Protein/creatinine ratio on random urine samples for prediction of proteinuria in preeclampsia

RUMA and RUPCR in children with Henoch–Schonlein purpura

Objective

The aim of this study was to compare the qualitative and quantitative targets in the detection of proteinuria in children with HSP.

Methods

Three hundred and forty children were taken as the research subjects. Qualitative and a series of quantitative indicators of urine protein were tested.

Results

The qualitative and quantitative of protein in 340 children were analyzed retrospectively. Correlation analysis found that 24hUTP had a strong correlation with age, RUMA, RUPCR, and qualitative urine occult blood (p < 0.01, for all). After regression analysis, RUMA and RUPCR were still significantly correlated with 24hUTP (p < 0.01). At the same time, RUMA and RUPCR had good diagnostic accuracy for proteinuria. When the RUPCR ratio was set as 0.415, the diagnostic sensitivity was 83%, and the specificity was 98.7%. When RUMA was set as 68.215, the sensitivity was 94.3% and the specificity was 96.2%.

Conclusion

Compared with 24hUTP, RUMA and RUPCR had high sensitivity and specificity for monitoring proteinuria in children with HSP.

The effect of amniotomy on urine protein creatinine ratio test accuracy

Introduction: While the gold standard for evaluation of maternal urinary protein is a 24-hr urine collection, spot urine protein/creatinine ratio has been instituted as an alternative for quantification proteinuria. Though it seems intuitive to obtain a catheterized urine sample on patients with ruptured amniotic membranes, it is a common practice to forgo this step under the argument that there is no data to show its necessity. Data on the effect of amniotomy, spontaneous or artificial, on the accuracy of the protein/creatinine ratio are scant. The present study was designed to address this issue and objectively compare protein/creatinine ratio values on samples obtained from the same patient before and after amniotomy.

Methods: We conducted a prospective non-interventional study. Women presenting in active labor or for labor induction with intact amnion were enrolled. Separate random catch urines for the protein/creatinine ratio were obtained prior to and immediately after spontaneous or assisted amniotomy. The urine samples were analyzed in the hospital chemistry department, and the results were compared.

Results: Of the 137 patients consented, 63 had pre- and post-amniotomy protein/creatinine ratios collected. The mean age was 28.5±5.6 y, Gravidity 2.7±1.6, Gestational age 39.2±1.8 wks, and BMI 31.6±6.4 kg/m². Comorbidities included gestational diabetes (5/63, 7.9%), chronic hypertension (3/63, 4.7%), and pre-eclampsia (5/63, 7.9%). Post-amniotomy protein/creatinine ratio was significantly higher than pre-amniotomy ratio (1.3±2.5 vs 0.34±0.83, p<0.001). In addition, the number of patients with protein/creatinine ratio greater than 0.3 was higher post-amniotomy than pre-amniotomy (41/63 vs 14/63, p<0.001).

Conclusion: Amniotomy results in a false elevation of the protein/creatinine ratio in term patients. Urine samples should be obtained by catheterization in the setting of ruptured membranes to reduce falsely elevated results. Although the same can be assumed for other gestational ages, further studies including this population need to be conducted.

Random urine protein/creatinine ratio readily predicts proteinuria in preeclampsia

Objective

To assess the diagnostic accuracy of random urine protein-creatinine (P/C) ratio for prediction of significant proteinuria in preeclampsia as an alternative to the time-consuming 24-hour urine protein collection.

Methods

Retrospective record analysis was performed on 140 pregnant women who were admitted with suspicion for preeclampsia from January 2006 to June 2011. Random urine protein and/or 24-hour urine protein levels were assessed and their correlation to random urine P/C ratio and 24-hour urine protein excretion was evaluated.

Results

Out of 140 patients, random urine P/C ratio or/and 24-hour urine protein was performed in 79 patients to evaluate significant proteinuria. Of 79 patients, 46 (58%) underwent both tests whereas in 33 women (42%) 24-hour urine collection was not available due to urgent delivery. In 39 cases (85%), significant proteinuria (≥300 mg/24 hr) was detected with 6 cases (13%) having values over 5,000 mg/24 hr, corresponding to the diagnosis of severe preeclampsia. Random urine P/C ratio highly correlated with 24-hour urine protein excretion (r=0.823, P<0.01). The optimal random urine P/C ratio cutoff points were 0.63 and 4.68 for 300 mg/24 hr and 5,000 mg/24 hr of protein excretion, respectively. with each sensitivity, specificity, and positive and negative predictive values of 87.1%, 100%, 100%, and 58.3%; and 100%, 85%, 50%, and 100%, for significant and severe preeclampsia, respectively.

Conclusion

Random urine P/C ratio is a reliable indicator of significant proteinuria in preeclampsia and may be better at providing earlier diagnostic information than the 24-hour urine protein excretion with more accuracy than the urinary dipstick test.