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Stamellou E, Nadal J, Hendry B, Mercer A, Seikrit C, Bechtel-Walz W, Schmid M, Moeller MJ, Schiffer M, Eckardt KU, Kramann R, Floege J. Long-term outcomes of patients with IgA nephropathy in the German CKD cohort. Clin Kidney J 2024; 17:sfae230. [PMID: 39149090 PMCID: PMC11324945 DOI: 10.1093/ckj/sfae230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Indexed: 08/17/2024] Open
Abstract
Background The importance of albuminuria as opposed to proteinuria in predicting kidney outcomes in primary immunoglobulin A nephropathy (IgAN) is not well established. Methods From 2010 to 2012, 421 patients with biopsy-proven IgAN have been enrolled into the German Chronic Kidney Disease (GCKD) cohort, a prospective observational cohort study (N = 5217). Adjudicated endpoints include a composite kidney endpoint (CKE) consisting of eGFR decline >40%, eGFR <15 ml/min/1.73 m2 and initiation of kidney replacement therapy; the individual components of the CKE; and combined major adverse cardiac events (MACE), including non-fatal myocardial infarction, non-fatal stroke and all-cause mortality. The associations between the incidence of CKE and baseline factors, including demographics, laboratory values and comorbidities were analysed using the Cox proportional hazards regression model. Results The mean age of IgAN patients at baseline was 51.6 years (± 13.6) and 67% were male. The patient-reported duration of disease at baseline was 5.9 ± 8.1 years. Baseline median urine albumin:creatinine ratio (UACR) was 0.4 g/g [interquartile range (IQR) 0.1-0.8] and mean eGFR was 52.5 ± 22.4 ml/min/1.73 m2. Over a follow-up of 6.5 years, 64 (15.2%) patients experienced a >40% eGFR decline, 3 (0.7%) reached eGFR <15 ml/min/1.73 m2, 53 (12.6%) initiated kidney replacement therapy and 28% of the patients experienced the CKE. Albuminuria, with reference to <0.1 g/g, was most associated with CKE. Hazard ratios (HRs) at UACRs of 0.1-0.6 g/g, 0.6-1.4 g/g, 1.4-2.2 g/g and >2.2 g/g were 2.03 [95% confidence interval (CI) 1.02-4.05], 3.8 (95% CI 1.92-7.5), 5.64 (95% CI 2.58-12.33) and 5.02 (95% CI 2.29-11-03), respectively. Regarding MACE, the presence of diabetes [HR 2.53 (95% CI 1.11-5.78)] was the most strongly associated factor, whereas UACR and eGFR did not show significant associations. Conclusion In the GCKD IgAN subcohort, more than every fourth patient experienced a CKE event within 6.5 years. Our findings support the use of albuminuria as a surrogate to assess the risk of poor kidney outcomes.
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Affiliation(s)
- Eleni Stamellou
- Division of Nephrology and Clinical Immunology, RWTH Aachen University Hospital, Aachen, Germany
- Department of Nephrology, School of Medicine, University of Ioannina, Ioannina, Greece
| | - Jennifer Nadal
- Department of Medical Biometry, Informatics and Epidemiology, Faculty of Medicine, University Hospital Bonn, Bonn, Germany
| | | | | | - Claudia Seikrit
- Division of Nephrology and Clinical Immunology, RWTH Aachen University Hospital, Aachen, Germany
| | - Wibke Bechtel-Walz
- Department of Medicine IV, University Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Berta-Ottenstein Program, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Matthias Schmid
- Department of Medical Biometry, Informatics and Epidemiology, Faculty of Medicine, University Hospital Bonn, Bonn, Germany
| | - Marcus J Moeller
- Division of Nephrology and Clinical Immunology, RWTH Aachen University Hospital, Aachen, Germany
| | - Mario Schiffer
- Department of Nephrology and Hypertension, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Kai-Uwe Eckardt
- Department of Nephrology and Hypertension, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Department of Nephrology and Medical Intensive Care, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Rafael Kramann
- Division of Nephrology and Clinical Immunology, RWTH Aachen University Hospital, Aachen, Germany
| | - Jürgen Floege
- Division of Nephrology and Clinical Immunology, RWTH Aachen University Hospital, Aachen, Germany
- Department of Cardiology, RWTH Aachen University Hospital, Aachen, Germany
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2
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Stevens PE, Ahmed SB, Carrero JJ, Foster B, Francis A, Hall RK, Herrington WG, Hill G, Inker LA, Kazancıoğlu R, Lamb E, Lin P, Madero M, McIntyre N, Morrow K, Roberts G, Sabanayagam D, Schaeffner E, Shlipak M, Shroff R, Tangri N, Thanachayanont T, Ulasi I, Wong G, Yang CW, Zhang L, Levin A. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int 2024; 105:S117-S314. [PMID: 38490803 DOI: 10.1016/j.kint.2023.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 03/17/2024]
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3
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Kim H, Hyun YY, Joo YS, Yun HR, Kim Y, Jung JY, Jeong JC, Kim J, Park JT, Yoo TH, Kang SW, Oh KH, Han SH. Proteinuria, measured or estimated albuminuria for risk prediction in patients with chronic kidney disease? Nephrol Dial Transplant 2024; 39:473-482. [PMID: 37723608 PMCID: PMC11024809 DOI: 10.1093/ndt/gfad195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Indexed: 09/20/2023] Open
Abstract
BACKGROUND Although albuminuria is the gold standard for defining chronic kidney disease (CKD), total proteinuria has also been widely used in real-world clinical practice. Moreover, the superiority of the prognostic performance of albuminuria over proteinuria in patients with CKD remains inconclusive. Therefore, we aimed to compare the predictive performances of albuminuria and proteinuria in these patients. METHODS From the Korean Cohort Study for Outcome in Patients with CKD we included 2099 patients diagnosed with CKD grades 1-5 who did not require kidney replacement therapy. We measured the spot urine albumin:creatinine ratio (mACR) and protein:creatinine ratio (PCR) and estimated the ACR (eACR) using the PCR. Kidney failure risk equation (KFRE) scores were calculated using the mACR, PCR and eACR. The primary outcome was the 5-year risk of kidney failure with replacement therapy (KFRT). RESULTS The eACR significantly underestimated mACR in patients with low albuminuria levels. The time-dependent area under the receiver operating characteristics curve showed excellent predictive performance for all KFRE scores from the mACR, PCR and eACR. However, eACR was inferior to mACR based on the continuous net reclassification index (cNRI) and integrated discrimination improvement index (IDI) in all CKD cause groups, except for the group with an unclassified aetiology. Moreover, the cNRI and IDI statistics indicated that both eACR and PCR were inferior to mACR in patients with low albuminuria (<30 mg/g). Conversely, the predictive performance of PCR was superior in severe albuminuria and nephrotic-range proteinuria, in which the IDI and cNRI of the PCR were greater than those of the mACR. CONCLUSIONS The mACR, eACR and PCR showed excellent performance in predicting KFRT in patients with CKD. However, eACR was inferior to mACR in patients with low albuminuria, indicating that measuring rather than estimating albuminuria is preferred for these patients.
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Affiliation(s)
- Hyoungnae Kim
- Division of Nephrology, Soonchunhyang University Seoul Hospital, Seoul, Korea
| | - Young Youl Hyun
- Department of Internal Medicine, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea
| | - Young Su Joo
- Department of Internal Medicine, Yonsei University, Institute of Kidney Disease Research, College of Medicine, Seoul, Korea
| | - Hae-Ryong Yun
- Department of Internal Medicine, Yonsei University, Institute of Kidney Disease Research, College of Medicine, Seoul, Korea
| | - Yaeni Kim
- Division of Nephrology, Department of Internal Medicine, Seoul St. Mary's Hospital, Seoul, Korea
| | - Ji Yong Jung
- Division of Nephrology, Department of Internal Medicine, Gil Medical Center, Gachon University, Incheon, Korea
| | - Jong Cheol Jeong
- Division of Nephrology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Jayoun Kim
- Medical Research Collaborating Center, Seoul National University Hospital, Seoul, Korea
| | - Jung Tak Park
- Department of Internal Medicine, Yonsei University, Institute of Kidney Disease Research, College of Medicine, Seoul, Korea
| | - Tae-Hyun Yoo
- Department of Internal Medicine, Yonsei University, Institute of Kidney Disease Research, College of Medicine, Seoul, Korea
| | - Shin-Wook Kang
- Department of Internal Medicine, Yonsei University, Institute of Kidney Disease Research, College of Medicine, Seoul, Korea
| | - Kook-Hwan Oh
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Seung Hyeok Han
- Department of Internal Medicine, Yonsei University, Institute of Kidney Disease Research, College of Medicine, Seoul, Korea
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Hammad FT, Lubbad L, Al-Salam S, Hammad WF, Yasin J, Meeran MFN, Ojha S, Arunachalam S, Hammad AF. Does Hypertension Affect the Recovery of Renal Functions after Reversal of Unilateral Ureteric Obstruction? Int J Mol Sci 2024; 25:1540. [PMID: 38338817 PMCID: PMC10855500 DOI: 10.3390/ijms25031540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/15/2024] [Accepted: 01/19/2024] [Indexed: 02/12/2024] Open
Abstract
Research has demonstrated that hypertension can lead to an exaggeration in the renal functional and histological changes caused by ureteral obstruction. These changes were particularly observed shortly after the release of a relatively brief period of unilateral ureteral obstruction (UUO). However, the long-term impact of hypertension on the recovery of renal functions has not been investigated beyond the immediate period after UUO reversal. In order to investigate this effect, a group of spontaneously hypertensive rats (G-SHR, n = 11) and a group of normotensive Wistar Kyoto rats (G-NTR, n = 11) were subjected to a 48 h reversible left UUO. The impact of UUO was then examined 45 days after the reversal of obstruction. The glomerular filtration rate, renal blood flow, and the fractional excretion of sodium in the post-obstructed left kidney (POK) showed similarities to the non-obstructed right kidney (NOK) in both groups. However, the changes in the albumin creatinine ratio, renal injury markers, pro-apoptotic markers, and histological changes in the G-SHR were much more pronounced compared to the G-NTR. We conclude that hypertension continues to have a significant impact on various aspects of renal injury and function, even several weeks after UUO reversal.
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Affiliation(s)
- Fayez T. Hammad
- Department of Surgery, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates;
| | - Loay Lubbad
- Department of Surgery, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates;
| | - Suhail Al-Salam
- Department of Pathology, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates;
| | - Waheed F. Hammad
- School of Medicine, University of Jordan, Amman 11942, Jordan; (W.F.H.); (A.F.H.)
| | - Javed Yasin
- Department of Internal Medicine, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates;
| | - Mohamed Fizur Nagoor Meeran
- Department of Pharmacology and Therapeutics, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates; (M.F.N.M.); (S.O.); (S.A.)
| | - Shreesh Ojha
- Department of Pharmacology and Therapeutics, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates; (M.F.N.M.); (S.O.); (S.A.)
| | - Seenipandi Arunachalam
- Department of Pharmacology and Therapeutics, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates; (M.F.N.M.); (S.O.); (S.A.)
| | - Awwab F. Hammad
- School of Medicine, University of Jordan, Amman 11942, Jordan; (W.F.H.); (A.F.H.)
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Harrison TG, Tonelli M. Measuring albuminuria or proteinuria: does one answer fit all? Kidney Int 2023; 104:904-909. [PMID: 37652205 DOI: 10.1016/j.kint.2023.08.008] [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: 04/18/2023] [Revised: 07/30/2023] [Accepted: 08/11/2023] [Indexed: 09/02/2023]
Abstract
Measurement of proteinuria is critical for diagnosing and monitoring kidney disease. A variety of measures are available to clinicians and can identify all urinary proteins (proteinuria) or urine albumin alone (albuminuria). Proteinuria and albuminuria can be measured in either a random urine sample or a timed urine collection (often over 24 hours). Although an international guideline advocates the use of the urinary albumin-to-creatinine ratio for most purposes, this measure is not universally available worldwide and historically has been more costly than alternatives. In addition, there may be important differences in accuracy between the albumin-to-creatinine ratio and others based on magnitude of albuminuria, sex, and certain clinical contexts. In this mini review, we review recommendations from international guidelines and discuss specific contexts where the optimal measure of proteinuria is unclear and, in some situations, controversial. We discuss the evidence supporting current recommendations for choice of measure, including the clinical settings of glomerulonephritis, transplantation, and pregnancy. We also discuss how patient sex and cost may impact this decision.
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Affiliation(s)
- Tyrone G Harrison
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada; O'Brien Institute for Public Health, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Marcello Tonelli
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada; O'Brien Institute for Public Health, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
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Development of Biomarkers and Molecular Therapy Based on Inflammatory Genes in Diabetic Nephropathy. Int J Mol Sci 2021; 22:ijms22189985. [PMID: 34576149 PMCID: PMC8465809 DOI: 10.3390/ijms22189985] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 02/06/2023] Open
Abstract
Diabetic Nephropathy (DN) is a debilitating consequence of both Type 1 and Type 2 diabetes affecting the kidney and renal tubules leading to End Stage Renal Disease (ESRD). As diabetes is a world epidemic and almost half of diabetic patients develop DN in their lifetime, a large group of people is affected. Due to the complex nature of the disease, current diagnosis and treatment are not adequate to halt disease progression or provide an effective cure. DN is now considered a manifestation of inflammation where inflammatory molecules regulate most of the renal physiology. Recent advances in genetics and genomic technology have identified numerous susceptibility genes that are associated with DN, many of which have inflammatory functions. Based on their role in DN, we will discuss the current aspects of developing biomarkers and molecular therapy for advancing precision medicine.
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Olaniyi KS, Amusa OA, Akinnagbe NT, Ajadi IO, Ajadi MB, Agunbiade TB, Michael OS. Acetate ameliorates nephrotoxicity in streptozotocin-nicotinamide-induced diabetic rats: Involvement of xanthine oxidase activity. Cytokine 2021; 142:155501. [PMID: 33775493 DOI: 10.1016/j.cyto.2021.155501] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 03/09/2021] [Accepted: 03/12/2021] [Indexed: 12/27/2022]
Abstract
Impaired renal function is a common complication of diabetes mellitus (DM) that often degenerates to cardiovascular disease, contributing to high morbidity and reduced survival worldwide. Short chain fatty acids (SCFAs), including acetate has shown potential benefits in glycemic or metabolic regulation but its effect on diabetes-associated renal toxicity/impairment is not clear. Herein, we investigated the hypothesis that acetate would ameliorate renal toxicity, accompanying DM, possibly by suppression of xanthine oxidase (XO) activity. Adult male Wistar rats (230-260 g) were allotted into groups (n = 6/group) namely: control (vehicle; po), sodium acetate (NaAc)-treated (200 mg/kg), diabetic with or without NaAc groups. DM was induced by intraperitoneal injection of streptozotocin 65 mg/kg after a dose of nicotinamide (110 mg/kg). Diabetic animals showed increased fasting glucose and insulin, renal triglyceride, total cholesterol, atherogenic lipid, malondialdehyde, XO, tissue necrosis factor-α, uric acid, interleukin-6, aspartate transaminase/alanine aminotransferase ratio, gamma-glutamyl transferase and decreased glutathione and nitric oxide concentration. The renal tissue was characterized with disrupted tissue architecture, enlarged Bowman's space, congested glomeruli and adherence of abnormal segments of tuft to Bowman's capsule with consequent elevated serum creatinine and urea concentration. However, these alterations were attenuated by NaAc. The study demonstrates that acetate ameliorates diabetes-induced nephrotoxicity, which is associated with suppressed XO and its accompanied pro-inflammatory mediators. Therefore, SCFAs, acetate would be a promising dietary-derived therapeutic agent for the prevention and management of diabetes-associated renal disturbances.
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Affiliation(s)
- Kehinde S Olaniyi
- Cardio/Repro-metabolic and Microbiome Research Unit, Department of Physiology, College of Medicine and Health Sciences, Afe Babalola University, Ado-Ekiti 360101, Nigeria; School of Laboratory Medicine & Medical Sciences, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Private Bag X54001, Congella 4013, Westville, Durban, South Africa.
| | - Oluwatobi A Amusa
- Cardio/Repro-metabolic and Microbiome Research Unit, Department of Physiology, College of Medicine and Health Sciences, Afe Babalola University, Ado-Ekiti 360101, Nigeria
| | - Nifesimi T Akinnagbe
- Cardio/Repro-metabolic and Microbiome Research Unit, Department of Physiology, College of Medicine and Health Sciences, Afe Babalola University, Ado-Ekiti 360101, Nigeria
| | - Isaac O Ajadi
- School of Laboratory Medicine & Medical Sciences, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Private Bag X54001, Congella 4013, Westville, Durban, South Africa
| | - Mary B Ajadi
- Department of Chemical Pathology, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomoso, Nigeria; Department of Medical Biochemistry, School of Laboratory Medicine, University of KwaZulu-Natal, Private Bag X54001, Congella 4013, Westville, Durban, South Africa
| | - Toluwani B Agunbiade
- Department of Medical Microbiology and Parasitology, College of Medicine and Health Sciences, Afe Babalola University, Ado-Ekiti 360101, Nigeria
| | - Olugbenga S Michael
- Cardiometabolic Research Unit, Department of Physiology, College of Health Sciences, Bowen University, Iwo, Nigeria
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Yoosefian M, Etminan N, Juan A, Mirhaji E. Ultra-low concentration protein detection based on phenylalanine-Pd/SWCNT as a high sensitivity nanoreceptor. RSC Adv 2020; 10:2650-2660. [PMID: 35496082 PMCID: PMC9048758 DOI: 10.1039/c9ra09243a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 12/26/2019] [Indexed: 11/21/2022] Open
Abstract
Pd doped single-walled carbon nanotubes as an enhanced physical transducer with phenylalanine amino acid can be efficiently used as a biocompatible nanoreceptor to detect proteins. DFT/B3LYP was used to calculate the optimized geometries, energies and electron density parameters to determine the stability and reactivity of the nanoreceptor. Among different adsorbed configurations of phenylalanine, the amine and carboxylic acid sites have higher adsorption energies and more stable complexes. With direct strong chemical adsorption of phenylalanine amino acid onto the Pd doped single-walled carbon nanotube, the free active carboxylic acid group of the amino acid can react with free amine groups on the surface of the proteins. More over the π-π stacking interaction between the free aromatic ring of adsorbed phenylalanine amino acid onto the functionalized single-walled carbon nanotube and the aromatic rings of the proteins also contributes to the intelligent detection of proteins. Frontier molecular orbital and molecular electrostatic potential (MPE) surface studies have been employed to investigate the active sites of the nanoreceptor. The effects of different solvents on the structural and electronic properties were investigated. Finally, in order to investigate biological function of the biosensor, docking studies were performed.
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Affiliation(s)
- Mehdi Yoosefian
- Department of Nanotechnology, Graduate University of Advanced Technology Kerman Iran
| | - Nazanin Etminan
- Chemistry Department, University of Payam-noor 19395-4697 Tehran Iran
| | - Alfredo Juan
- Departamento de Física & IFISUR (UNS-CONICET), Universidad Nacional del Sur Av. Alem 1253 8000 Bahia Blanca Argentina
| | - Elnaz Mirhaji
- Department of Nanotechnology, Graduate University of Advanced Technology Kerman Iran
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9
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Sulaiman MK. Diabetic nephropathy: recent advances in pathophysiology and challenges in dietary management. Diabetol Metab Syndr 2019; 11:7. [PMID: 30679960 PMCID: PMC6343294 DOI: 10.1186/s13098-019-0403-4] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 01/17/2019] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Diabetic nephropathy (DN) or diabetic kidney disease refers to the deterioration of kidney function seen in chronic type 1 and type 2 diabetes mellitus patients. The progression of the disease is known to occur in a series of stages and is linked to glycemic and blood pressure control. However, despite aggressive blood sugar control the prevalence of chronic kidney disease (CKD) in diabetic patients has not witnessed any decrease in the last two decades; which has lead to identification of additional factors in its progression. The nutritional status of patients is an important and modifiable factor that may influence CKD processes and outcome. It directly stems from the traditional dietary choices that patients make due to poor nutritional awareness. Dietary management of DN patients is challenging, as the twin factors of diet overload on kidney function needs to be balanced with malnutrition. Patient education seems to be the key in avoiding overindulgence of carbohydrate and protein-rich foods while favoring inclusion of essential fats in their diet. CONCLUSION This review will summarize current advances in staging and molecular pathogenesis of DN. It will highlight recent studies focusing on patient-customized dietary interventions that offer new hope as an effective tool in improving quality of life and delaying disease progression in DN patients.
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Kim JH, Oh SY, Kim EH, Lee MJ, Jeon YK, Kim BH, Kim JM, Kim YK, Kim SS, Kim IJ. Addition of nonalbumin proteinuria to albuminuria improves prediction of type 2 diabetic nephropathy progression. Diabetol Metab Syndr 2017; 9:68. [PMID: 28912839 PMCID: PMC5588678 DOI: 10.1186/s13098-017-0267-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 08/31/2017] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Albuminuria is generally accepted as a sensitive marker of diabetic nephropathy but has limitations in predicting its progression. The aim of this study was to evaluate the use of nonalbumin proteinuria in addition to albuminuria for predicting the progression of type 2 diabetic nephropathy. METHODS In this retrospective observational study, the urine albumin-to-creatinine ratio (ACR) and the nonalbumin protein-to-creatinine ratio (NAPCR) were measured in 325 patients with type 2 diabetes and estimated glomerular filtration rates (eGFR) ≥30 mL/min/1.73 m2. The patients were divided into four groups based on the cutoff points for the urinary ACR (30 mg/g) and NAPCR (120 mg/g). The renal outcomes were chronic kidney disease (CKD) progression and accelerated eGFR decline. RESULTS During the 4.3-year follow-up period, 25 (7.7%) patients showed CKD progression and 69 (21.2%) patients showed accelerated eGFR decline. After adjusting for nine clinical parameters, the group with a NAPCR greater than 120 mg/g exhibited higher cumulative incidences of CKD progression (hazard ratio 6.84; P = 0.001) and accelerated eGFR decline (hazard ratio 1.95; P = 0.011) than the group with a NAPCR < 120 mg/g. In patients with normoalbuminuria, the group with NAPCR levels greater than 120 mg/g also exhibited a higher cumulative incidence than that with NAPCR levels <120 mg/g of CKD progression (hazard ratio 21.82; P = 0.005). The addition of NAPCR to ACR improved the model fit for CKD progression and accelerated eGFR decline. CONCLUSION Nonalbumin proteinuria showed additional value over and above that of albuminuria for predicting the progression of CKD in patients with type 2 diabetes.
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Affiliation(s)
- Jong Ho Kim
- Department of Internal Medicine, Pusan National University Hospital, Busan, South Korea
- Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Seo Young Oh
- Department of Internal Medicine, Pusan National University Hospital, Busan, South Korea
- Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Eun Heui Kim
- Department of Internal Medicine, Pusan National University Hospital, Busan, South Korea
- Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Min Jin Lee
- Department of Internal Medicine, Pusan National University Hospital, Busan, South Korea
- Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Yun Kyung Jeon
- Department of Internal Medicine, Pusan National University Hospital, Busan, South Korea
- Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Bo Hyun Kim
- Department of Internal Medicine, Pusan National University Hospital, Busan, South Korea
- Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Jin Mi Kim
- Department of Biostatistics, Pusan National University Hospital, Busan, South Korea
| | - Yong Ki Kim
- Kim Yong Ki Internal Medicine Clinic, Busan, South Korea
| | - Sang Soo Kim
- Department of Internal Medicine, Pusan National University Hospital, Busan, South Korea
- Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Pusan National University Hospital, 179 Gudeok-Ro, Seo-Gu, Busan, 602-739 South Korea
| | - In Joo Kim
- Department of Internal Medicine, Pusan National University Hospital, Busan, South Korea
- Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Pusan National University Hospital, 179 Gudeok-Ro, Seo-Gu, Busan, 602-739 South Korea
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11
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Zhao YF, Zhu L, Liu LJ, Shi SF, Lv JC, Zhang H. Measures of Urinary Protein and Albumin in the Prediction of Progression of IgA Nephropathy. Clin J Am Soc Nephrol 2016; 11:947-955. [PMID: 27026518 PMCID: PMC4891752 DOI: 10.2215/cjn.10150915] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 02/17/2016] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Proteinuria is an independent predictor for IgA nephropathy (IgAN) progression. Urine albumin-to-creatinine ratio (ACR), protein-to-creatinine ratio, and 24-hour urine protein excretion (UPE) are widely used for proteinuria evaluation in clinical practice. Here, we evaluated the association of these measurements with clinical and histologic findings of IgAN and explored which was the best predictor of IgAN prognosis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Patients with IgAN were followed up for ≥12 months, were diagnosed between 2003 and 2012, and had urine samples available (438 patients). Spot urine ACR, protein-to-creatinine ratio, and 24-hour UPE at the time of renal biopsy were measured on a Hitachi Automatic Biochemical Analyzer 7180 (Hitachi, Yokohama, Japan). RESULTS In our patients, ACR, protein-to-creatinine ratio, and 24-hour UPE were highly correlated (correlation coefficients: 0.71-0.87). They showed good relationships with acknowledged markers reflecting IgAN severity, including eGFR, hypertension, and the biopsy parameter (Oxford severity of tubular atrophy/interstitial fibrosis parameter). However, only ACR presented with positive association with the Oxford segmental glomerulosclerosis/adhesion parameter and extracapillary proliferation lesions. The follow-up time was 37.0 (22.0-58.0) months, with the last follow-up on April 18, 2014. In total, 124 patients reached the composite end point (30% eGFR decline, ESRD, or death). In univariate survival analysis, ACR consistently had better performance than protein-to-creatinine ratio and 24-hour UPE as represented by higher area under the curve using time-dependent survival analysis. When adjusted for well known risk factors for IgAN progression, ACR was most significantly associated with the composite end point (hazard ratio, 1.56 per 1-SD change of standard normalized square root-transformed ACR; 95% confidence interval, 1.29 to 1.89; P<0.001). Compared with protein-to-creatinine ratio and 24-hour UPE, addition of ACR to traditional risk factors resulted in more improvement in the predictive ability of IgAN progression (c statistic: ACR=0.70; protein-to-creatinine ratio =0.68; 24-hour UPE =0.69; Akaike information criterion: ACR=1217.85; protein-to-creatinine ratio =1229.28; 24-hour UPE =1234.96; P<0.001). CONCLUSIONS In IgAN, ACR, protein-to-creatinine ratio, and 24-hour UPE had comparable association with severe clinical and histologic findings. Compared with protein-to-creatinine ratio and 24-hour UPE, ACR showed slightly better performance in predicting IgAN progression.
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Affiliation(s)
- Yan-feng Zhao
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and
- Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Li Zhu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and
- Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Li-jun Liu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and
- Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Su-fang Shi
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and
- Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Ji-cheng Lv
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and
- Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Hong Zhang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and
- Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
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Kim SS, Kim JH, Kim IJ. Current Challenges in Diabetic Nephropathy: Early Diagnosis and Ways to Improve Outcomes. Endocrinol Metab (Seoul) 2016; 31:245-53. [PMID: 27246284 PMCID: PMC4923408 DOI: 10.3803/enm.2016.31.2.245] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 05/04/2016] [Accepted: 05/13/2016] [Indexed: 12/29/2022] Open
Abstract
Diabetes is often associated with chronic kidney disease (CKD) and is the primary cause of kidney failure in half of patients who receive dialysis therapy. Given the increasing prevalence of diabetes and its high morbidity and mortality, diabetic nephropathy is a serious drawback in individual patients and a tremendous socioeconomic burden on society. Despite growing concern for the management of diabetic nephropathy, the prevalence of CKD with diabetes is the same today as it was 20 years ago. The current strategy to manage diabetic nephropathy, including the control of hyperglycemia, dyslipidemia, and blood pressure and the wide-spread use of renin-angiotensin-aldosterone system inhibitors, is well established to be beneficial in the early stages of diabetic nephropathy. However, the effects are uncertain in patients with relatively progressed CKD. Therefore, early diagnosis or risk verification is extremely important in order to reduce the individual and socioeconomic burdens associated with diabetic nephropathy by providing appropriate management to prevent the development and progression of this condition. This review focuses on recent research and guidelines regarding risk assessment, advances in medical treatment, and challenges of and future treatments for diabetic nephropathy.
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Affiliation(s)
- Sang Soo Kim
- Department of Internal Medicine and Biomedical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | - Jong Ho Kim
- Department of Internal Medicine and Biomedical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | - In Joo Kim
- Department of Internal Medicine and Biomedical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea.
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Kim SS, Song SH, Kim IJ, Kim WJ, Jeon YK, Kim BH, Kwak IS, Lee EK, Kim YK. Nonalbuminuric proteinuria as a biomarker for tubular damage in early development of nephropathy with type 2 diabetic patients. Diabetes Metab Res Rev 2014; 30:736-41. [PMID: 24687388 DOI: 10.1002/dmrr.2546] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 03/04/2014] [Accepted: 03/17/2014] [Indexed: 01/28/2023]
Abstract
AIM The aim of this study was to evaluate the association between urinary nonalbumin protein (NAP) and urinary tubular markers in early diabetic nephropathy. METHODS Urinary NAP was measured in 118 patients with type 2 diabetes with estimated glomerular filtration rates (eGFR) ≥60 mL/min/1.73 m². Urine levels of tubular markers [kidney injury molecule (KIM)-1, neutrophil gelatinase-assoicated lipocalin (NGAL) and liver-type fatty acid-binding protein (L-FABP)] were measured by using an Enzyme-linked immunosorbent assay (ELISA). Patients were divided into three groups according to urinary NAP values. RESULTS The urine levels of KIM-1, NGAL and L-FABP were significantly higher in the third tertile group than in the first tertile group (all p < 0.001). There was a significant positive correlation between NAP and each tubular marker (KIM-1, NGAL and L-FABP) in univariate analysis (all p < 0.001). Urinary NAP was positively correlated with all urinary tubular markers after adjustment for age, duration of diabetes, systolic blood pressure, eGFR, low-density lipoprotein cholesterol, HbA1c and albumin-to-creatinine ratio (KIM-1 r = 0.170, p < 0.001; NGAL r = 0.142, p < 0.015 and L-FABP r = 0.262, p < 0.001). In normoalbuminuric patients (n = 58), urinary NAP was also significantly correlated with NGAL and L-FABP in multivariate regression analyses (r = 0.302, p = 0.030 and r = 0.430, p = 0.001). CONCLUSIONS These findings suggest that urinary NAP reflects tubular damage in the early-stage type 2 diabetic nephropathy (eGFR ≥ 60 mL/min/1.73 m²). We suggest that urinary NAP could be used as a biomarker for tubular damage in clinical practice.
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Affiliation(s)
- Sang Soo Kim
- Department of Internal Medicine, Pusan National University Hospital, Busan, South Korea; Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
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Early Predictors of Renal Dysfunction in Egyptian Patients with β-Thalassemia Major and Intermedia. Mediterr J Hematol Infect Dis 2014; 6:e2014057. [PMID: 25237470 PMCID: PMC4165495 DOI: 10.4084/mjhid.2014.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 07/23/2014] [Indexed: 01/19/2023] Open
Abstract
Background Better survival of thalassemia patients allowed previously unrecognized renal complications to emerge. Objectives Assess prevalence and early predictors of renal dysfunction in young β-thalassemia major (β-TM) and intermedia (β-TI) patients. Subjects 66 β-TM (group I), 26 β-TI (group II) Egyptian patients and 40 healthy controls. Methods Clinical assessment and laboratory data including kidney and liver function tests, such as serum ferritin, serum bicarbonate, plasma osmolality and urinary total proteins, microalbuminuria (MAU), N-acetyl-β-D-glucosaminidase (NAG), retinol binding protein (RBP), α-1 microglobulin, bicarbonate, osmolality, creatinine clearance (CrCl), % fractional excretion of bicarbonate (% FE-HCO3). Results The prevalent renal abnormality was proteinuria (71%), followed by increased urinary level of RBP (69.4%), NAG (58.1%), α-1 microglobulin (54.8%) and microalbuminuria (29%) and also decreased urinary osmolality (58.1%). CrCl was a better assessment of renal function and significantly lowered in thalassemia patients. Tubular dysfunctions were more significant in splenectomized β-TM patients who showed more elevation of NAG and α-1 microglobulin and lower urinary osmolality. NAG, RBP and α-1 microglobulin were negatively correlated with CrCl and positively correlated with serum ferritin and urinary total protein. Z-score analysis for identifying patients with renal dysfunction proved superiority of urine total protein and RBP. Comparative statistics of different frequencies revealed significant difference between the urinary total protein and both MAU and % FE-HCO3. Conclusion Asymptomatic renal dysfunctions are prevalent in young β-TM and β-TI patients that necessitate regular screening. Urinary total protein and RBP may be cost-effective for early detection.
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Fisher H, Hsu CY, Vittinghoff E, Lin F, Bansal N. Comparison of associations of urine protein-creatinine ratio versus albumin-creatinine ratio with complications of CKD: a cross-sectional analysis. Am J Kidney Dis 2013; 62:1102-8. [PMID: 24041612 PMCID: PMC3840083 DOI: 10.1053/j.ajkd.2013.07.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 07/23/2013] [Indexed: 01/13/2023]
Abstract
BACKGROUND Urine albumin-creatinine ratio (ACR) and protein-creatinine ratio (PCR) are important markers of kidney damage and are used for prognosis in persons with chronic kidney disease (CKD). Despite how commonly these measurements are done in clinical practice, relatively few studies have directly compared the performance of these 2 measures with regard to associations with clinical outcomes, which may inform clinicians about which measure of urinary protein excretion is best. We studied the association of ACR and PCR with common complications of CKD. STUDY DESIGN Cross-sectional study. SETTING & PARTICIPANTS 3,481 participants with CKD in the Chronic Renal Insufficiency Cohort (CRIC) Study. PREDICTORS ACR and PCR. OUTCOMES We examined the association between ACR and PCR with measures of common CKD complications: serum hemoglobin, bicarbonate, parathyroid hormone, phosphorus, potassium, and albumin. MEASUREMENTS Restricted cubic spline analyses adjusted for estimated glomerular filtration rate (eGFR; calculated by the MDRD [Modification of Diet in Renal Disease] Study equation) were performed to study the continuous association with our predictors with each outcome. RESULTS Mean eGFR was 43±13 (SD)mL/min/1.73 m2 and median values for PCR and ACR were 140 and 46 mg/g, respectively. In continuous analyses adjusted for eGFR, higher ACRs and PCRs were similar and both were associated with lower serum hemoglobin, bicarbonate, and albumin levels and higher parathyroid hormone, phosphorus, and potassium levels. Across all outcomes, the associations of ACR and PCR were similar, with only small absolute differences in the outcome measure. Similar associations were seen in patients with diabetes mellitus. LIMITATIONS Participants largely had moderate CKD with low values for ACR and PCR, so results may not be generalizable to all CKD populations. CONCLUSIONS In persons with CKD, ACR and PCR are relatively similar in their associations with common complications of CKD. Thus, routine measurement of PCR may provide similar information as ACR in managing immediate complications of CKD.
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Affiliation(s)
| | | | | | - Feng Lin
- University of California, San Francisco
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Lamb EJ, McTaggart MP, Stevens PE. Why albumin to creatinine ratio should replace protein to creatinine ratio: it is not just about nephrologists. Ann Clin Biochem 2013; 50:301-5. [DOI: 10.1177/0004563212473284] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Edmund J Lamb
- Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, Canterbury, UK
| | - Malcolm P McTaggart
- Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, Canterbury, UK
| | - Paul E Stevens
- Kent Kidney Care Centre, East Kent Hospitals NHS Trust, Canterbury, UK
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Guy M, Borzomato JK, Newall RG, Kalra PA, Price CP. Protein and albumin-to-creatinine ratios in random urines accurately predict 24 h protein and albumin loss in patients with kidney disease. Ann Clin Biochem 2009; 46:468-76. [PMID: 19729498 DOI: 10.1258/acb.2009.009001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Random urine protein-to-creatinine (PCR) and albumin-to-creatinine (ACR) ratios have been proposed as alternatives to 24 h urine measurements to simplify sample collection and overcome errors. The aim of this study was to examine the ability of PCR and ACR to predict urinary 24 h protein and albumin loss, respectively, in patients with kidney disease, and determine the most appropriate time of collection. METHODS Eighty-three patients were recruited from a renal outpatient clinic. In a 24 h period, each collected an early-morning urine (EMU), second and third voids, and the remaining urine passed that day. PCR and ACR were determined in random urines and compared with the 24 h loss of protein and albumin, respectively. RESULTS For all patients, median (range) 24 h urine protein and albumin losses were 220 (30-15600) and 60 (<8-10,557) mg, respectively. Ratios derived from each of three random urines correlated well with 24 h protein or albumin loss (Spearman's r(s) > 0.87, P < 0.0001). Receiver operator characteristic (ROC) curve analysis showed PCR accurately predicted both an abnormal 24 h urine protein > or =150 mg/24 h (areas under curves [AUC] 0.90-0.92) and significant proteinuria above 300 mg/24 h (AUC between 0.97 and 1.00). ACR accurately predicted both an abnormal 24 h urine albumin > or =30 mg/24 h (AUC 0.98 to 0.99) and frank albuminuria at > or =300 mg/24 h or > or =700 mg/24 h (AUC between 0.99 and 1.00). EMU and random urines performed equally well in predicting proteinuria and albuminuria from PCR and ACR, respectively. CONCLUSIONS By careful choice of cut-offs, both PCR and ACR can be used in patients with kidney disease to rule in or rule out abnormal 24 h losses of protein and albumin. EMU and, importantly, random samples can be used as surrogates for 24 h urine collections.
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Affiliation(s)
- Mark Guy
- Department of Clinical Biochemistry, Salford Royal NHS Foundation Trust, Hope Hospital, UK.
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Lamb EJ, MacKenzie F, Stevens PE. How should proteinuria be detected and measured? Ann Clin Biochem 2009; 46:205-17. [PMID: 19389884 DOI: 10.1258/acb.2009.009007] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Proteinuria is a classic sign of kidney disease and its presence carries powerful prognostic information. Although proteinuria testing is enshrined in clinical practice guidelines, there is surprising variation among such guidelines as to the definition of clinically significant proteinuria. There is also poor agreement as to whether proteinuria should be defined in terms of albumin or total protein loss, with a different approach being used to stratify diabetic and non-diabetic nephropathy. Further, the role of reagent strip devices in the detection and assessment of proteinuria is unclear. This review explores these issues in relation to recent national and international guidelines on chronic kidney disease (CKD) and epidemiological evidence linking proteinuria and clinical outcome. The authors argue that use of urinary albumin measurement as the front-line test for proteinuria detection offers the best chance of improving the sensitivity, quality and consistency of approach to the early detection and management of CKD.
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Affiliation(s)
- Edmund J Lamb
- Department of Clinical Biochemistry, East Kent Hospital University NHS Foundation Trust, Canterbury, Kent, UK.
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21
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Pahwa MB, Seth S, Khosla A. Significance of urine protein/creatinine ratio in pregnancy-induced hypertension. Clin Chim Acta 2007; 382:145-7. [PMID: 17507004 DOI: 10.1016/j.cca.2007.03.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Revised: 03/13/2007] [Accepted: 03/22/2007] [Indexed: 11/17/2022]
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Price CP, Newall RG, Boyd JC. Use of protein:creatinine ratio measurements on random urine samples for prediction of significant proteinuria: a systematic review. Clin Chem 2005; 51:1577-86. [PMID: 16020501 DOI: 10.1373/clinchem.2005.049742] [Citation(s) in RCA: 183] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Proteinuria is recognized as an independent risk factor for cardiovascular and renal disease and as a predictor of end organ damage. The reference test, a 24-h urine protein estimation, is known to be unreliable. A random urine protein:creatinine ratio has been shown to correlate with a 24-h estimation, but it is not clear whether it can be used to reliably predict the presence of significant proteinuria. METHODS We performed a systematic review of the literature on measurement of the protein:creatinine ratio on a random urine compared with the respective 24-h protein excretion. Likelihood ratios were used to determine the ability of a random urine protein:creatinine ratio to predict the presence or absence of proteinuria. RESULTS Data were extracted from 16 studies investigating proteinuria in several settings; patient groups studied were primarily those with preeclampsia or renal disease. Sensitivities and specificities for the tests ranged between 69% and 96% and 41% and 97%, respectively, whereas the positive and negative predictive values ranged between 46% and 95% and 45% and 98%, respectively. The positive likelihood ratios ranged between 1.8 and 16.5, and the negative likelihood ratios between 0.06 and 0.35. The cumulative negative likelihood ratio for 10 studies on proteinuria in preeclampsia was 0.14 (95% confidence interval, 0.09-0.24). CONCLUSION The protein:creatinine ratio on a random urine specimen provides evidence to "rule out" the presence of significant proteinuria as defined by a 24-h urine excretion measurement.
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Bergón E, Granados R, Fernández-Segoviano P, Miravalles E, Bergón M. Classification of renal proteinuria: a simple algorithm. Clin Chem Lab Med 2002; 40:1143-50. [PMID: 12521234 DOI: 10.1515/cclm.2002.201] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Total protein, albumin, alpha1-microglobulin, and immunoglobulin G (IgG) were analyzed in 1,622 urine samples without Bence-Jones proteinuria or gross hematuria. There was correlation with the histological picture obtained on renal biopsy in 61 patients. We established 24-h reference intervals for alpha1-microglobulin and IgG on 659 urine samples with total protein and albumin excretion rates below 100 mg/24 h and 30 mg/24 h, respectively, and creatinine clearance above 80 ml/min. The central 95% reference interval was found to be between 4 and 17 mg/24 h for alpha1-microglobulin and between 3 and 8.5 mg/24 h for IgG. In 80 urine samples with albumin excretion rate above 30 mg/24 h and alpha1-microglobulin and IgG within their reference intervals, we analyzed the 95% central interval of the distribution of the IgG/albumin ratios, and it was found to be within 0.01 and 0.20 (0.90 confidence interval: 0.17-0.24). Proteinuria was considered to be of the selective glomerular type if the albumin excretion rate was abnormal and the IgG/albumin ratio was under 0.20, even when the IgG excretion was within a pathological range. For the classification of proteinuria as predominantly tubular, we estimated the alpha1-microglobulin/albumin ratio in 173 urine samples with normal excretion rates of albumin and IgG and pathological excretion of alpha1-microglobulin. The discriminating value of 0.91 (0.90 confidence interval: 0.78-1.08) was accepted in order to define proteinuria of a tubular origin in the presence of a pathological albumin excretion rate. The association between albumin and IgG excretion rates and tubular reabsorption of the alpha1-microglobulin normally filtered by the glomerulus was studied in 33 urine samples from patients with no histologically significant tubulo-interstitial or vascular disease and a serum creatinine concentration below 141 pmol/l. The optimal curve-fitting function between albumin plus IgG and alpha1-microglobulin excretion rates was of the quadratic type (r = 0.927). Mixed proteinuria was considered when both, albumin and alpha1-microglobulin excretion rates were pathological and could not be included in the previously described groups.
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Affiliation(s)
- Enrique Bergón
- Department of Clinical Pathology, Hospital Universitario de Getafe, Madrid, Spain.
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Guy JM, Brammah TB, Holt L, Bernstein RM, McMurray JR, Tieszen K, Cooper RG. Urinary excretion of albumin and retinol binding protein in systemic lupus erythematosus. Ann Clin Biochem 1997; 34 ( Pt 6):668-74. [PMID: 9367006 DOI: 10.1177/000456329703400612] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have measured the urinary excretion of total protein, albumin and retinol binding protein (RBP) in random urine specimens obtained from 40 female patients with systemic lupus erythematosus (SLE). Thirty-three of these patients had no clinical evidence of any renal impairment (non-renal SLE); seven had overt renal disease (renal SLE). RBP:creatinine ratios were significantly higher in non-renal SLE patients compared with female controls (P = 0.002). There was no significant difference between urine total protein concentrations, albumin:creatinine or total protein:creatinine ratios in non-renal SLE patients when compared with controls, despite approximately 20% of these patients having elevated excretion of total protein or albumin. All seven renal SLE patients had elevated albumin:creatinine ratios but only four of them had an increased RBP:creatinine ratio. Of 29 non-renal SLE patients who had urinary total protein concentrations below 0.2 g/L, (i.e. approximating to a negative protein dipstick), 14 had increases in either albumin or RBP:creatinine ratios. Only two patients had increases in both. In the absence of clinical evidence of renal disease, increases in urinary albumin or RBP excretion could indicate subclinical nephropathy and measurements may have a role in the early diagnosis and subsequent monitoring of renal disease in SLE.
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Affiliation(s)
- J M Guy
- Department of Clinical Biochemistry, Salford Royal Hospitals Trust, Hope Hospital, UK
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Thakkar H, Newman DJ, Holownia P, Davey CL, Wang CC, Lloyd J, Craig AR, Price CP. Development and validation of a particle-enhanced turbidimetric inhibition assay for urine albumin on the Dade aca® analyzer. Clin Chem 1997. [DOI: 10.1093/clinchem/43.1.109] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractThe measurement of urine albumin now has a well-established role in the monitoring of patients with diabetes mellitus. We have developed a particle-enhanced immunoturbidimetric inhibition assay for urine albumin on the Dade aca® analyzer. The inhibition approach removes any of the potential antigen excess difficulties that could be expected from the wide clinical range of urine albumin, but retains the sensitivity advantages of latex-enhanced immunoturbidimetry. Human serum albumin (HSA) is covalently attached to 40-nm poly(chloromethyl)styrene-modified latex particles. This reagent, along with monoclonal antibody to HSA, is aliquoted into the aca reagent pack along with polyethylene glycol 8000 in a tablet form (giving a final reaction concentration of 15 g/L). A 150 mmol/L phosphate buffer, pH 7.8, is used to fill the reagent pack in the instrument and the agglutination reaction is monitored at 340 nm. The sample volume is 100 μL and the calibration curve covers the range 2–250 mg/L. Evaluation of commercial scale reagents against the Beckman Array nephelometric immunoassay system gave a Deming regression correlation of aca = 0.87 × Beckman + 8.5,r = 0.995, n = 145. Mean analytical recovery was 104 ± 4.5%, n = 20, and there was no evidence of a lack of parallelism. Interassay precision was 8.8% at 10.0 mg/L and <2.5% at >65 mg/L. Calibrator stability was in excess of 60 days. A small reference range study (24-h urine collections, n = 27) gave a mean of 5.6 mg/L with a range of 0.5–16.2 mg/L. Analytical sensitivity (2.5 SD from zero) was 0.40 mg/L.
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Affiliation(s)
- Hansa Thakkar
- Department of Clinical Biochemistry, St Bartholomew’s and the Royal London School of Medicine and Dentistry, Turner Street, London E1 2AD, UK
| | - David J Newman
- Department of Clinical Biochemistry, St Bartholomew’s and the Royal London School of Medicine and Dentistry, Turner Street, London E1 2AD, UK
| | - Peter Holownia
- Department of Clinical Biochemistry, St Bartholomew’s and the Royal London School of Medicine and Dentistry, Turner Street, London E1 2AD, UK
| | - Carol L Davey
- Department of Clinical Biochemistry, St Bartholomew’s and the Royal London School of Medicine and Dentistry, Turner Street, London E1 2AD, UK
| | | | - Joseph Lloyd
- Glasgow site, Dade International, Wilmington, DE
| | - Alan R Craig
- Glasgow site, Dade International, Wilmington, DE
| | - Christopher P Price
- Department of Clinical Biochemistry, St Bartholomew’s and the Royal London School of Medicine and Dentistry, Turner Street, London E1 2AD, UK
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MacRury SM, Pinion S, Quin JD, O'Reilly DS, Lunan CB, Lowe GD, MacCuish AC. Blood rheology and albumin excretion in diabetic pregnancy. Diabet Med 1995; 12:51-5. [PMID: 7712704 DOI: 10.1111/j.1464-5491.1995.tb02062.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Blood rheology is altered in diabetes and also in non-diabetic pregnant women. The cumulative effect of hyperfiltration, abnormal rheology of pregnancy, and diabetes could be one mechanism contributing to increased intraglomerular pressure and albuminuria in diabetic pregnancy. We conducted a prospective study of 22 Type 1 (insulin-dependent) diabetic patients and 22 non-diabetic women to determine if there was an association of altered blood rheology on glomerular function in diabetic pregnancy. Albumin excretion showed no increment with increasing gestation and was similar in diabetic and non-diabetic women throughout pregnancy (first trimester: 5.0 (3.0-14.0) vs 5.8 (3.7-10.7) mg l-1, p = 0.89; second trimester: 6.0 (5.0-12.0) vs 5.1 (3.6-10.4) mg l-1, p = 0.25; third trimester: 7.5 (3.5-16.0) vs 4.9 (2.9-7.3) mg l-1, p = 0.18). Red cell aggregation index increased in both groups between the first and third trimesters (diabetic patients: mean difference 2.0; Cl: 1.0-2.9, p = 0.003, and control patients: mean difference 2.3, Cl: 1.0-3.5, p = 0.002). Fibrinogen levels were significantly higher between the third and first trimesters in diabetic patients (mean difference 0.7, Cl: 0.2-1.3 g l-1, p = 0.006). Pregnancy, therefore, was associated with increased red cell aggregation, related in part to increased fibrinogen levels but the extent of change was similar in diabetic and nondiabetic women and appeared to have no adverse effect on glomerular function in pregnant insulin-dependent diabetic women.
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Affiliation(s)
- S M MacRury
- Diabetic Obstetric Clinic, Royal Maternity Hospital, Glasgow, UK
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Beetham R, Cattell WR. Proteinuria: pathophysiology, significance and recommendations for measurement in clinical practice. Ann Clin Biochem 1993; 30 ( Pt 5):425-34. [PMID: 8250494 DOI: 10.1177/000456329303000502] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- R Beetham
- Department of Clinical Biochemistry, Frenchay Hospital, Bristol, UK
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