasma clearance should be measured with appropriate protocols. Over-simplified procedures should be avoided.
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Affiliation(s)
- Fabiola Carrara
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
| | - Flavio Gaspari
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
| | - Matias Trillini
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
| | - Tobia Peracchi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
| | - Diego Fidone
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
| | - Nadia Stucchi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
| | - Silvia Ferrari
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
| | - Daniela Cugini
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
| | - Norberto Perico
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
| | - Aneliya Parvanova
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
| | - Piero Ruggenenti
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, Bergamo, Italy
- Unit of Nephrology, Azienda Socio-Sanitaria Territoriale (ASST) Papa Giovanni XXIII, Bergamo, Italy
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Schwaderer AL, Maier P, Greenbaum LA, Furth SL, Schwartz GJ. Application of GFR estimating equations to children with normal, near-normal, or discordant GFR. Pediatr Nephrol 2023; 38:4051-4059. [PMID: 37418011 DOI: 10.1007/s00467-023-06045-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/22/2023] [Accepted: 05/22/2023] [Indexed: 07/08/2023]
Abstract
BACKGROUND The objective was to determine the extent that eGFR formulas correspond to measured plasma iohexol clearance (iGFR) in children with normal or near normal kidney function, particularly how different eGFR formulas yield discordant results. METHODS iGFR from 2 (iGFR-2pt) and 4 (iGFR-4pt) time points along with creatinine and/or cystatin C-based eGFR were measured in children with mild CKD, stages 1-2. eGFR was calculated using 6 equations: 3 under 25 (U25) formulas from the Chronic Kidney Disease in Children (CKiD) study, the full age-combined cystatin C (cysC) and creatinine spectrum (FAS-combined), the European Kidney Function Consortium (EKFC-creatinine) equation, and the Chronic Kidney Disease Epidemiology Collaboration (CKD-epi) cysC-based equation. RESULTS Twenty-nine children were included, of which 22 had discordant creatinine vs. cystatin C-based eGFR by ≥ 15mL/min/1.73 m2. Overall, the FAS-combined had the least bias, while the U25 most accurately identified children with an eGFR < 90 mL/min/1.73 m2. When Cr-eGFR was ≥ 15 mL/min higher than CysC-eGFR, the U25 creatinine eGFR was closest to iGFR-4pt. When CysC eGFR was higher, the U25-combined was closest to iGFR-4pt. CONCLUSION The formulas that most closely approximated the measured GFR varied depending on the pattern of discordant eGFR results. Based on the results, we recommend using the CKiD U25-combined formula to screen for children with a low GFR. Either the CKiD U25-combined or FAS-combined would be recommended for changes in eGFR longitudinally. However, because all formulas were discordant from the iGFR-4pt in over a third of participants, further refinement of pediatric eGFR formulas is needed at the normal/near-normal range. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Andrew L Schwaderer
- Department of Pediatrics, Division of Nephrology, Indiana University, Indianapolis, USA
| | - Paula Maier
- Department of Pediatrics, Division of Nephrology, University of Rochester Medical Center, Room 4-8105, 601 Elmwood Avenue, Box 777, Rochester, NY, 14642, USA
| | - Larry A Greenbaum
- Department of Pediatrics, Division of Nephrology, Emory University and Children's Healthcare of Atlanta, Atlanta, USA
| | - Susan L Furth
- Departments of Pediatrics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, and the Children's Hospital of Philadelphia, Philadelphia, USA
| | - George J Schwartz
- Department of Pediatrics, Division of Nephrology, University of Rochester Medical Center, Room 4-8105, 601 Elmwood Avenue, Box 777, Rochester, NY, 14642, USA.
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Wesolowski CA. Reference standard analysis of multiple new and old plasma clearance models and renal clearance with special attention to measurement of reduced glomerular filtration rate. Scand J Clin Lab Invest 2023; 83:548-568. [PMID: 38219224 DOI: 10.1080/00365513.2023.2275278] [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: 03/15/2023] [Accepted: 10/22/2023] [Indexed: 01/16/2024]
Abstract
Nine models were evaluated as candidate glomerular filtration rate (GFR) reference standards in three datasets using [51Cr(EDTA)]- or [169Yb(DTPA)]2- anions in 98 studies. Noncompartmental methods formed an upper limit for estimating mass excreted and voluntary urine collection formed a lower limit. For current models and methods, reduced GFR in adults resulted in inflated clearance estimates. Two different logarithmic models with exponential tails were created and may have underestimated reduced clearance. The logarithmic formulae can be used with only two plasma samples, and fit 13 multiple time-samples from 5 min to 24 h with an 8% standard deviation of residuals compared to 20% error for monoexponentials. For shorter times (4 or 5 h) the fit errors decreased but the ratio of errors remained at circa 2.5 times lesser for the logarithmic versus monoexponential models. Adaptively regularised gamma variate, Tk-GV, models that are well documented, but not in common use, were largely contained within the reference extreme values, were unbiased for different levels of clearance and were the only models to be uncorrelated to volume of distribution from mean residence time divided by weight. Using Tk-GV as a candidate reference standard, potentially better methods for routine clinical usage were discussed. Prospective clinical testing, and metabolic scaling of decreased renal function is advised for potential changes to patient triage.
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Affiliation(s)
- Carl A Wesolowski
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada
- Department of Medical Imaging, Royal University Hospital, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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Ng DK, Furth SL, Warady BA, Crews DC, Seegmiller JC, Schwartz GJ. Self-reported Race, Serum Creatinine, Cystatin C, and GFR in Children and Young Adults With Pediatric Kidney Diseases: A Report From the Chronic Kidney Disease in Children (CKiD) Study. Am J Kidney Dis 2022; 80:174-185.e1. [PMID: 34974031 PMCID: PMC9243196 DOI: 10.1053/j.ajkd.2021.10.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 10/24/2021] [Indexed: 01/27/2023]
Abstract
RATIONALE & OBJECTIVE Recent reassessment of the use of race in estimated glomerular filtration rate (eGFR) in adults has instigated questions about the role of race in eGFR expressions for children. Little research has examined the associations of self-reported race with measured GFR (mGFR) adjusting for serum creatinine or cystatin C in children and young adults with chronic kidney disease (CKD). This study examined these associations and evaluated the performance of the previously published "U25" (under the age of 25 years) eGFR equations in a large cohort of children and young adults with CKD. STUDY DESIGN Observational cohort study. SETTING & PARTICIPANTS Participants in the Chronic Kidney Disease in Children (CKiD) study including 190 Black and 675 non-Black participants contributing 473 and 1,897 annual person-visits, respectively. EXPOSURE Self- or parental-reported race (Black, non-Black). Adjustment for serum creatinine or cystatin C, body size, and socioeconomic status. OUTCOME mGFR based on iohexol clearance. ANALYTICAL APPROACH Linear regression with generalized estimating equations, stratified by age (<6, 6-12, 12-18, and ≥18 years) incorporating serum creatinine or serum cystatin C. Contrasting performance in different self-reported racial groups of the U25 eGFR equations. RESULTS Self-reported Black race was significantly associated with 12.8% higher mGFR among children in regression models including serum creatinine. Self-reported Black race was significantly associated with 3.5% lower mGFR after adjustment for cystatin C overall but was not significant for those over 12 years. The results were similar after adjustment for body size and socioeconomic factors. The average of creatinine- and cystatin C-based U25 equations was unbiased by self-reported race groups. LIMITATIONS Small number of children < 6 years; lean body mass was estimated. CONCLUSIONS Differences in the creatinine-mGFR relationship by self-reported race were observed in children and young adults with CKD and were consistent with findings in adults. Smaller and opposite differences were observed for the cystatin C-mGFR relationship, especially in the younger age group. We recommend inclusion of children for future investigations of biomarkers to estimate GFR. Importantly, for GFR estimation among those under 25 years of age, the average of the new U25 creatinine and cystatin C equations without race coefficients yields unbiased estimates of mGFR.
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Affiliation(s)
- Derek K. Ng
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Susan L. Furth
- Children’s Hospital of Philadelphia, Philadelphia, PA, USA,Department of Pediatrics, Division of Nephrology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Bradley A. Warady
- Division of Pediatric Nephrology, Children’s Mercy Kansas City, Kansas City, MO, USA
| | - Deidra C. Crews
- Division of Nephrology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Jesse C. Seegmiller
- Department of Laboratory Medicine and Pathology, School of Medicine, University of Minnesota, Minneapolis, MN
| | - George J. Schwartz
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA
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Pottel H, Goffin K, De Waele L, Levtchenko E, Delanaye P. 51Cr-EDTA plasma clearance in children: One, two, or multiple samples? Medicine (Baltimore) 2022; 101:e28608. [PMID: 35060531 PMCID: PMC8772627 DOI: 10.1097/md.0000000000028608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 12/24/2021] [Indexed: 01/05/2023] Open
Abstract
Plasma disappearance curves using multiple blood samples are a recognized reference method for measuring glomerular filtration rate (GFR). However, there is no consensus on the protocol for this type of measurement. A two-compartment model is generally considered acceptable for the mathematical description of the concentration-time decay curve. The impact of the fitting procedure on the reported GFR has not been questioned.We defined 8 different fitting procedures to calculate the area under the curve, and from this area under the curve, the GFR. We applied the 8 fitting methods (all considering a full concentration-time curve) on the multiple sample data (8 samples) of 20 children diagnosed with Duchenne muscular dystrophy. We evaluated the effect (variability) on the reported GFR from the different fitting methods and compared these results with GFR-values calculated from late samples only (samples after 120 minutes) and from one-sample methods.In 6 out of 20 cases, the fitting methods on the full concentration-time curve resulted in very different reported GFR-values, mainly because some methods were not able to fit the data, or methods resulted in GFR-values ranging from 0 to 120 mL/min. The reported GFR-result therefore strongly depends on the fitting method, making the full concentration-time method less robust than expected. Compared with a consensus reference GFR, the late sample models did not show fitting issues and may therefore be considered as more robust. Also the one-sample methods showed acceptable accuracy.The late sample methods (using 3 time-points) provide robust and reliable methods to determine GFR.
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Affiliation(s)
- Hans Pottel
- Department of Public Health and Primary Care, Katholieke Universiteit Leuven Kulak, Kortrijk, Belgium
| | - Karolien Goffin
- Department of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Liesbeth De Waele
- Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Elena Levtchenko
- Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Pierre Delanaye
- Department of Nephrology-Dialysis-Transplantation, University of Liège (ULg Centre Hospitalier Universitaire), Centre Hospitalier Universitaire Sart Tilman, Liège, Belgium
- Department of Nephrology-Dialysis-Apheresis, Hôpital Universitaire Caremeau, Nîmes, France
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Zhang X, Yao C, Xiao Q, Wu J, Wu G. Enhanced external counterpulsation: A new method to alleviate contrast-induced acute kidney injury. Contemp Clin Trials 2022; 113:106653. [PMID: 34999282 DOI: 10.1016/j.cct.2021.106653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 12/05/2021] [Accepted: 12/06/2021] [Indexed: 12/28/2022]
Abstract
BACKGROUND Contrast-induced acute kidney injury (CI-AKI) is a common complication after exposure to contrast media. Renal ischaemia occurs in the initial stage of CI-AKI, however, there are very few effective measures to improve renal perfusion. METHODS A total of 114 patients with an estimated glomerular filtration rate (eGFR) of 60-89 ml/min/1.73m2 were randomly assigned to two groups: enhanced external counterpulsation (EECP) group (N = 57) and control group (N = 57). Two hours after contrast exposure, EECP group received EECP treatment for 1 h while no intervention was performed control group. The primary outcome was the incidence of serum cystatin C concentration to 10% above the baseline concentration at 24 h after contrast administration. The secondary outcomes were the incidence of CI-AKI (defined as an increase in serum creatinine concentration to ≥0.5 mg/dl or by 25% compare to the baseline after contrast exposure), contrast clearance and adverse clinical events. RESULTS The primary outcome was observed in 26 patients (6 EECP and 20 control; 11% vs. 35%; P = 0.002). CI-AKI occurred in four patients (0 EECP and 4 control; 0% vs. 7%; P = 0.042). The clearance rate of iopromide in the initial 3 h was significantly different between EECP and control group (59.92 ± 8.84 vs 46.80 ± 9.26 ml/min/1.73 m2; P < 0.001). No adverse clinical events were observed in this study. CONCLUSIONS This study demonstrates that EECP increases the contrast clearance and may have an effect in reducing the risk of CI-AKI. The study has been registered in Chinese Clinical Trial Registry (ChiCTR 2,000,039,190).
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Affiliation(s)
- Xiaocong Zhang
- Department of Cardiology, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China; Department of Cardiology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Chun Yao
- Department of Cardiology, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China; Department of Cardiology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Qunlin Xiao
- Department of Cardiology, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China
| | - Jiansheng Wu
- Department of Cardiology, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China
| | - Guifu Wu
- Department of Cardiology, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China; Guangdong Innovative Engineering and Technology Research Center for Assisted Circulation, Shenzhen, Guangdong, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, Guangzhou, Guangdong, China.
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7
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Destere A, Gandonnière CS, Åsberg A, Loustaud-Ratti V, Carrier P, Ehrmann S, Guellec CBL, Marquet P, Woillard JB. A single Bayesian estimator for iohexol clearance estimation in ICU, liver failure and renal transplant patients. Br J Clin Pharmacol 2021; 88:2793-2801. [PMID: 34951499 DOI: 10.1111/bcp.15197] [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: 04/30/2021] [Revised: 12/09/2021] [Accepted: 12/13/2021] [Indexed: 11/28/2022] Open
Abstract
AIM Iohexol clearance has been proposed to estimate the glomerular filtration rate (GFR). A population pharmacokinetics (popPK) model was developed from heterogenous patients. A Bayesian estimator (MAP-BE) based on a limited sampling strategy (LSS) was derived and evaluated in external patients. METHODS Full pharmacokinetic data (7-12 samples) from 172 patients receiving iohexol for measurement of their GFR (unstable and stable ICU patients, liver failure patients and kidney transplant patients) were split into a development (n=136) and validation (n=36) datasets. A PopPK model was developed in Monolix and was used to develop MAP-BE based on LSS. Its performances for GFR estimation were evaluated in the validation set. RESULTS A two-compartment model with first-order elimination best described the data. The final model included the type of patients on volume of distribution (Vd), clearance and intercompartmental constants, serum creatinine on clearance and body weight on Vd. The best LSS included samples at 0.1-1-9h exhibiting a relative MPE(RMSE) = -3.7%(14.3%) and better performances than the Bröchner-Mortensen Formula (-3.0%/17%). Split by type of patients, the highest interindividual variability and imprecision was observed in unstable ICU patients MPE(RMSE)=3.7%(18.8%) while the best performances were obtained for renal transplant patients MPE(RMSE)=1.0%(5.8%). All LSS that included samples before 9h for the third sample were associated with an increased imprecision. CONCLUSION A single MAP-BE of iohexol based on a 3-sample-LSS for 4 heterogeneous population was developed and allowed accurate estimation of GFR in kidney transplant patients, slightly biased in stable ICU patients and slightly imprecise in unstable ICU patients.
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Affiliation(s)
- Alexandre Destere
- Pharmacology & Transplantation, INSERM U1248, Université de Limoges, Limoges, France.,Department of Pharmacology, Toxicology and Pharmacovigilance, University Hospital of Limoges, Limoges, France
| | - Charlotte Salmon Gandonnière
- Médecine Intensive Réanimation, INSERM CIC 1415, CRICS-TriggerSep Research Network, CHRU de Tours, Tours, France
| | - Anders Åsberg
- Department of Transplantation Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway.,Department of Pharmacy, University of Oslo, Norway
| | - Véronique Loustaud-Ratti
- Pharmacology & Transplantation, INSERM U1248, Université de Limoges, Limoges, France.,Department of hepato-gastro-enterology, University Hospital of Limoges, Limoges, France
| | - Paul Carrier
- Department of hepato-gastro-enterology, University Hospital of Limoges, Limoges, France
| | - Stephan Ehrmann
- Médecine Intensive Réanimation, INSERM CIC 1415, CRICS-TriggerSep Research Network, CHRU de Tours, Tours, France.,Centre d'Etude des Pathologies Respiratoires INSERM U1100, Faculté de médecine, Université de Tours, Tours, France
| | | | - Pierre Marquet
- Pharmacology & Transplantation, INSERM U1248, Université de Limoges, Limoges, France.,Department of Pharmacology, Toxicology and Pharmacovigilance, University Hospital of Limoges, Limoges, France
| | - Jean-Baptiste Woillard
- Pharmacology & Transplantation, INSERM U1248, Université de Limoges, Limoges, France.,Department of Pharmacology, Toxicology and Pharmacovigilance, University Hospital of Limoges, Limoges, France
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Ng DK, Pierce CB. Kidney Disease Progression in Children and Young Adults With Pediatric CKD: Epidemiologic Perspectives and Clinical Applications. Semin Nephrol 2021; 41:405-415. [PMID: 34916001 DOI: 10.1016/j.semnephrol.2021.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Chronic kidney disease (CKD) progression is typically characterized as either time to a clinically meaningful event (such as dialysis or transplant), or longitudinal changes in kidney function. This review describes pediatric kidney disease progression using these two distinct frameworks by reviewing and discussing data from the Chronic Kidney Disease in Children study. We first describe new equations to estimate glomerular filtration rate (GFR) for patients younger than age 25 years, and how the average of serum creatinine-based and cystatin C-based GFR equations yield valid estimates than either alone. Next, we present a life course description of CKD onset to kidney replacement therapy, prediction models based on clinical measurements, and show the importance of diagnosis (broadly classified as nonglomerular and glomerular in origin), GFR level, and proteinuria on progression. Literature on longitudinal GFR in children and young adults are reviewed and new data are presented to characterize nonlinear changes in estimated GFR in patients younger than age 25 years. These models showed accelerated progression associated with glomerular diagnosis, lower GFR level, and higher proteinuria, which was congruent with time-to-event analyses. Descriptions of online tools for GFR estimation and risk stratification for clinical applications are presented and we offer key epidemiologic considerations for the analysis of longitudinal pediatric CKD studies.
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Affiliation(s)
- Derek K Ng
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.
| | - Christopher B Pierce
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
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Gong K, Zou Y, Zhu H, Peng X, Qin D, Sun B, Wang X. Comparative study of plasma clearance of iohexol at different injection doses. Clin Chim Acta 2021; 525:34-39. [PMID: 34906558 DOI: 10.1016/j.cca.2021.12.009] [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: 08/27/2021] [Revised: 11/25/2021] [Accepted: 12/08/2021] [Indexed: 11/03/2022]
Abstract
BACKGROUND Our goal was to compare the metabolic curves of plasma clearance of iohexol (ClIOH) at standard dose (5 ml) and contrast-level dose (50 ml). METHODS The concentration of iohexol was measured at fasting state and at nine different time periods after a single bolus of iohexol injection. The interval between the injection of the two doses was longer than 24 hrs. Using a multi-point method and a dual-sample method, ClIOH-M and ClIOH-D were calculated, and the correlation and consistency of ClIOH between the two doses were compared. RESULTS The metabolic curves of iohexol at the 5 ml and 50 ml injection were substantially identical. The correlation of ClIOH-M between the two doses was 0.930, the mean deviation was 1.3 ± 6.9 ml/min/1.73 m2. Taking ClIOH-5ml-M as the standard, the ClIOH-50ml-D at 2 h and 4 h had a correlation coefficient of 0.975, a mean deviation of 0.1 ± 5.3 ml/min/1.73 m2, and the concordances were 100% corresponding to P30, 88.9% corresponding to P10, and 77.8% corresponding to P5. CONCLUSION When a regular dose of iohexol is used for enhanced CT, ClIOH can be used for the measurement of GFR, and a proper time for blood collection can be 2 h and 4 h.
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Affiliation(s)
- Ke Gong
- Department of Clinical Laboratory, Civil Aviation General Hospital, Beijing, China; Peking University Civil Aviation School of Clinical Medicine, Beijing, China
| | - Yingshu Zou
- Beijing Institute of Medical Device Testing, Beijing, China; NMPA Key Laboratory for Quality Evaluation of In Vitro Diagnostics, Beijing, China
| | - Haifeng Zhu
- Department of Radiology, Civil Aviation General Hospital, Beijing, China; Peking University Civil Aviation School of Clinical Medicine, Beijing, China
| | - Xu Peng
- Beijing Institute of Medical Device Testing, Beijing, China; NMPA Key Laboratory for Quality Evaluation of In Vitro Diagnostics, Beijing, China
| | - Dongfang Qin
- Department of Clinical Laboratory, Civil Aviation General Hospital, Beijing, China; Peking University Civil Aviation School of Clinical Medicine, Beijing, China
| | - Bixuan Sun
- Department of Clinical Laboratory, Civil Aviation General Hospital, Beijing, China
| | - Xuejing Wang
- Department of Clinical Laboratory, Civil Aviation General Hospital, Beijing, China; Peking University Civil Aviation School of Clinical Medicine, Beijing, China.
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10
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Pottel H, Schaeffner E, Ebert N, van der Giet M, Delanaye P. Iohexol plasma clearance for measuring glomerular filtration rate: effect of different ways to calculate the area under the curve. BMC Nephrol 2021; 22:166. [PMID: 33952185 PMCID: PMC8101203 DOI: 10.1186/s12882-021-02376-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 04/20/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Measuring glomerular filtration rate (GFR) using iohexol plasma clearance has been proposed as the preferred way for GFR determination. The extended multiple-sample protocol is based on fitting the full concentration-time decay-curve, and from the obtained fit-parameters, the area under the curve (AUC) and GFR (the injected dose divided by the AUC) were calculated. The goal of the current study is to evaluate the impact of different fitting procedures on the precision of GFR-results obtained from the full concentration-time curve, and compare these results with those obtained with simplified multiple-samples and single-sample protocols. METHODS The concentration-time curves of 8 samples at times 30, 60, 90, 120, 150, 180, 240 and 300 min after bolus injection of iohexol of 570 adults, aged 70+, from the Berlin Initiative Study (BIS), were analysed. The fit-parameters for the two-compartment model (double-exponential decay curve), and from these, the AUC and GFR were obtained with 8 different fitting procedures. RESULTS The two-compartmental non-linear least squares fitting procedure showed the best accuracy (541 out of 570 reported GFR-results were within 5% of the majority of the 8 fitting methods). The two-compartmental slope-intercept fitting procedure was not always applicable and the non-compartmental fitting procedures did not always allow to calculate the GFR. All correction formulas for the simplified late multiple-samples methods showed acceptable accuracy and precision with a preference for Ng's correction formula (Lin's CCC = 0.992, bias = 0.5 ± 2.5). Jacobsson's iterative method was the best one-sample method, with Lin's CCC = 0.983 and bias = - 0.6 ± 3.4. CONCLUSION The fitting procedure has an important impact on the precision of the calculated AUC and GFR. The simplified late-sample protocols and one-sample methods did not suffer from fitting problems and showed acceptable equivalence when compared to the full compartment GFR-results. TRIAL REGISTRATION The "Berlin Initiative Study" is officially registered with the German Register for Clinical Studies ("Deutschen Register Klinischer Studien"(DRKS)) under registration number DRKS00017058 , since April 12, 2019, and it is also visible on the WHO clinical trials registry platform (within the next 4 weeks after the registration date).
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Affiliation(s)
- Hans Pottel
- Department of Public Health and Primary Care, KU Leuven Campus Kulak Kortrijk, Etienne Sabbelaan 53, 8500, Kortrijk, Belgium.
| | - Elke Schaeffner
- Institute of Public Health, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Natalie Ebert
- Institute of Public Health, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Markus van der Giet
- Department of Nephrology and Intensive Care Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Pierre Delanaye
- Department of Nephrology-Dialysis-Transplantation, University of Liège (ULg CHU), CHU Sart Tilman, Liège, Belgium
- Department of Nephrology-Dialysis-Apheresis, Hopital Universitaire Caremeau, Nimes, France
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11
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Comparison of Plasma Clearance With Early-Compartment Correction Equations and Urinary Clearance in High GFR Ranges. Kidney Int Rep 2021; 6:1622-1628. [PMID: 34169202 PMCID: PMC8207320 DOI: 10.1016/j.ekir.2021.03.886] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/15/2021] [Accepted: 03/15/2021] [Indexed: 12/04/2022] Open
Abstract
Introduction Glomerular filtration rate (GFR) is measured from the late plasma disappearance curve of an exogenous tracer, after correction for the early decay—corresponding to the distribution of the tracer—using various equations. These equations display the highest discrepancies in the GFR range above 90 ml/min per 1.73 m2, and their respective performances against a reference, urinary GFR measurement are unclear. Methods In patients with mGFR >90 ml/min per 1.73 m2 from 6 different cohorts, we compared GFR obtained from the plasma clearance of iohexol or 51Cr-ethylenediamine tetraacetic acid (EDTA), after correction using Chantler (C), Bröchner-Mortensen (BM), Fleming (F), Jodal-Bröchner-Mortensen (JBM), and Ng (N) equations, with urinary clearance of the same tracers or inulin. Results In 438 participants (median age 41 [39–42] years, 43% women), the median urinary clearance was 100.8 (94.7–112.6) ml/min per 1.73 m2. Plasma clearances using the correction equations were 105.7 (96.8–119.2), 102.4 (95.2–112.9), 100.7 (93.6–111.1), 102.6 (95.2–113.4), and 106.0 (98.2–117.6) ml/min per 1.73 m2 for C, BM, F, JBM, and N, respectively. Concordance correlation coefficients between plasma and urinary clearances were poor for all equations. Compared with urinary clearances, BM, F, and JBM displayed the best accuracy within 10% (73%, 72%, and 71%, respectively, vs. 63% and 66% for C and N), whereas BM and JBM had the lowest median biases. Accuracy of all equations was especially low in the hyperfiltration range (urinary clearance >130 ml/min per 1.73 m2). Conclusion The BM and JBM equations displayed the best overall performances to correct for the early disappearance curve. Results of these equations should be interpreted with caution, especially in the highest GFR range.
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12
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Atkinson MA, Ng DK, Warady BA, Furth SL, Flynn JT. The CKiD study: overview and summary of findings related to kidney disease progression. Pediatr Nephrol 2021; 36:527-538. [PMID: 32016626 PMCID: PMC7396280 DOI: 10.1007/s00467-019-04458-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 12/10/2019] [Accepted: 12/16/2019] [Indexed: 12/15/2022]
Abstract
The Chronic Kidney Disease in Children (CKiD) cohort study is a North American (USA and Canada) multicenter, prospective study of children with chronic kidney disease (CKD). The original aims of the study were (1) to identify novel risk factors for CKD progression; (2) to measure the impact of kidney function decline on growth, cognition, and behavior; and (3) to characterize the evolution of cardiovascular disease risk factors. CKiD has developed into a national and international resource for the investigation of a variety of factors related to CKD in children. This review highlights notable findings in the area of CKD progression and outlines ongoing opportunities to enhance understanding of CKD progression in children. CKiD's contributions to the clinical care of children with CKD include updated and more accurate glomerular filtration rate estimating equations for children and young adults, and resources designed to help estimate the CKD progression timeline. In addition, results from CKiD have strengthened the evidence that treatment of hypertension and proteinuria should continue as a primary strategy for slowing the rate of disease progression in children.
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Affiliation(s)
| | - Derek K Ng
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | | | - Susan L Furth
- Children's Hospital of Philadelphia, Philadelphia, PA, USA
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13
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Lucas GM, Atta MG, Zook K, Vaidya D, Tao X, Maier P, Schwartz GJ. Cross-Sectional and Longitudinal Performance of Creatinine- and Cystatin C-Based Estimating Equations Relative to Exogenously Measured Glomerular Filtration Rate in HIV-Positive and HIV-Negative Persons. J Acquir Immune Defic Syndr 2020; 85:e58-e66. [PMID: 33136753 PMCID: PMC8301492 DOI: 10.1097/qai.0000000000002471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Reliable estimates of glomerular filtration rate (GFR) are important in the clinical management of HIV-positive patients. Data on the performance of widely used estimating equations (eGFR) relative to exogenously measured GFR are sparse in this population. METHODS We evaluated cross-sectional and longitudinal accuracy and bias of eGFR, based on creatinine and cystatin C, relative to disappearance of infused iohexol from plasma (iGFR) in a cohort of participants followed annually for up to 7 years. RESULTS A total of 222 HIV-positive and 139 HIV-negative participants contributed 1240 visits with valid iGFR and eGFR measures. Estimated GFR based on both creatinine and cystatin C performed the best. Estimated GFR based on creatinine alone overestimated iGFR by 9 mL·min·1.73 m on average and was significantly less accurate in HIV-positive than HIV-negative individuals. The performance of equations based on either creatinine alone or cystatin C alone were significantly affected by participant factors (eg, non-suppressed HIV RNA, nadir CD4 count, hepatitis C virus coinfection). The average iGFR slope was -4% per year in HIV-positive participants. In both HIV-positive and HIV-negative participants, eGFR slope measures were generally unbiased but inaccurate, with only 60%-74% of observations falling within ±5% points of iGFR slope. CONCLUSIONS Both creatinine and cystatin C have limitations as GFR indices in HIV-positive individuals. Estimated GFR based on both creatinine and cystatin C performed best in our study and may be preferred in HIV-positive persons with kidney disease or comorbidities that place them at high risk for kidney disease.
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Affiliation(s)
- Gregory M. Lucas
- Johns Hopkins University School of Medicine, Department of Medicine, Baltimore, MD 21287, United States
| | - Mohamed G. Atta
- Johns Hopkins University School of Medicine, Department of Medicine, Baltimore, MD 21287, United States
| | - Katie Zook
- Johns Hopkins University School of Medicine, Department of Medicine, Baltimore, MD 21287, United States
| | - Dhananjay Vaidya
- Johns Hopkins University School of Medicine, Department of Medicine, Baltimore, MD 21287, United States
| | - Xueting Tao
- Johns Hopkins University School of Medicine, Department of Medicine, Baltimore, MD 21287, United States
| | - Paula Maier
- University of Rochester Medical Center, Department of Pediatrics, Rochester, NY 14642, United States
| | - George J. Schwartz
- University of Rochester Medical Center, Department of Pediatrics, Rochester, NY 14642, United States
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14
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Dubourg L, Lemoine S, Joannard B, Chardon L, de Souza V, Cochat P, Iwaz J, Rabilloud M, Selistre L. Comparison of iohexol plasma clearance formulas vs. inulin urinary clearance for measuring glomerular filtration rate. Clin Chem Lab Med 2020; 59:571-579. [PMID: 33068376 DOI: 10.1515/cclm-2020-0770] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 09/28/2020] [Indexed: 11/15/2022]
Abstract
OBJECTIVES The one-compartment iohexol plasma clearance has been proposed as a reliable alternative to renal inulin clearance. However, this method's performance depends on the formula used to calculate glomerular filtration rate (GFR). This study reports on performance comparisons between various mathematical formulas proposed for iohexol plasma clearance vs. inulin urinary clearance. METHODS GFR was simultaneously determined by inulin and iohexol clearance in 144 participants (age: 10-84 years; glomerular filtration rate: 15-169 mL/min/1.73 m2). A retrospective cross-sectional study evaluated the performance of four formulas proposed to calculate plasma iohexol clearance (Brøchner-Mortensen, Fleming et al., Jødal-Brøchner-Mortensen, and Ng-Schwartz-Munoz). The performance of each formula was assessed using bias, precision (standard deviation of the bias), accuracy (percentage iohexol within 5, 10, and 15%), root mean square error, and concordance correlation coefficient vs. renal inulin clearance as reference. RESULTS Regarding accuracy, there was no difference in root mean square error (RMSE), P5, P10, or P15 between the four formulas. The four concordance correlation coefficients (CCC) between the value from each formula and in-GFR were high and not significantly different. At in-GFR ≥90 mL/min/1.73 m2, Ng-Schwartz-Munoz formula performed slightly better than other formulas regarding median bias (-0.5; 95% CI [-3.0 to 2.0] and accuracy P15 (95.0; 95% CI [88.0-100.0]). CONCLUSIONS The studied formulas were found equivalent in terms of precision and accuracy, but the Ng-Schwartz-Munoz formula improved the accuracy at higher levels of in-GFR.
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Affiliation(s)
- Laurence Dubourg
- Néphrologie, Dialyse, Hypertension et Exploration Fonctionnelle Rénale, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France.,Université Claude Bernard Lyon 1, Lyon, France.,Laboratoire de Biologie Tissulaire et Ingénierie Thérapeutique, CNRS UMR 5305/Université Lyon 1, Lyon, France
| | - Sandrine Lemoine
- Néphrologie, Dialyse, Hypertension et Exploration Fonctionnelle Rénale, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France.,Université Claude Bernard Lyon 1, Lyon, France.,Laboratoire CarMeN, INSERM 1060, Lyon, France
| | - Brune Joannard
- Néphrologie, Dialyse, Hypertension et Exploration Fonctionnelle Rénale, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France
| | - Laurence Chardon
- Laboratoire de biochimie, Groupement Hospitalier Est, Hospices Civils de Lyon, Lyon, France
| | - Vandréa de Souza
- Néphrologie, Dialyse, Hypertension et Exploration Fonctionnelle Rénale, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France.,Universidade de Caxias do Sul, Programa de Pós-graduação em Ciências da Saúde, Caxias do Sul, Brazil.,CAPES Foundation, Ministry of Education of Brazil, Brasilia, Brazil.,Hospital Geral de Caxias do Sul, Caxias do Sul, Brasil
| | - Pierre Cochat
- Université Claude Bernard Lyon 1, Lyon, France.,Laboratoire de Biologie Tissulaire et Ingénierie Thérapeutique, CNRS UMR 5305/Université Lyon 1, Lyon, France.,Centre de Référence des Maladies Rénales et Phosphocalciques Rares, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Lyon, France
| | - Jean Iwaz
- Université Claude Bernard Lyon 1, Lyon, France.,Service de Biostatistique-Bioinformatique, Pôle Santé Publique, Hospices Civils de Lyon, Lyon, France.,CNRS UMR 5558, Laboratoire de Biométrie et Biologie Évolutive, Équipe Biostatistique-Santé, Villeurbanne, France
| | - Muriel Rabilloud
- Université Claude Bernard Lyon 1, Lyon, France.,Service de Biostatistique-Bioinformatique, Pôle Santé Publique, Hospices Civils de Lyon, Lyon, France.,CNRS UMR 5558, Laboratoire de Biométrie et Biologie Évolutive, Équipe Biostatistique-Santé, Villeurbanne, France
| | - Luciano Selistre
- Néphrologie, Dialyse, Hypertension et Exploration Fonctionnelle Rénale, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France.,Universidade de Caxias do Sul, Programa de Pós-graduação em Ciências da Saúde, Caxias do Sul, Brazil.,CAPES Foundation, Ministry of Education of Brazil, Brasilia, Brazil.,Hospital Geral de Caxias do Sul, Caxias do Sul, Brasil
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15
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Ng DK, Levey AS, Shlipak MG, Muñoz A, Inker LA, Shafi T. Validation of a simple equation for glomerular filtration rate measurement based on plasma iohexol disappearance. Clin Kidney J 2020; 13:397-401. [PMID: 32699620 PMCID: PMC7367109 DOI: 10.1093/ckj/sfz083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 06/02/2019] [Indexed: 11/25/2022] Open
Abstract
Background A simple equation for glomerular filtration rate (GFR) measurement based on only plasma samples during the slow compartment after injection of iohexol was previously developed among children with chronic kidney disease and adult men with or at risk of HIV infection [Chronic Kidney Disease in Children (CKiD)-Multicenter AIDS Cohort Study (MACS) equation], but has not been externally validated. We aimed to evaluate the performance of the CKiD-MACS equation among elderly participants in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort who underwent directly measured iohexol GFR. Methods Using data from 287 participants of the MESA-Kidney study who underwent a five-sample measured iohexol GFR (two and three samples in the fast and slow compartments, respectively), we assessed the performance of the CKiD-MACS equation using only plasma samples in the slow compartment by sex, race and age. Agreement was assessed by bias, correlation, proportion within 5 and 10%, and the root mean square error (RMSE). Results The average age and GFR of the participants were 71 years and 70.8 mL/min/1.73 m2, respectively, and 46% were black. The equation yielded excellent agreement within stratified groups with high correlation (>0.96), low bias (≤1.2 mL/min/1.73 m2) and low RMSE (<4.2 mL/min/1.73 m2). Conclusions The CKiD-MACS equation demonstrated valid GFR measurement using only samples in the slow compartment in this racially diverse, elderly population. While the equation yielded practically the same results as the original Brochner-Mortensen equation, the CKiD-MACS equation conforms to theoretical principles embedded in the two-compartment model of direct GFR measurement.
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Affiliation(s)
- Derek K Ng
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Andrew S Levey
- Division of Nephrology, Tufts Medical Center, Boston, MA, USA
| | - Michael G Shlipak
- Kidney Health Research Collaborative, San Francisco VA Medical Center, University of California, San Francisco, CA, USA
| | - Alvaro Muñoz
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Lesley A Inker
- Division of Nephrology, Tufts Medical Center, Boston, MA, USA
| | - Tariq Shafi
- Division of Nephrology, The University of Mississippi Medical Center, Jackson, MS, USA
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16
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Comparison of Early-Compartment Correction Equations for GFR Measurements. Kidney Int Rep 2020; 5:1079-1081. [PMID: 32647768 PMCID: PMC7335969 DOI: 10.1016/j.ekir.2020.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 04/10/2020] [Accepted: 04/16/2020] [Indexed: 11/24/2022] Open
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Staples A, Wong C, Schwartz GJ. Iohexol-measured glomerular filtration rate in children and adolescents with chronic kidney disease: a pilot study comparing venous and finger stick methods. Pediatr Nephrol 2019; 34:459-464. [PMID: 30315406 PMCID: PMC6581035 DOI: 10.1007/s00467-018-4110-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 09/28/2018] [Accepted: 10/02/2018] [Indexed: 11/27/2022]
Abstract
BACKGROUND Measurement of glomerular filtration rate by iohexol disappearance (iGFR) has become a gold standard in the pediatric chronic kidney disease (CKD) population. The need for serial phlebotomy can be difficult and minimizing venipunctures would be beneficial. Furthermore, finger stick collection for dried blood spot (DBS) may be more tolerable in the pediatric population, and equivalence between these two methods may further simplify the process. METHODS This was a cross-sectional study in children and adolescents 1 to 21 years with stages I-IV CKD. Iohexol was infused and blood drawn 10, 30, 120, and 300 min later. Blood spots on filter paper were collected by finger stick after each of the latter two blood draws. The rate of iohexol plasma disappearance was used to calculate GFR. Pearson's correlation coefficient and bias, Students t test, and Bland-Altman graphical representations were used to compare methods. RESULTS Forty-one patients were recruited. The mean creatinine was 1.13 mg/dL (SD 0.45), the mean 4-point iGFR was 73.2 ml/min/1.73m2 (SD 27.5) and the mean 2-point iGFR was 75.6 ml/min/1.73m2 (SD 27.3). Correlation between 2-point and 4-point venous GFR was r = 0.97; p < 0.001. The correlation between the DBS and the 2-point venous GFR was r = 0.95; p < 0.001, with no significant bias. Ninety-four percent of the 2-point GFR's were within 10% of the 4-point GFR's and 80% of DBS-GFRs were within 10% of the 2-point GFR's. CONCLUSIONS The 2-point iGFR was highly correlated and agreed well with the 4-point iGFR. The same was true for the DBS method and the 2-point venous method. DBS sampling by finger stick sampling at 2 time points after iohexol infusion gave an acceptably accurate measurement of GFR.
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Affiliation(s)
- Amy Staples
- University of New Mexico, MSC10-5590, Albuquerque, NM, 87131, USA.
| | - Craig Wong
- University of New Mexico, MSC10-5590, Albuquerque, NM, 87131, USA
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Wan-Li Z, Jun T, Yu-Dong Z, Fei S, Zhijian H, Chen-Jiang W, Zijie W, Yongjun L, Hongliang Q, Zhengkai H, Zengjun W, Ruoyun T, Min G. Prospective comparison between DCE-MRR and 99m Tc-DTPA-based SPECT for determination of allograft renal function. J Magn Reson Imaging 2018; 49:262-269. [PMID: 30102449 DOI: 10.1002/jmri.26188] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 04/23/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Glomerular filtration rate (GFR) is a preferred indicator of allograft renal function, but direct measurement of GFR remains complicated. PURPOSE To prospectively compare dynamic contrast-enhanced MR renography (DCE-MRR) with 99m Tc-DTPA-based single-photon emission computed tomography (SPECT) for determination of allograft renal function. STUDY TYPE Prospective. POPULATION Seventy kidney-transplant recipients FIELD STRENGTH: A low-dose DCE-MRR with a 3.0T scanner and a 99m Tc-DTPA-based SPECT after renal transplantation were performed. ASSESSMENT A Baumann-Rudin (BR) and a modified two-compartment model (JZ2C) were used for DCE-MRR analysis. Standard Gate's method was used for SPECT analysis. An endogenous creatinine clearance rate (CCr) constituted the reference standard. STATISTICAL TESTS Pearson correlation test and Bland-Altman agreement analysis. RESULTS The reference CCr-GFR was 59.58 ± 23.72 mL/min/1.73 m2 . GFR determined by eGFR, BR, JZ2C, and SPECT was 90.22 ± 34.38, 36.78 ± 14.46, 48.99 ± 23.88, and 67.32 ± 18.44 mL/min/1.73 m2 , respectively. DCE-MRR using JZ2C had the best overall performance, with a Pearson correlation coefficient of 0.81, a bias of -10.58 mL/min/1.73 m2 , and a precision of 14.61 mL/min/1.73 m2 , as well as high accuracy (30-50% intervals: 74.3-90.0%). Although SPECT had a small bias (7.74 mL/min/1.73 m2 ), it had a poor correlation coefficient (0.38), poor precision (23.93 mL/min/1.73 m2 ), and low accuracy (64.3-72.3%) as compared with DCE-MRR using JZ2C. DATA CONCLUSION DCE-MRR using JZ2C is superior to 99m Tc-DTPA-based SPECT to determine allograft renal function. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:262-269.
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Affiliation(s)
- Zhou Wan-Li
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Tao Jun
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Zhang Yu-Dong
- Department of Radiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Shuang Fei
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Han Zhijian
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Wu Chen-Jiang
- Department of Radiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Wang Zijie
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Li Yongjun
- Department of Nuclear Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Que Hongliang
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Huang Zhengkai
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Wang Zengjun
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Tan Ruoyun
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Gu Min
- Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
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Ng DK, Schwartz GJ, Schneider MF, Furth SL, Warady BA. Combination of pediatric and adult formulas yield valid glomerular filtration rate estimates in young adults with a history of pediatric chronic kidney disease. Kidney Int 2018; 94:170-177. [PMID: 29735307 PMCID: PMC6015546 DOI: 10.1016/j.kint.2018.01.034] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 01/19/2018] [Accepted: 01/25/2018] [Indexed: 02/06/2023]
Abstract
As patients with chronic kidney disease (CKD) transition from pediatric nephrology care to adult care, their kidney function is clinically assessed by estimated glomerular filtration rate (eGFR) using both pediatric and adult equations, which may not be congruent. Here we evaluated commonly used eGFR equations and directly measured iohexol GFR (iGFR) among participants between ages 18 and 26 with a diagnosis of pediatric CKD in the Chronic Kidney Disease in Children (CKiD) cohort. The bedside serum creatinine (SCr)-only equation (CKiDSCr), the SCr-only CKD-EPI (CKD-EPISCr), the cystatin C (Cys)-only CKD-EPI (CKD-EPICys) and the combined SCr and Cys CKD-EPI (CKD-EPISCr-Cys) were compared with a) 279 measured iGFRs obtained from 187 participants and b) 548 eGFRs from the SCr and Cys-based CKiD equation (CKiDSCr-Cys) obtained from 219 participants. Among emerging adults with a median iGFR of 49 ml/min/1.73m2, the CKiDSCr-Cys equation had low bias (+1.5 ml/min/1.73m2) and high correlation (0.94), while CKiDSCr underestimated iGFR and CKiDSCr-Cys (-5.6 and -7.4 ml/min/1.73m2, respectively) and CKD-EPISCr had an overestimation bias (+8.2 and +6.1 ml/min/1.73m2, respectively). However, the CKD-EPICys and CKD-EPISCr-Cys exhibited strong agreement with both iGFR and CKiDSCr-Cys. GFR may also be validly estimated in this population by taking the simple average of CKiDSCr and CKD-EPISCr (average bias +1.3 compared to iGFR and -0.6 compared to CKiDSCr-Cys). Clinicians should be aware that individually the pediatric and adult SCr-based estimates of GFR had large discrepancies among emerging adults with pediatric CKD. Thus, when cystatin C is not available, we recommend the average of pediatric and adult SCr-based eGFR as a valid tool for clinical use.
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Affiliation(s)
- Derek K Ng
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
| | - George J Schwartz
- Department of Pediatrics, Division of Pediatric Nephrology, University of Rochester Medical Center, Rochester, New York, USA
| | - Michael F Schneider
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Susan L Furth
- Department of Pediatrics, Division of Nephrology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bradley A Warady
- Division of Pediatric Nephrology, Children's Mercy Kansas City, Kansas City, Missouri, USA
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Furth SL, Pierce C, Hui WF, White CA, Wong CS, Schaefer F, Wühl E, Abraham AG, Warady BA. Estimating Time to ESRD in Children With CKD. Am J Kidney Dis 2018; 71:783-792. [PMID: 29653769 PMCID: PMC5970998 DOI: 10.1053/j.ajkd.2017.12.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 12/19/2017] [Indexed: 11/11/2022]
Abstract
RATIONALE & OBJECTIVE The KDIGO (Kidney Disease: Improving Global Outcomes) guideline for chronic kidney disease (CKD) presented an international classification system that ranks patients' risk for CKD progression. Few data for children informed guideline development. STUDY DESIGN Observational cohort study. SETTINGS & PARTICIPANTS Children aged 1 to 18 years enrolled in the North American Chronic Kidney Disease in Children (CKiD) cohort study and the European Effect of Strict Blood Pressure Control and ACE Inhibition on the Progression of CRF in Pediatric Patients (ESCAPE) trial. PREDICTOR Level of estimated glomerular filtration rate (eGFR) and proteinuria (urine protein-creatinine ratio [UPCR]) at study entry. OUTCOME A composite event of renal replacement therapy, 50% reduction in eGFR, or eGFR<15mL/min/1.73m2. eGFR was estimated using the CKiD-derived "bedside" equation. ANALYTICAL APPROACH Accelerated failure time models of the composite outcome using a conventional generalized gamma distribution. Likelihood ratio statistics of nested models were used to amalgamate levels of similar risk. RESULTS Among 1,232 children, median age was 12 (IQR, 8-15) years, median eGFR was 47 (IQR, 33-62) mL/min/1.73m2, 60% were males, and 13% had UPCRs>2.0mg/mg at study entry. 6 ordered stages with varying combinations of eGFR categories (60-89, 45-59, 30-44, and 15-29mL/min/1.73m2) and UPCR categories (<0.5, 0.5-2.0, and >2.0mg/mg) described the risk continuum. Median times to event ranged from longer than 10 years for eGFRs of 45 to 90mL/min/1.73m2 and UPCRs<0.5mg/mg to 0.8 years for eGFRs of 15 to 30mL/min/1.73m2 and UPCRs>2mg/mg. Children with glomerular disease were estimated to have a 43% shorter time to event than children with nonglomerular disease. Cross-validation demonstrated risk patterns that were consistent across the 10 subsample validation models. LIMITATIONS Observational study, used cross-validation rather than external validation. CONCLUSIONS CKD staged by level of eGFR and proteinuria characterizes the timeline of progression and can guide management strategies in children.
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Affiliation(s)
- Susan L Furth
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA; Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA.
| | - Chris Pierce
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Wun Fung Hui
- Department of Pediatrics, Queen Elizabeth Hospital, Hong Kong
| | - Colin A White
- Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Craig S Wong
- Division of Pediatric Nephrology, University of New Mexico Children's Hospital, Albuquerque, NM
| | - Franz Schaefer
- Pediatric Nephrology Division, Center for Pediatrics and Adolescent Medicine, Im Neuenheimer Feld 430, Heidelberg, Germany
| | - Elke Wühl
- Pediatric Nephrology Division, Center for Pediatrics and Adolescent Medicine, Im Neuenheimer Feld 430, Heidelberg, Germany
| | - Alison G Abraham
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Bradley A Warady
- Division of Pediatric Nephrology, Children's Mercy Hospital, Kansas City, MO
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Turner ME, Laverty KJ, Jeronimo PS, Kaufmann M, Jones G, White CA, Holden RM, Adams MA. Validation of a routine two-sample iohexol plasma clearance assessment of GFR and an evaluation of common endogenous markers in a rat model of CKD. Physiol Rep 2018; 5:5/9/e13205. [PMID: 28483858 PMCID: PMC5430119 DOI: 10.14814/phy2.13205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 02/13/2017] [Indexed: 11/24/2022] Open
Abstract
Endogenous markers of kidney function are insensitive to early declines in glomerular filtration rate (GFR) and in rodent models, validated, practical alternatives are unavailable. In this study, we determined GFR by modeling the plasma clearance of two compounds, iohexol and inulin, and compared the findings to common endogenous markers. All plasma clearance methods of both iohexol and inulin detected a decline in renal function weeks prior to any increase in endogenous marker. Iohexol plasma clearance and inulin plasma clearance had a very high agreement and minimal bias when using 12‐sample models. However, only iohexol could be accurately simplified to a two‐sample, one‐compartment estimation strategy. Following an IV injection of low‐dose iohexol and two timed blood samples at 30 and 90 min, one can accurately approximate a complex 12‐sample strategy of plasma clearance. This method is simple enough to use in routine, longitudinal analysis of larger cohort animal studies.
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Affiliation(s)
- Mandy E Turner
- Department of Biomedical and Molecular Sciences, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - Kimberly J Laverty
- Department of Biomedical and Molecular Sciences, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - Paul S Jeronimo
- Department of Biomedical and Molecular Sciences, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - Martin Kaufmann
- Department of Biomedical and Molecular Sciences, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - Glenville Jones
- Department of Biomedical and Molecular Sciences, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - Christine A White
- Department of Medicine, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - Rachel M Holden
- Department of Biomedical and Molecular Sciences, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada.,Department of Medicine, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - Michael A Adams
- Department of Biomedical and Molecular Sciences, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
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22
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Mian AN, Schwartz GJ. Measurement and Estimation of Glomerular Filtration Rate in Children. Adv Chronic Kidney Dis 2017; 24:348-356. [PMID: 29229165 DOI: 10.1053/j.ackd.2017.09.011] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Rapid, accurate, and precise measures of kidney function are essential for daily management of patients. While plasma and urinary clearances provide the greatest accuracy for assessing glomerular filtration rate (GFR), these are often impractical particularly for the care of children. Serum creatinine, the most commonly used endogenous marker, is simple, convenient, and practical but less accurate because of the influence of non-GFR determinants such as muscle mass, which increases with age in children. GFR estimating equations have been developed for adults and children to improve the accuracy of endogenous biomarkers, such as creatinine and cystatin C, by accounting for some of the non-GFR determinants, thus enhancing the practitioner's ability to assess GFR. In the steady state, when height is used as a surrogate for growth, there is a strong correlation between height/SCr and GFR. Current national guidelines recommend routine reporting of the estimated GFR alongside the serum creatinine value for adults using the Chronic Kidney Disease Epidemiology Collaboration creatinine-based formula and the updated Schwartz "bedside" formula (CKiD 2009) for children.
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Schwartz GJ, Wang H, Erway B, Nordin G, Seegmiller J, Lieske JC, Back SE, Miller WG, Eckfeldt JH. Multicenter Laboratory Comparison of Iohexol Measurement. J Appl Lab Med 2017; 2:711-724. [PMID: 31276084 DOI: 10.1373/jalm.2017.024240] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Iohexol is utilized for measurement of kidney glomerular filtration rate (GFR). Until recently, there have not been available proficiency standards to assist in calibrating a laboratory's results. In view of a shift in calibration at the University of Rochester Medical Center (URMC) laboratory, serving as Central Biochemistry Laboratory for the CKiD study, we performed a multi-centered laboratory comparison. Methods Two batches of 30 fortified sera and patient samples from serum or heparinized plasma were sent for duplicate analysis to URMC, University of Minnesota (UMN), Mayo Clinic, and University of Lund. Five proficiency testing materials from Equalis AB were also provided. Iohexol calibration was performed using dilutions of Omnipaque™ 300 and concentrations measured by HPLC or LC-MS/MS (Mayo). Results UMN and Lund agreed well. URMC calibration was 11-13% lower, and Mayo was 4-8% lower for fortified samples. URMC corrected calibration was 3-8% higher for these samples. When measured values were adjusted for the results of the Equalis samples, all laboratories agreed within 1-2% on all iohexol concentrations. Conclusions For 12 URMC calibrator lots from 11/ 2006 to 3/ 2016, the factor quantifying the underestimation of measured to true iohexol concentration was 0.89. If each concentration were divided by 0.89, the calculated GFRs would be reduced by 10-11%. GFR results for CKiD were adjusted for this shift in calibration. Regular examination of iohexol proficiency testing materials, free exchange of samples among laboratories, and standardized dilution of the stock iohexol for calibration would help to bring more universal agreement to this assay.
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Affiliation(s)
- George J Schwartz
- Division of Pediatric Nephrology, University of Rochester Medical Center, Rochester, NY
| | | | | | | | | | | | | | - W Greg Miller
- Department of Pathology, Virginia Commonwealth University, Richmond, VA
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Ng DK, Schwartz GJ, Warady BA, Furth SL, Muñoz A. Relationships of Measured Iohexol GFR and Estimated GFR With CKD-Related Biomarkers in Children and Adolescents. Am J Kidney Dis 2017; 70:397-405. [PMID: 28549535 DOI: 10.1053/j.ajkd.2017.03.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/23/2017] [Indexed: 11/11/2022]
Abstract
BACKGROUND 2 valid and reliable estimated glomerular filtration rate (GFR) equations for the pediatric population have been developed from directly measured GFR data in the Chronic Kidney Disease in Children (CKiD) cohort: the full CKiD and bedside CKiD equations. Although adult GFR estimating equations replicate relationships of measured GFR with biomarkers, it is unclear whether similar patterns exist among children and adolescents with chronic kidney disease (CKD). STUDY DESIGN Prospective cohort study in children and adolescents. SETTINGS & PARTICIPANTS 730 participants contributed 1,539 study visits. PREDICTORS Measured GFR by plasma iohexol disappearance (mGFR), estimated GFR by the full CKiD equation (eGFRCKiDfull; based on serum creatinine, cystatin C, serum urea nitrogen, height, and sex), and estimated GFR by the bedside CKiD equation (eGFRCKiDbed; calculated as 41.3 × height [m]/serum creatinine [mg/dL]) were predictors of CKD-related biomarkers. Deviations of mGFR from eGFRCKiDfull and deviations of eGFRCKiDfull from eGFRCKiDbed from linear regressions (ie, residuals) were included in bivariate analyses. OUTCOMES & MEASUREMENTS CKD-related biomarkers included values for urine protein-creatinine ratio, blood hemoglobin, serum phosphate, bicarbonate, potassium, systolic and diastolic blood pressure z scores, and height z scores. RESULTS The median age of 730 participants with CKD was 12.5 years, with median mGFR, eGFRCKiDfull, and eGFRCKiDbed of 51.8, 54.0, and 53.2mL/min/1.73m2, respectively. eGFRCKiDfull demonstrated as strong or stronger associations with CKD-related biomarkers than mGFR; eGFRCKiDbed associations were significantly attenuated (ie, closer to the null). Residual information in mGFR did not substantially increase explained variability. eGFRCKiDbed estimated faster GFR decline relative to mGFR and eGFRCKiDfull. LIMITATIONS Simple linear summaries of biomarkers may not capture nonlinear associations. CONCLUSIONS eGFRCKiDfull closely approximated mGFR to describe relationships with CKD-severity indicators and progression in this pediatric CKD population. eGFRCKiDbed offered similar inferences, but associations were attenuated and rate of progression was overestimated. The eGFRCKiDfull equation from 2012 is preferred for pediatric research purposes.
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Affiliation(s)
- Derek K Ng
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.
| | | | | | - Susan L Furth
- The Children's Hospital of Philadelphia, Philadelphia, PA; Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Alvaro Muñoz
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
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25
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Pottel H. Measuring and estimating glomerular filtration rate in children. Pediatr Nephrol 2017; 32:249-263. [PMID: 27115887 DOI: 10.1007/s00467-016-3373-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 03/08/2016] [Accepted: 03/08/2016] [Indexed: 01/01/2023]
Abstract
Glomerular filtration rate (GFR) is the best index for kidney function in health and disease. Knowledge of the GFR is essential for the detection (diagnosis) and monitoring of renal function during disease progression and for ensuring correct medication doses. Inulin clearance (plasma or urine) is currently considered to be the gold standard for measuring GFR, but in clinical practice the measurement of other exogenous filtration markers from the plasma often replaces that of inulin clearance. Different protocols can be used to determine the area under the plasma disappearance curve, and an understanding of these methods is important. GFR can also be estimated by GFR equations (eGFR), which are most often used in clinical practice because they only require a knowledge of the serum creatinine or cystatin C level and demographic information. eGFR equations are easy to use but they do have their limitations, and it is important to know how these equations were derived and in which circumstances they can be used most accurately. The aim of this review is to explain how GFR can be measured using the renal clearance and the plasma clearance method and which eGFR equations can be applied to children, as well as how and when these equations can be used in clinical practice.
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Affiliation(s)
- Hans Pottel
- Department of Public Health and Primary Care, Campus Kulak Kortrijk, KU Leuven, Etienne Sabbelaan 53, 8500, Kortrijk, Belgium.
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26
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Tøndel C, Bolann B, Salvador CL, Brackman D, Bjerre A, Svarstad E, Brun A. Iohexol plasma clearance in children: validation of multiple formulas and two-point sampling times. Pediatr Nephrol 2017; 32:311-320. [PMID: 27369694 PMCID: PMC5203838 DOI: 10.1007/s00467-016-3436-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 05/02/2016] [Accepted: 05/17/2016] [Indexed: 12/03/2022]
Abstract
BACKGROUND In children, estimated glomerular filtration rate (eGFR) methods are hampered by inaccuracy, hence there is an obvious need for safe, simplified, and accurate measured GFR (mGFR) methods. The aim of this study was to evaluate different formulas and determine the optimal sampling points for calculating mGFR based on iohexol clearance measurements on blood samples drawn at two time points (GFR2p). METHODS The GFR of 96 children with different stages of chronic kidney disease (CKD) (median age 9.2 years, range 3 months to 17.5 years) was determined using the iohexol plasma clearance, with blood sampling at seven time points within 5 h (GFR7p) as the reference method. Median GFR7p was 65.9 (range 6.3-153) mL/min/1.73 m2. The performance of seven different formulas with early and late normalization to body surface area (BSA) was validated against the reference. RESULTS The highest percentage (95.8 %) of GFR2p within 10 % of the reference was calculated using the formula of Jødal and Brøchner-Mortensen (JBM) from 2009, with sampling at 2 and 5 h. Normalization to BSA before correction of the distribution phase improved the performance of the original Brøchner-Mortensen method from 1972; P10 of 92.7 % compared to P10 of 82.3 % with late normalization, and a similar result was obtained with other formulas. CONCLUSIONS GFR2p performed well across a wide spectrum of GFR levels with the JBM formula. Several other formulas tested performed well provided that early BSA normalization was performed. Blood sampling at 2 and 5 h is recommended for an optimal GFR2p assessment.
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Affiliation(s)
- Camilla Tøndel
- Department of Pediatrics, Haukeland University Hospital, N-5021, Bergen, Norway. .,Department of Clinical Medicine, University of Bergen, Bergen, Norway.
| | - Bjørn Bolann
- Department of Clinical Science, University of Bergen, Bergen, Norway ,Laboratory for Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway
| | | | - Damien Brackman
- Department of Pediatrics, Oslo University Hospital, Oslo, Norway
| | - Anna Bjerre
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Einar Svarstad
- Department of Clinical Medicine, University of Bergen, Bergen, Norway ,Department of Medicine, Haukeland University Hospital, Bergen, Norway
| | - Atle Brun
- Department of Clinical Science, University of Bergen, Bergen, Norway ,Laboratory for Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway
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Ruebner RL, Ng D, Mitsnefes M, Foster BJ, Meyers K, Warady B, Furth SL. Cardiovascular Disease Risk Factors and Left Ventricular Hypertrophy in Girls and Boys With CKD. Clin J Am Soc Nephrol 2016; 11:1962-1968. [PMID: 27630183 PMCID: PMC5108185 DOI: 10.2215/cjn.01270216] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 07/22/2016] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND OBJECTIVES Prior studies suggested that women with CKD have higher risk for cardiovascular disease (CVD) and mortality than men, although putative mechanisms for this higher risk have not been identified. We assessed sex differences in (1) CVD risk factors and left ventricular hypertrophy (LVH), and (2) the relationship of left ventricular mass (LVM) with different measures of body size in children with CKD. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS The study population comprised 681 children with CKD from the Chronic Kidney Disease in Children cohort, contributing 1330 visits. CVD risk factors were compared cross-sectionally by sex. LVH was defined as LVM/height2.7 >95th percentile and LVM relative to estimated lean body mass (eLBM) >95th percentile for age and sex. Differences in LVM by sex were assessed by adjusting for age, weight, height, and eLBM using bivariate and multivariate regression models. RESULTS Girls were less likely to have uncontrolled hypertension (26% versus 38%, P=0.001), had lower diastolic BP z-scores (+0.3 versus +0.6, P=0.001), and had lower prevalence of high triglycerides (38% versus 47%, P=0.03) compared with boys. When LVH was defined by LVM indexed to height, girls had higher prevalence of LVH (16% versus 9%, P=0.01); when LVH was defined by LVM relative to eLBM, prevalence of LVH was similar between girls and boys (18% versus 17%, P=0.92). In regression models adjusting for eLBM, no sex differences in LVM were observed. CONCLUSIONS Despite lack of increased prevalence of CVD risk factors, indexing LVM to height showed a higher proportion of LVH among girls, while estimates of LVH based on eLBM showed no sex differences. Indexing LVM to eLBM may be an alternative to height indexing in children with CKD.
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Affiliation(s)
| | - Derek Ng
- Department of Epidemiology, Johns Hopkins University, Baltimore, Maryland
| | - Mark Mitsnefes
- Division of Nephrology, Department of Pediatrics, Cincinnati Children’s Hospital, Cincinnati, Ohio
| | - Bethany J. Foster
- Department of Pediatrics, Montreal Children’s Hospital, Montreal, Quebec, Canada
| | - Kevin Meyers
- Division of Nephrology, Department of Pediatrics, Children’s Hospital of Philadelphia, and
| | - Bradley Warady
- Division of Nephrology, Department of Pediatrics, Children’s Mercy Hospital, Kansas City, Missouri
| | - Susan L. Furth
- Division of Nephrology, Department of Pediatrics, Children’s Hospital of Philadelphia, and
- Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania; and
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Delanaye P, Ebert N, Melsom T, Gaspari F, Mariat C, Cavalier E, Björk J, Christensson A, Nyman U, Porrini E, Remuzzi G, Ruggenenti P, Schaeffner E, Soveri I, Sterner G, Eriksen BO, Bäck SE. Iohexol plasma clearance for measuring glomerular filtration rate in clinical practice and research: a review. Part 1: How to measure glomerular filtration rate with iohexol? Clin Kidney J 2016; 9:682-99. [PMID: 27679715 PMCID: PMC5036902 DOI: 10.1093/ckj/sfw070] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 07/08/2016] [Indexed: 01/31/2023] Open
Abstract
While there is general agreement on the necessity to measure glomerular filtration rate (GFR) in many clinical situations, there is less agreement on the best method to achieve this purpose. As the gold standard method for GFR determination, urinary (or renal) clearance of inulin, fades into the background due to inconvenience and high cost, a diversity of filtration markers and protocols compete to replace it. In this review, we suggest that iohexol, a non-ionic contrast agent, is most suited to replace inulin as the marker of choice for GFR determination. Iohexol comes very close to fulfilling all requirements for an ideal GFR marker in terms of low extra-renal excretion, low protein binding and in being neither secreted nor reabsorbed by the kidney. In addition, iohexol is virtually non-toxic and carries a low cost. As iohexol is stable in plasma, administration and sample analysis can be separated in both space and time, allowing access to GFR determination across different settings. An external proficiency programme operated by Equalis AB, Sweden, exists for iohexol, facilitating interlaboratory comparison of results. Plasma clearance measurement is the protocol of choice as it combines a reliable GFR determination with convenience for the patient. Single-sample protocols dominate, but multiple-sample protocols may be more accurate in specific situations. In low GFRs one or more late samples should be included to improve accuracy. In patients with large oedema or ascites, urinary clearance protocols should be employed. In conclusion, plasma clearance of iohexol may well be the best candidate for a common GFR determination method.
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Affiliation(s)
- Pierre Delanaye
- Department of Nephrology, Dialysis and Transplantation , University of Liège Hospital (ULg CHU) , Liège , Belgium
| | - Natalie Ebert
- Charité University Medicine , Institute of Public Health , Berlin , Germany
| | - Toralf Melsom
- Metabolic and Renal Research Group, UiT The Arctic University of Norway, Tromsø, Norway; Section of Nephrology, University Hospital of North Norway, Tromsø, Norway
| | - Flavio Gaspari
- IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Centro di Ricerche Cliniche per le Malattie Rare 'Aldo e Cele Daccò', Ranica, Bergamo, Italy
| | - Christophe Mariat
- Department of Nephrology, Dialysis, Transplantation and Hypertension , CHU Hôpital Nord, University Jean Monnet, PRES Université de LYON , Saint-Etienne , France
| | - Etienne Cavalier
- Department of Clinical Chemistry , University of Liège Hospital (ULg CHU) , Liège , Belgium
| | - Jonas Björk
- Department of Occupational and Environmental Medicine , Lund University , Lund , Sweden
| | | | - Ulf Nyman
- Department of Translational Medicine, Division of Medical Radiology , Skåne University Hospital , Malmö , Sweden
| | - Esteban Porrini
- University of La Laguna, CIBICAN-ITB, Faculty of Medicine, Hospital Universtario de Canarias, La Laguna, Tenerife , Spain
| | - Giuseppe Remuzzi
- Centro di Ricerche Cliniche per le Malattie Rare 'Aldo e Cele Daccò, Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; Unit of Nephrology, Azienda Socio Sanitaria Territoriale (ASST) Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - Piero Ruggenenti
- Centro di Ricerche Cliniche per le Malattie Rare 'Aldo e Cele Daccò, Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; Unit of Nephrology, Azienda Socio Sanitaria Territoriale (ASST) Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - Elke Schaeffner
- Charité University Medicine , Institute of Public Health , Berlin , Germany
| | - Inga Soveri
- Department of Medical Sciences , Uppsala University , Uppsala , Sweden
| | - Gunnar Sterner
- Department of Nephrology , Skåne University Hospital , Malmö , Sweden
| | - Bjørn Odvar Eriksen
- Metabolic and Renal Research Group, UiT The Arctic University of Norway, Tromsø, Norway; Section of Nephrology, University Hospital of North Norway, Tromsø, Norway
| | - Sten-Erik Bäck
- Department of Clinical Chemistry , Skåne University Hospital , Lund , Sweden
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Ayestaran FW, Schneider MF, Kaskel FJ, Srivaths PR, Seo-Mayer PW, Moxey-Mims M, Furth SL, Warady BA, Greenbaum LA. Perceived appetite and clinical outcomes in children with chronic kidney disease. Pediatr Nephrol 2016; 31:1121-7. [PMID: 26857711 PMCID: PMC5627603 DOI: 10.1007/s00467-016-3321-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 01/11/2016] [Accepted: 01/11/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND Children with chronic kidney disease (CKD) may have impaired caloric intake through a variety of mechanisms, with decreased appetite as a putative contributor. In adult CKD, decreased appetite has been associated with poor clinical outcomes. There is limited information about this relationship in pediatric CKD. METHODS A total of 879 participants of the Chronic Kidney Disease in Children (CKiD) study were studied. Self-reported appetite was assessed annually and categorized as very good, good, fair, or poor/very poor. The relationship between appetite and iohexol or estimated glomerular filtration rate (ieGFR), annual changes in anthropometrics z-scores, hospitalizations, emergency room visits, and quality of life were assessed. RESULTS An ieGFR < 30 ml/min per 1.73 m(2) was associated with a 4.46 greater odds (95 % confidence interval: 2.80, 7.09) of having a worse appetite than those with ieGFR >90. Appetite did not predict changes in height, weight, or BMI z-scores. Patients not reporting a very good appetite had more hospitalizations over the next year than those with a very good appetite. Worse appetite was significantly associated with lower parental and patient reported quality of life. CONCLUSIONS Self-reported appetite in children with CKD worsens with lower ieGFR and is correlated with clinical outcomes, including hospitalizations and quality of life.
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Affiliation(s)
| | | | | | | | | | - Marva Moxey-Mims
- National Institute of Diabetes and Digestive Kidney Disease, National Institutes of Health, Bethesda, MD
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30
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Ebert N, Loesment A, Martus P, Jakob O, Gaedeke J, Kuhlmann M, Bartel J, Schuchardt M, Tölle M, Huang T, van der Giet M, Schaeffner E. Iohexol plasma clearance measurement in older adults with chronic kidney disease-sampling time matters. Nephrol Dial Transplant 2015; 30:1307-14. [PMID: 26044836 DOI: 10.1093/ndt/gfv116] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/25/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Accurate and precise measurement of GFR is important for patients with chronic kidney disease (CKD). Sampling time of exogenous filtration markers may have great impact on measured GFR (mGFR) results, but there is still uncertainty about optimal timing of plasma clearance measurement in patients with advanced CKD, for whom 24-h measurement is recommended. This satellite project of the Berlin Initiative Study evaluates whether 24-h iohexol plasma clearance reveals a clinically relevant difference compared with 5-h measurement in older adults. METHODS In 104 participants with a mean age of 79 years and diagnosed CKD, we performed standard GFR measurement over 5 h (mGFR300) using iohexol plasma concentrations at 120, 180, 240 and 300 min after injection. With an additional sample at 1440 min, we assessed 24-h GFR measurement (mGFR1440). Study design was cross-sectional. Calculation of mGFR was conducted with a one compartment model using the Brochner-Mortensen equation to calculate the fast component. mGFR values were compared with estimated GFR values (MDRD, CKD-EPI, BIS1, Revised Lund-Malmö and Cockcroft-Gault). RESULTS In all 104 subjects, mGFR1440 was lower than mGFR300 (23 ± 8 versus 29 ± 9 mL/min/1.73 m(2), mean ± SD; P < 0.001). mGFR1440 was highly correlated with mGFR300 (r = 0.9). The mean absolute difference mGFR300 - mGFR1440 was 5.9 mL/min/1.73 m(2) corresponding to a mean percentage difference of 29%. In individuals with eGFRCKD-EPI ≤ 30 mL/min/1.73 m(2), percentage difference of mGFR300 and mGFR1440 was even higher (35%). To predict mGFR1440 from mGFR300, we developed the correction formula: mGFR1440 = -2.175 + 0.871 × mGFR300 (1-fold standard error of estimate: ±2.3 mL/min/1.73 m(2)). The GFR estimating equation with the best accuracy and precision compared with mGFR300 and mGFR1440 was the Revised Lund Malmö. CONCLUSIONS In elderly CKD patients, measurement of iohexol clearance up to 5 h leads to a clinically relevant overestimation of GFR compared with 24-h measurement. In clinical care, this effect should be bore in mind especially for patients with considerably reduced GFR levels. A new correction formula has been developed to predict mGFR1440 from mGFR300. For accurate GFR estimates in elderly CKD patients, we recommend the Revised Lund Malmö equation.
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Affiliation(s)
- Natalie Ebert
- Division of Nephrology, Charité University Medicine, Campus Virchow, Berlin, Germany
| | - Amina Loesment
- Division of Nephrology, Charité University Medicine, Campus Virchow, Berlin, Germany
| | - Peter Martus
- Institute of Clinical Epidemiology and Medical Biostatistics, University of Tübingen, Tübingen, Germany
| | - Olga Jakob
- Institute of Biostatistics and Clinical Epidemiology, Charité, Berlin, Germany
| | - Jens Gaedeke
- Division of Nephrology, Charité University Medicine, Campus Mitte, Berlin, Germany
| | - Martin Kuhlmann
- Department of Nephrology, Vivantes Klinikum im Friedrichshain, Berlin, Germany
| | | | - Mirjam Schuchardt
- Division of Nephrology, Charité University Medicine Campus Benjamin Franklin, Berlin, Germany
| | - Markus Tölle
- Division of Nephrology, Charité University Medicine Campus Benjamin Franklin, Berlin, Germany
| | - Tao Huang
- Division of Nephrology, Charité University Medicine Campus Benjamin Franklin, Berlin, Germany
| | - Markus van der Giet
- Division of Nephrology, Charité University Medicine Campus Benjamin Franklin, Berlin, Germany
| | - Elke Schaeffner
- Division of Nephrology, Charité University Medicine, Campus Virchow, Berlin, Germany
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Abraham AG, Darilay A, McKay H, Margolick JB, Estrella MM, Palella FJ, Bolan R, Rinaldo CR, Jacobson LP. Kidney Dysfunction and Markers of Inflammation in the Multicenter AIDS Cohort Study. J Infect Dis 2015; 212:1100-10. [PMID: 25762788 DOI: 10.1093/infdis/jiv159] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 03/02/2015] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Human immunodeficiency virus (HIV)-infected individuals are at higher risk for chronic kidney disease than HIV-uninfected individuals. We investigated whether the inflammation present in treated HIV infection contributes to kidney dysfunction among HIV-infected men receiving highly active antiretroviral therapy. METHODS The glomerular filtration rate (GFR) was directly measured (using iohexol) along with 12 markers of inflammation in Multicenter AIDS Cohort Study participants. Exploratory factor analysis was used to identify inflammatory processes related to kidney dysfunction. The estimated levels of these inflammatory processes were used in adjusted logistic regression analyses evaluating cross-sectional associations with kidney function outcomes. RESULTS There were 434 HIV-infected men receiving highly active antiretroviral therapy and 200 HIV-uninfected men. HIV-infected men were younger (median age, 51 vs 53 years) and had higher urine protein-creatinine ratios (median, 98 vs 66 mg/g) but comparable GFRs (median, 109 vs 106 mL/min|1.73 m(2)). We found an inflammatory process dominated by markers: soluble tumor necrosis factor receptor 2, soluble interleukin 2 receptor α, soluble gp130, soluble CD27, and soluble CD14. An increase of 1 standard deviation in that inflammatory process was associated with significantly greater odds of GFR ≤90 mL/min/1.73 m(2) (odds ratio, 2.0) and urine protein >200 mg/g (odds ratio, 2.3). CONCLUSIONS Higher circulating levels of immune activation markers among treated HIV-infected men may partially explain their higher burden of kidney dysfunction compared with uninfected men.
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Affiliation(s)
| | | | | | - Joseph B Margolick
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health
| | | | - Frank J Palella
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | | | - Charles R Rinaldo
- Department of Infectious Diseases and Microbiology, University of Pittsburgh Graduate School of Public Health, Pennsylvania
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Response to the letter concerning measuring glomerular filtration rate using chromium-51 EDTA. Nucl Med Commun 2015; 36:297-300. [DOI: 10.1097/mnm.0000000000000252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Hingorani S, Pao E, Schoch G, Gooley T, Schwartz GJ. Estimating GFR in adult patients with hematopoietic cell transplant: comparison of estimating equations with an iohexol reference standard. Clin J Am Soc Nephrol 2015; 10:601-10. [PMID: 25717073 DOI: 10.2215/cjn.06470614] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 01/04/2015] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Formal evaluation of kidney function before and after hematopoietic cell transplant is important to determine conditioning regimens, type of transplant, and medication dosing. Serum creatinine and estimating equations may not accurately assess kidney function. DESIGN, STUDY, PARTICIPANTS, & MEASUREMENTS Existing estimating equations for GFR were compared with an iohexol measure of GFR in a prospective cohort study of 50 patients undergoing hematopoietic cell transplant and subsequent care at the Fred Hutchinson Cancer Research Institute from 2009 to 2013. Patients underwent iohexol GFR, serum creatinine, and cystatin C determination at baseline and day 100 posthematopoietic cell transplant. Iohexol GFR measurements were compared with the CKD Epidemiology Collaboration, Inker CKD Epidemiology Collaboration cystatin C with and without serum creatinine, Modification of Diet in Renal Disease, and Cockcroft-Gault estimating equations using Bland-Altman analysis and McNemar's test. The iohexol measurements were also compared with blood samples collected simultaneously on filter paper. RESULTS Mean differences between iohexol GFR and eGFR on the basis of Bland-Altman analyses ranged from -20.6 to +15.4 ml/min per 1.73 m(2) at baseline and -12.7 to +12.9 ml/min per 1.73 m(2) at day 100. The CKD Epidemiology Collaboration and Modification of Diet in Renal Disease estimating equations classified 64% of patients with a GFR<90 at baseline compared with 38% by iohexol GFR (P=0.003 and P<0.01, respectively). No statistically significant differences were seen at day 100. The filter paper GFR had a mean difference of 0 at baseline and 5.9 at day 100. Additionally, 21%-37% and 57%-89% of eGFRs were within 10% and 30%, respectively, of the iohexol GFR at baseline, and 16%-34% and 72%-84% were within 10% and 30%, respectively, of the iohexol GFR at day 100; 98% of the filter paper estimates at baseline were within 30%, and 46% were within 10% of iohexol GFR. CONCLUSIONS The estimating equations are neither accurate nor precise in the hematopoietic cell transplant population, and clinical decision may require measurement of GFR.
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Affiliation(s)
- Sangeeta Hingorani
- Seattle Children's Hospital, University of Washington Seattle, Washington; Division of Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, Washington; and
| | - Emily Pao
- Seattle Children's Hospital, University of Washington Seattle, Washington
| | - Gary Schoch
- Division of Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, Washington; and
| | - Ted Gooley
- Division of Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, Washington; and
| | - George J Schwartz
- Division of Pediatric Nephrology, University of Rochester, Rochester, New York
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Lin KY, Furth SL, Schwartz GJ, Shaddy RE, Ruebner RL. Renal function assessment in child and adolescent heart transplant recipients during routine cardiac catheterization. Pediatr Transplant 2014; 18:757-63. [PMID: 25112413 DOI: 10.1111/petr.12331] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/12/2014] [Indexed: 11/28/2022]
Abstract
CKD identification after pediatric heart transplantation (PHT) is limited by inaccuracies in estimates of GFR. We hypothesized that GFR can be measured by a modified iohexol clearance protocol in PHT recipients and that the CKiD formula provides a better estimate of GFR than other estimating equations. A cross-sectional study of PHT recipients, ages 2-18 yr, undergoing coronary angiography was undertaken. The angiography dose of iohexol was divided by the area under the curve from three iohexol levels post-infusion to calculate GFR. Agreement between iGFR and multiple estimating equations (eGFR) was assessed. In 31 subjects, median age was 15.0 yr (IQR 7.6, 16.6). Mean iGFR was 93.8 (s.d. 22.5) mL/min/1.73 m(2) ; 16 (52%) had an iGFR <90 mL/min/1.73 m(2) . The full CKiD formula (mean eGFR 88.9, s.d. 14.9) had low bias (-5.0), narrowest 95% limits of agreement (-42.0, 32.1), highest 30% (94%) and 10% (52%) accuracy, and highest correlation coefficient (0.576) relative to iGFR. We describe a novel modified iohexol clearance method to assess GFR after PHT. Over half of the cohort had an iGFR <90, suggesting CKD. The full CKiD formula performs best with respect to bias, accuracy, and correlation.
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Affiliation(s)
- Kimberly Y Lin
- Division of Cardiology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
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Margolick JB, Jacobson LP, Schwartz GJ, Abraham AG, Darilay AT, Kingsley LA, Witt MD, Palella FJ. Factors affecting glomerular filtration rate, as measured by iohexol disappearance, in men with or at risk for HIV infection. PLoS One 2014; 9:e86311. [PMID: 24516530 PMCID: PMC3917840 DOI: 10.1371/journal.pone.0086311] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 12/11/2013] [Indexed: 01/09/2023] Open
Abstract
OBJECTIVE Formulae used to estimate glomerular filtration rate (GFR) underestimate higher GFRs and have not been well-studied in HIV-infected (HIV(+)) people; we evaluated the relationships of HIV infection and known or potential risk factors for kidney disease with directly measured GFR and the presence of chronic kidney disease (CKD). DESIGN Cross-sectional measurement of iohexol-based GFR (iGFR) in HIV(+) men (n = 455) receiving antiretroviral therapy, and HIV-uninfected (HIV(-)) men (n = 258) in the Multicenter AIDS Cohort Study. METHODS iGFR was calculated from disappearance of infused iohexol from plasma. Determinants of GFR and the presence of CKD were compared using iGFR and GFR estimated by the CKD-Epi equation (eGFR). RESULTS Median iGFR was higher among HIV(+) than HIV(-) men (109 vs. 106 ml/min/1.73 m(2), respectively, p = .046), and was 7 ml/min higher than median eGFR. Mean iGFR was lower in men who were older, had chronic hepatitis C virus (HCV) infection, or had a history of AIDS. Low iGFR (≤90 ml/min/1.73 m(2)) was associated with these factors and with black race. Other than age, factors associated with low iGFR were not observed with low eGFR. CKD was more common in HIV(+) than HIV(-) men; predictors of CKD were similar using iGFR and eGFR. CONCLUSIONS iGFR was higher than eGFR in this population of HIV-infected and -uninfected men who have sex with men. Presence of CKD was predicted equally well by iGFR and eGFR, but associations of chronic HCV infection and history of clinically-defined AIDS with mildly decreased GFR were seen only with iGFR.
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Affiliation(s)
- Joseph B. Margolick
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Lisa P. Jacobson
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - George J. Schwartz
- Department of Pediatrics, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Alison G. Abraham
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Annie T. Darilay
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Lawrence A. Kingsley
- Department of Infectious Diseases and Microbiology and Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Mallory D. Witt
- Department of Medicine, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
- Los Angeles Biomedical Research Institute at Harbor-UCLA, University of California Los Angeles, Los Angeles, California, United States of America
| | - Frank J. Palella
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
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Ng DK, Jacobson LP, Brown TT, Palella FJ, Martinson JJ, Bolan R, Miller ER, Schwartz GJ, Abraham AG, Estrella MM. HIV therapy, metabolic and cardiovascular health are associated with glomerular hyperfiltration among men with and without HIV infection. AIDS 2014; 28:377-86. [PMID: 24670523 PMCID: PMC3972628 DOI: 10.1097/qad.0000000000000094] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Diabetes and hypertension, common conditions in antiretroviral-treated HIV-infected individuals, are associated with glomerular hyperfiltration, which precedes the onset of proteinuria and accelerated kidney function decline. In the Multicenter AIDS Cohort Study, we examined the extent to which hyperfiltration is present and associated with metabolic, cardiovascular, HIV and treatment risk factors among HIV-infected men. DESIGN Cross-sectional cohort using direct measurement of glomerular filtration rate by iohexol plasma clearance for 367 HIV-infected men and 241 HIV-uninfected men who were free of chronic kidney disease. METHODS Hyperfiltration was defined as glomerular filtration rate above 140-1 ml/min per 1.73 m per year over age 40. Multivariate logistic regression was used to estimate the odds ratios (ORs) of prevalent hyperfiltration for metabolic, cardiovascular, HIV and cumulative antiretroviral exposure factors. RESULTS Among individuals without chronic kidney disease, the prevalence of hyperfiltration was higher for HIV-infected participants (25%) compared to uninfected participants (17%; P = 0.01). After adjustment, HIV infection remained associated with hyperfiltration [OR 1.70, 95% confidence interval (CI) 1.11-2.61] and modified the association between diabetes and hyperfiltration, such that the association among HIV-uninfected men (OR 2.56, 95% CI 1.33-5.54) was not observed among HIV-infected men (OR 1.19, 95% CI 0.69-2.05). These associations were independent of known risk factors for hyperfiltration. Indicators of hyperglycemia and hypertension were also associated with hyperfiltration as was cumulative zidovudine exposure. CONCLUSION Hyperfiltration, a potential modifiable predictor of kidney disease progression, is significantly higher among antiretroviral-treated HIV-infected men. Furthermore, HIV-infection nullifies the association of diabetes and hyperfiltration present in HIV-uninfected men.
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Affiliation(s)
- Derek K Ng
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Lisa P Jacobson
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Todd T Brown
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Frank J Palella
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Jeremy J Martinson
- Graduate School of Public Health, Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robert Bolan
- Los Angeles Gay and Lesbian Center, Los Angeles, CA, USA
| | - Edgar R Miller
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
- Welch Center for Prevention, Epidemiology and Clinical Research, Baltimore, MD, USA
| | - George J Schwartz
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA
| | - Alison G Abraham
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Michelle M Estrella
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
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Delanaye P, Pottel H, Botev R, Inker LA, Levey AS. Con: Should we abandon the use of the MDRD equation in favour of the CKD-EPI equation? Nephrol Dial Transplant 2014; 28:1396-403; discussion 403. [PMID: 23780677 DOI: 10.1093/ndt/gft006] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Pierre Delanaye
- Department of Nephrology-Dialysis-Transplantation, University of Liège, CHU Sart Tilman, Liège, Belgium.
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Improved equations estimating GFR in children with chronic kidney disease using an immunonephelometric determination of cystatin C. Kidney Int 2013; 82:445-53. [PMID: 22622496 PMCID: PMC3433576 DOI: 10.1038/ki.2012.169] [Citation(s) in RCA: 362] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The Chronic Kidney Disease in Children study is a cohort of about 600 children with chronic kidney disease (CKD) in the United States and Canada. The independent variable for our observations was a measurement of glomerular filtration rate (GFR) by iohexol disappearance (iGFR) at the first two visits one year apart and during alternate years thereafter. In a previous report, we had developed GFR estimating equations utilizing serum creatinine, blood urea nitrogen, height, gender and cystatin C measured by an immunoturbidimetric method; however the correlation coefficient of cystatin C and GFR (-0.69) was less robust than expected. Therefore, 495 samples were re-assayed using immunonephelometry. The reciprocal of immunonephelometric cystatin C was as well correlated with iGFR as was height/serum creatinine (both 0.88). We developed a new GFR estimating equation using a random 2/3 of 965 person-visits and applied it to the remaining 1/3 as a validation data set. In the validation data set, the correlation of the estimated GFR with iGFR was 0.92 with high precision and no bias; 91% and 45% of eGFR values were within 30% and 10% of iGFR, respectively. This equation works well in children with CKD in a range of GFR from 15 to 75 ml/min per 1.73 m2. Further studies are needed to establish the applicability to children of normal stature and muscle mass, and higher GFR.
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Wyatt CM, Schwartz GJ, Owino Ong'or W, Abuya J, Abraham AG, Mboku C, M'mene LB, Koima WJ, Hotta M, Maier P, Klotman PE, Wools-Kaloustian K. Estimating kidney function in HIV-infected adults in Kenya: comparison to a direct measure of glomerular filtration rate by iohexol clearance. PLoS One 2013; 8:e69601. [PMID: 23950899 PMCID: PMC3738577 DOI: 10.1371/journal.pone.0069601] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 06/10/2013] [Indexed: 01/02/2023] Open
Abstract
Background More than two-thirds of the world's HIV-positive individuals live in sub-Saharan Africa, where genetic susceptibility to kidney disease is high and resources for kidney disease screening and antiretroviral therapy (ART) toxicity monitoring are limited. Equations to estimate glomerular filtration rate (GFR) from serum creatinine were derived in Western populations and may be less accurate in this population. Methods We compared results from published GFR estimating equations with a direct measure of GFR by iohexol clearance in 99 HIV-infected, ART-naïve Kenyan adults. Iohexol concentration was measured from dried blood spots on filter paper. The bias ratio (mean of the ratio of estimated to measured GFR) and accuracy (percentage of estimates within 30% of the measured GFR) were calculated. Results The median age was 35 years, and 60% were women. The majority had asymptomatic HIV, with median CD4+ cell count of 355 cells/mm3. Median measured GFR was 115 mL/min/1.73 m2. Overall accuracy was highest for the Chronic Kidney Disease Epidemiology Consortium (CKD-EPI) equation. Consistent with a prior report, bias and accuracy were improved by eliminating the coefficient for black race (85% of estimates within 30% of measured GFR). Accuracy of all equations was poor in participants with GFR 60–90 mL/min/1.73 m2 (<65% of estimates within 30% of measured GFR), although this subgroup was too small to reach definitive conclusions. Conclusions Overall accuracy was highest for the CKD-EPI equation. Eliminating the coefficient for race further improved performance. Future studies are needed to determine the most accurate GFR estimate for use in individuals with GFR <90 mL/min/1.73 m2, in whom accurate estimation of kidney function is important to guide drug dosing. Direct measurement of GFR by iohexol clearance using a filter paper based assay is feasible for research purposes in resource-limited settings, and could be used to develop more accurate GFR estimates in African populations.
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Affiliation(s)
- Christina M Wyatt
- Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, New York, New York, United States of America.
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Evans M, van Stralen KJ, Schon S, Prutz KG, Stendahl M, Rippe B, Jager KJ. Glomerular filtration rate-estimating equations for patients with advanced chronic kidney disease. Nephrol Dial Transplant 2013; 28:2518-26. [DOI: 10.1093/ndt/gft226] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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Fuhrman DY, Maier PS, Schwartz GJ. Rapid assessment of renal reserve in young adults by cystatin C. Scandinavian Journal of Clinical and Laboratory Investigation 2013; 73:265-8. [PMID: 23461550 DOI: 10.3109/00365513.2013.765964] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND The kidney can increase glomerular filtration rate (GFR) in response to a protein load (renal reserve). In a pilot study of healthy young adults we examined renal reserve using changes in serum cystatin C (cysC). METHODS Glomerular filtration rate was obtained using iohexol single slope plasma disappearance. To stimulate GFR, subjects ingested a beefburger containing 60 grams of protein. CysC was measured by immunonephelometry before and 125-141 minutes after protein loading. RESULTS All subjects were found to have a normal iohexol plasma disappearance GFR with a mean of 104.6 ± 9.9 mL/min per 1.73 m(2). CysC decreased in each subject after the meat meal. Baseline cysC-based estimated GFR was 98.1 ± 9.1 mL/min per 1.73 m(2) with a mean increase of 12.0 ± 5.2 (p = 0.0003). CONCLUSIONS Our study showed a consistent decrease in serum cysC and increase in cysC-based estimated GFR following a protein load in young adults. Further studies are needed using renal clearance methods to confirm that cysC accurately determines renal reserve in patients with and without chronic kidney disease.
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Affiliation(s)
- Dana Y Fuhrman
- a Pediatric Nephrology, University of Rochester Medical Center , Rochester, NY USA
| | - Paula S Maier
- a Pediatric Nephrology, University of Rochester Medical Center , Rochester, NY USA
| | - George J Schwartz
- a Pediatric Nephrology, University of Rochester Medical Center , Rochester, NY USA
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Van Pottelbergh G, Hoste L, Degryse J, Pottel H, Claes K, Demoulin N, Jadoul M, Bammens B, Wallemacq P. Measuring the glomerular filtration rate in different age groups using iohexol, the protocol from the Belgian iohexol study. Clin Biochem 2012; 46:31-6. [PMID: 23099194 DOI: 10.1016/j.clinbiochem.2012.10.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 10/12/2012] [Accepted: 10/15/2012] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Measuring the exact glomerular filtration rate (GFR) is difficult. Iohexol can be used instead of inulin or labeled EDTA or DTPA. In recent years, different studies have validated GFR-estimating equations in adults. Validation of these estimations in adolescents and elderly is lacking. With this study, we aim to develop a simplified (only 1-3 blood collections) iohexol protocol to measure the true GFR for patients of all ages and try to develop GFR-estimating equations for adolescents and the elderly. DESIGN AND SETTING Participants of different ages will be recruited: 50 adolescent (14-18 years) and 30 adults (20-65 years), 60 elderly (65-80 years) and 60 very elderly (80+ years old) stratified based on their GFR. Biometric data, serum creatinine and cystatin C will be measured. After injecting 5 mL iohexol, 9 blood samples will be taken between 20 and 360 min. First, the GFR will be calculated by using the double exponential decay method and different GFRs based on 1-3 blood samples, which will be compared with the GFR of the abovementioned 9 samples. Second, the GFR will be calculated by using new and existing equations and compared to the true GFR. DISCUSSION The availability of a reliable GFR measurement is important in situations such as screening patients for kidney donation or when taking potentially nephrotoxic treatments. This study will allow us to develop a simplified protocol for measuring the true GFR in all ages and will allow us to validate existing equations and develop new eGFR equations for adolescents and the elderly.
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Affiliation(s)
- G Van Pottelbergh
- Department of General Practice, KULeuven, Leuven, Belgium; IRSS, UCLouvain, Brussels, Belgium.
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Wong CJ, Moxey-Mims M, Jerry-Fluker J, Warady BA, Furth SL. CKiD (CKD in children) prospective cohort study: a review of current findings. Am J Kidney Dis 2012; 60:1002-11. [PMID: 23022429 DOI: 10.1053/j.ajkd.2012.07.018] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 07/02/2012] [Indexed: 11/11/2022]
Abstract
Chronic kidney disease (CKD) is a life-long condition associated with substantial morbidity and premature death due to complications from a progressive decrease in kidney function. The incidence and prevalence of all stages of CKD in children continues to increase worldwide. Between 2000 and 2008, the kidney replacement therapy incidence rate in those aged 0-19 years increased 5.9% to 15 per million population, highlighting the importance of CKD research in children. Many comorbid conditions seen in adults with CKD, including cardiovascular disease and cognitive impairment, also are highly prevalent in children, implicitly demonstrating the crucial need for initiating therapy early to improve health outcomes in children with CKD. The CKiD (Chronic Kidney Disease in Children) Study is a prospective cohort study of 586 children aged 1-16 years with an estimated glomerular filtration rate of 30-90 mL/min/1.73 m(2). Since its inception, CKiD has identified risk factors for CKD progression and cardiovascular disease in children with CKD and highlighted the effects of CKD on outcomes unique to children, including neurocognitive development and growth. This review summarizes the findings to date, illustrating the spectrum of CKD-associated complications in children and emphasizing areas requiring further investigation. Taken in sum, these elements stress that initiating treatment at an early age is essential for reducing long-term morbidity and mortality in children with CKD.
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Affiliation(s)
- Cynthia J Wong
- Department of Pediatrics, Division of Nephrology, Lucile Packard Children's Hospital, Palo Alto, CA, USA.
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Copelovitch L, Warady BA, Furth SL. Insights from the Chronic Kidney Disease in Children (CKiD) study. Clin J Am Soc Nephrol 2011; 6:2047-53. [PMID: 21784815 PMCID: PMC4898858 DOI: 10.2215/cjn.10751210] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Over the last 5 years, the Chronic Kidney Disease in Children (CKiD) prospective cohort study has enrolled close to 600 children ages 1 to 16 years with mild to moderate chronic kidney disease (CKD). The main purpose of this interim report is to review the initial cross-sectional data and conclusions derived from the clinical studies conducted within CKiD in the context of findings from other pediatric CKD and end-stage renal disease (ESRD) registry and cohort studies. In particular, special emphasis was placed on studying four aspects of chronic kidney disease in children, including the identification of risk factors related to disease progression, the impact of CKD on neurocognition and quality of life (QoL), the cardiovascular morbidity associated with CKD, and identifying the causes and effects of growth failure in the context of mild to moderate kidney failure.
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