BACKGROUND: The protein/creatinine (P/C) ratio in urine samples has been used in the clinical management of patients with glomerular diseases. The aim of this study is to perform a prospective evaluation of the P/C ratio accuracy in determining critical levels of proteinuria in patients with glomerulopathies. METHODS: This is a longitudinal study of 41 adult patients with primary glomerulopathies treated with immunosuppressive drugs or angiotensin-converting enzyme inhibitors in a 6-month follow-up. Correlation and agreement level between P24 and the P/C ratio were evaluated. Kappa statistic was employed to evaluate concordance between the two methods taking into account clinically relevant categories of proteinuria. ANOVA for repeated measures was employed. Diagnostic accuracy of the P/C ratio was evaluated by receiver-operator curves (ROC). RESULTS: There was a significant correlation between P24 and the P/C ratio during the 6-month period (P < 0.001 in all time points). Mean differences between P24 and P/C ratios at baseline and from the first to the sixth month were 2.00, 1.88, 1.22, 1.07, 0.65, 0.34 and 0.57 respectively. In spite of the lower agreement between P24 and the P/C ratio for higher levels of proteinuria, we found substantial Kappa values for categories of proteinuria in all periods. ROC considering the cut-off levels of 0.20 g and 3.5 g for P24 showed that the P/C ratio had a very good accuracy, with areas under the curve of 0.99 (95% CI: 0.97-1.00) and 0.99 (95% CI: 0.99-1.00), respectively. CONCLUSION: This longitudinal analysis corroborates the findings of previous cross-sectional studies, supporting the use of the P/C ratio as an accurate test to define critical levels of proteinuria.
BACKGROUND: The protein/creatinine (P/C) ratio in urine samples has been used in the clinical management of patients with glomerular diseases. The aim of this study is to perform a prospective evaluation of the P/C ratio accuracy in determining critical levels of proteinuria in patients with glomerulopathies. METHODS: This is a longitudinal study of 41 adult patients with primary glomerulopathies treated with immunosuppressive drugs or angiotensin-converting enzyme inhibitors in a 6-month follow-up. Correlation and agreement level between P24 and the P/C ratio were evaluated. Kappa statistic was employed to evaluate concordance between the two methods taking into account clinically relevant categories of proteinuria. ANOVA for repeated measures was employed. Diagnostic accuracy of the P/C ratio was evaluated by receiver-operator curves (ROC). RESULTS: There was a significant correlation between P24 and the P/C ratio during the 6-month period (P < 0.001 in all time points). Mean differences between P24 and P/C ratios at baseline and from the first to the sixth month were 2.00, 1.88, 1.22, 1.07, 0.65, 0.34 and 0.57 respectively. In spite of the lower agreement between P24 and the P/C ratio for higher levels of proteinuria, we found substantial Kappa values for categories of proteinuria in all periods. ROC considering the cut-off levels of 0.20 g and 3.5 g for P24 showed that the P/C ratio had a very good accuracy, with areas under the curve of 0.99 (95% CI: 0.97-1.00) and 0.99 (95% CI: 0.99-1.00), respectively. CONCLUSION: This longitudinal analysis corroborates the findings of previous cross-sectional studies, supporting the use of the P/C ratio as an accurate test to define critical levels of proteinuria.
Authors: Outi Jauhola; Jaana Ronkainen; Helena Autio-Harmainen; Olli Koskimies; Marja Ala-Houhala; Pekka Arikoski; Tuula Hölttä; Timo Jahnukainen; Jukka Rajantie; Timo Ormälä; Matti Nuutinen Journal: Pediatr Nephrol Date: 2011-05-28 Impact factor: 3.714
Authors: Ganesh Shidham; Isabelle Ayoub; Dan Birmingham; Paul Hebert; Brad Rovin; Betty Diamond; David Wofsy; Lee Hebert Journal: Kidney Int Rep Date: 2018-04-27
Authors: Byung Chul Yu; Min Sung Lee; Jong Joo Moon; Soo Jeong Choi; Jin Kuk Kim; Seung Duk Hwang; Moo Yong Park Journal: Kidney Res Clin Pract Date: 2018-09-30