Comparison of random urine protein/creatinine ratio with 24-hour urine protein in suspected pre-eclampsia

Lily Olayinka; Emily Garnett; Brian Burnett; Sridevi Devaraj

doi:10.1016/j.plabm.2023.e00316

Comparison of random urine protein/creatinine ratio with 24-hour urine protein in suspected pre-eclampsia

Pract Lab Med. 2023 Jun 21:36:e00316. doi: 10.1016/j.plabm.2023.e00316. eCollection 2023 Aug.

Authors

Lily Olayinka^{1

2}, Emily Garnett^{1

2}, Brian Burnett³, Sridevi Devaraj^{1

2}

Affiliations

¹ Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, 77030, USA.
² Section of Clinical Chemistry, Division of Laboratory Medicine, Department of Pathology, Texas Children's Hospital, Houston, TX, 77030, USA.
³ Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.

Abstract

Introduction: Proteinuria is one of the classical criteria for the diagnosis of pre-eclampsia. The gold standard remains the measurement of 24-h urine protein which is time consuming and prone to preanalytical errors. Random urine protein creatinine ratio (UPCR) is endorsed by clinical practice guidelines as a faster alternative. The aim of this study was to evaluate the correlation between the 24-h urine protein excretion and UPCR in the identification of proteinuria in suspected preeclamptic patients.

Method: A total of 51 women with suspected pre-eclampsia from the maternal fetal clinic of our institution were retrospectively studied. The correlation between the UPCR in random urine samples and protein excretion in the 24-h urine collection was determined by Deming Regression analysis and Pearson correlation on EP evaluator and SPSS respectively.

Result: There was a significant positive correlation between the numerical values obtained by 24-h urine protein and the UPCR (R = 0.88, P < 0.001). Concordance analysis showed 81.1% positive agreement for proteinuria between methods (>300 mg/24hr and >0.3) and 71.4% negative agreement. The clinical sensitivity and specificity of the UPCR was 74% and 69% respectively.

Conclusion: Overall, UPCR was well correlated with 24-h urine protein and could be an effective and compliant screening tool to indicate proteinuria in preeclamptic patients.

Keywords: 24-H urine protein excretion; Pre-eclampsia; Protein-creatinine-ratio; Proteinuria.