Prediction using serum glycosylated fibronectin of imminent pre-eclampsia in women with new-onset hypertension

Point-of-Care Tests for Preeclampsia: Systematic Review and Meta-Analysis of Diagnostic Test Accuracy Studies

BACKGROUND

Preeclampsia is a common condition associated with significant maternal and foetal complications. The diagnosis of preeclampsia is based on clinical criteria, with recent introduction of angiogenic markers as an aid to clinical triage. Several biomarkers are now available in a point-of-care test format, which provide swift results to support clinical decision-making.

OBJECTIVES

To determine sensitivity and specificity of available point-of-care tests used for preeclampsia prediction.

SEARCH STRATEGY

Systematic searches of databases (PubMed/Medline, Ovid Embase) from inception till May 2024 were done to identify relevant studies.

SELECTION CRITERIA

we included studies reporting on the diagnostic test accuracy of any point-of-care test for short-term prediction of preeclampsia in the second or third trimester.

DATA COLLECTION AND ANALYSIS

Data were extracted using pre-designed template, and statistical analysis was performed to pool sensitivity and specificity and a hierarchal summary receiver operating characteristic curve model was used. Quality of included studies and risk of bias were assessed following the QUADAS-2 tool.

MAIN RESULTS

We identified 17 studies that met the inclusion criteria, six of which described the use of glycosylated fibronectin, five with Congo red, two with placental growth factor (PlGF) and one study each investigated nephrin, misfolded protein, CD44/FKBPL ratio and inositol phosphoglycan-P. Meta-analysis was possible only for glycosylated fibronectin with a pooled sensitivity of 0.80 (95% CI: 0.51-0.94) and a specificity of 0.84 (95% CI: 0.71-0.93). Five studies were included in meta-analysis, all of which had a low risk of bias on the QUADAS assessment.

CONCLUSIONS

These findings suggest that the point-of-care glycosylated fibronectin testing might be beneficial in clinical triage for preeclampsia in an at-risk population.

Comparison of glycosylated fibronectin versus soluble fms-like tyrosine kinase/placental growth factor ratio testing for the assessment of pre-eclampsia: protocol for a multicentre diagnostic test accuracy study

INTRODUCTION

Pre-eclampsia is a condition associated with significant maternal and neonatal morbidity and mortality. The prediction of pre-eclampsia in high-risk populations using angiogenic markers, such as serum placental growth factor (PlGF) assessment, has been shown to improve maternal outcomes and is recommended by the National Institute for Health and Care Excellence (NICE). However, such tests are not yet available at the point of care (POC). Glycosylated fibronectin (GlyFn) level for the prediction of pre-eclampsia development is available as a POC test (Lumella) and has the potential to aid rapid clinical decision making. This study aimed to test the hypothesis that the sensitivity of the GlyFn test is not inferior to that of the current gold standard of soluble fms-like tyrosine kinase (sFlt)/PlGF-based laboratory testing for pre-eclampsia.

METHODS AND ANALYSIS

This is a multicentre prospective study. Women at risk for pre-eclampsia based on predefined clinical and/or obstetric risk factors will be invited to participate in the study. The recruitment target is 400 participants. Consenting participants will have paired samples for sFlt/PlGF together with POC GlyFn testing. Two follow-up visits are planned at 2 and 4 weeks after the initial recruitment where repeat testing with both tests will be performed. The clinical team will be blinded to the results of the GlyFn test but not that of the sFlt/PlGF test. Clinical care will be based on established protocols incorporating maternal/fetal evaluation and the results of sFlt/PlGF levels. Maternal and neonatal outcome data will be collected to compare the sensitivity and specificity of the tests, with the primary outcome being delivery for pre-eclampsia within 4 weeks.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Health Research Authority and Health and Care Research Wales Ethics Committee. The results of this study will be published in peer-reviewed journals and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

ISRCTN13430018.

Intermanufacturer assessment of diagnostic performance of angiogenic ratio vs glycosylated fibronectin in women with suspected pre-eclampsia

OBJECTIVE

To compare the diagnostic performance of different manufacturers' immunoassays for the soluble fms-like tyrosine kinase-1 (sFlt-1)-to-placental growth factor (PlGF) ratio with that of a point-of-care (PoC) test for glycosylated fibronectin (GlyFn) in women with suspected pre-eclampsia (PE).

METHODS

This was a prospective, single-center, double-blinded, non-interventional study of East Asian women with a singleton pregnancy who presented with hypertension with or without clinical features of PE after 20 weeks' gestation between January 2020 and March 2022. Maternal serum samples were collected at the time of presentation, and subsequent management followed the departmental protocol, based on gestational age, severity of hypertension, fetal condition and presence of severe PE features. Women diagnosed with PE at presentation were excluded. PE was diagnosed according to the 2018 International Society for the Study of Hypertension in Pregnancy classification. Levels of sFlt-1 and PlGF were measured using the Cobas e411 (Roche Diagnostics), BRAHMS KRYPTOR (ThermoFisher Scientific) and iMAGIN 1800 (Ningbo Aucheer) platforms. GlyFn levels were measured using the Lumella™ GlyFn PoC test (DiabetOmics Inc.). The predictive performance of each test to rule out PE within 7 days and rule in PE within 28 days from the date of presentation was assessed. Based on the PROGNOSIS study, a sFlt-1/PlGF ratio of ≤ 38 on the Roche platform was used to predict the absence of PE within 7 days. The sFlt-1/PlGF ratio was classified as high or low using platform-specific thresholds equivalent to a Roche sFlt-1/PlGF ratio of 38, which were derived using Passing-Bablok regression. GlyFn was categorized as high or low using two reported clinical management thresholds (263 μg/mL and 510 μg/mL).

RESULTS

Overall, 236 women with suspected PE were included, of whom 70 (29.7%) were diagnosed with PE; 36 (51.4%) and 70 (100%) developed PE within 7 days and 28 days, respectively. Eighty-eight (37.3%) women had a sFlt-1/PlGF ratio of > 38 on the Roche platform, 79 (33.5%) women had a sFlt-1/PlGF ratio of > 55 on the KRYPTOR platform and 96 (40.7%) women had a sFlt-1/PlGF ratio of > 40 on the iMAGIN 1800 platform. Furthermore, 62 (26.3%) and four (1.7%) women had a GlyFn level of > 263 μg/mL and > 510 μg/mL, respectively. The negative predictive value (NPV) of the sFlt-1/PlGF ratio measured on the Roche, KRYPTOR and iMAGIN 1800 platforms to rule out PE within 7 days after presentation was 83.3%, 82.0% and 82.9%, respectively, while that for GlyFn > 263 μg/mL and > 510 μg/mL was 82.6% and 70.4%, respectively. The corresponding positive predictive values (PPV) to rule in PE within 28 days after presentation were 50.5%, 52.3% and 46.7%, respectively, for the sFlt-1/PlGF ratio, and 35.4% and 50.0%, respectively, for GlyFn > 263 μg/mL and > 510 μg/mL.

CONCLUSIONS

The predictive performance of different manufacturers' assays for the sFlt-1/PlGF ratio to rule in and rule out PE were similar once standardized to a common threshold. Our findings suggest that the sFlt-1/PlGF ratio and GlyFn using a cut-off of 263 μg/mL can both be utilized to rule out PE within 7 days after assessment, with a moderate NPV. The PPV for ruling in PE within 28 days remains poor. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Screening for pre-eclampsia by maternal serum glycosylated fibronectin and angiogenic markers at 36 weeks' gestation

OBJECTIVES

First, to examine the predictive performance of maternal serum glycosylated fibronectin (GlyFn) at 35 + 0 to 36 + 6 weeks' gestation in screening for delivery with pre-eclampsia (PE) and delivery with gestational hypertension (GH) at ≥ 37 weeks' gestation, both within 3 weeks and at any time after the examination. Second, to compare the predictive performance for delivery with PE and delivery with GH of various combinations of biomarkers, including GlyFn, mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1). Third, to compare the predictive performance for delivery with PE and delivery with GH by serum PlGF concentration, sFlt-1/PlGF concentration ratio and the competing-risks model with different combinations of biomarkers as above. Fourth, to compare the predictive performance of screening at 11 + 0 to 13 + 6 weeks vs 35 + 0 to 36 + 6 weeks for delivery with PE and delivery with GH at ≥ 37 weeks' gestation.

METHODS

This was a case-control study in which maternal serum GlyFn was measured in stored samples from a non-intervention screening study in singleton pregnancies at 35 + 0 to 36 + 6 weeks' gestation using a point-of-care device. We used samples from women who delivered at ≥ 37 weeks' gestation, including 100 who developed PE, 100 who developed GH and 600 controls who did not develop PE or GH. In all cases, MAP, UtA-PI, PlGF and sFlt-1 were measured during the routine visit at 35 + 0 to 36 + 6 weeks. We used samples from patients that had been examined previously at 11 + 0 to 13 + 6 weeks' gestation. Levels of GlyFn were transformed to multiples of the expected median (MoM) values after adjusting for maternal demographic characteristics and elements from the medical history. Similarly, the measured values of MAP, UtA-PI, PlGF and sFlt-1 were converted to MoM. The competing-risks model was used to combine the prior distribution of the gestational age at delivery with PE, obtained from maternal risk factors, with various combinations of biomarker MoM values to derive the patient-specific risks of delivery with PE. The performance of screening of different strategies was estimated by examining the detection rate (DR) at a 10% fixed false-positive rate (FPR) and McNemar's test was used to compare the DRs between the different methods of screening.

RESULTS

The DR, at 10% FPR, of screening by the triple test (maternal risk factors plus MAP, PlGF and sFlt-1) was 83.7% (95% CI, 70.3-92.7%) for delivery with PE within 3 weeks of screening and 80.0% (95% CI, 70.8-87.3%) for delivery with PE at any time after screening, and this performance was not improved by the addition of GlyFn. The performance of screening by a combination of maternal risk factors, MAP, PlGF and GlyFn was similar to that of the triple test, both for delivery with PE within 3 weeks and at any time after screening. The performance of screening by a combination of maternal risk factors, MAP, UtA-PI and GlyFn was similar to that of the triple test, and they were both superior to screening by low PlGF concentration (PE within 3 weeks: DR, 65.3% (95% CI, 50.4-78.3%); PE at any time: DR, 56.0% (95% CI, 45.7-65.9%)) or high sFlt-1/PlGF concentration ratio (PE within 3 weeks: DR, 73.5% (95% CI, 58.9-85.1%); PE at any time: DR, 63.0% (95% CI, 52.8-72.4%)). The predictive performance of screening at 35 + 0 to 36 + 6 weeks' gestation for delivery with PE and delivery with GH at ≥ 37 weeks' gestation was by far superior to screening at 11 + 0 to 13 + 6 weeks.

CONCLUSION

GlyFn is a potentially useful biomarker in third-trimester screening for term PE and term GH, but the findings of this case-control study need to be validated by prospective screening studies. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Prediction using serum glycosylated fibronectin and angiogenic factors of superimposed pre-eclampsia in women with chronic hypertension

OBJECTIVE

To compare the predictive performance for delivery with pre-eclampsia (PE) within 2 weeks of assessment in women with chronic hypertension at 24-41 weeks' gestation between serum glycosylated fibronectin (GlyFn) concentration, serum placental growth factor (PlGF) concentration and soluble fms-like tyrosine kinase-1 (sFlt-1) to PlGF concentration ratio.

METHODS

This was a prospective study of 104 women with a singleton pregnancy and chronic hypertension presenting at 24-41 weeks' gestation. Twenty-six (25.0%) cases developed superimposed PE within 2 weeks of sampling. We compared the predictive performance for superimposed PE between GlyFn, PlGF and the sFlt-1/PlGF ratio at a fixed screen-positive rate of approximately 10%.

RESULTS

The median gestational age at sampling was 34.1 (interquartile range, 31.5-35.6) weeks and 84.6% (88/104) of cases were sampled at < 36 weeks. The predictive performance for superimposed PE of the three methods of screening was similar, with detection rates of about 23-27%, at a screen-positive rate of 11% and a false-positive rate of about 5%.

CONCLUSIONS

Measurement of GlyFn is a simple point-of-care test that can be carried out without need for a laboratory and provide results within 10 min of testing. In this respect, it could potentially replace the angiogenic markers that are used currently in the prediction of imminent PE in high-risk women. However, neither GlyFn nor angiogenic factors are likely to improve the management of women with chronic hypertension because their predictive performance for superimposed PE is poor. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.