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Abstract Background Laboratory results are influenced by presence and severity of disease, as well as preanalytical factors, analytical variation, and biological variation. Biological variation data for urinary protein: creatinine ratio (UPC) and urine specific gravity (USG) in cats are lacking. Objectives Determine the biological variation of UPC and USG in cats. Animals Eighty healthy client‐owned cats. Methods Prospective study. Urine was collected on days 0, 14, and 56 from all 80 cats to investigate the persistence of borderline or overt proteinuria or suboptimal urine concentration. In 15 of these cats, urine was collected weekly from day 0 to 42 to calculate the index of individuality (II) and reference change value (RCV), and on days 56 and 57 to evaluate day‐to‐day variability of UPC and USG. Results Borderline or overt proteinuria (UPC ≥0.2) was present in 18/80 (23%) cats at baseline and persisted on 3 occasions in 2 months in 8/18 (44%) cats. Urine concentration was suboptimal at inclusion (USG 82% increase in UPC in a healthy cat is not solely attributable to physiological and analytical variation. For USG, a decrease of >36% is considered clinically relevant.

Abstract Background Urinalysis is necessary for the diagnostic evaluation of chronic kidney disease in cats. Performing cystocentesis is not always feasible, but data comparing urine obtained by cystocentesis in the clinic with voided samples collected at home are lacking in cats. Objectives To compare urinary protein:creatinine ratio (UPC) and urine specific gravity (USG) and to detect clinically relevant changes in proteinuria substage or urine concentration between urine collected at home and in‐clinic by cystocentesis in cats. Animals Ninety‐two healthy and diseased client‐owned cats. Methods Prospective study. Owners collected voided urine at home and within 1 to 15 hours, cystocentesis was performed in the clinic. Results In a subset of motivated owners, 55% succeeded in collecting urine at home. Overall, UPC was higher (mean ±SD difference = 0.09 ±0.22; P 0.4) was present in paired urine samples from 28% of cats. In 18% of cats, urine concentrating ability (USG

This study aimed at understanding the reasons veterinarians conduct a urinary protein/creatinine ratio (UPCR) in cats, correlating it with signalment, dipstick proteinuria tests, and urine specific gravity (USG) and assessing its role in chronic kidney disease (CKD) diagnosis and monitoring. A retrospective study was conducted, including medical data from cats consulted between 2016 and 2018 in a veterinary teaching hospital and submitted to at least one UPCR measurement. A total of 140 cats were included: 35% non-proteinuric (UPCR < 0.2), 25% borderline proteinuric (0.2 < UPCR < 0.4), and 40% overtly proteinuric (UPCR > 0.4). In contrast to other studies, there was no association between UPCR and male reproductive status. UPCR was mainly requested for CKD diagnosis and monitoring. Correlation between UPCR and combined results from dipstick tests and USG was low and inconsistent. Proteinuric CKD cats had a worse outcome at both 6 (odds ratio (OR 4.04) and 12 months (OR 4.36)), and this finding was more pronounced for severely proteinuric cases in which the OR for death was 4.36 and 6.00 at 6 and at 12 months, respectively. In addition to reinforcing the negative prognostic value of proteinuria, this study stresses the low and the inconsistent agreement between UPCR and the combined results of dipstick tests and USG in cats.

Proteinuria is common in heart failure with preserved ejection fraction (HFpEF) but its biologic correlates are poorly understood. We assessed the relationship between 49 plasma proteins and the urinary protein to creatinine ratio (UPCR), among 365 Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist Trial (TOPCAT) participants. Linear regression and network analysis was used to represent relationships between protein biomarkers and UPCR. UPCR was associated with older age, a greater proportion of female sex, lower prevalence of previous myocardial infarction, higher prevalence of diabetes, insulin use, smoking and statin use, as well as a lower estimated glomerular filtration rate, hematocrit and diastolic blood pressure. Growth differentiation factor (GDF-15; β=0.15; P <0.0001), followed by NT-proANP (β=0.774; P <0.0001), adiponectin (β=0.0005; P <0.0001), fibroblast growth factor 23 (FGF-23; β=0.177; P <0.0001), and soluble TNF receptors I (β=0.002; P <0.0001) and II (β=0.093; P <0.0001) demonstrated the strongest associations with UPCR. Network analysis showed that UPCR is linked to various proteins primarily through FGF-23, which along with GDF-15, demonstrated node characteristics with strong connectivity, whereas UPCR did not. In a model that included FGF-23 and UPCR, the former was predictive of the risk of death or heart failure hospital admission (Standardized HR=1.83; 95%CI=1.49-2.26; P< 0.0001) and or all-cause death (Standardized HR=1.59; 95%CI=1.22-2.07; P =0.0005), whereas UPCR was not prognostic. Proteinuria in HFpEF exhibits distinct proteomic correlates, primarily through its association with FGF-23, a well-known prognostic marker in HFpEF. However, in contrast to FGF-23, UPCR does not hold independent prognostic value. [ABSTRACT FROM AUTHOR]

Introduction: Nephrotic Syndrome is the commonest glomerular disease in children and is often characterized by multiple relapses. 24 hour urinary protein excretion is the accepted method used in quantification of proteinuria, but it's a time consuming, inconvenient and cumbersome method and difficult in very young children. Spot urine examination would be a simpler, easy, acceptable, and less time consuming method for detection of proteinuria in children. Aim: To evaluate the utility of protein: Creatinine ratio in random urine samples as a reliable diagnostic tool to quantify proteinuria and to determine the correlation of protein: Creatinine ratio to 24 hour protein excretion which is the gold standard reference method. Materials and Methods: The study was done on forty pediatric patients with nephrotic syndrome admitted in relapse, or presenting for the first time. Nephrotic syndrome was diagnosed on the basis of massive proteinuria (>40 mg/m2/hr), hypoalbuminemia (

Objective: To determine an optimal cutoff level of urinary protein-creatinine ratio (PCR) obtaining from 2 hours urine collection from women admitted with suspected preeclampsia for predicting significant proteinuria. Study design: Diagnostic test. Subject: Pregnant women with gestational age > 20 weeks who were admitted at Bangkok Metropolitan Administration Medical College and Vajira Hospital for evaluation of preeclampsia were studied prospectively. They were instructed to collect a 24-hour urine in two separate containers: one for the first 2 hours urine and the other for the following 22 hours urine specimens. Each sample was measured for volume, protein, and creatinine values. The first 2-hour urinary PCR and total 24-hour proteinuria were calculated. A receiver operating characteristic curve (ROC) of the 2-hour urinary PCR was constructed in order to determine the optimal cutoff level for estimate the degree of proteinuria. Results: A total of 182 out of 187 women completed the study; 137 (75%) had significant proteinuria. This study demonstrated moderate correlation between 2-hour urine protein and 24-hour urine protein(r=0.451). By using a 2-hour urinary PCR, the optimal cutoff level to predict significant proteinuria was ≥ 0.30 which yielded sensitivity, specificity, PPV, NPV and area under the ROC curve of 71.5%, 71.1%, 88.3%, 45.1% and 0.801 respectively. On the other hand, a cutoff level of ≥ 0.05 had a sensitivity of 100%, while the cutoff level of ≥ 2.0 offered 100% specificity. Conclusions: The 2-hour urinary PCR is not a good test to predict significant proteinuria due to its high false negative rate.

Objective: To determine an optimal cutoff level of urinary protein-creatinine ratio (PCR) obtaining from 6-hour urine collection specimens from women admitted with suspected preeclampsia for investigation of significant proteinuria. Study design: Diagnostic test. Subject: Pregnant women admitted for evaluation of preeclampsia were studied prospectively. They were instructed to collect a 24-hour urine in two separate containers: one for first six hours urine specimen, the other for following 18 hours urine specimen. Each sample was measured for volume, protein, and creatinine values. The first 6-hour urinary PCR and total 24-hour proteinuria were calculated. A receiver operating characteristic curve (ROC) of the 6-hour urinary PCR was constructed in order to determine the optimal cutoff level for estimate the degree of proteinuria. Results: A total of 120 out of 126 women completed the study; 96 (80%) had significant proteinuria. This study had shown moderate correlation between 6-hour urine protein and 24-hour urine protein.By using a 6-hour urinary PCR, the optimal cutoff level to predict significant proteinuria was ≥ 0.20 which yielded sensitivity, specificity, PPV, NPV and area under the ROC curve of 93.7%, 64.0%, 90.8%,72.7% and 0.788 respectively. On the other hand, a cutoff level of ≥ 0.10 had shown a sensitivity of 100% and specificity of 20.8%, while the cutoff level of ≥ 0.75 offered 100% specificity, but poor sensitivity of 55.7%. Conclusions: The 6-hour urinary PCR at ≥ 0.20 is the most appropriate value for diagnosis of significant proteinuria in preeclampsia.

Background: Lupus nephritis (LN) occurs in approximately 50% of people with systemic lupus erythematosus (SLE). The 24-h proteinuria (gold standard) is measured among other tests for the control and monitoring of LN activity. This study investigates the use of the protein/creatinine ratio (PCR) as an alternative for the detection of proteinuria and its accuracy compared to the gold standard in a predominantly non-white population., Methods: This was a prospective study conducted in Salvador, Brazil, between December 2021 and May 2022. We invited adult patients diagnosed with SLE and LN, regardless of their disease activity. The estimation of the PCR and 24-h proteinuria was performed using conventional methods. The analysis used was Spearman's r correlation coefficient (rs), coefficient of determination (r2), and concordance by the Bland-Altman method. A specific sensitivity was measured by the ROC curve with its respective cut-off by the Youden Index., Results: We compared 112 samples of 75 patients with LN, with a mean age of 34.5 ± 11.8 years. Of these patients, 85% were women, 87.9% were non-white. A high degree of correlation was observed between PCR with 24-h proteinuria (rs = 0.77 and r2 = 0.59). The ROC analysis shows an area under the curve of 0.92 and the cut-off point calculated by the Youden Index was 0.78 with a sensitivity of 90.0% and specificity of 82%. However, the Bland-Altman graph indicated decreasing concordance as the degree of proteinuria increased, despite showing concordance at high levels of proteinuria., Conclusion: The PCR shows high sensitivity to follow-up patients with LN when compared with 24-h proteinuria. Our findings suggest that PCR is a useful parameter for the evaluating and monitoring patients in complete remission. However, in cases of partial remission, the utility of PCR is limited., (© 2023 S. Karger AG, Basel.)

Background: Laboratory results are influenced by presence and severity of disease, as well as preanalytical factors, analytical variation, and biological variation. Biological variation data for urinary protein: creatinine ratio (UPC) and urine specific gravity (USG) in cats are lacking. Objectives: Determine the biological variation of UPC and USG in cats. Animals: Eighty healthy client‐owned cats. Methods: Prospective study. Urine was collected on days 0, 14, and 56 from all 80 cats to investigate the persistence of borderline or overt proteinuria or suboptimal urine concentration. In 15 of these cats, urine was collected weekly from day 0 to 42 to calculate the index of individuality (II) and reference change value (RCV), and on days 56 and 57 to evaluate day‐to‐day variability of UPC and USG. Results: Borderline or overt proteinuria (UPC ≥0.2) was present in 18/80 (23%) cats at baseline and persisted on 3 occasions in 2 months in 8/18 (44%) cats. Urine concentration was suboptimal at inclusion (USG <1.035) in 8/80 (10%) cats and at all 3 time points during 2 months in 3/8 (38%) cats. The II of UPC and USG indicated intermediate individuality. The 1‐sided RCV was 82% for UPC and 36% for USG. Proteinuria substage was identical on 2 consecutive days in 13/15 (87%) cats, and urine concentrating ability remained the same in all 15 cats. Conclusions and Clinical Importance: A >82% increase in UPC in a healthy cat is not solely attributable to physiological and analytical variation. For USG, a decrease of >36% is considered clinically relevant. [ABSTRACT FROM AUTHOR]

To evaluate the value of random urinary protein creatinine ratio in prediction of 24h proteinuria in hypertensive pregnancies. Method: Random urine samples and routine 24h urine collections were collected from hypertensive pregnant women (n=100). Reliability of random urinary protein-creatinine ratio was assessed by receiver operator characteristic (ROC) curve to detect significant proteinuria (300mg/day) using 24h. Urine protein as a gold standard. Forty six patients (46%) had significant proteinuria. The random protein creatinine ratio was correlated to 24h urine protein excretion (r2=0.777, P

Introduction: Early neonates (1-7-day-old) may develop acute kidney injury or acute renal failure due to functional (pre-renal, may be caused by decreased renal perfusion), intrinsic (renal, may be caused by acute insult), or obstructive (due to anatomic urinary tract obstruction) causes. Urinary protein estimation is important for diagnosis, follow-up and prognosis of disease. The Protein Creatinine Ratio (PCR) has been successfully used to establish proteinuria in different types of patients. Aim: This study was undertaken to establish normal PCR range in neonates, to rule out abnormal protein excretion in sick neonates. Materials and Methods: A total of 37 normal early neonates of age 0-3 days were enrolled for this study. Random spot urine samples were collected in paediatric urine bags for protein and creatinine estimation. Results: The urinary PCR varied between 0.1-0.8. The range of PCR values obtained was greater in 0-1 day old infants, compared to infants older than one day. Changes in PCR values were due to variations in the creatinine excretion. Conclusion: Urinary PCR values ≤ 0.8 indicate normal protein excretion. However, reference intervals of PCR should be established for narrow age groups in case of early neonates, e.g. 0-6h, 6-12h, 12-24h, 24-72h old babies.

IntroductionBy using spectral domain optical coherence tomography (SD-OCT) to measure retinal blood vessels. The correlation between the changes of retinal vascular structure and the degree of diabetic nephropathy is analyzed with a full-pixel Semantic segmentation method.MethodsA total of 120 patients with diabetic nephropathy who were treated in the nephrology department of Quzhou People’s Hospital from March 2023 to March 2024 were selected and divided into three groups according to the urinary albumin creatinine ratio (UACR). The groups included simple diabetes group (UACR < 30 mg/g), microalbuminuria group (30 mg/g ≤ UACR 0.05). Additionally, the differences in RVOD and RVLD among the three groups were found to be statistically significant (p

Aim: School urine screening has been established in several countries of Asia, including Japan, Korea and Taiwan. In Osaka prefectural schools, the urine screening system had some problematic issues including an unclear referral procedure for students with abnormal urinary findings. Therefore, the school urine screening system was reviewed and restructured in 2004. The aim of this study was to assess the improvement in school urine screening through evaluation of the restructured Osaka prefectural school urinary screening system., Methods: The Osaka prefectural school urinary screening system was reviewed, mainly considering two points. One was the incorporation of standard urinary protein/creatinine ratio measurement instead of the traditional urine dipstick and urine sediment tests; the second point was that all students requiring further examination were referred to regional nephrologists., Results: After restructuring, the number of students who were referred to a medical institute for detailed examinations decreased to 10%, although the number of students newly diagnosed with kidney disease and the types of diagnosis did not change. The positive predictive value of screening increased to about 8 times the value before the system restructuring. The reductions enabled students who required further examination to be referred to regional nephrologists and has contributed to a decreased cost for these examinations., Conclusion: Incorporating urinary protein/creatinine ratio measurement into the school urinary screening system, and updating the guiding principles, including referral to nephrology specialists, has enabled the school urinary screening system in Osaka Prefecture to become more efficient and have better cost performance., (© 2019 Asian Pacific Society of Nephrology.)

Background: Urinalysis is necessary for the diagnostic evaluation of chronic kidney disease in cats. Performing cystocentesis is not always feasible, but data comparing urine obtained by cystocentesis in the clinic with voided samples collected at home are lacking in cats. Objectives: To compare urinary protein:creatinine ratio (UPC) and urine specific gravity (USG) and to detect clinically relevant changes in proteinuria substage or urine concentration between urine collected at home and in‐clinic by cystocentesis in cats. Animals: Ninety‐two healthy and diseased client‐owned cats. Methods: Prospective study. Owners collected voided urine at home and within 1 to 15 hours, cystocentesis was performed in the clinic. Results: In a subset of motivated owners, 55% succeeded in collecting urine at home. Overall, UPC was higher (mean ±SD difference = 0.09 ±0.22; P <.001) and USG was lower (mean ±SD difference = −0.006 ±0.009; P <.001) in cystocentesis samples than in voided urine. Substantial agreement existed between sampling methods for UPC (weighted к = 0.68) and USG (к = 0.64) categories. A different proteinuria substage (UPC < 0.2, 0.2‐0.4, >0.4) was present in paired urine samples from 28% of cats. In 18% of cats, urine concentrating ability (USG < or ≥1.035) differed between both samples. Conclusions and Clinical Importance: Home sampling of urine is a valid alternative to cystocentesis in cats. However, because clinically relevant differences in UPC and USG were present in 28% and 18% of cats, respectively, by the same collection method for monitoring each cat is advised. [ABSTRACT FROM AUTHOR]

Measurement of massive proteinuria is vital for diagnosis of childhood Nephrotic syndrome. Quantification of 24 hours urinary protein is the gold standard test. Dipstick method of urinary protein measurement gives instant result for massive proteinuria. Spot urinary protein creatinine ratio measurement is variable. This was a hospital based prospective cross sectional study done at Department of Paediatric Nephrology, Rangpur Medical College Hospital from January 2014 to December 2015 to evaluate accuracy of dipstick method versus spot urinary protein-creatinine ratio in estimation of massive proteinuria in childhood nephrotic syndrome. Total 100 children diagnosed as Nephrotic syndrome fulfilling the inclusion and exclusion criteria were enrolled into the study. After collection of spot urine sample, proteinuria was estimated by dipstick method and same sample was sent to laboratory for measuring protein creatinine ratio. All data were collected in individual predetermined case record form and analyzed by SPSS version 17.Dipstick had sensitivity 97%, specificity 70%, positive predictive value 96.7%, negative predictive value 77% and efficacy 95%. There was a significant correlation between spot urinary protein creatinine ratio and dipstick testing of Nephrotic range of proteinuria (p<0.05).The dipstick result of proteinuria significantly correlates with spot urinary protein creatinine ratio. Dipstick method of urinary protein measurement yields accurate result instantly.

Simple Summary: Urinary protein/creatinine ratio allows veterinary clinicians to quantify proteinuria, i.e., the amount of protein that is lost in urine. This ratio is commonly performed in daily practice for several medical reasons, namely the diagnosis and the monitoring of feline chronic kidney disease. This study aimed at understanding the main reasons to perform UPCR in cats, correlating it with signalment, exploring the agreement between UPCR, urine dipstick protein value, and urine specific gravity and assessing its role in chronic kidney disease diagnosis and monitoring. A retrospective study was conducted, including medical data from cats consulted in a veterinary teaching hospital over two years and submitted to UPCR measurement. A total of 140 cats were included: 35% were non-proteinuric, 25% borderline proteinuric, and 40% showed overt proteinuria. This study found that UPCR is mainly requested for the diagnosis and the monitoring of chronic kidney disease and proteinuric cats with kidney disease have a worse outcome at 6-months and at 12-months. This study found and reinforced the negative prognostic value of UPCR in cats in comparison to dipstick and urine specific gravity. This study aimed at understanding the reasons veterinarians conduct a urinary protein/creatinine ratio (UPCR) in cats, correlating it with signalment, dipstick proteinuria tests, and urine specific gravity (USG) and assessing its role in chronic kidney disease (CKD) diagnosis and monitoring. A retrospective study was conducted, including medical data from cats consulted between 2016 and 2018 in a veterinary teaching hospital and submitted to at least one UPCR measurement. A total of 140 cats were included: 35% non-proteinuric (UPCR < 0.2), 25% borderline proteinuric (0.2 < UPCR < 0.4), and 40% overtly proteinuric (UPCR > 0.4). In contrast to other studies, there was no association between UPCR and male reproductive status. UPCR was mainly requested for CKD diagnosis and monitoring. Correlation between UPCR and combined results from dipstick tests and USG was low and inconsistent. Proteinuric CKD cats had a worse outcome at both 6 (odds ratio (OR 4.04) and 12 months (OR 4.36)), and this finding was more pronounced for severely proteinuric cases in which the OR for death was 4.36 and 6.00 at 6 and at 12 months, respectively. In addition to reinforcing the negative prognostic value of proteinuria, this study stresses the low and the inconsistent agreement between UPCR and the combined results of dipstick tests and USG in cats. [ABSTRACT FROM AUTHOR]

Context: Glomerulonephritis is an important cause of morbidity and mortality among all age group in Bangladesh This cross sectional study was carried out with an aim to observe the comparison of 24 hour urinary protein and spot urinary protein- creatinine ratio in patients with glomerulonephritis in 3 group: on basis of 24 hour total protein, GFR level and serum albumin level. Methods: A total number of 128 consecutive patients having glomerulonephritis with 18 to 70 years who came in the Nephrology Unit, Dhaka Medical College Hospital, Dhaka, during the period of January to December of 2011 were included in this study. Patients with proteinuria other than glomerulonephritis like DM, UTI and Hypertension and <18 years of age were excluded from the study. Results: A significant positive correlation was found between 24 hour Urine Protein with Protein Creatinine Ratio on the patients having 24 hour Urinary protein <0.2 gm, 0.2-<1 gm, 1-3.4 gm and 3.5-6 gm respectively. No correlation was found between 24 hr Urine Protein with Protein Creatinine Ratio on the patients having 24 hour Urinary protein >6 gm. A significant positive correlation was also found between 24 hour Urine Protein (gm/24 hour) with Protein Creatinine Ratio, which were in patients having GFR <15 ml/min/1.73m² body surface area, 15-29 ml/min/1.73m² body surface area, 30-59 ml/min/1.73m² body surface area, 60-89 ml/ min/1.73m² body surface area and e"90 ml/min/1.73m² body surface area respectively. However, the result of the group having GFR <15 ml/min/1.73m² body surface was positively correlated but not very convincing. In this present series it was observed that a significant positive correlation was found between 24 hr Urine Protein (gm/24 hour) with Spot Urinary Protein Creatinine Ratio in relation to serum albumin level; r=0.658; (p<0.001) and r=0.707; (p<0.001) in patients having serum albumin level >30gm/dl and 20-30 gm/dl respectively. But because of only one sample in the group having <20 gm/dl serum albumin, no comparison could be carried out. Conclusion: P/C ratio provided a very useful, simple and convenient method for quantitative assessment of protein and can replace 24 hour urine collection method in indoor, outpatients and in follow up clinics as it gives quick and reliable results and avoids the inconvenience and short comings associated with 24 hour urine collection. [ABSTRACT FROM AUTHOR]

Objective: To systematically review literature on the utility of spot urinary protein-creatinine ratio (PCR) as a screening test for proteinuria and its ability to accurately measure proteinuria compared with 24-hour urine collection (24H-P) in patients with systemic lupus erythematosus (SLE)., Methods: We conducted a literature search (1900-2015) for articles comparing PCR and 24H-P in SLE patients in the databases Medline, Web of Science, and Embase. Included studies and their results were critically appraised and analyzed., Results: Thirteen studies (1,001 patients; 84.01% women) were included. Ten studies reported on Pearson's correlation (range 0.67-0.94), and 3 studies reported on Spearman's correlation (range 0.78-1.00). The meta-analysis of studies with Pearson's correlation showed a high overall correlation of 0.80 between 24H-P and PCR, yet with high heterogeneity (I(2)  = 97.2%). Correlation analysis is not sufficient to evaluate the utility of a new test against the gold standard test, and analysis on agreement is required. Seven studies reported on agreement: 3 studies analyzed concordance correlation coefficient (0.48-0.94), 3 analyzed intraclass correlation coefficient (0.66-0.95), and 1 analyzed kappa coefficient (0.58). These results confirmed that the agreement between 24H-P and PCR was inappropriate. Three studies included Bland-Altman plots, and the results also demonstrated poor agreement between both tests., Conclusion: The PCR has a utility as a screening test for proteinuria in SLE patients. The studies' results of 24H-P and PCR showed poor agreement between both tests, signifying that PCR should not be a substitute for the gold standard test (24H-P) to accurately measure proteinuria., (© 2016, American College of Rheumatology.)

To evaluate the value of random urinary protein creatinine ratio in prediction of 24h proteinuria in hypertensive pregnancies. Method: Random urine samples and routine 24h urine collections were collected from hypertensive pregnant women (n=100). Reliability of random urinary protein-creatinine ratio was assessed by receiver operator characteristic (ROC) curve to detect significant proteinuria (≥300mg/day) using 24h. Urine protein as a gold standard. Forty six patients (46%) had significant proteinuria. The random protein creatinine ratio was correlated to 24h urine protein excretion (r²=0.777, P<0.001) Area under ROC curve to predict proteinuria was 0.926 (95% CI: 0.854-0.995, P<0.001). A cut off value of 0.22mg/mg for protein creatinine ratio best predicted significant proteinuria with sensitivity, specificity, positive and negative predictive values of 87%, 92.6%, 90.6% and 89.3% respectively. Random urinary protein creatinine ratio is a simple inexpensive and excellent alternative to 24h urine collection. It's helpful in diagnosis of preeclampsia and can be used as a pre admission test in PIH cases. [ABSTRACT FROM AUTHOR]

Objective. Three main tests are commonly employed for the measurement of proteinuria: the dipstick test, the urinary protein/creatinine ratio (P/C) and the 24‐h urine collection. The aim of this study was to evaluate the correlation between these methods, comparing linear regression and ROC curve data. Material and methods. A total of 297 consecutive outpatients with different renal diseases were included in the study. Twenty‐four‐hour proteinuria was considered the reference test. Results. A high degree of correlation was observed between all the tests ( p [ABSTRACT FROM AUTHOR]

Background: For clinicians, it is important to rely on accurate laboratory results for patient care and optimal use of health care resources. We sought to explore our observations that urine protein:creatinine ratios (PrCr) ≥30 mg/mmol are seen not infrequently associated with normal pregnancy outcome., Methods: Urine samples were collected prospectively from 160 pregnant women attending high-risk maternity clinics at a tertiary care facility. Urinary protein was measured using a pyrocatechol violet assay and urinary creatinine by an enzymatic method on Vitros analysers. Maternal/perinatal outcomes were abstracted from hospital records., Results: 91/233 (39.1%) samples had a PrCr ≥30 mg/mmol, especially when urinary creatinine concentration was <3 mM (94.1%) vs. ≥3 mM (16.4%) (p < 0.001). When using the last sample before delivery, 47/160 (29.4%) had a PrCr ≥30 mg/mmol in diluted urine vs. only 17/160 (15.4%) in more concentrated urine (p < 0.001); PrCr positive results were also more frequent among the 32 (20.0%) women with known normal pregnancy outcome (90.9% vs. 0) (p < 0.001). Using the same analyser, 0.12 g/L urinary protein was 'detected' in deionised water. Re-analysis of data from two cohorts revealed substantially less inflation of PrCr in dilute urine using a pyrogallol red assay., Conclusions: Random urinary PrCr was overestimated in dilute urine when tested using a common pyrocatechol violet dye-based method. This effect was reduced in cohorts when pyrogallol red assays were used. False positive results can impact on diagnosis and patient care. This highlights the need for both clinical and laboratory quality improvement projects and standardization of laboratory protein measurement.

Introduction: Proteinuria assessment is important in pregnancy, particularly in determining whether or not a woman has pre-eclampsia. The random protein to creatinine ratio (PrCr) has been recommended as a confirmatory test for dipstick proteinuria in pregnancy, defined as random PrCr ⩾30mg/mmol. However, it has been our clinical impression that women with normal pregnancy outcomes have fluctuating or persistently elevated PrCr values., Objectives: As the primary goal of proteinuria testing in pregnancy should be to identify women at increased risk of adverse outcomes, we sought to explore our clinical impression that an elevated PrCr is seen not infrequently in pregnancies with normal outcome., Methods: In this prospective cohort study, consecutive inpatients or outpatients (attending high-risk maternity clinics) were evaluated at a tertiary care facility. Random midstream urine samples were obtained as part of normal clinical care. Urine protein was measured using a pyrocatechol violet molybdate dye-binding method, and urine creatinine by an enzymatic method, both on an automated analyser (Vitros® 5.1 FS or Vitros® 5600, Ortho-Clinical Diagnostics, Rochester, NY) followed by PrCr calculation. Maternal and perinatal outcomes were abstracted from the hospital case notes., Results: 160 women (81.9% outpatients) were screened at one/more antenatal visits providing a total of 233 samples for analysis. Ninety one (39.1%) samples had a random PrCr ⩾30 mg/mmol. This result was more common when urinary creatinine concentration was <3mM [64 (94.1%)] compared with ⩾3mM [27 (16.4%)], even among the 32 (20.0%) women with known normal pregnancy outcome [(13 (92.9%) vs. 0 (0%), respectively] (Panel A). In dilution studies using the same automated analyser, urinary protein (at a concentration of 0.12g/L) was 'detected' in deionised, double-distilled water. Method-specific re-analysis of data from two other published cohorts from our centre revealed substantially less inflation of PrCr values in dilute 24h urine samples tested using a pyrogallol red dye-binding based protein assay. When results were categorized according to urinary creatinine <3mM vs. ⩾3mM, PrCr ⩾30mg/mmol occurred in 12 (66.7%) vs. 99 (55.3%) respectively (p=0.35) in a 24-h urine completeness cohort and 92 (73.6%) vs. 313 (64.9%) respectively (p=0.07) in a cohort of women hospitalised for pre-eclampsia (Panel B)., Conclusion: Random urinary PrCr results may be inflated in dilute urines because of overestimation of proteinuria in a common pyrocatechol violet dye-based method. This inflation was reduced but not eliminated when the dye used was pyrogallol red. Analytical methods do matter in the assessment of proteinuria in pregnant women. It may be prudent to consider the potential for falsely positive PrCr ⩾30mg/mmol in dilute urine, and to order PrCr testing on first voided (concentrated) urines whenever possible., (Copyright © 2010. Published by Elsevier B.V.)

Introduction: The urinary protein/creatinine ratio has been used instead of 24-hour proteinuria in Nephrology practice for the follow-up of glomerular diseases, considering the advantages of collection and the low cost. However, there are still doubts as to its applicability both for an isolated evaluation and for the follow-up of patients with lupus nephritis., Objective: To evaluate 24-hour proteinuria determinations and random urine samples, performing urinary creatinine correction and urinary protein/creatinine ratio in subjects with lupus nephritis., Methods: 24-hour proteinuria and urinary protein/creatinine ratio were determined by conventional methods (automated Pyrogallol for proteinuria and alkaline picrate for creatinine)., Results: Seventy-eight urine samples of 41 patients diagnosed with systemic lupus erythematosus, according to the American Rheumatology Association, with lupus nephritis, were analyzed, and a good correlation between 24-hour proteinuria and urinary protein/creatinine ratio (r = 0.9010 and r² = 0.813) was observed. However, a poor correlation between random proteinuria (without creatinine correction) versus 24-hour proteinuria (r = 0.635 and r² = 0.403) or versus urinary protein/creatinine ratio (r = 0.754 and r² = 0.569) was seen., Conclusion: 24-hour proteinuria and urinary protein/creatinine ratio were useful in the follow-up of each case. However, we observed that the absolute values were different, which did not allow the replacement of one for the other during follow-up, especially when this result is used to define the activity of the disease. Based on these results, we suggest a period of intersection from one to the other (two to three determinations by both methods), and the choice of one marker for proteinuria follow-up, if necessary.

The initial goal of this study was to evaluate proteinuria by using the protein to creatinine (UPC) ratio of urine obtained by cystocentesis of healthy adult captive chimpanzees. Urine samples were collected by using ultrasound-guided cystocentesis from 125 (80 male, 45 female) captive chimpanzees. All samples were collected over a 17-mo time period (August 2008 to January 2010) during the animal's annual physical examination. Samples were assayed at a veterinary diagnostic laboratory. Results indicated that both age and blood contamination affect the UPC ratio and therefore alter the diagnostic utility of the UPC ratio in chimpanzees. In addition, this research establishes reference ranges by age for the UPC ratio in healthy adult chimpanzees. Chimps younger than the median age of 24.6 y have a median UPC ratio of 0.098 (range, 0 to 1.76), whereas older animals have a median UPC of 0.288 (range, 0 to 2.44). Our results likely will enable veterinarians working with chimpanzees to better evaluate their renal function.

Pregnancy induced hypertension (PIH) is a major complication of pregnancy and is associated with high maternal and perinatal morbidity and mortality. The aim of this study was to investigate the possible causal association of PIH with maternal serum PAPP-A and urinary protein-creatinine ratio (UPCr) as well as to evaluate the usefulness of these two variables as predictive markers of PIH. A total 200 women of 8-16 weeks of pregnancy were enrolled in this study. All the patients were followed up till delivery for the development of pregnancy induced hypertension. Thirty patients were lost in the follow up, 3(1.76%) developed preeclampsia (PE) and 14(8.23%) gestational hypertension (GH). By a nested case-control design the 17 pregnancy induced hypertension cases were compared with 48 Controls with normal pregnancy outcome. Maternal serum PAPP-A was significantly lower in the pregnancy induced hypertension group compared to Control [mIU/ml, median (range) 1.8(0.70-4.1) vs. 5.45(2.7-10), p<0.001]. UPCr was significantly higher in the pregnancy induced hypertension group compared to Control (mg/mmol, mean+/-SD, 6.86+/-1.56 vs. 4.75+/-0.96, p<0.001). When tested as a predictive marker of pregnancy induced hypertension the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of maternal serum PAPP-A in the lowest 25th percentile were 82%, 95%, 87% and 93%. At 75th percentile the sensitivity, specificity, PPV and NPV of UPCr were 52%, 85%, 56% and 83% respectively.

Objectives: The quantification of 24 hrs urinary protein excretion is valuable for diagnosing and monitoring renal disease. However, because of its practical difficulties, the spot urinary protein/creatinine (P/C) ratio has been utilized. We aimed to evaluate the analytical performance of P/C ratio by comparing with the qualitative urinary protein values and the microscopic urine sediment analysis., Methods: We obtained 5,538 urinary samples from the outpatients of Juntendo University Hospital. Testing for urinary P/C ratio was performed by Atlas Pro12 (cut-off 150 mg/g x Cr), urinary protein (proteinuria) was detected quantitatively by full-automated system ATLAS XL (cut-off 30 mg/dL). Microscopic exams were conducted following to the JCCLS reference method., Results: The P/C ratio demonstrated higher sensitivity but lower specificity for urinary abnormal casts detected by microscopic exams compared to proteinuria (sensitivity; P/C 87%, proteinuria 77%. specificity; P/C 74%, proteinuria 93%). From the comparative study with microscopic exams, both P/C and proteinuria performed high positive rate (> 80%) for the granular cast type and mixture cast type. For the cellular cast type, however, the positive rate of P/C was 56% and that of proteinuria was only 36%. The overall abnormal casts by microscopic exams showed better correlation with the positive P/C ratio than proteinuria., Conclusion: This study emphasizes that a spot urine P/C ratio is useful in screening for the further microscopic exams. P/C ratio can be a convincing index of urinary protein excretion when attenuation urine is doubted.

The concentrations of protein and creatinine were measured in urine samples from 74 healthy domestic pet rabbits, 54 of them seronegative to Encephalitozoon cuniculi and 20 seropositive. The calculated reference range for the urinary protein:creatinine ratio (UPC) of E cuniculi-seronegative rabbits was 0.11 to 0.40. There was no significant variation in the UPC due to the bodyweight, breed, sex, neutered status or husbandry of the rabbits. Seroconversion to E cuniculi was not found to be associated with clinical renal disease because none of the seropositive rabbits had azotaemia or proteinuria.

Objective: To evaluate the diagnostic accuracy of the first 4-hour urinary protein - creatinine ratio for prediction of the significant proteinuria in preeclampsia., Study Design: Diagnostic test, Subjects: One hundred and sixty-four pregnant women who were initially diagnosed with hypertensive disorder and hospitalized in the obstetric ward and labor room at Bangkok Metropolitan Administration Medical Collage and Vajira Hospital between July 2005 and April 2006., Material and Method: Urine samples were collected within 24 hours in two consecutive periods: the first 4 hours and the next 20 hours. The urine volume, urine protein and creatinine concentration were separately measured and the first 4-hour urinary protein - creatinine ratio were calculated. With the use of a protein level > or = 300 mg in 24 hours urine collection as the gold standard, the sensitivity and specificity of the first 4-hour urinary protein-creatinine ratio for diagnosis of significant proteinuria were determined with cutoffs range., Results: One hundred and sixty four patients were recruited for this study including 112 patients (68.3%) who had preeclampsia. The first 4-hour urinary protein-creatinine ratio was most accurate for diagnosis of preeclampsia is 0.30 with 81% sensitivity, 88% specificity, PPV of 93%, and NPV of 71%., Conclusion: The first 4-hour urinary protein-creatinine ratio at 0.3 is the most accurate value for diagnosis of significant proteinuria in preeclampsia

Objective: To assess the urine protein/creatinine ratio in urine samples of pregnant women with hypertension in regard to: 1) the presence of significant variation at different periods of the day; 2) the differences if they exist, to identify the most reliable period of the day for sampling; and 3) whether the first sample, obtained when the patient arrives at the clinic, correlates with the same accuracy, with the 24-hour proteinuria., Design: Cross-sectional study., Place: Obstetrics Emergency Department, Hospital de Clínicas de Porto Alegre, a teaching hospital in Porto Alegre, Brazil., Population: Seventy-five women with hypertension with 20-week gestation or over., Methods: Urine samples for determination of the protein/creatinine ratio were obtained on arrival (first specimen) and every 6 hours thereafter, totaling four samples in 24 hours. Four sampling periods were established: 1) from 8 am to 2 pm, 2) from 2 pm to 8 pm, 3) from 8 pm to 2 am, and 4) from 2 am to 8 am. The protein/creatinine ratio in the four different day periods were compared with the 24-hour proteinuria obtained simultaneously. The results were analyzed by the Spearman correlation and the receiver-operator characteristic (ROC) curve., Results: The urine protein/creatinine ratio is strongly correlated (Spearman correlation equal to 0.8 or greater) with the 24-hour proteinuria at all four periods of the day (p<0.001), as well as the first sample obtained on arrival (p=0.003). These findings were corroborated by the ROC curve in which the values of four day periods and that of the first sample were equal to or greater than 0.930., Conclusion: In hypertensive pregnant women, the single voided urine sample protein/creatinine ratio, irrespective of sampling time, is strongly correlated with the 24-hour proteinuria, as is the sample obtained on arrival.

Background: This cross-sectional study was conducted to determine whether a spot urine protein/creatinine ratio (UPr/UCr) provides accurate quantitation of 24-hr urinary protein excretion (24-hr Prot) in out-patients with primary glomerulonephritis (GN) and different renal function levels., Methods: Patients were classified into three groups according to creatinine (Cr) clearance (ml/min) and into five categories according to morning UPr/UCr. Correlation between 24-hr Prot and UPr/UCr was calculated according to the three renal function levels. The Bland and Altman method was used to assess agreement between 24-hr Prot and UPr/UCr. Agreement limits were obtained calculating the mean difference between 24-hr Prot and morning UPr/UCr +/- 2SD. Sensitivity and specificity were determined for different renal function levels and UPr/UCr cut-off values., Results: High correlation coefficients (r=0.91, 0.95 and 0.98) were observed in patients with normal, reduced and severely reduced renal function. Differences and variability between 24-hr Prot and UPr/UCr tended to increase with higher proteinuria levels, and this trend was observed for the three renal function levels. The best UPr/UCrcut-off values to detect abnormal or nephrotic proteinuria were, respectively, 0.3 and 2.6., Conclusions: Correlation and agreement between UPr/UCr and 24-hr Prot was good for all renal function levels, but demonstrated more marked differences as urinary protein excretion increased. Morning UPr/UCr had good sensitivity and specificity for the diagnosis of 24-hr Prot, even in patients with reduced renal function.

Objectives: To determine the correlation between the protein/creatinine ratio and 24-h proteinuria; to estimate the sensitivity and specificity of this ratio for the diagnosis of significant proteinuria; to establish its cutoff point with the best predictive value for the diagnosis of significant proteinuria in patients with systemic arterial hypertension., Study Design: A cross-sectional study of 47 hypertensive patients who had been pregnant for 20 weeks or more seen at the Maternity of the University Hospital of Porto Alegre. The studied factor was the protein/creatinine ratio measured in a single random urine sample and the outcome was protein determination in 24-h urine. The level of significance was set at 0.05., Results: The correlation coefficient between the protein/creatinine ratio and 24-h proteinuria was 0.94 when urine was properly collected. A receiver-operator characteristic curve was constructed to determine the sensitivity and specificity of the ratio for the diagnosis of significant proteinuria (> or = 300 mg in 24 h). Specificity and predictive positive value were 100% for a ratio > or = 0.8. The best values for sensitivity, specificity, positive predictive value, and negative predictive value in the diagnosis of proteinuria > or = 300 mg in 24 h were obtained when the protein/creatinine ratio was 0.5 (0.96, 0.96, 0.96, and 0.96, respectively)., Conclusion: The protein/creatinine ratio measured in a single urine sample taken at random from hypertensive pregnant women showed good sensitivity and specificity for the diagnosis of 24-h proteinuria > or = 300 mg and was strongly correlated with 24-h proteinuria. A ratio of 0.5 mg/mg is predictive of significant proteinuria and can be used for the diagnosis and follow-up of hypertensive pregnant women.

This study aims to assess the main causes of proteinuria in dogs from the region of Lisbon (Portugal), estimating the relevance of screening for canine vector-borne diseases (CVBDs). A cross-sectional retrospective study was conducted. Medical records from proteinuric dogs (urinary protein–creatinine ratio > 0.5) presented to a Veterinary Teaching Hospital over a two-year period were reviewed for signalment, established diagnosis, proteinuria origin, and CVBD screening results. A total of 106 dogs were included. The median age was 9.5 years old (IQR: 7–12). Proteinuria was considered of renal origin in 76% of cases (46% of them had a presumptive diagnosis of glomerulonephritis secondary to CVBD, 27% chronic kidney disease, 26% systemic disease possible to induce proteinuria, and 1% leptospirosis). Proteinuria was classified as post-renal or mixed-origin in 17% and 7% of cases, respectively. About 35% of proteinuric dogs were positive for at least one CVBD. Of them, 84% were seropositive for one CVBD, while 16% tested positive for two or more. Among dogs testing positive for CVBD, 89% were seropositive for Leishmania infantum. This study showed that about one-third of proteinuric dogs tested positive for CVBDs, highlighting the relevance of their screening in dogs with proteinuria living in endemic regions.

The follow-up of renal function in kidney transplant patients requires sensitive and specific parameters which allow the detection of clinically significant changes. In this prospective study, we have evaluated the accuracy of the urinary protein/creatinine ratio (UP/UCreat), determined in morning urine specimens, in assessing 24-hour proteinuria (P24). Fivehundred and twenty paired samples were provided by 133 kidney transplant patients. The correlation coefficient of the linear regression was 0.93 in both in the first set of paired samples (133 samples) and in all paired samples (520 samples). In complete urine collections, the UP/UCreat predicted the level of proteinuria with both a good specificity (95 to 99%) and sensitivity (97 to 99%) at different levels of 24-hour protein excretion. The intraindividual coefficients of variation of P24 and UP/UCreat were evaluated in 82 patients (442 samples) and were 23% and 29% respectively. These results confirm that the UP/UCreat ratio in morning samples is a reliable estimate of the 24-hour proteinuria in kidney transplant patients. Additionally, its variation appears to accurately reflect changes in the rate of protein excretion.