P116 The occurrence of venous thromboembolisms in paediatric-onset IBD

M. Aardoom1, P. Kemos2, F.M. Ruemmele3, C.H. van Ommen4, N.M. Croft2, L. de Ridder1, On Behalf of the PIBD-SETQuality Consortium and PIBDnet

1Erasmus MC/Sophia Children’s Hospital, Department of Paediatric Gastroenterology, Rotterdam, The Netherlands, 2Centre for Immunobiology, Blizard Institute, Barts and the London School of Medicine, Queen Mary University of London, Department of Paediatric Gastroenterology, London, UK, 3Université Paris Descartes, Sorbonne Paris Cité, APHP, Hôpital Necker Enfants Malades, Department of Pediatric Gastroenterology, Paris, France, 4Erasmus Medical Center, Sophia Children’s Hospital, Department of Pediatric Hematology, Rotterdam, The Netherlands

Background

Venous thromboembolisms (VTEs) are one of the severe adverse events that may occur in patients with paediatric-onset inflammatory bowel disease (IBD). Based on available literature VTE incidence in the general paediatric population ranges from 0.07 to 0.49 per 10,000 children. Several studies in adults suggest an increased risk of venous thromboembolism in adult IBD patients, but data in paediatric IBD patients is limited. Due to the rarity of these events, international studies are needed to gain information on risk factors for this complication and optimise guidelines. With this study, we aim to assess the incidence and characteristics of VTEs in children with IBD.

Methods

As part of an international prospective safety registry in the PIBD-SETQuality project, paediatric gastroenterologists reply monthly to an electronic survey to indicate whether they have seen one of 10 predetermined complications, including VTE, in an IBD patient <19 years of age. When a VTE is reported, additional information on patient and disease characteristics and previous therapy strategies is collected. In addition, participating physicians annually report the number of new and current PIBD patients under their care, which combined with the reporting period, is the denominator data for this project.

Results

Since October 2016, 150 paediatric gastroenterologists from 26 different countries are participating in the safety registry. In total, 14 cases of VTE were reported for 28,793 patient-years of follow-up. This results in an observed incidence of 4.86 per 10,000 PIBD patients annually (95% CI 2.66–8.16), which is a 10-fold increase compared with the VTE incidence reported in the literature in the general paediatric population. Among cases with available additional information (n = 10) were five cases of intracranial thromboembolism, four upper or lower limbs VTE and one pulmonary embolism, which occurred mainly in children with ulcerative colitis (UC) or IBD unclassified (IBDU) (5/8). Seventy per cent of cases occurred during an exacerbation of IBD, but only 40% during hospitalisation. Physicians reported steroid therapy (n = 4), immobility (n = 1), surgery (n = 1) and the presence of a central venous catheter (n = 1) as risk factors.

Conclusion

This registry has the ability to collect rare but severe complications and patient-at-risk information in paediatric IBD. Our data suggest a 10-fold increase of the VTE incidence in the paediatric IBD population compared with the general paediatric population. Most VTEs were reported in UC/IBD-U patients and occurred during an exacerbation of IBD. Ongoing data collection will help to understand possible causes and gain insight in differences in management and outcomes of these complications per country or region.