OC 38.4 - Transient Antiphospholipid Antibodies, Antiphospholipid Syndrome and Clinical Outcomes in Patients <21 Years Old with Provoked Venous Thromboembolism: Analysis from the Kids-DOTT Multinational Trial

Monday, June 26, 2023

11:30 – 11:45 ET

Room: 518

Session Available As: On-Demand

Presenting Author(s)

Marisol Betensky, MD, MPH

Assistant Professor
Institute for Clinical and Translational Research, Johns Hopkins All Children's Hospital, St. Petersburg, USA
Saint Petersburg, Florida, United States

Co-Author(s)

mM

maua Mosha

Senior Biostatistician
Johns Hopkins All Children's Hospital
St Petersburg, Florida, United States
CT

Cristina Tarango

Associate Professor
Cincinnati Children's Hospital Medical Center.
Cincinnati, Ohio, United States
VA

Verma Anupam

Assistant Professor
University of Utah
Salt Lake City, Utah, United States
Rukhmi Bhat, MD,MS, DNB

Associate Professor of Pediatrics (Hematology, Oncology, and Stem Cell Transplantation)
Ann & Robert H. Lurie Children's Hospital
Chicago, Illinois, United States
Nicole Kucine, MD, MS (she/her/hers)

Associate Professor
Weill Cornell Medicine
New York, New York, United States
TN

Taizo Nakano

Associate Professor
Children's Hospital of Colorado
Denver, Colorado, United States
Gary Woods, MD

Assistant Professor
Children's Healthcare of Atlanta
Atlanta, Georgia, United States
CN

Charles Nakar

Physician
Indiana Hemophilia and Thrombosis Center
Indianapolis, Indiana, United States
EA

Ernest Amankwah

Associate Professor
Johns Hopkins All Children's Hospital
St Petersburg, Florida, United States
Leonardo R. Brandão, MD, MSc (he/him/his)

Staff Hematologist, Thrombosis Program Director, Professor of Paediatrics
The Hospital for Sick Children, University of Toronto
Toronto, Ontario, Canada
Sam Schulman, MD, PhD

MD, PhD
Department of Medicine, Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada.
Hamilton, Ontario, Canada
Neil A. Goldenberg, MD, PhD (he/him/his)

Professor
Johns Hopkins All Children's Institute for Clinical and Translational Research, Johns Hopkins University, USA
Saint Petersburg, Florida, United States

Background: Few studies have prospectively evaluated the incidence of transient and persistent antiphospholipid antibodies (aPL) in children with provoked venous thromboembolism (VTE). While antiphospholipid antibody syndrome (APS) may increase the risk of recurrent VTE (rVTE) in unprovoked VTE, outcomes in provoked VTE remain undefined.

Aims: Describe outcomes of patients < 21 years with first-episode provoked VTE and positive aPL (+aPL) in the Kids-DOTT trial.

Methods: Patients with +aPL at the time of enrollment were included. aPL testing was obtained at enrollment and at 6 weeks post-VTE. Subsequent testing was performed at discretion of the treating hematologist. Data were prospectively collected. Descriptive statistics were used to summarize patient characteristics and outcomes (persistent veno-occlusion, post-thrombotic syndrome [PTS], rVTE and clinically-relevant bleeding [CRB]).

Results: Of 595 patients, 130 (22%) had +aPL at enrollment and were included. Sixty-nine (53%) had transient aPL, 15 persistent (APS, 12%), and 46 (35%) had no repeat testing (Figure 1). Median age was 9.2 years (range, 0.0-20.5). The incidence of complete veno-occlusion at 6-weeks and PTS were non-statistically significantly higher in the APS vs. the transient aPL group (veno-occlusion=20% vs. 8%, p= 0.16; PTS= 10% vs. 8.%, p=1.00). Despite the overall low CRB incidence, this was considerably higher in the APS group compared to the transient aPL group (27% vs. 9%, p=0.07), albeit not statistically significant. There were two symptomatic rVTE in the APS group (13%), none in the transient aPL (p=0.03).

Conclusion(s): +aPL were found in 22% of children with provoked VTE, and approximately 3% met criteria for APS on follow-up testing. While the overall number of events was low, patients with APS and provoked VTE had higher rates of adverse VTE outcomes, including increased incidence of rVTE, compared to those with transient aPL.

*Preliminary findings of this work were previously presented as an oral abstract (61st ASH Annual Meeting)

Learning Objectives:

To describe the incidence of transient and persistent antiphospholipid antibodies in children with provoked VTE
To describe the natural history of transient antiphospholipid antibodies in children with provoked VTE
To describe the VTE-associated outcomes of children with persistent antiphospholipid antibodies and provoked VTE