Usage of spot urine protein to creatinine ratios in the evaluation of preeclampsia

Biomarker role of maternal soluble human leukocyte antigen G in pre-eclampsia: A meta-analysis

INTRODUCTION

Human leukocyte antigen-G (HLA-G) is a non-classical class I HLA molecule shown to regulate the immunomodulation of maternal immune cells to prevent fetal tissue destruction. Low levels of freely circulating maternal soluble HLA-G (sHLA-G) have been observed in pre-eclampsia, however, no pooled evidence exists. This meta-analysis aimed to generate pooled findings on the association of sHLA-G levels with pre-eclampsia and is the first study to perform a trimester-wise comparison of the levels of sHLA-G in preeclamptic cases and normal pregnant controls.

METHODS

The databases PubMed, Emba, Web of Science, and Google Scholar through May 31, 2023. Preeclamptic women were defined as cases and normal pregnancies as controls. Data on the level of sHLA-G in cases and controls was extracted and subjected to a meta-analysis using a random-effects model. The pooled effect was expressed in terms of standardized mean difference (SMD). Sensitivity analysis was performed to investigate the effect of the exclusion of each study on the pooled results. Publication bias was assessed statistically.

RESULTS

Nine studies with altogether 567 PE cases and 1132 normal pregnancy controls were included in the meta-analysis. The first and third trimester levels of sHLA-G in PE cases were significantly lower than that of normal pregnant controls: (SMD: -0.84 [-1.29; -0.38]; p = .003; I2 = 54%) and (SMD: -0.39 [-0.71; -0.06]; p = .02; I2 = 79%) respectively. Sensitivity analysis revealed significant fluctuations in the pooled findings when few studies were excluded, raising questions on the consistency of results among studies.

CONCLUSION

Although we found that first and third-trimester sHLA-G levels in pre-eclampsia are significantly lower, taking into consideration the inconsistent results from the sensitivity analysis, our findings advocate the demand for more studies with larger sample sizes to generate solid ground pooled evidence on the predictive role of sHLA-G in pre-eclampsia.

A meta-analysis on diagnostic accuracy of spot urinary protein to creatinine ratio versus 12-h proteinuria in preeclampsia

To systematically review the diagnostic accuracy of spot urinary protein to creatinine ratio (PCR) and 12-h proteinuria in preeclampsia and to estimate which is a preferred alternative method for 24-h proteinuria, we carried out this meta-analysis. 25 primary studies were included based on searching strategy. For spot urinary PCR, our results showed pooled sensitivity of 87% (95% confidence interval [CI] 83%-91%) and specificity of 86% (95% CI 79%-91%), with an area under curve (AUC) of 0.93 (0.90-0.95). For 12-h proteinuria, pooled sensitivity and specificity were 92% (95% CI 87%-96%) and 99% (95% CI 75%-100%), respectively, with an AUC of 0.97 (0.95-0.98). Fagan plot and likelihood ratio scattergram showed that 12-h proteinuria yielded a better discriminatory performance on diagnosis of proteinuria (≥0.3 g/24 h). These results indicated that 12-h proteinuria estimation shows better clinical value than spot urine PCR for diagnosis of preeclampsia. However, due to the severity of condition and the fact that preeclampsia patients cannot wait for 12 h, spot urine PCR can be used as one of the diagnostic indicators.

Diagnosis of proteinuria using a random urine protein-creatinine ratio and its correlation with adverse outcomes in pregnancy with preeclampsia characterized by renal damage

Based on a limited number of studies, a random urine protein‐creatinine ratio (uPCR) value of ≥ 0.3 indicates abnormal proteinuria in preeclampsia with renal damage. However, current guidelines do not recommend a reasonable diagnostic threshold of uPCR for severe preeclampsia with renal damage. Furthermore, the correlation between the uPCR value and clinical adverse outcomes remains poorly understood. The aim of the present study was to evaluate the value of uPCR in the diagnosis of significant proteinuria and to assess its correlation with adverse pregnancy outcomes in preeclampsia characterized by renal damage. In all, 1837 women were enrolled in this retrospective cohort study. Eventually, 961 women were enrolled under the exclusion criteria. First, the authors found that uPCR and 24‐hour proteinuria showed a significant association (r = 0.901). The optimal threshold of uPCR for diagnosing preeclampsia was 0.295, and for diagnosing severe preeclampsia the cut‐off was 0.625. Meanwhile, the adjusted odds ratio per 1 unit increase in ln (uPCR) was 1.679 (95% confidence interval [CI]:1.142–2.469) for severe adverse perinatal outcomes; 1.456 (95% CI: 1.242–1.705) for small for gestational age; 1.380 (95% CI: 1.051–1.811) for severe small for gestational age; 1.672 (95% CI: 1.210–2.310) for very early preterm birth; 1.989 (95% CI 1.726–2.293) for severe hypertension; and 2.279 (95% CI 1.906–2.724) for preterm birth. This study indicated that there was a significant and positive correlation between uPCR and 24‐hour urine protein. For neonatal and maternal adverse outcomes, uPCR is an independent predictor of prognosis.

Urinary Protein-to-Creatinine Ratio: An Indicator of Adverse Clinical Outcomes in Preeclampsia With Proteinuria

Background and objective

Preeclampsia is a major contributor to morbidity and mortality among pregnant women and leads to poor fetomaternal outcomes. Predicting fetal and maternal health outcomes will enable early interventions so as to reduce further damage. Various biochemical tests like beta-human chorionic gonadotropin (β-HCG), inhibin A, activin A, pregnancy-associated plasma protein-A (PAPP-A), fetal DNA, and color Doppler have been studied for their ability to predict fetal and maternal health outcomes; however, most of these tests are complex and costly. Among the many variables that indicate the severity of outcomes in hypertensive disorders of pregnancy, the urinary protein-to-creatinine ratio (UPCR) is an important index. The aim of the study was to find out the association between UPCR and fetomaternal outcomes in preeclampsia.

Material and methods

A prospective observational study was conducted among 141 women with preeclampsia presenting with proteinuria, who were divided into two groups: 11% with UPCR <0.3 and 89% with UPCR ≥0.3. These patients were followed up till delivery to look for maternal and fetal outcomes.

Results

The sensitivity of UPCR for predicting adverse maternal outcomes was 79.37% (95% CI: 71.25-86.06), specificity was 46.67% (95% CI: 21.27-73.41), positive predictive value (PPV) was 92.59% (95% CI: 88.53-95.29), negative predictive value (NPV) was 21.21% (95% CI: 12.43-33.81), and the accuracy was 75.79% (95% CI: 67.97-82.69); for adverse fetal outcomes, the sensitivity was 76.98% (95% CI: 68.65-84.01), specificity was 13.33% (95% CI: 1.66-40.46), PPV was 88.18% (95% CI: 85.69-90.29), NPV was 6.45% (95% CI: 1.79-20.67), and the accuracy was 70.21% (95% CI: 61.94-77.62).

Conclusion

Based on our findings, UPCR is a simple laboratory tool that can help predict abnormal fetomaternal outcomes in preeclampsia with good sensitivity and PPV and can be used as an adjunct to assist in clinical decisions.

Outcomes before and after Adopting Guidelines for Expectant Management of Severe Preeclampsia

OBJECTIVE

This study aimed to compare maternal and neonatal outcomes in women with severe preeclampsia before and after implementation of the American College of Obstetricians and Gynecologists (ACOG) taskforce hypertensive guidelines.

STUDY DESIGN

Single-center retrospective cohort study of women with severe preeclampsia delivering live nonanomalous singletons 23 to 34^2/7 weeks from 2013 to 2017. In 2015, the ACOG guidelines for expectant management of severe preeclampsia were implemented at our institution. Based on this, patients were categorized as preguideline (January 2013-December 2015) or postguideline adoption (January 2016-December 2017). Primary outcomes included composite maternal morbidity and composite neonatal morbidity; secondary outcomes included composite components, length of stay, birth weight, and delivery gestational age. Groups were compared with Student's t-test, Chi-square, and Wilcoxon's rank-sum tests; adjusted odds ratios (aOR; 95% confidence intervals [CIs]) were calculated. Yearly composite outcomes were compared using the Cochran-Armitage trend test. We estimated a sample size of 250 per group would provide 80% power at α = 0.05 to detect a 50% reduction in neonatal morbidity from a baseline rate of 21.5%.

RESULTS

From 2013 to 2017, a total of 543 women with severe preeclampsia were identified: 278 (51%) preguideline and 265 (49%) postguideline. Baseline characteristics were overall similar between groups. There were no significant differences in maternal (aOR = 0.96, 95% CI: 0.6-1.41) or neonatal (aOR = 0.88, 95% CI: 0.61-1.28) composite morbidity between groups. Furthermore, there were no differences in composite maternal or neonatal morbidity over time.

CONCLUSION

Perinatal outcomes were similar before and after implementation of severe preeclampsia management guidelines at our institution. Studies to evaluate if benefits are limited to subsets of this population, such as earlier gestational ages, are needed.

KEY POINTS

· Expectant management of severe preeclampsia has yet to be fully evaluated outside of trial conditions.. · We did not see a significant improvement in neonatal composite morbidity/mortality.. · We also did not see a worsened composite maternal morbidity/mortality..

Protein-creatinine ratio and albumin-creatinine ratio for the diagnosis of significant proteinuria in pregnant women with hypertension: Systematic review and meta-analysis of diagnostic test accuracy

BACKGROUND

The gold standard for assessment and diagnosis of significant proteinuria in pregnancy has been by 24-hour urine collection and analysis. Determining fast, accurate methods to identify clinically significant proteinuria would aid diagnosis of pre-eclampsia. The objective of this study was to determine the accuracy of spot protein-creatinine ratio (PCR) and albumin-creatinine ratio (ACR) measurements compared with 24-hour urine collection for the identification of clinically significant proteinuria in women with hypertensive disorders of pregnancy.

METHODS

Search strategies were developed for electronic databases from inception to 1st October 2020. Data were assessed for methodological quality using the QUADAS-II checklist for risk of bias and quality of the evidence using GRADE. Meta-analysis was performed where there were at least four studies presenting data for the same comparison (test and threshold). This is an update of the review for NICE guideline NG133 (published June 2019) and includes additional data.

RESULTS

Twenty-nine studies were included. PCR measurements (28 studies) showed high sensitivity (91%) and specificity (89%) at a threshold of 30 mg/mmol (n = 3577). Higher thresholds (>60 mg/mmol) increased specificity, but reduced sensitivity. At a threshold of PCR 30 mg/mmol, diagnostic accuracy improved for sensitivity and specificity (93% for both) in studies where the first morning void was excluded (n = 1868). Data available (4 studies) for ACR supports ruling out of significant proteinuria at less than 2 mg/mmol, though evidence was limited by paucity of data and wide confidence intervals around the result.

CONCLUSIONS

PCR and ACR have high accuracy compared to the gold standard 24-hour urine collection.

Diagnostic accuracy of random urinary protein-to-creatinine ratio for proteinuria in patients with suspected pre-eclampsia

PURPOSE

To evaluate the correlation between urine protein/creatinine ratio (UPCR) and proteinuria in a 24-h urine collection and to calculate the predicative accuracy of different cutoffs of UPCR for the diagnosis of proteinuria.

METHODS

A retrospective cohort study including women who admitted for the evaluation for suspected preeclampsia (PET) beyond 20 weeks of gestation in a single tertiary center. Both UPCR test and quantification of proteinuria using 24-h urine collection were obtained during their index hospitalization no more than 48 h apart. Women with pre-existing diabetes mellitus, known renal disease or proteinuria prior to pregnancy or chronic hypertension were excluded. Predictive accuracy of UPCR for several cutoffs of proteinuria was evaluated. Multivariate logistic regression analysis was used to assess diagnostic accuracy of UPCR in sub-populations according to obstetrical characteristics.

RESULTS

Overall 463 patients were included. Of them 316 (68.3%) have 24-h urine protein collection of ≥ 300 mg/day. Mean gestational age at evaluation was 34.0 ± 3.4 weeks. Median (and interquartile range) time interval between UPCR and 24-h urine collection was 1.8 (1.6-1.9) days. Sensitivity and specificity of UPCR of 0.3 for predicting proteinuria ≥ 300 mg/day were 90.1% and 63.3%, respectively. The corresponding values for difference proteinuria cutoffs: ≥ 1000 mg/day and 5000 mg/day were 98.4, 100% and 29.1, 36.0%, respectively. The optimal UPCR thresholds for 24-h urine protein collection of ≥ 300 mg/day,  ≥ 1000 mg/day and 5000 mg/day were 0.31, 0.70 and 2.49, respectively. The predictive accuracy of UPCR > 0.30 in predicting proteinuria was unaffected by demographic and obstetrical characteristics as maternal age, pre-pregnancy BMI, gestational age at examination, creatinine levels or by multiple gestation [adjusted OR 18.27 (95% CI 9.97-33.47)].

CONCLUSION

UPCR was strongly correlated with various cutoffs of proteinuria obtained by 24-h urine collection. UPCR cutoff varied depending on the specific measured outcome. This correlation was not affected by gestational age at examination.

Preeclampsia-Associated Multivessel Spontaneous Coronary Artery Dissection

Pregnancy-associated spontaneous coronary artery dissection (PASCAD) accounts for less than 5% of spontaneous coronary artery dissection cases and is comparatively more fulminant or clinically aggressive. Several factors associated with PASCAD include black ethnicity, multiparity, hypertension, advanced maternal age, and age at first childbirth. This atypical case highlights a preeclamptic patient presenting with an ST-segment elevation myocardial infarction in which multivessel dissection of both the left anterior descending and right coronary arteries were deemed co-culprit lesions for the index event.

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.

Spot protein/creatinine ratio in preeclampsia as an alternative for 24-hour urine protein

BACKGROUND

Proteinuria is a major component of preeclampsia. Urine protein measurement after 24-hour urine collection is the traditional standard method for the detection of proteinuria. It is time-consuming. As an alternative, random spot sampling for a urine protein to creatinine (P/C) ratio has been investigated.

AIMS

The aim of the study was to determine the diagnostic accuracy of the protein to creatinine ratio (P/C) compared with 24-hour urine collection for the detection of remarkable proteinuria and to evaluate the P/C ratio for different proteinuria ranges in patients with preeclampsia.

STUDY DESIGN

Case-control study.

METHODS

Two hundred and eleven pregnant women who met the criteria of preeclampsia comprised the study group and fifty three pregnant women were taken as the control group. Spot urine specimens for measuring P/C ratio were obtained taken immediately before 24-hour urine collection. The correlation between the P/C ratio in the spot urine samples and urinary protein excretion in the 24-hour collections was examined using the Spearman correlation test.

RESULTS

It was found a good positive correlation between the P/C ratio and 24-hour protein excretion, with a correlation coefficient (r) of 0.758. The best cut-off which gave the maximum area under the curve was 0.45 for 300 mg, 0.9 for 1000 mg, 1.16 for 2000 mg, 1.49 for 3000 mg, 2.28 for 4000 mg and 2.63 for 5000 mg per 24h. A P/C ratio above 0.9 strongly predicts significant proteinuria for more than 1 gram (AUC 0.97, 95% CI: 0.94-0.99 and sensitivity, specificity, positive and negative predictive value of 91%, 95.4%, 95.2%, and 91.2%, respectively).

CONCLUSION

The P/C ratio can be used as a screening test as a good predictor for remarkable proteinuria. The P/C ratio seems to be highly predictive for diagnosis to detect proteinuria over one gram and it could be used as a rapid alternative test in preeclamptic patients not to delay implementation treatment.

Reduced uterine perfusion pressure induces hypertension in the pregnant mouse

Despite preeclampsia being one of the leading causes of maternal death and a major contributor of maternal and perinatal morbidity, the mechanisms responsible for its pathogenesis have yet to be fully elucidated. Growing evidence indicates that reduced uteroplacental perfusion and the resulting placental ischemia triggers the cascade of events leading to this maternal disorder. While the well-established rat model of reduced uterine perfusion pressure (RUPP) is providing invaluable insight into the etiology of preeclampsia, the aim of this study was to develop a mouse model of reduced uterine perfusion to expand mechanistic investigation by incorporation with novel gene-targeted mice. To accomplish this aim, a sham surgical procedure or a restriction of blood flow at the abdominal aorta and the ovarian arteries was initiated at day 13 of gestation in C57BL/6J mice. Mean arterial pressure measured in conscious, chronically instrumented mice was significantly elevated in the RUPP (120 ± 4 mmHg) compared with the sham (104 ± 4 mmHg) mice at day 18 of gestation (P < 0.01). Placental ischemia reduced fetal weights (0.95 ± 0.04 and 0.80 ± 0.02 g; RUPP vs. Sham, respectively; P < 0.02) and increased circulating levels of antiangiogenic soluble fms-related tyrosine kinases (sFlt)-1 (P < 0.05) in the RUPP at day 18 of gestation. Plasma concentrations of sFlt-1 are increased in preeclamptic patients and in response to reduced uterine perfusion in the rat. Thus, these results suggest that the mouse model of reduced uterine perfusion is applicable to facilitate novel mechanistic investigation into the etiology of hypertension that results from placental ischemia during pregnancy.

Quantifying proteinuria in hypertensive disorders of pregnancy

Background. Progressive proteinuria indicates worsening of the condition in hypertensive disorders of pregnancy and hence its quantification guides clinician in decision making and treatment planning. Objective. To evaluate the efficacy of spot dipstick analysis and urinary protein-creatinine ratio (UPCR) in hypertensive disease of pregnancy for predicting 24-hour proteinuria. Subjects and Methods. A total of 102 patients qualifying inclusion criteria were evaluated with preadmission urine dipstick test and UPCR performed on spot voided sample. After admission, the entire 24-hour urine sample was collected and analysed for daily protein excretion. Dipstick estimation and UPCR were compared to the 24-hour results. Results. Seventy-eight patients (76.5%) had significant proteinuria of more than 300 mg/24 h. Dipstick method showed 59% sensitivity and 67% specificity for prediction of significant proteinuria. Area under curve for UPCR was 0.89 (95% CI: 0.83 to 0.95, P < 0.001) showing 82% sensitivity and 12.5% false positive rate for cutoff value of 0.45. Higher cutoff values (1.46 and 1.83) predicted heavy proteinuria (2 g and 3 g/24 h, resp.). Conclusion. This study suggests that random urinary protein : creatine ratio is a reliable investigation compared to dipstick method to assess proteinuria in hypertensive pregnant women. However, clinical laboratories should standardize the reference values for their setup.

Correlation between 24-h urine protein, spot urine protein/creatinine ratio, and serum uric acid and their association with fetomaternal outcomes in preeclamptic women

Background:

It is well-known that estimation of 24-h urine protein and spot urine protein/creatinine (P/C) ratio are commonly performed investigations to assess proteinuria in preeclamptic women. Serum uric acid has been shown to correlate well with disease severity in preeclampsia.

Materials and Methods:

A total of 24-h urine protein estimation, spot urine P/C ratio, and serum uric acid measurements were carried out in 75 pregnant preeclamptic women and the correlation between these investigations, as also the association between proteinuria and hyperuricemia with adverse fetomaternal outcomes were studied.

Results:

Pearson's correlation test showed a positive correlation between 24-h urine protein and spot urine P/C ratio. A statistically significant and direct correlation was also found between serum uric acid and spot urine P/C ratio, while there was no statistically significant difference between proteinuria and hyperuricemia with respect to the various fetal and maternal outcome parameters studied.

Conclusion:

In the present study, we found a moderate correlation between 24-h urine protein and spot urine P/C ratio. There was a moderate correlation between spot urine P/C ratio and uric acid, while there was no statistical significance of the association between proteinuria and uric acid with fetomaternal outcomes in preeclampsia.

Spot urine protein-creatinine ratio and 24-h urine protein excretion: Diagnostic accuracy in women with pre-eclampsia

OBJECTIVE

To compare the efficacy of spot urinary protein/creatinine ratio with 24h urinary protein excretion in women with pre-eclampsia.

METHODS

A total of 85 women with hypertensive disorders during pregnancy were prospectively studied. Urine protein/creatinine ratio in spot urine sample was compared with 24h urinary protein. Sensitivity and specificity for urinary spot P/C (protein/creatinine) ratio was assessed, and receiver operating curve was used to determine the value against the gold standard of >300mg proteinuria in 24h urinary sample.

RESULTS

Of 85 women, complete data were available for 81 women. There was a strong correlation between spot urinary P/C ratio and 24h urine protein excretion (r=0.81, P value <0.000). The optimal spot P/C ratio cut-off point was 0.14 for 300mg/24h of protein excretion (preeclampsia) with a sensitivity of 82% and specificity of 79%.

CONCLUSION

We found a strong correlation between spot urinary P/C and 24h urinary protein. Spot urinary protein/creatinine ratio is a good predictor of proteinuria for pre-eclampsia.

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.

Diagnostic accuracy of spot urinary protein and albumin to creatinine ratios for detection of significant proteinuria or adverse pregnancy outcome in patients with suspected pre-eclampsia: systematic review and meta-analysis

OBJECTIVE

To determine the diagnostic accuracy of two "spot urine" tests for significant proteinuria or adverse pregnancy outcome in pregnant women with suspected pre-eclampsia.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Searches of electronic databases 1980 to January 2011, reference list checking, hand searching of journals, and contact with experts.

INCLUSION CRITERIA

Diagnostic studies, in pregnant women with hypertension, that compared the urinary spot protein to creatinine ratio or albumin to creatinine ratio with urinary protein excretion over 24 hours or adverse pregnancy outcome. Study characteristics, design, and methodological and reporting quality were objectively assessed.

DATA EXTRACTION

Study results relating to diagnostic accuracy were extracted and synthesised using multivariate random effects meta-analysis methods.

RESULTS

Twenty studies, testing 2978 women (pregnancies), were included. Thirteen studies examining protein to creatinine ratio for the detection of significant proteinuria were included in the multivariate analysis. Threshold values for protein to creatinine ratio ranged between 0.13 and 0.5, with estimates of sensitivity ranging from 0.65 to 0.89 and estimates of specificity from 0.63 to 0.87; the area under the summary receiver operating characteristics curve was 0.69. On average, across all studies, the optimum threshold (that optimises sensitivity and specificity combined) seems to be between 0.30 and 0.35 inclusive. However, no threshold gave a summary estimate above 80% for both sensitivity and specificity, and considerable heterogeneity existed in diagnostic accuracy across studies at most thresholds. No studies looked at protein to creatinine ratio and adverse pregnancy outcome. For albumin to creatinine ratio, meta-analysis was not possible. Results from a single study suggested that the most predictive result, for significant proteinuria, was with the DCA 2000 quantitative analyser (>2 mg/mmol) with a summary sensitivity of 0.94 (95% confidence interval 0.86 to 0.98) and a specificity of 0.94 (0.87 to 0.98). In a single study of adverse pregnancy outcome, results for perinatal death were a sensitivity of 0.82 (0.48 to 0.98) and a specificity of 0.59 (0.51 to 0.67).

CONCLUSION

The maternal "spot urine" estimate of protein to creatinine ratio shows promising diagnostic value for significant proteinuria in suspected pre-eclampsia. The existing evidence is not, however, sufficient to determine how protein to creatinine ratio should be used in clinical practice, owing to the heterogeneity in test accuracy and prevalence across studies. Insufficient evidence is available on the use of albumin to creatinine ratio in this area. Insufficient evidence exists for either test to predict adverse pregnancy outcome.

Hypertension in pregnancy

Hypertension in pregnancy is diagnosed on systolic blood pressure greater than or equal to 140 mm Hg and/or diastolic greater than or equal to 90 mm Hg. The classification systems separate chronic and gestational hypertension from preeclampsia. Significant uncertainty regarding optimal management is reflected in the differing major international society recommendations. Blood pressure treatment is designed to minimize maternal end-organ damage. Methyldopa, labetalol, hydralazine, and nifedipine are oral options; angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists are contraindicated. Women with preeclampsia should be closely monitored and receive intravenous magnesium sulfate.

Diagnosis and management of pre-eclampsia: an update

Pre-eclampsia is a significant, multifactorial, multiorgan disease affecting 5%-8% of all pregnancies in the US where it is the third leading cause of maternal mortality. Despite improvements in the diagnosis and management of pre-eclampsia, severe complications can occur in both the mother and the fetus, and there is no effective method of prevention. Early detection and identification of pregnant women most at risk of developing the disease have proven challenging, but recent efforts combining biochemical and biophysical markers are promising. Efforts at prevention of pre-eclampsia with aspirin and calcium have had limited success, but research on modifiable risk factors, such as obesity surgery, are encouraging. Obstetric management of severe pre-eclampsia focuses on medical management of blood pressure and prevention of seizures using magnesium sulfate, but the ultimate cure remains delivery of the fetus and placenta. Timing of delivery depends on several factors, including gestational age, fetal lung maturity, and most importantly, disease severity. Anesthetic management includes regional anesthesia with careful evaluation of the patient's airway, volume status, and coagulation status to reduce morbidity and mortality. The potential complications of general anesthesia, including intracranial hemorrhage, in these patients make regional anesthesia the preferred choice in many cases. Nevertheless, it is important to be aware of the contraindications to neuraxial anesthesia and to prepare always for the possibility of encountering a difficult airway.

Interpreting abnormal proteinuria in pregnancy: the need for a more pathophysiological approach

This review and opinion article focuses on the definitions and meanings of abnormal protein excretion in pregnancy, asking the following questions: Are our tests to determine abnormal proteinuria adequately performed? Are current guidelines for diagnosis of excessive proteinuria, especially when used to identify preeclampsia, supported by adequate data? Can the magnitude of proteinuria be used as a reliable clinical biomarker of the gravity of preeclampsia? Should timed urine collections, primarily 24-hour excretions, be supplanted by the urine protein/creatinine ratio in clinical practice? The answers to most of these questions are: We are not sure, or some guidelines are poorly supported by data and may prove erroneous. We suggest a more physiologic approach to assessment of proteinuria and believe that if clinicians and investigators looked at proteinuria in terms of how the kidney handles protein in health and disease it would lead to a more rational and evidence-based approach to proteinuria in pregnancy. Finally, we recommend that current cutoff for abnormal proteinuria be used to diagnose preeclampsia, but the level of proteinuria should not guide management. Other variables, such as status of blood pressure control, evidence of increasing organ damage in the liver and hematological systems, evidence of falling glomerular filtration rate, and signs of neurological involvement, are more reliable indicators of severity of preeclampsia.

Periodic urinary protein creatinine ratio for predicting significant proteinuria in preeclampsia in different alternatives: time effectiveness analysis

Preeclampsia is a big problem in obstetrics. The diagnosis relies mainly on the detection of both hypertension and proteinuria. The gold standard for the determination of proteinuria is 24 h urinary protein creatinine ratio; however, this approach is inconvenient and it is a considerable time consuming process that might bring a delayed diagnosis which might result in delayed treatment. Although spot urine measurement can be done, it has very poor prediction. The use of periodic urinary protein creatinine ratio is proposed as a possible alternative to solve this problem. Here, the author tries to perform a time effectiveness analysis for reported models on periodical urinary protein creatinine ratio for predicting significant proteinuria in preeclampsia. Data from previously published reports on this topic are used for further analysis. It seems that the alternative, 4 h, gives the most effectiveness in the shortest period of turnaround time. Hence, this alternative is recommended for screening proteinuria.

Correlation of catheterized and clean catch urine protein/creatinine ratios in preeclampsia evaluation

OBJECTIVE

To examine whether clean catch urine specimens correlate with catheterized specimens for determination of protein/creatinine ratios in pregnant women being evaluated for preeclampsia.

METHODS

Sixty pregnant women who were at least at 20 weeks of gestation were enrolled. Patients with ruptured membranes, vaginal bleeding, or urinary tract infections were excluded. Midstream clean catch urine specimens were collected. Catheterized specimens were then collected and used for clinical management. The specimens were analyzed for protein, creatinine, urinalysis, and culture. Based on sample size calculations, 60 participants were needed to detect a correlation of 0.90 with 80% power and alpha=0.05.

RESULTS

Mean gestational age at enrollment was 35.9 weeks (range 23.1-41.7 weeks). Median (range) clean catch and catheterized protein/creatinine ratios were 0.204 (0.089-3.465) and 0.181 (0.067-3.335), respectively, with a correlation coefficient of 0.897 (P<.001). When results were categorized by degree of proteinuria using a cutoff of 0.3, sensitivity and specificity of the clean catch protein/creatinine ratios were 95.2% and 97.4%. When using a more conservative cutoff of 0.19, sensitivity and specificity of the clean catch protein/creatinine ratios were 96.4% and 75.0%.

CONCLUSION

Clean catch and catheterized urine specimens correlate well in women with suspected preeclampsia. Routine catheterization of pregnant women is not necessary in the evaluation of preeclampsia.

Practical approaches to proteomic biomarkers within prostate cancer radiotherapy trials

INTRODUCTION

Proteomic biomarkers may be useful for monitoring therapeutic response and to triage cancer patients to best therapy.

OBJECTIVES

In this review, we highlight the importance of specimen acquisition, preparation and analysis in radiotherapy proteomic studies. We also discuss practical approaches for the design and execution of clinical proteomic studies using our recent experience based on specimens accrued during prostate cancer radiation therapy.

DISCUSSION AND CONCLUSIONS

Numerous proteomic methods are being employed, including high-throughput mass spectrometry and immunoassays, and using solid tissues, blood and urine for analysis. Given the potential complexity of cytokine and other protein responses, there is a need to assess proteomic signatures within serial samples as longitudinal studies during a course of fractionated radiotherapy (RT).