Protein:creatinine ratio in random urine samples is a reliable marker of increased 24-hour protein excretion in hospitalized women with hypertensive disorders of pregnancy

GDF-15 Suppresses Puromycin Aminonucleoside-Induced Podocyte Injury by Reducing Endoplasmic Reticulum Stress and Glomerular Inflammation

GDF15, also known as MIC1, is a member of the TGF-beta superfamily. Previous studies reported elevated serum levels of GDF15 in patients with kidney disorder, and its association with kidney disease progression, while other studies identified GDF15 to have protective effects. To investigate the potential protective role of GDF15 on podocytes, we first performed in vitro studies using a Gdf15-deficient podocyte cell line. The lack of GDF15 intensified puromycin aminonucleoside (PAN)-triggered endoplasmic reticulum stress and induced cell death in cultivated podocytes. This was evidenced by elevated expressions of Xbp1 and ER-associated chaperones, alongside AnnexinV/PI staining and LDH release. Additionally, we subjected mice to nephrotoxic PAN treatment. Our observations revealed a noteworthy increase in both GDF15 expression and secretion subsequent to PAN administration. Gdf15 knockout mice displayed a moderate loss of WT1+ cells (podocytes) in the glomeruli compared to wild-type controls. However, this finding could not be substantiated through digital evaluation. The parameters of kidney function, including serum BUN, creatinine, and albumin-creatinine ratio (ACR), were increased in Gdf15 knockout mice as compared to wild-type mice upon PAN treatment. This was associated with an increase in the number of glomerular macrophages, neutrophils, inflammatory cytokines, and chemokines in Gdf15-deficient mice. In summary, our findings unveil a novel renoprotective effect of GDF15 during kidney injury and inflammation by promoting podocyte survival and regulating endoplasmic reticulum stress in podocytes, and, subsequently, the infiltration of inflammatory cells via paracrine effects on surrounding glomerular cells.

Simultaneous determination of multiple urine biomarkers for kidney injury using SPE combined with LC-MS/MS

BACKGROUND AND OBJECTIVES

Urinary biomarkers such as low molecular weight proteins and small molecular weight metabolites are crucial in the diagnosis of kidney injury. The objective of this study was to develop and preliminarily validate a sensitive and specific method using solid-phase extraction (SPE) in conjunction with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the simultaneous measurement of these biomarkers in human urine.

METHOD

This study presents the development of a solid-phase extraction method integrated with LC-MS/MS analyzing biomarkers including creatinine, urea, β2-microglobulin, α1-microglobulin, and cystatin C in human urine. An enhanced solid-phase cartridge technique was employed for peptide purification and dilution of small molecule metabolites during sample preparation.

RESULTS

The developed LC-MS/MS method achieved satisfactory separation of the five analytes within 15 min. Accuracy levels ranged from -8.6% to 13.6%. Both intra-assay and inter-assay imprecision rates were maintained below 7.9% for all analytes.

CONCLUSIONS

The established LC-MS/MS method effectively quantifies creatinine, urea, β2-microglobulin, α1-microglobulin and cystatin C concurrently. This offers a viable alternative for the detection of kidney injury biomarkers in human urine, demonstrating potential for clinical application in kidney injury diagnosis.

Correlation between Random Urinary Protein-to-creatinine Ratio and 24-h Urinary Protein Excretion in Preeclampsia

This study aimed to determine the correlation between random urinary protein-to-creatinine ratio in single-voided urine samples and 24-h urinary protein excretion in pregnant women with preeclampsia. A cross-sectional study was conducted at the Department of Gynecology and Obstetrics, Abbasi Shaheed Hospital, Karachi, Pakistan, from July 2019 to June 2020. Fifty women with singleton pregnancy after 20 weeks of gestation with hypertension and 2+ proteinuria or more, according to a dipstick test, were included. Those with chronic hypertension; preexisting renal disease; gestational diabetes; eclampsia; hemolysis, elevated liver enzymes, a low platelet count syndrome; and coexisting urinary tract infections were excluded. Two random urine samples taken at 9:00 a.m. and 2:00 p.m. and 24-h urine samples were collected to evaluate the random urinary protein-to-creatinine and the 24-h protein excretion, respectively. The correlation coefficient (r) between them was calculated using Pearson's correlation test. The patients' mean age was 28.58 ± 5.09 years and their mean gestational age was 32.74 ± 4.44 weeks. Twenty-eight (56%) women were primigravidas, and 22 (44%) were multiparous. The average serum creatinine was 0.80 ± 0.16 mg/dL. The mean random urinary protein-to-creatinine ratio was 0.93 ± 0.7 mg/mg, and the mean 24-h urine was 481.08 ± 20.10 mL. A strong positive correlation was found between the protein-to-creatinine ratio and 24-h urinary protein excretion (r = 0.655; P = 0.01). We concluded that the protein-to-creatinine ratio in spot urine samples could be used as an alternative to in 24-h collection of urine to determine protein excretion in preeclamptic pregnant women.

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.

Comparisons of urine protein-to-creatinine ratios and their dynamic change patterns during labor at term between normal pregnant women and women with pregnancy induced hypertension

Introduction: To evaluate patterns of change in the urine protein-to-creatinine ratios (uPCRs) during labor at term between normal and women with pregnancy-induced hypertension (PIH). Methods: This is an observational study in tertiary referral hospital, recruiting 269 women at term delivery in Taiwan from April 19, 2019 to April 18, 2021. uPCRs in four phases (latent, active, recovery and early postpartum) and related clinical data at delivery were collected. Multivariate analyses with a linear regression model were performed to analyze continuous variables after adjusting for clinical data between two groups. Results: Based on exclusion criteria, 68 normal and 24 pregnant women with PIH were included. There were no differences in the uPCR or the proportion cases of uPCRs ≥ 300 mg/g between normal and PIH group in the four phases. There was a statistically significant tendency for the proportion of uPCRs ≥ 300 mg/g to increase from the latent to the early postpartum phase in both groups. The proportion of uPCRs ≥ 300 mg/g significantly increased from the active to the recovery phase and then declined from the recovery to the early postpartum phase in the normal group. Thus no differences in uPCRs cases change between any two phases in women with PIH, except the duration above stated. Conclusion: This is the first study to demonstrate that uPCRs data are not different between normal pregnant and PIH groups during the course of labor, but it did show different dynamic change patterns throughout the labor phases.

Soluble Endoglin and Uterine Artery Flow Doppler Ultrasonography as Markers of Progression to Preeclampsia in Women with Gestational Hypertension

INTRODUCTION

Gestational hypertension (GH) pregnancies are at a high risk of developing adverse outcomes, including progression to preeclampsia. Prediction of GH-related adverse outcomes is challenging because there are no available clinical tests that may predict their occurrence.

OBJECTIVE

The aim of the study was to determine the clinical usefulness of the soluble endoglin (sEng) and parameters of uterine artery flow (UtAF) measured by Doppler ultrasonography as markers of progression to preeclampsia in women with GH.

SETTING

Mexico City, Mexico.

MATERIAL AND METHODS

We included 77 singleton pregnant women with GH in a nested case-control study. Cases were women who progressed to preeclampsia (n = 36), and controls were those who did not (n = 41). Serum sEng and UtAF measurements were performed at enrollment. The main outcomes measured were progression to preeclampsia and occurrence of preterm delivery (PD) <37 and <34 weeks of gestation, small for gestational age infant (SGA), and fetal growth restriction (FGR).

RESULTS

Women with sEng values in the highest tertile had higher risk of progression to preeclampsia, preterm delivery <34 weeks of gestation, and fetal growth restriction, odds ratios (ORs) ≥3.7. Patients with abnormal UtAF Dopp-ler-pulsatility index had higher risk of progression to preeclampsia, preterm delivery <34 weeks of gestation, small for gestational age infant, and fetal growth restriction (ORs ≥3.3). The presence of notch was associated with higher risk of progression to preeclampsia, preterm delivery <37 and <34 weeks of gestation, SGA infant, and fetal growth restriction (ORs ≥2.9). However, logistic regression analysis revealed that only serum sEng was a significant and independent risk factor for progression of GH to preeclampsia, preterm delivery <34 weeks of gestation, and fetal growth restriction (ORs ≥3.1).

CONCLUSIONS

In GH pregnancies, UtAF Doppler ultrasonography is associated with increased risk of adverse outcomes and progression to preeclampsia. However, serum sEng concentration appears to be a better predictor to assess the risk of adverse maternal and perinatal outcomes and progression to preeclampsia.

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.

Circulating angiogenic factors are associated with progression to preeclampsia and the occurrence of adverse outcomes in women with gestational hypertension

OBJECTIVE

Gestational hypertension is characterized by an imbalance in angiogenic factors. The goal of the current study was to evaluate whether circulating concentrations of proangiogenic and antiangiogenic factors are associated with the risk of progression to preeclampsia and development of adverse outcomes in women with gestational hypertension.

METHODS

We studied 496 women with gestational hypertension. Patients were divided into three groups based on their degree of angiogenic imbalance, evaluated by the soluble fms-like tyrosine kinase-1/placental growth factor ratio: no angiogenic imbalance (≤38), mild angiogenic imbalance (>38-<85), and severe angiogenic imbalance (≥85) or stratified into tertiles according to soluble endoglin (sEng) levels.

RESULTS

The concentrations of all angiogenic factors were significantly different in patients with gestational hypertension than in healthy pregnancy. A significant trend towards higher serum sEng levels was observed as the degree of angiogenic imbalance increased. Patients with severe angiogenic imbalance had higher rates of adverse maternal and perinatal outcomes and progression to preeclampsia (P < 0.001) when compared with patients with no or mild angiogenic imbalance. The risk of combined adverse maternal outcomes and specific adverse outcomes (hemolysis, elevated liver enzymes, low platelet count syndrome, preterm delivery, small-for-gestational-age infant, perinatal death, and progression to preeclampsia within 7, 14, 28, and 56 days) was higher in patients with severe angiogenic imbalance or sEng values in the highest tertile (odds ratio ≥5.6 and ≥2.0, respectively), compared with no angiogenic imbalance or the lowest tertile.

CONCLUSION

In women with gestational hypertension at the time of initial evaluation, circulating concentrations of the soluble fms-like tyrosine kinase-1/placental growth factor ratio and sEng appear to be suitable markers to assess the risk of adverse maternal and perinatal outcomes and progression to preeclampsia.

Usefulness of the sFlt-1/PlGF (Soluble fms-Like Tyrosine Kinase-1/Placental Growth Factor) Ratio in Diagnosis or Misdiagnosis in Women With Clinical Diagnosis of Preeclampsia

Preeclampsia is characterized by angiogenic imbalance (AI), sFlt-1 (soluble fms-like tyrosine kinase-1)/PlGF (placental growth factor) is useful for its diagnosis and prediction of adverse outcomes, but the relationship among the degrees of AI as assessed by this ratio with the correct diagnosis, clinical characteristics, and outcomes in women with clinical diagnosis of preeclampsia are unclear. We studied 810 women with clinical diagnosis of preeclampsia. Patients were divided into 3 groups based on their degree of AI, evaluated by the sFlt-1/PlGF ratio: no AI (≤38), mild AI (>38-<85), and severe AI (≥85). Patients with no AI were more likely to have comorbidities and false significant proteinuria compared with patients with mild and severe AI (P<0.001). The rates of preterm delivery, delivery within 14 days, and small-for-gestational-age infant were higher among patients with severe AI than in patients with no and mild AI (P<0.001) and in patients with mild AI that in those with no AI (P≤0.01). The occurrence of any adverse maternal outcome (HELLP syndrome, elevated liver enzymes, thrombocytopenia, placental abruption, acute kidney injury) was only present in patients with severe AI. Interestingly, the frequency of misdiagnosis of preeclampsia was progressively lower as the degrees of AI increased (no AI: 100%, mild AI: 88.2%, and severe AI: 15.6%). We concluded that in women with clinical diagnosis of preeclampsia, severe AI is characterized by high frequency of true preeclampsia and preeclampsia-related adverse outcomes, in contrast, no and mild AI, are characterized by unnecessary early deliveries, often due to misdiagnosis.

Soluble Endoglin As a Marker for Preeclampsia, Its Severity, and the Occurrence of Adverse Outcomes

Preeclampsia is characterized by an imbalance in angiogenic factors, including sEng (soluble endoglin). However, the relationship of sEng with the severity of preeclampsia, clinical, and laboratory parameters, and the occurrence of adverse outcomes are not fully elucidated. We studied 1002 women with preeclampsia. Serum concentrations of sEng were measured by ELISA. Serum sEng levels were significantly different (P<0.001) in patients with preeclampsia than in healthy pregnancy. In addition, these factors were markedly different in patients with hemolysis, elevated liver enzymes, low platelet count syndrome and eclampsia than in patients with preeclampsia with or without severe features (P<0.001) and in patients with preeclampsia with severe features than in those without severe features (P<0.001). sEng correlated positively with blood pressure, proteinuria, and levels of creatinine, uric acid, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase; and inversely with gestational age, infant's birth weight, and platelets counts (P<0.001 for all). The risk of combined and specific adverse outcomes (pulmonary edema, acute renal failure, placental abruption, hepatic hematoma or rupture, maternal death, cerebral hemorrhage, thrombocytopenia, elevated liver enzymes, preterm delivery, small for gestational age infant, and need for endotracheal intubation, positive inotropic drug support, and hemodialysis) was higher in patients with sEng values in the highest quartile (odds ratio ≥3.1) compared with the lowest quartile. Patients in the highest quartile of sEng were more likely to deliver early compared with those in the lowest quartile (HR, 2.33; 95% CI, 1.91-2.84). We concluded that circulating concentrations of sEng seem to be a suitable marker to assess the severity of preeclampsia and are associated with increased risk of adverse outcomes.

Analysis of Proteinuria Estimation Methods in Hypertensive Disorders of Pregnancy

Purpose of the Study

The gold-standard 24-h urine collection method for protein estimation is inconvenient and is associated with a delay in laboratory analysis. This study was undertaken to compare sulphosalicylic acid test, urine dipstick test, urine protein-to-creatinine ratio with 24-h urine protein estimation in pre-eclampsia cases.

Methods

This is a comparative study and consists of a single group of 764 subjects. This study was conducted in the Department of Obstetrics and Gynaecology in collaboration with the Department of Biochemistry, JIPMER, Pondicherry, India, from February 2011 to January 2014. The subjects included were 764 pre-eclampsia women. A first voided morning sample was obtained for sulphosalicylic acid test, dipstick test, urine protein and creatinine estimation and urine culture, and subsequent urine samples were collected for the 24-h urine protein estimation.

Main Findings

For significant proteinuria, sulphosalicylic acid test with 1 + proteinuria has sensitivity, specificity, PPV and NPV of 59, 48, 39, 67, whereas with 2 + has sensitivity, specificity,PPV and NPV of 44, 88, 75 and 67%, respectively, dipstick test with 1 + proteinuria has sensitivity, specificity, PPV and NPV of 71, 52, 54 and 70%, whereas with 2 + has sensitivity, specificity,PPV and NPV of 49, 87, 75 and 69%, respectively. The spot urine protein-to-creatinine ratio and 24-h urine protein were significantly correlated (r = 0.98; p < 0.0001). The cut-off value for the protein-to-creatinine ratio as an indicator of protein excretion ≥ 300 mg/day was 0.285. The sensitivity, specificity PPV and NPV were 100, 99, 100 and 99%, respectively.

Conclusion

The spot urine protein-to-creatinine ratio is a better method for estimation of proteinuria in pre-eclampsia.

Urinary IgM excretion: a reliable marker for adverse pregnancy outcomes in women with chronic kidney disease

Objective

Chronic kidney disease (CKD) pregnancies are at high risk of developing adverse outcomes. In non-pregnant subjects with CKD, higher urinary IgM levels are associated with poor renal survival and higher rates of cardiovascular deaths. In this study, we assessed whether urinary IgM levels are associated with an increased risk of adverse pregnancy outcomes (APO) in CKD pregnancies.

Methods

We performed a nested case–control study within a cohort of CKD patients with singleton pregnancies attended at a tertiary care hospital. The study included 90 CKD patients who eventually developed one or more APO and 77 CKD patients who did not. Urinary IgM excretion was determined from the 24-h urine samples at enrollment by an ultrasensitive enzyme immunoassay.

Results

The risk for combined APO and for preeclampsia (PE) was higher among women with urinary IgM and proteinuria levels values in the highest quartile or with CKD stages 4–5 (odds ratios, OR ≥ 2.9), compared with the lowest quartile or with CKD stage 1. Urinary IgM levels were more closely associated with the risk of either combined or specific APO (PE, preterm birth, and for having a small-for-gestational-age infant; OR ≥ 5.9) than either the degree of total proteinuria or CKD stages. Among patients with CKD stage 1, the risk of combined APO, PE, and preterm birth was higher in women with urinary IgM levels values in the highest quartile (OR ≥ 4.8), compared with the three lower quartiles, independently of proteinuria.

Conclusion

In CKD pregnancies, at the time of initial evaluation, proteinuria and CKD stage are associated with increased risk of combined APO. However, urinary IgM concentrations appear to be better predictors of an adverse outcome and may be useful for risk stratification in CKD pregnancies.

Lower circulating angiotensin II levels are related to the severity of preeclampsia and its risk as disclosed by a specific bioassay

Preeclampsia is characterized by an increased sensitivity to angiotensin II (Ang II). We herein assessed whether serum Ang II levels measured by a new developed bioassay are associated with preeclampsia, its severity, and the risk for developing this disease.Using a cross-sectional design, we studied 90 pregnant women (30 healthy pregnant and 60 with preeclampsia [30 with- and 30 without severe features]). We also used a nested case-control study with 30 women who eventually developed preeclampsia and 31 normotensive controls. Serum samples were collected at diagnosis of preeclampsia or at 4-week intervals (from weeks 12th to 36th). Ang II was measured using a bioassay.At diagnosis of preeclampsia, serum Ang II concentrations were significantly lower in preeclampsia without and with severe features (P = .001 and P < .001, respectively) than in healthy pregnancy. In addition, Ang II was different in preeclampsia with severe features than in those without severe features (P = .048). Women who subsequently developed preeclampsia had lower Ang II levels than women with normal pregnancies, and these changes became significant at 24 weeks onward. The risk to developing preeclampsia was higher among women with Ang II concentration values in the lowest quartile of the control distribution from 12 weeks onward (odds ratio ranging from 3.8 [95% CI 1.3-11.1] to 6.5 [95% CI 1.6-26.9]).We concluded that concentrations of Ang II are markedly diminished at diagnosis of preeclampsia and are closely associated with the severity of disease. Changes in circulating levels of Ang II precede the clinical presentation of preeclampsia.

Physiologic proteinuria in labor and postpartum: The results of the postpartum proteinuria trial (PoPPy)

The urine protein to creatinine ratio (PC) is a sensitive and specific means of diagnosing preeclampsia in the antepartum period, but the 0.3 g protein per gram of creatinine threshold may be non-specific postpartum due to physiologic proteinuria after delivery. The objective of this study was to examine the reliability of PC in labor and postpartum and to determine if PC is affected by mode of delivery. This is the first study of its kind to examine physiologic proteinuria by catheterized PC in individual patients before and after delivery. This single-center prospective cohort study included two groups: term uncomplicated nulliparous patients in labor with epidural analgesia and patients for scheduled repeat cesarean deliveries. Patients with hypertension, antepartum proteinuria, renal disease, gross hematuria, or evidence of infection were excluded. Catheterized pre- and post-delivery urine PC were compared using paired t-tests. 27 and 40 patients were included in the vaginal and cesarean delivery groups, respectively. 52% of the vaginal delivery and 58% of the cesarean delivery groups were positive for proteinuria at the 0.3 g protein per g creatinine threshold. Pre- and post-delivery specimens were significantly different in the vaginal (mean difference 0.28, p = 0.05) and cesarean (mean difference 0.25, p < 0.01) delivery groups. The conclusions reached included the finding that PC measurements are unreliable in the immediate postpartum period regardless of mode of delivery, and utilizing the 0.3 threshold to diagnose preeclampsia in close proximity to delivery would contribute to increased false positive tests.

Circulating angiogenic factors are related to the severity of gestational hypertension and preeclampsia, and their adverse outcomes

Gestational hypertension (GH) and preeclampsia (PE) are characterized by an imbalance in angiogenic factors. However, the relationship among these factors with the severity of hypertensive disorders of pregnancy (HDP) and adverse outcomes are not fully elucidated. We examined whether these biomarkers are related with the severity of HDP and adverse outcomes.Using a cross-sectional design, serum concentrations of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and soluble endoglin were determined in 764 pregnant women: 75 healthy pregnant, 83 with mild GH (mGH), 105 with severe GH (sGH), 122 with mild PE (mPE), and 379 with severe PE (sPE).All angiogenic factors' concentrations were significantly different (P ≤ 0.041) in HDP than in healthy pregnancy. In addition, these factors were markedly different in sPE than in mPE, sGH, or mGH (P ≤ 0.027) and in patients with sGH that in those with mPE or mGH (P < 0.05). As compared to mGH and mPE, patients with sGH and sPE had higher rates of both preterm delivery at <34 weeks of gestation and small-for-gestational age infants. Moreover, patients with sPE had higher rates of adverse maternal outcomes (P < 0.001) when compared to patients with mGH, sGH, or mPE. In all cases, levels of sFlt-1/PlGF ratio were significantly higher in patients with sGH and sPE who had adverse perinatal and maternal outcomes than in those with sGH and sPE who did not (P ≤ 0.016).Circulating concentrations of angiogenic factors appear to be suitable markers to assess the severity of GH and PE, and adverse outcomes.

Circulating Angiogenic Factors and the Risk of Preeclampsia in Systemic Lupus Erythematosus Pregnancies

OBJECTIVE

To investigate whether angiogenic factors are associated with risk of developing preeclampsia in pregnant women with systemic lupus erythematosus (SLE).

METHODS

We performed a nested case-control study within a cohort of SLE women with singleton pregnancies. The study included 42 patients with SLE who eventually developed preeclampsia and 75 normal SLE pregnancies. Serum samples were collected at 4-week intervals (from weeks 12 to 36). Serum samples were analyzed for soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), and soluble endoglin (sEng).

RESULTS

Women destined to develop preeclampsia had lower PlGF levels and higher sFlt-1 and sEng levels, and a higher sFlt-1/PlGF ratio than normal pregnancies. These changes became significant at 12 weeks in patients destined to develop either early onset (< 34 weeks, p ≤ 0.003) or late-onset preeclampsia (≥ 34 weeks, p ≤ 0.02). The risk to develop preeclampsia was higher among patients with PlGF concentration values in the lowest quartile or with sFlt-1 and sEng levels, and sFlt-1/PlGF ratio, in the highest quartile of the normal SLE pregnancies distribution. The OR were higher and appeared earlier in patients destined to develop early onset preeclampsia (OR ≥ 16.2, from Week 12 onward) than in patients who presented preeclampsia later (OR ≥ 8.9, from Week 24 onward).

CONCLUSION

Changes in circulating concentrations of sFlt-1, PlGF, sEng, and the sFlt-1/PlGF ratio precede the onset of preeclampsia in SLE pregnancies. The risk profile of circulating angiogenic factors for developing preeclampsia distinctly evolves depending on whether this condition is manifested earlier or later.

The value of the urinary protein:creatinine ratio for the detection of significant proteinuria in women with suspected preeclampsia

To explore the correlation between urinary protein:creatinine ratio and 24-h excretion of protein, we studied 149 women referred to a day assessment unit for investigations for suspected preeclampsia. Paired samples were obtained for measurement of urinary protein:creatinine ratio and 24-h protein excretion. Collection of a 24-h urine sample was validated by the daily creatinine excretion. The outcome measure was proteinuria of 300 mg/day or more. Inaccurate 24-h collection was observed in 17% of women. All women (n = 56) with a protein:creatinine ratio >60 mg/mM had significant proteinuria. No woman with protein:creatinine ratio <18 mg/mM (n = 20) had significant proteinuria. We recommend that a dual cut-off should be used for excluding and "ruling in" the diagnosis of significant proteinuria. A 24-h urine collection should be used only for urinary protein:creatinine ratio values between 18 and 60 mg/mM in the detection of significant proteinuria.

Preeclampsia is associated with lower production of vascular endothelial growth factor by peripheral blood mononuclear cells

BACKGROUND

Recent studies show that vascular endothelial growth factor (VEGF) downregulation is implicated in preeclampsia (PE) pathophysiology. This study assessed the relationship between PE and VEGF levels produced by peripheral blood mononuclear cells (PBMCs) and their serum levels.

METHODS

A cross-sectional design was performed in 36 patients who had hypertensive disorders during pregnancy. We also used a longitudinal design with 12 pregnant women with risk factors for PE development and/or abnormal uterine arteries by Doppler study. VEGF and soluble fms-like tyrosine kinase-1 (sFlt-1) levels were measured for all patients in both designs.

RESULTS

sFlt-1 serum was higher in preeclamptic patients (n = 26), whereas VEGF produced by stimulated PBMCs was lower than in healthy pregnant women and VEGF levels produced by stimulated PBMCs were even lower (p <0.003) in severe PE (n = 16). The receiver-operating characteristic curve analysis allowed establishing a cut-off value to identify patients with PE. VEGF production by PBMCs was 339.87 pg/mL. In addition, a robust linear regression model was performed to adjust the variance in VEGF levels. The patients' age decreased VEGF levels and was adjusted by weeks of gestation (WG) in our model. In the longitudinal study, 7/12 patients developed PE. VEGF produced by PBMCs cells was significantly lower in PE at 24-26 WG.

CONCLUSIONS

VEGF production by PBMCs is inhibited during PE, creating a downregulation of the microenvironment; this deficiency may contribute to the pathogenesis of disease.

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.

A random protein-creatinine ratio accurately predicts baseline proteinuria in early pregnancy

OBJECTIVE

Data surrounding the use of a random urine protein:creatinine ratio (PCR) in the diagnosis of preeclampsia is conflicting. We sought to determine whether PCR in early pregnancy can replace the 24-hour urine collection as the primary screening test in patients at risk for baseline proteinuria.

METHODS

Women requiring a baseline evaluation for proteinuria supplied a urine sample the morning after their 24-hour collection. The PCR was analyzed as a predictor of significant proteinuria (≥150 mg). A regression equation to estimate the 24-hour protein value from the PCR was then developed.

RESULTS

Sixty of 135 subjects enrolled completed the study. The median 24-hour urine protein and PCR were 90 mg (IQR: 50-145) and 0.063 (IQR: 0.039-0.083), respectively. Fifteen patients (25%) had significant proteinuria. PCR was strongly correlated with the 24-hour protein value (r = 0.99, p < 0.001) and highly predictive of significant proteinuria (AUC = 0.86). A PCR cut-point of 0.079 yielded a sensitivity of 93.3% and a specificity of 57.8%. The resulting regression equation [total protein = 46.5 + 904.2*PCR] accurately estimates the actual 24-hour protein (95% CI: ±88 mg).

CONCLUSION

A random urine PCR accurately estimates the 24-hour protein excretion in the first half of pregnancy and can be used as the primary screening test for baseline proteinuria in at-risk patients.

Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy

OBJECTIVE

This guideline summarizes the quality of the evidence to date and provides a reasonable approach to the diagnosis, evaluation and treatment of the hypertensive disorders of pregnancy (HDP).

EVIDENCE

The literature reviewed included the previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines from 2008 and their reference lists, and an update from 2006. Medline, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Registry of Controlled Trials (CCRCT) and Database of Abstracts and Reviews of Effects (DARE) were searched for literature published between January 2006 and March 2012. Articles were restricted to those published in French or English. Recommendations were evaluated using the criteria of the Canadian Task Force on Preventive Health Care and GRADE.

Detection of proteinuria in pregnancy: comparison of qualitative tests for proteins and dipsticks with urinary protein creatinine index

BACKGROUND AND OBJECTIVES

Excretion of urinary protein increases to 300 mg/d (from up to 150 mg/d) in normal pregnancy. Values above this may be due to disorders that can endanger the patient or her pregnancy. Quantitative analysis of 24-hour urine is considered the gold standard for ascertaining daily protein excretion. Routine laboratory tests performed on spot urine samples indicate protein concentration in the particular sample, and can lead to diagnostic error if urine output is less or more than 1L/d. The Protein Creatinine Index (PCI) shows good correlation with 24-hour protein estimation. However, PCI varies with sex and race. We have correlated the results of qualitative estimation procedures and the dipstick values with protein creatinine index.

MATERIAL AND METHODS

We measured protein and creatinine in spot urine samples obtained from 57 pregnant and 80 non-pregnant healthy women of 18-36 years, and calculated PCI. We also tested the samples qualitatively for proteins by routine tests and dipsticks.

RESULTS

Normal range of PCI in non-pregnant women, determined by a non-parametric method was 30-150. PCI was increased significantly in pregnancy (maximum increase in the third trimester). Amongst the qualitative tests, heat coagulation test gave the lowest percentage of false positives and a slightly higher percentage of false negatives compared to Heller's nitric acid and sulphosalicylic acid tests, and dipsticks.

INTERPRETATIONS AND CONCLUSIONS

We conclude that heat coagulation test be used for initial screening, with PCI being performed on all samples testing positive to rule out false positives.

Circulating Angiogenic Factors and Urinary Prolactin as Predictors of Adverse Outcomes in Women With Preeclampsia

Preeclampsia is characterized by an imbalance in angiogenic factors. Urinary prolactin (PRL) levels and its antiangiogenic PRL fragments have been associated with disease severity. In this study, we assessed whether these biomarkers are associated with an increased risk of adverse maternal and perinatal outcomes in preeclamptic women. We studied 501 women with preeclampsia attended at a tertiary care hospital. Serum concentrations of soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), and soluble endoglin (sEng), as well as urinary PRL levels, were measured by enzymed-linked immunosorbent assay. Antiangiogenic PRL fragments were determined by immunoblotting. The risk for any adverse maternal outcome and for having a small-for-gestational-age infant was higher among women with sFlt-1/PlGF ratios, sEng, and urinary PRL level values in the highest quartile (odds ratios ≥2.7), compared with the lowest quartile. Both urinary PRL levels and the presence of antiangiogenic PRL fragments were more closely associated with the risk of specific adverse maternal outcomes (placental abruption, hepatic hematoma or rupture, acute renal failure, pulmonary edema, maternal death, and need for endotracheal intubation, positive inotropic drug support, and hemodialysis; odds ratios ≥5.7 and ≥4.7, respectively) than either sFlt-1/PlGF ratio or sEng alone. We concluded that in preeclamptic women at the time of initial evaluation, sFlt-1/PlGF ratio and sEng are associated with increased risk of combined adverse maternal outcomes. However, urinary PRL concentrations and its antiangiogenic fragments appear to be better predictors of an adverse maternal outcome and may be useful for risk stratification in preeclampsia.

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.

Proteinuria in special populations: pregnant women and children

Proteinuria is the hallmark of glomerular kidney disease. It is used diagnostically to follow disease progression and to determine response to therapy. Thus, it is necessary to have an understanding of the mechanisms of proteinuria and the limitations to its accurate assessment in special populations. In this article, we review 2 special populations--pregnant women and children--providing insight into their unique circumstances that require consideration when assessing proteinuria.

Stimulating autoantibodies against the angiotensin II type 1 receptor are not associated with preeclampsia in Mexican-Mestizo women

OBJECTIVE

Recent studies have demonstrated that stimulating autoantibodies against the angiotensin II type 1 receptor (AT1R-AA) are frequently detected in the sera from women with preeclampsia, suggesting that they may play an important role in the pathogenesis of this disease. Nevertheless, the real clinical significance of AT1R-AA in preeclampsia is still controversial due to the paucity of appropriate large comparative studies that require cumbersome, time-consuming, and expensive bioassays to detect AT1R-AA. At present, the prevalence of AT1R-AA in large populations of preeclamptic women is unknown. In an attempt to clarify this issue, we assessed the presence and potential clinical significance of AT1R-AA in a large population of Mexican-Mestizo women with preeclampsia.

METHODS

Using a cross-sectional design, we determined the presence of AT1R-AA in 525 pregnant women (99 healthy pregnant, 96 with mild preeclampsia, and 330 with severe preeclampsia) by a new bioassay that employs human embryonic kidney-293 cells stably expressing the recombinant rat AT1R and a 4x nuclear factor of activated T cells responsive luciferase construct as well as by the reference assay in Chinese hamster ovary (CHO) cells.

RESULTS

We found that IgG obtained from sera of healthy pregnant women and patients with preeclampsia were unable to induce luciferase activity in both HEK-293 and Chinese hamster ovary cells expressing functional angiotensin II receptor type 1. Therefore, the frequency of patients with AT1R-AA was zero.

CONCLUSION

We concluded that in Mexican-Mestizo women agonistic AT1R-AA cannot be invoked as a factor involved in the pathogenesis of preeclampsia. Whether these findings can be attributed to genetic or environmental factors remains unknown.

Correlation of random urine protein creatinine (P-C) ratio with 24-hour urine protein and P-C ratio, based on physical activity: a pilot study

Quantification of proteinuria is usually predicated upon 24-hour urine collection. Multiple factors influence urine collection and the rate of protein and creatinine excretion. Urine collection is often incomplete, and therefore creatinine and protein excretion rates are underestimated. A random urine protein-creatinine (P-C) ratio has been shown over the years to be a reliable alternative to the 24-hour collection for detection and follow up of proteinuria. However, urine protein excretion may be influenced by physical activity. We studied 48 patients with proteinuria and varying levels of physical activity to determine the correlation between the measures of urine protein excretion. The correlation coefficient (r) between 24-hour urine total protein and random urine P-C ratio was 0.75 (P < 0.01) in the overall study population, but varied according to the level of proteinuria and physical activity in a stratified analysis: r = 0.99 (P < 0.001) and r = 0.95 (P < 0.01) in bedridden patients; r = 0.44 (P = not significant [NS]) and r = 0.54 (P = NS) in semiactive patients; and r = 0.44 (P = NS) and r = 0.58 (P < 0.05) in active patients with nephrotic- (>3500 mg/day) and non-nephrotic (<3500 mg/day) range proteinuria, respectively. The correlation appeared to be stronger between random urine and 24-hour urine P-C ratio for the overall study population (r = 0.84; P < 0.001), and when stratified according to the level of proteinuria and physical activity: r = 0.99 (P < 0.001) and r = 0.92 (P < 0.01) in bedridden patients; r = 0.61 (P = NS) and r = 0.54 (P = NS) in semiactive patients; and r = 0.64 (P < 0.02) and r = 0.52 (P < 0.05) in active patients with nephrotic and non-nephrotic range proteinuria, respectively. We conclude that the random urine P-C ratio is a reliable and practical way of estimating and following proteinuria, but its precision and accuracy may be affected by the level of patient physical activity.

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.

Protein and albumin-to-creatinine ratios in random urines accurately predict 24 h protein and albumin loss in patients with kidney disease

BACKGROUND

Random urine protein-to-creatinine (PCR) and albumin-to-creatinine (ACR) ratios have been proposed as alternatives to 24 h urine measurements to simplify sample collection and overcome errors. The aim of this study was to examine the ability of PCR and ACR to predict urinary 24 h protein and albumin loss, respectively, in patients with kidney disease, and determine the most appropriate time of collection.

METHODS

Eighty-three patients were recruited from a renal outpatient clinic. In a 24 h period, each collected an early-morning urine (EMU), second and third voids, and the remaining urine passed that day. PCR and ACR were determined in random urines and compared with the 24 h loss of protein and albumin, respectively.

RESULTS

For all patients, median (range) 24 h urine protein and albumin losses were 220 (30-15600) and 60 (<8-10,557) mg, respectively. Ratios derived from each of three random urines correlated well with 24 h protein or albumin loss (Spearman's r(s) > 0.87, P < 0.0001). Receiver operator characteristic (ROC) curve analysis showed PCR accurately predicted both an abnormal 24 h urine protein > or =150 mg/24 h (areas under curves [AUC] 0.90-0.92) and significant proteinuria above 300 mg/24 h (AUC between 0.97 and 1.00). ACR accurately predicted both an abnormal 24 h urine albumin > or =30 mg/24 h (AUC 0.98 to 0.99) and frank albuminuria at > or =300 mg/24 h or > or =700 mg/24 h (AUC between 0.99 and 1.00). EMU and random urines performed equally well in predicting proteinuria and albuminuria from PCR and ACR, respectively.

CONCLUSIONS

By careful choice of cut-offs, both PCR and ACR can be used in patients with kidney disease to rule in or rule out abnormal 24 h losses of protein and albumin. EMU and, importantly, random samples can be used as surrogates for 24 h urine collections.

How should proteinuria be detected and measured?

Proteinuria is a classic sign of kidney disease and its presence carries powerful prognostic information. Although proteinuria testing is enshrined in clinical practice guidelines, there is surprising variation among such guidelines as to the definition of clinically significant proteinuria. There is also poor agreement as to whether proteinuria should be defined in terms of albumin or total protein loss, with a different approach being used to stratify diabetic and non-diabetic nephropathy. Further, the role of reagent strip devices in the detection and assessment of proteinuria is unclear. This review explores these issues in relation to recent national and international guidelines on chronic kidney disease (CKD) and epidemiological evidence linking proteinuria and clinical outcome. The authors argue that use of urinary albumin measurement as the front-line test for proteinuria detection offers the best chance of improving the sensitivity, quality and consistency of approach to the early detection and management of CKD.

Aims of obstetric critical care management

The aims of critical care management are broad. Critical illness in pregnancy is especially pertinent as the patient is usually young and previously fit, and management decisions must also consider the fetus. Assessment must consider the normal physiological changes of pregnancy, which may complicate diagnosis of disease and scoring levels of severity. Pregnant women may present with any medical or surgical problem, as well as specific pathologies unique to pregnancy that may be life threatening, including pre-eclampsia and hypertension, thromboembolic disease and massive obstetric haemorrhage. There are also increasing numbers of pregnancies in those with high-risk medical conditions such as cardiac disease. As numbers are small and clinical trials in pregnancy are not practical, management in most cases relies on general intensive care principles extrapolated from the non-pregnant population. This chapter will outline the aims of management in an organ-system-based approach, focusing on important general principles of critical care management with considerations for the pregnant and puerperal patient.

Protein/creatinine ratio in preeclampsia: a systematic review

OBJECTIVE

To estimate the accuracy of the protein/creatinine ratio in predicting 300 mg of protein in 24-hour urine collection in pregnant patients with suspected preeclampsia.

DATA SOURCES

Articles were identified through electronic databases (MEDLINE, CINHAL, and Cochrane) using the terms "preeclampsia," "protein/creatinine ratio," and "diagnosis," during the period January 1966 to October 2007. The relevant citations were hand searched.

METHODS OF STUDY SELECTION

Included studies evaluated patients for suspected preeclampsia with a 24-hour urine sample and a protein/creatinine ratio. Only English-language articles were included. Studies including patients with only chronic illness such as chronic hypertension, diabetes mellitus, or renal impairment were excluded. Using the Quality Assessment of Diagnostic Accuracy Studies questionnaire, we created group 1 satisfying all the required criteria and group 2 not satisfying all of it. Two researchers independently extracted the accuracy data. A graph comparing six receiver operating characteristic curves was plotted.

TABULATION, INTEGRATION, AND RESULTS

Twenty-one studies were identified, but only seven met our inclusion criteria (1,717 total patients). Group 1, with three studies, had 510 patients. The studies evaluated different cut points for positivity of protein/creatinine ratio from 130 mg/g to 700 mg/g. For protein/creatinine ratio 130-150 mg/g, sensitivity ranged from 90-99%, and specificity ranged from 33-65%; for protein/creatinine ratio 300 mg/g, sensitivity ranged from 81-98% and specificity ranged from 52-99%; for protein/creatinine ratio 600-700 mg/g, sensitivity ranged from 85-87%, and specificity ranged from 96-97%.

CONCLUSION

Random protein/creatinine ratio determinations are helpful primarily when they are below 130-150 mg/g, in that 300 mg or more proteinuria is unlikely below this threshold. Midrange protein/creatinine ratio (300 mg/g) has poor sensitivity and specificity, requiring a full 24-hour urine for accurate results. Higher thresholds have not been adequately studied.

Health status and renal function evaluation of kidney vendors: a report from Pakistan

Unrelated kidney transplants have lead to commerce and kidney vending in Pakistan. This study on 104 vendors reports demographics, history, physical and systemic examination, ultrasound findings, renal and liver function and GFR by Cockcroft-Gault. Results were compared with 184 age, sex and nephrectomy duration matched living-related donors controls. Comparison of vendors versus controls showed mean age of 30.55 +/- 8.1 versus 30.65 +/- 7.85 (p = 0.91) years, M:F of 4.5:1 versus 4.2:1 and nephrectomy period of 33.89 +/- 30 versus 32.01 +/- 29.71 (p = 0.60) months respectively. Of the vendors 67% were bonded laborers earning <50 $/month as compared to controls where 68% were skilled laborers and self-employed earning >100 $/month. History of vendors revealed jaundice in 8%, stone disease in 2% and urinary tract symptoms in 4.8%. Postnephrectomy findings between vendors versus donors showed BMI of 21.02 +/- 2.8 versus 23.02 +/- 4.2 (p = 0.0001), hypertension in 17% versus 9.2% (p = 0.04), serum creatinine (mg/dL) of 1.17+/-0.21 versus 1.02 +/- 0.27 (p = 0.0001), GFR (mL/min) of 70.94 +/- 14.2 versus 95.4 +/- 20.44 (p = 0.0001), urine protein/creatinine of 0.150 +/- 0.109 versus 0.10 +/- 0.10 (p = 0.0001), hepatitis C positivity in 27% versus 1.0% (p = 0.0001) and hepatitis B positive 5.7% versus 0.5% (p = 0.04), respectively. In conclusion, vendors had compromised renal function suggesting inferior selection and high risk for developing chronic kidney disease in long term.

Urinary prolactin as a reliable marker for preeclampsia, its severity, and the occurrence of adverse pregnancy outcomes

CONTEXT

It has been proposed that preeclampsia may result from of an imbalance in angiogenic factors. Although prolactin (PRL) is mainly related to lactation, it is also involved in other biological functions, including angiogenesis.

OBJECTIVE

Our objective was to determine the relationship among preeclampsia, serum and urinary PRL (uPRL) levels, and excretion of antiangiogenic PRL fragments in urine.

STUDY DESIGN

Using a cross-sectional design, uPRL and serum PRL levels, and the presence of PRL isoforms were determined in 546 pregnant women: 207 healthy pregnant, 124 with gestational hypertension, 48 with mild preeclampsia, and 167 with severe preeclampsia (sPE).

RESULTS

uPRL concentrations were significantly (P < 0.001) higher in preeclampsia (11.99 ng/mg creatinine) than in healthy pregnancy (0.20 ng/mg creatinine) and gestational hypertension (0.19 ng/mg creatinine), and were even higher in sPE compared with mild preeclampsia (21.20 vs. 2.77 ng/mg creatinine, respectively; P < 0.001). Antiangiogenic PRL fragments (14-16 kDa) were detected in 21.6% of urine samples from women with sPE but in none from other groups. Patients with hemolysis, elevated liver enzymes, low platelet count syndrome, and/or eclampsia, placental abruption, acute renal failure, and pulmonary edema exhibited highest uPRL concentrations (P < or = 0.028) and frequency of antiangiogenic PRL fragments in urine (P < or = 0.036). High-serum PRL levels were associated with sPE independently of gestational age, proteinuria, and prolactinuria (P = 0.032).

CONCLUSIONS

Preeclampsia is characterized by increased uPRL excretion. uPRL concentrations and their isoforms appear to be suitable markers to assess the severity of preeclampsia and occurrence of adverse outcomes. PRL and and/or its isoforms might be involved in the pathophysiology of preeclampsia.