PB0838 - Association Between Hemoglobin Values and VWF Assays: A Multi-Center Investigation

Monday, June 26, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

JS

Jillian Simoneau, MD

Fellow
University of Michigan, Ann Arbor, MI, USA
Whitmore Lake, Michigan, United States

Co-Author(s)

CT

Cindy Tay

PGY-2
Vanderbilt University Medical Center, Nashville, TN, USA
Nashville, Tennessee, United States
AW

Allison P. Wheeler

Associate Professor in Pediatrics
Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
Nashville, Tennessee, United States
LA

Lauren Amos

Associate Professor of Pediatrics
Children's Mercy Hospital, Kansas City, MO, USA
Kansas City, Missouri, United States
MM

Meghan McCormick

Pediatric Hematology Oncology Provider
UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
Pittsburgh, Pennsylvania, United States
YC

Yonairy Collado

PGY-3
UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
Pittsburgh, Pennsylvania, United States
Megan C. Brown, MD, MSc

Assistant Professor of Pediatrics
Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University School of Medicine
Atlanta, Georgia, United States
Angela C. Weyand, MD (she/her/hers)

Associate Professor
University of Michigan Medical School
Ann Arbor, Michigan, United States

Background: Von Willebrand disease (VWD) is the most common inherited bleeding disorder. Diagnosing VWD is challenging as factor levels are influenced by a multitude of variables including ABO blood type, age, stress induced hypothalamic-pituitary-adrenal axis changes, and environmental factors such as inflammation and hormone exposure. An association between hemoglobin, von Willebrand Factor (VWF), and Factor VIII activity has been described in single institution studies but further study is needed.

Aims: To investigate the association between hemoglobin and VWF assays. We hypothesized that a negative association exists.

Methods: A retrospective review was performed across five medical centers of subjects aged 0-21 years. Laboratory results included hemoglobin, von Willebrand factor antigen (VWF Ag), and a von Willebrand platelet binding assay (ristocetin cofactor or GP1b). Laboratory assessments with recent desmopressin or VWF replacement therapy were excluded. Age and estrogen use at time of laboratory assessment were also collected. Absolute differences were calculated between the two timepoints for hemoglobin, VWF Ag, ristocetin cofactor assay, GP1b binding activity, age and estrogen dose. Simple and multiple linear regression were performed.

Results: 481 subjects were included in analysis (Table 1). 459 subjects had information on estrogen exposure at both timepoints. There was a statistically significant negative association between absolute change in hemoglobin and VWF Ag, ristocetin cofactor assay, and GP1b binding activity (p < 0.0001, p< 0.0001, p=0.01, Figure 1). Incorporating change in estrogen and age into multiple linear regression, this association held (p < 0.001, p< 0.001, p=0.02 respectively).

Conclusion(s): This multi-institutional study found a negative association between hemoglobin values and VWF Ag level, ristocetin cofactor activity and GP1b binding activity on simple and multiple linear regression. This study impacts clinical practice by calling attention to the potential of missing an underlying VWD diagnosis in patients presenting with anemia.