Pediatric-Onset IBD Associated With Increased Risk for VTE

Hematology Advisor spoke with experts about the new ASH clinical practice guidelines for VTE.
A new risk stratification score for venous thromboembolism was developed and validated in a cohort of more than 4000 patients with multiple myeloma.
Investigators examined the incidence of and risk factors for venous thromboembolism in pediatric patients with IBD compared with the general pediatric population.

Patients with pediatric-onset inflammatory bowel disease (PIBD) are at an almost 14-fold higher risk for venous thromboembolism (VTE) compared with the general pediatric population, according to a study in the Journal of Crohn’s and Colitis.

Researchers obtained data from the PIBD-SETQuality Safety Registry, an international, prospective, electronic registry of rare and severe complications in children and adolescents with IBD. Pediatric gastroenterologists prospectively replied to the registry monthly, from October 2016 through September 2020, indicating if they had observed a VTE case in a patient aged <19 years with IBD. The study authors also conducted a systematic literature review to estimate the incidence of VTE in the general pediatric population.

A total of 149 PIBD specialists from 129 centers cared for 24,802 patients with PIBD and reported 20 cases of a first VTE diagnosis. This resulted in a VTE incidence of 3.72 per 10,000 patient-years (95% CI, 2.27-5.74), which was 13.8 times higher (95% CI, 8.8-21.7) than the pooled incidence rate in the general pediatric population (3.72 vs 0.27; P <.001).

Among the 20 VTE cases, 10 were cerebral sinus venous thrombosis (CSVT) cases, with an incidence of 1.86 per 10,000 patient-years (95% CI, 0.71-3.01), 41.3 times higher (95% CI, 20.8-82.0) than the pooled incidence rate of CSVT in the general pediatric population (1.86 vs 0.045; P <.001).

The estimated VTE incidence for patients with PIBD who were hospitalized was 1144 (95% CI, 523-2173) per 10,000 patient-years, and the estimated VTE incidence for outpatients with PIBD was 2.05 (95% CI, 1.02-3.66) per 10,000 patient-years.

Patients had a median age at VTE occurrence of 13.6 (IQR, 9.6-16.1) years, and 60% were girls. After their VTE event, 8 of 20 patients received long-term antithrombotic prophylaxis when antithrombotic therapy was ceased.

Non-IBD risk factors were identified in 65% of cases, including steroids use (45%; n=9) and immobility (15%; n=20). Most VTEs (90%) occurred during active disease. Of the cohort, 16 patients fully recovered from their VTE and 2 patients with CSVT died.

Among several study limitations, the data did not include full coverage of entire countries and relied on clearly defined geographical catchment areas reported by the local investigators, which could have introduced heterogeneity. Another limitation is the transition from pediatric to adult care in those aged 14 to 19 years in some centers. The study authors were also unable to conduct a multivariate analysis on the risk factors for developing a VTE.

“With this increased risk of VTE in paediatric IBD patients, especially in those hospitalized, and potentially negative outcomes in paediatric IBD patients, we would advise to consider thromboprophylaxis for all hospitalized patients with active [ulcerative colitis]/IBD-[unclassified], regardless of age or presence of additional VTE risk factors, and for all hospitalized children with moderate-to-severe [Crohn disease] with at least one additional VTE risk factor,” the researchers advised.


Aardoom MA, Klomberg RCW, Kemos P, et al. The incidence and characteristics of venous thromboembolisms in paediatric-onset inflammatory bowel disease; a prospective international cohort study based on the PIBD-SETQuality Safety Registry. J Crohns Colitis. Published online October 2, 2021. doi: 10.1093/ecco-jcc/jjab171