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Clinical Journal of the American... Jun 2010We compared the estimations of Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations... (Comparative Study)
Comparative Study
BACKGROUND AND OBJECTIVES
We compared the estimations of Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations to a gold standard GFR measurement using (125)I-iothalamate, within strata of GFR, gender, age, body weight, and body mass index (BMI).
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS
For people who previously underwent a GFR measurement, bias, precision, and accuracies between measured and estimated kidney functions were calculated within strata of the variables. The relation between the absolute bias and the variables was tested with linear regression analysis.
RESULTS
Overall (n = 271, 44% male, mean measured GFR 72.6 ml/min per 1.73 m(2) [SD 30.4 ml/min per 1.73 m(2)]), mean bias was smallest for MDRD (P < 0.01). CKD-EPI had highest accuracy (P < 0.01 compared with Cockcroft-Gault), which did not differ from MDRD (P = 0.14). The absolute bias of all formulas was related to age. For MDRD and CKD-EPI, absolute bias was also related to the GFR; for Cockcroft-Gault, it was related to body weight and BMI as well. In all extreme subgroups, MDRD and CKD-EPI provided highest accuracies.
CONCLUSIONS
The absolute bias of all formulas is influenced by age; CKD-EPI and MDRD are also influenced by GFR. Cockcroft-Gault is additionally influenced by body weight and BMI. In general, CKD-EPI gives the best estimation of GFR, although its accuracy is close to that of the MDRD.
Topics: Adult; Age Factors; Bias; Biomarkers; Body Mass Index; Body Weight; Chronic Disease; Creatinine; Cross-Sectional Studies; Female; Glomerular Filtration Rate; Humans; Iodine Radioisotopes; Iothalamic Acid; Kidney; Kidney Diseases; Linear Models; Male; Middle Aged; Models, Biological; Netherlands; Predictive Value of Tests; Reproducibility of Results; Severity of Illness Index; Sex Factors
PubMed: 20299365
DOI: 10.2215/CJN.06870909 -
Clinical Journal of the American... Jul 2018Black Americans with and without kidney disease risk variants face high risk of ESKD. Soluble urokinase-type plasminogen activator receptor (suPAR), a circulating...
BACKGROUND AND OBJECTIVES
Black Americans with and without kidney disease risk variants face high risk of ESKD. Soluble urokinase-type plasminogen activator receptor (suPAR), a circulating signaling protein and marker of immune activation, constitutes a promising biomarker of CKD-associated risks. We aimed to quantify the associations between serum suPAR concentration and adverse outcomes in Black Americans with and without kidney disease risk variants, over and above iodine-125 iothalamate measured GFR and proteinuria.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS
Using data from the African-American Study of Kidney Disease and Hypertension, a multicenter clinical trial followed by a cohort phase with a median total follow-up of 9.7 years (interquartile range, 6.5-10.9 years), we examined the associations of suPAR with CKD progression (defined as doubling of serum creatinine or ESKD), ESKD, worsening proteinuria (defined as pre-ESKD doubling of 24-hour urine protein-to-creatinine ratio to ≥220 mg/g), and all-cause death.
RESULTS
At baseline, the median suPAR was 4462 pg/ml, mean measured GFR was 46 ml/min per 1.73 m, and median 24-hour urine protein-to-creatinine ratio was 80 mg/g. After controlling for baseline demographics, randomization arm, GFR, proteinuria, risk status, and clinical risk factors, there was a 1.26-times higher risk for CKD progression per SD higher baseline log-transformed suPAR (hazard ratio [HR], 1.26; 95% confidence interval [95% CI], 1.11 to 1.43; <0.001). Higher suPAR was also independently associated with risk of ESKD (HR, 1.36; 95% CI, 1.17 to 1.58; <0.001) and death (HR, 1.25; 95% CI, 1.08 to 1.45; =0.003). suPAR was only associated with worsening proteinuria in patients with two risk alleles (HR, 1.46; 95% CI, 1.08 to 1.99; =0.02).
CONCLUSIONS
Higher suPAR was associated with various adverse outcomes in Black Americans with CKD, with and without kidney disease risk variants, independently of proteinuria and GFR.
Topics: Black or African American; Apolipoprotein L1; Female; Humans; Male; Middle Aged; Prospective Studies; Receptors, Urokinase Plasminogen Activator; Renal Insufficiency, Chronic
PubMed: 29903900
DOI: 10.2215/CJN.13631217 -
BMC Nephrology Mar 2020Prior papers have been inconsistent regarding how much creatinine clearance (CrCl) overestimates glomerular filtration rate (GFR). A recent cross-sectional study... (Observational Study)
Observational Study
BACKGROUND
Prior papers have been inconsistent regarding how much creatinine clearance (CrCl) overestimates glomerular filtration rate (GFR). A recent cross-sectional study suggested that measurement error alone could entirely account for the longstanding observation that CrCl/GFR ratio is larger when GFR is lower among patients with chronic kidney disease (CKD); but there have been no validation of this in other cohorts.
METHODS
To fill these gaps in knowledge regarding the relation between CrCl and GFR, we conducted cross-sectional and longitudinal analysis of the Modification of Diet in Renal Disease study (MDRD) and African American Study of Kidney Disease and Hypertension (AASK); and cross-sectional analysis of a clinical dataset from the Mayo Clinic of four different patient populations (CKD patients, kidney transplant recipients, post kidney donation subgroup and potential kidney donors). In the cross-sectional analyses (MDRD, AASK and Mayo Clinic cohort), we examined the relation between the CrCl/iothalamate GFR (iGFR) ratio at different categories of iGFR or different levels of CrCl. In the MDRD and AASK longitudinal analyses, we studied how the CrCl/iGFR ratio changed with those who had improvement in iGFR (CrCl) over time versus those who had worsening of iGFR (CrCl) over time.
RESULTS
Observed CrCl/iGFR ratios were generally on the lower end of the range reported in the literature for CKD (median 1.24 in MDRD, 1.13 in AASK and 1.25 in Mayo Clinic cohort). Among CKD patients in whom CrCl and iGFR were measured using different timed urine collections, CrCl/iGFR ratio were higher with lower iGFR categories but lower with lower CrCl categories. However, among CKD patients in whom CrCl and iGFR were measured using the same timed urine collections (which reduces dis-concordant measurement error), CrCl/iGFR ratio were higher with both lower iGFR categories and lower CrCl categories.
CONCLUSIONS
These data refute the recent suggestion that measurement error alone could entirely account for the longstanding observation that CrCl/GFR ratio increases as GFR decreases in CKD patients. They also highlight the lack of certainty in our knowledge with regard to how much CrCl actually overestimates GFR.
Topics: Bias; Contrast Media; Creatinine; Cross-Sectional Studies; Female; Glomerular Filtration Rate; Humans; Iothalamic Acid; Kidney Function Tests; Kidney Tubules; Male; Metabolic Clearance Rate; Middle Aged; Renal Elimination; Renal Insufficiency, Chronic; Statistics as Topic
PubMed: 32228497
DOI: 10.1186/s12882-020-01736-6 -
American Journal of Kidney Diseases :... May 2021Glomerular filtration rate (GFR) estimation based on creatinine and cystatin C (eGFR) is more accurate than estimated GFR (eGFR) based on creatinine or cystatin C alone...
RATIONALE AND OBJECTIVE
Glomerular filtration rate (GFR) estimation based on creatinine and cystatin C (eGFR) is more accurate than estimated GFR (eGFR) based on creatinine or cystatin C alone (eGFR or eGFR, respectively), but the inclusion of creatinine in eGFR requires specification of a person's race. β-Microglobulin (B2M) and β-trace protein (BTP) are alternative filtration markers that appear to be less influenced by race than creatinine is.
STUDY DESIGN
Study of diagnostic test accuracy.
SETTING AND PARTICIPANTS
Development in a pooled population of 7 studies with 5,017 participants with and without chronic kidney disease. External validation in a pooled population of 7 other studies with 2,245 participants.
TESTS COMPARED
Panel eGFR using B2M and BTP in addition to cystatin C (3-marker panel) or creatinine and cystatin C (4-marker panel) with and without age and sex or race.
OUTCOMES
GFR measured as the urinary clearance of iothalamate, plasma clearance of iohexol, or plasma clearance of [Cr]EDTA.
RESULTS
Mean measured GFRs were 58.1 and 83.2 mL/min/1.73 m, and the proportions of Black participants were 38.6% and 24.0%, in the development and validation populations, respectively. In development, addition of age and sex improved the performance of all equations compared with equations without age and sex, but addition of race did not further improve the performance. In validation, the 4-marker panels were more accurate than the 3-marker panels (P < 0.001). The 3-marker panel without race was more accurate than eGFR (percentage of estimates greater than 30% different from measured GFR [1 - P] of 15.6% vs 17.4%; P = 0.01), and the 4-marker panel without race was as accurate as eGFR (1 - P of 8.6% vs 9.4%; P = 0.2). Results were generally consistent across subgroups.
LIMITATIONS
No representation of participants with severe comorbid illness and from geographic areas outside of North America and Europe.
CONCLUSIONS
The 4-marker panel eGFR is as accurate as eGFR without requiring specification of race. A more accurate race-free eGFR could be an important advance.
Topics: Adolescent; Adult; Black or African American; Aged; Aged, 80 and over; Black People; Case-Control Studies; Chromium Radioisotopes; Creatinine; Cystatin C; Edetic Acid; Female; Glomerular Filtration Rate; Humans; Intramolecular Oxidoreductases; Iohexol; Iothalamic Acid; Lipocalins; Male; Middle Aged; Renal Insufficiency, Chronic; Reproducibility of Results; Severity of Illness Index; White People; Young Adult; beta 2-Microglobulin
PubMed: 33301877
DOI: 10.1053/j.ajkd.2020.11.005 -
AJNR. American Journal of Neuroradiology 1983Iopromide (Schering, Berlin) is a new nonionic, monomeric contrast medium containing three different substituents on the triiodinated benzene ring. Iopromide exhibits... (Comparative Study)
Comparative Study
Iopromide (Schering, Berlin) is a new nonionic, monomeric contrast medium containing three different substituents on the triiodinated benzene ring. Iopromide exhibits low osmolality and viscosity in aqueous solutions of high concentrations. It has been shown to have a remarkably low intravenous toxicity in mice and rats. Neural tolerance was found to be equal to or better than that of metrizamide when injected in rats intracisternally and intracerebrally, respectively. The effects of iopromide after selective peripheral and cerebral arterial injections in rats were demonstrated to be very moderate at high dosages. The interaction of iopromide with proteins and membranes was found to be considerably low due to its hydrophilicity. Excretion of iopromide is fast and predominantly by the renal route. On the basis of the preclinical profile iopromide is a very promising contrast agent, being most suitable for all angiographic indications, including digital subtraction angiography, urography, and computed tomography.
Topics: Animals; Blood Proteins; Brain; Contrast Media; Drug Tolerance; Erythrocytes; Hemolysis; Humans; Iodobenzoates; Iohexol; Iopamidol; Iothalamic Acid; Male; Metrizamide; Mice; Rats; Rats, Inbred Strains; Triiodobenzoic Acids
PubMed: 6410742
DOI: No ID Found -
Kidney International Jul 2012Increased acid excretion may promote renal injury. To evaluate this in African Americans with hypertensive nephrosclerosis, we studied the association between the net... (Randomized Controlled Trial)
Randomized Controlled Trial
Increased acid excretion may promote renal injury. To evaluate this in African Americans with hypertensive nephrosclerosis, we studied the association between the net endogenous acid production and progression of kidney disease in 632 patients in the AASK trial. Protein and potassium intakes were estimated from 24 h urea nitrogen and potassium excretion, and used to estimate net endogenous acid production, averaged over 2 years, approximating routine intake. The link between net endogenous acid production and the I(125)iothalamate glomerular filtration rate (iGFR) and time to end-stage renal disease or doubling of serum creatinine was analyzed using mixed models and Cox proportional hazards regressions. The trend in higher net endogenous acid production was significantly associated with a faster decline in iGFR over a median of 3.2 years. After adjustment for age, body mass index, baseline iGFR, urine protein-to-creatinine ratio, and randomized treatment group, the trend in higher net endogenous acid production remained significantly associated with a faster decline in iGFR at a rate of 1.01 ml/min per 1.73 m(2) per year faster in the highest compared to the lowest quartile. However, in time-to-event analyses over a median of 7.7 years, the adjusted hazard ratio (1.10) for composite renal events per 25 mEq/day higher net endogenous acid production was not significant. Hence, our findings implicate endogenous acid production as a potential modifiable risk factor for progressive kidney disease.
Topics: Acid-Base Equilibrium; Adult; Black or African American; Aged; Biomarkers; Blood Urea Nitrogen; Chi-Square Distribution; Creatinine; Dietary Proteins; Disease Progression; Glomerular Filtration Rate; Humans; Hypertension; Iothalamic Acid; Kidney; Kidney Failure, Chronic; Middle Aged; Nephrosclerosis; Potassium; Proportional Hazards Models; Proteinuria; Radiopharmaceuticals; Risk Assessment; Risk Factors; Time Factors; United States; Young Adult
PubMed: 22475819
DOI: 10.1038/ki.2012.82 -
Blood Advances Jul 2022The reduced-intensity conditioning regimen, fludarabine and melphalan, is frequently used in allogeneic hematopoietic stem cell transplantation (HSCT). Melphalan and the...
The reduced-intensity conditioning regimen, fludarabine and melphalan, is frequently used in allogeneic hematopoietic stem cell transplantation (HSCT). Melphalan and the active metabolite of fludarabine, F-ara-A, are excreted via the kidneys. Existing methods to assess clearance in this setting are based on serum creatinine, which has known limitations for glomerular filtration rate (GFR) estimation in patients with malignancy. Measured GFR (mGFR) may better predict drug dosing to mitigate toxicity and increase the chances of successful engraftment. The primary objective of this study was to assess the association between mGFR and risk for nonrelapse mortality (NRM) in patients who have undergone allogeneic HSCT receiving conditioning with fludarabine and melphalan. In the 109 included patients, mGFR <65 mL/min/1.73 m2 predicted a significantly higher rate of overall NRM (hazard ratio [HR], 2.13; 95% confidence interval [CI], 1.03-4.35; P = 04) and 1-year incidence of infection (HR, 2.63; 95% CI, 1.54-4.55; P < .001) in addition to a significantly lower 2-year survival (P = .019). Kidney function estimated via estimated GFR (eGFR) and estimated creatinine clearance did not correlate with posttransplant outcomes. These results suggest that mGFR is a promising approach for assessing clearance in patients who have undergone allogeneic HSCT and may be preferred to standard creatinine-based eGFR strategies.
Topics: Creatinine; Graft vs Host Disease; Humans; Iothalamic Acid; Melphalan; Retrospective Studies; Vidarabine
PubMed: 35522968
DOI: 10.1182/bloodadvances.2021006395 -
AJNR. American Journal of Neuroradiology 1983Iohexol is a new, nonionic water-soluble contrast agent undergoing early clinical trials in the United States. Using a double-blind, parallel format, iohexol was... (Clinical Trial)
Clinical Trial
Iohexol is a new, nonionic water-soluble contrast agent undergoing early clinical trials in the United States. Using a double-blind, parallel format, iohexol was compared with meglumine iothalamate (60 patients) for selective cerebral angiography, and with sodium meglumine diatrizoate (40 patients) for arch aortography. Iohexol produced significantly less pain than meglumine iothalamate or sodium meglumine diatrizoate. There were no significant differences in terms of heart rate, blood pressure, or electrocardiogram (ECG) changes. Both produced a transient tachycardia and hypotension after arch aortography, but significantly less so with iohexol. No significant complications occurred. Film quality was comparable between contrast agents except for diminished motion artifacts with iohexol. Iohexol appears to be a superior neuroangiographic contrast agent to current ionic drugs.
Topics: Adult; Aortography; Cerebral Angiography; Contrast Media; Diatrizoate Meglumine; Humans; Iodobenzoates; Iohexol; Iothalamate Meglumine; Triiodobenzoic Acids
PubMed: 6410740
DOI: No ID Found -
Chemistry Central Journal 2016Glomerular filtration rate (GFR) is usually determined by estimation of iothalamate (IOT) clearance. We have developed and validated an accurate and robust method for...
Glomerular filtration rate (GFR) is usually determined by estimation of iothalamate (IOT) clearance. We have developed and validated an accurate and robust method for the analysis of IOT in human plasma and urine. The mobile phase consisted of methanol and 50 mM sodium phosphate (10:90; v/v). Flow rate was 1.2 mL/min on a C18 reverse phase column, Synergi-hydro (250 × 4.6 mm) 4 µm 80 Å, with an ultraviolet detector set to 254 nm. Acetonitrile was used for the deproteination and extraction of IOT from human plasma and urine. Precision and accuracy were within 15% for IOT in both plasma and urine. The recoveries of IOT in urine and plasma ranged between 93.14% and 114.74 and 96.04-118.38%, respectively. The linear range for urine and plasma assays were 25-1500 and 1-150 µg/mL respectively. The lower limits of detection were 0.5 µg/mL for both urine and plasma, with no interference from plasma and urine matices. This method has been fully validated according to FDA guidelines and the new HPLC assay has been applied to a new formulation of IOT (Conray™ 43), to calculate GFR in healthy volunteers. The new method is simple, less expensive and it would be instrumental in future clinical and pharmacokinetic studies of iothalamate in kidney patients.
PubMed: 28028385
DOI: 10.1186/s13065-016-0227-3 -
AJNR. American Journal of Neuroradiology 1983Two hundred patients who underwent myelography with iopamidol were independently assessed as to film quality and adverse side effects. Comparison was made with a... (Comparative Study)
Comparative Study
Two hundred patients who underwent myelography with iopamidol were independently assessed as to film quality and adverse side effects. Comparison was made with a similarly assessed group of 1,000 patients who underwent myelography with metrizamide. Diagnostic quality was generally excellent with both contrast media. The incidence of side effects, notably vomiting and headache, was significantly less with iopamidol but remains appreciable. More severe side effects may occasionally occur with either contrast medium.
Topics: Contrast Media; Humans; Iopamidol; Iothalamic Acid; Metrizamide; Myelography
PubMed: 6410871
DOI: No ID Found