PB0254 - Factor XI and XII in children undergoing extracorporeal membrane oxygenation (ECMO)

Sunday, June 25, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

JD

Joppe Drop, MD (he/him/his)

PhD student
Department of Paediatrics Division of Paediatric Hematology Erasmus Medical Centre – Sophia Children’s Hospital Rotterdam the Netherlands
Rotterdam, Zuid-Holland, Netherlands

Co-Author(s)

NL

Natasha Letunica

Research assistant
Haematology Research Murdoch Children’s Research Institute Melbourne Australia
Melbourne, Victoria, Australia
SV

Suelyn Van Den Helm

PhD Student
Haematology Research, Murdoch Children's Research Institute
Parkville, Victoria, Australia
EW

Enno Wildschut

Pediatric intensivist
Department of Paediatrics Division of Pediatric Intensive care and Pediatric surgery Erasmus Medical Centre – Sophia Children’s Hospital Rotterdam The Netherlands
Rotterdam, Zuid-Holland, Netherlands
Md

Matthijs de hoog

Professor
Department of Paediatrics Division of Pediatric Intensive care and Pediatric surgery Erasmus Medical Centre – Sophia Children’s Hospital Rotterdam The Netherlands
Rotterdam, Zuid-Holland, Netherlands
RB

Rebecca Barton

Pediatric hematologist
Haematology Research Murdoch Children’s Research Institute Melbourne Australia
Melbourne, Victoria, Australia
HY

Hui Ping Yaw

post doc
Haematology Research Murdoch Children’s Research Institute Melbourne Australia
Melbourne, Victoria, Australia
FN

Fiona Newall

Professor
Haematology Research Murdoch Children’s Research Institute Melbourne Australia
Melbourne, Victoria, Australia
SH

Stephen Horton

Director of Perfusion
Perfusion Department, The Royal Children's Hospital, Melbourne, Australia
Melbourne, Victoria, Australia
RC

Roberto Chiletti

Pediatric intensivist
Department of Intensive Care The Royal Children’s Hospital Melbourne Australia
Melbourne, Victoria, Australia
AJ

Amy Johansen

Clinical nurse consultant
Department of Intensive Care The Royal Children’s Hospital Melbourne Australia
Melbourne, Victoria, Australia
DB

Derek Best

Clinical nurse consultant
Department of Intensive Care The Royal Children’s Hospital Melbourne Australia
Melbourne, Victoria, Australia
JM

Joanne McKittrick

Clinical nurse consultant
Department of Intensive Care The Royal Children’s Hospital Melbourne Australia
Melbourne, Victoria, Australia
WB

Warwick Butt

Pediatric intensivist
Department of Paediatrics The University of Melbourne Melbourne Australia
Melbourne, Victoria, Australia
Yd

Yves d’Udekem

Cardiac surgeon
Department of Cardiac Surgery Children’s National Heart Institute Washington DC USA
Washington DC, Washington, United States
GM

Graeme MacLaren

Intensivist
Cardiothoracic Intensive Care Unit National University Health System Singapore
Singapore, Singapore
Vera Ignjatovic, PhD (she/her/hers)

Assistant Director for Translational Research
Institute for Clinical and Translational Research, Johns Hopkins All Children's Hospital, St. Petersburg, USA
St. Petersburg, Florida, United States
Chantal Attard, BSc (Hons), PhD (she/her/hers)

Senior Research Officer
Haematology Research, Murdoch Children's Research Institute
Parkville, Victoria, Australia
C. Heleen Van Ommen, MD, PhD (she/her/hers)

Head dept. Pediatric Hematology & Oncology
Erasmus MC Sophia Children's Hospital
Rotterdam, Zuid-Holland, Netherlands
Paul Monagle, MD

Professor
Haematology Research, Murdoch Children's Research Institute
Melbourne, Victoria, Australia

Background: ECMO is used to support children with severe refractory cardiac and/or pulmonary failure. The majority of ECMO centres use unfractionated heparin as primary anticoagulant. However, other anticoagulants targeting the contact activation pathway are emerging, including anti-factor XI and XII. Hence, the understanding of changes in FXI and FXII concentration and function throughout ECMO could be used to guide the use of these novel agents.

Aims: To describe FXI- and FXII-antigen levels and functional activity before, during and after ECMO in children.

Methods: This is a prospective observational study in neonatal and pediatric ECMO patients (1 day to < 18 years). This study was approved by the Royal Children's Hospital Human Research Ethics Committee and informed consent was obtained. All veno-arterial ECMO patients with sufficient plasma volume available prior to ECMO initiation and on day 1, day 3 and 24 hours post-decannulation were included. Antigen levels and functional activity of FXI and FXII were determined using ELISA and STA-R Max analyzer (Diagnostica Stago) (following heparin neutralization). FXI and FXII deficiencies were defined as a those below 2.5 centile of previously published age-appropriate values.

Results: Sixteen ECMO patients were included in this study. Eight (50%) patients were male, seven (44%) were neonates and 11 (69%) patients had pre-ECMO cardiopulmonary bypass. The number of patients with within range and deficient FXI and FXII per timepoint is depicted in Table 1, with median and range shown in figure 1.

Conclusion(s): This study describes changes of the contact activation pathway over the duration of ECMO in children. There was a discrepancy between antigenic and functional assays, and while factor XI deficiency was common, FXII deficiency was rare. Results from this study can be used as a starting point for contact pathway anticoagulant studies in pediatric ECMO patients in the future.