(172) Reference range for Elecsys sFlt-1/PlGF ratio in a diverse U.S population

Thursday, January 30, 2025

10:30 AM – 12:30 PM

Presenting Author(s)

Antonio F. Saad, MBA, MD (he/him/his)

Director of Perinatal Research Unit, MFM Fellowship Program Director
Inova Health
Falls Church, Virginia, United States

Coauthor(s)

DH

David M. Haas, MD, MS

Attending Physician
Indiana University School of Medicine
Indianapolis, Indiana, United States
EC

Eugene Y. Chang, MD

Division Director
Medical University of South Carolina
Charleston, South Carolina, United States
Scott A. Shainker, DO

Associate Professor of Obstetrics, Gynecology, and Reproductive Biology
Maternal Fetal Care Center Associate Professor of Surgery Associate Professor of Obstetrics, Gynecology and Reproductive Biology Harvard Medical School
Boston, Massachusetts, United States
MS

Michelle Silasi, MD

Mercy Hospital St. Louis
St. Louis, Montana, United States
George R. Saade, MD (he/him/his)

Professor and Chair, Associate Dean for Women's Health Obstetrics and Gynecology
Macon & Joan Brock Virginia Health Sciences Eastern Virginia Medical School at Old Dominion University
Norfolk, Virginia, United States
SR

Sarosh Rana, MD, MPH

University of Chicago Medicine
Chicago, Illinois, United States
Tetsuya Kawakita, MD, MS

Associate Professor
Macon & Joan Brock Virginia Health Sciences Eastern Virginia Medical School at Old Dominion University
Norfolk, VA, United States
Luis D. Pacheco, MD

Professor
University of Texas Medical Branch
Galveston, Texas, United States
JP

Jennifer Powers Carson, PhD

Washington University Core Lab for Clinical Studies
St. Louis, Montana, United States
AD

Angela Dietl, BSc, PhD

Roche Diagnostics GmbH
Penzberg, Bayern, Germany

Submitting Author(s)

Deirdre Allegranza, MSc

Clinical Development Lead
Roche Diagnostics International
Zug, Zug, Switzerland

Coauthor(s)

GG

Ge Guo, MS

Roche Diagnostics Operations, Inc.
Indianapolis, Indiana, United States
David M. Stamilio, MD, MSCE

Professor, Maternal and Fetal Medicine
Wake Forest University School of Medicine
Winston Salem, North Carolina, United States

Objective: Preeclampsia (PE) is a major cause of maternal and neonatal mortality and morbidity. The imbalance of two proteins, soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF), are known to contribute significantly to the development of PE.
The sFlt-1/PlGF ratio test is used for the clinical prediction of PE in many countries worldwide but has not been widely adopted in the US. This study aimed to determine the reference range for the Roche Elecsys^Ⓡ sFlt-1/PlGF ratio (electrochemiluminescent immunoassays) in a racially and ethnically diverse healthy US population of pregnant women at 23+0 - 34+6 gestational weeks.

Study Design: A non-interventional sample and data collection study performed from November 2022 to December 2023 at nine US hospitals. Consented apparently healthy pregnant individuals (≥18 years old) had one serum sample collected (frozen at -60 to -90°C) with postpartum maternal and neonatal clinical outcomes collected to confirm eligibility for analysis. To ensure a healthy study population subjects were excluded from analysis if they met any of the pre-defined exclusion criteria including diagnosis of specific health conditions or preterm delivery < 37 weeks. The sFlt-1/PlGF ratio was not known to the enrolling sites at any time. A nonparametric method per CLSI EP28-A3c was used to calculate the central 95% reference interval and the 90% confidence intervals (CIs) around the lower and upper reference limits (2.5th and 97.5th percentiles) for the overall cohort and three gestational age windows subgroups (23+6 - 26+6, 27+0 - 30+6, 31+0 - 34+6).

Results: Of 591 enrolled, 380 subjects met criteria for analysis in gestational weeks 23+0 - 34+6 days. Gestational hypertension was the main reason for exclusion followed by PE and preterm delivery. The cohort (n=380) was representative of the US population in terms of self-reported race and ethnicity: 78.16% White, 14.21% Black/African American, 5.53% Asian and 18.95% Hispanic or Latina.

Conclusion: This study is the first to estimate sFlt-1/PlGF ratio reference ranges in a diverse US population using the Roche Elecsys assays.