Immunosuppressive therapy for inflammatory bowel disease (IBD) in pediatric patients is thought to increase the risk of malignancy and lymphoproliferative disorders, including hemophagocytic lymphohistiocytosis.
Dr Meena Thayu and colleagues from Pennsylvani, USA compared unadjusted incidence rates of malignancy and hemophagocytic lymphohistiocytosis in pediatric patients with IBD exposed to infliximab with patients not exposed to biologics and calculated standardized incidence ratios.
The researchers collected and analyzed data from 5766 participants in a prospective study of long-term outcomes of pediatric patients with IBD, from 2007 through 2016.
Patients were 17 years old or younger and had Crohn’s disease, ulcerative colitis, or IBD-unclassified with 24,543 patient-years of follow-up.
|10 patients with malignancy had also been exposed to a biologic agent |
The team estimated incidence rates for malignancy and hemophagocytic lymphohistiocytosis as events per 1000 patient-years of follow-up.
The researchers calculated age-, sex-, and race-adjusted SIRs, with 95% confidence intervals, using the Surveillance, Epidemiology, and End Results Program (SEER) database.
The team found that 13 of the 15 patients who developed a malignancy and all 5 of the patients who developed hemophagocytic lymphohistiocytosis had been exposed to thiopurines.
The team noted that 10 patients with malignancy had also been exposed to a biologic agent.
The researchers showed no increased risk of malignancy or hemophagocytic lymphohistiocytosis in patients exposed to infliximab as the only biologic vs those unexposed to biologics.
Standardized incidence ratios did not demonstrate an increased risk of malignancy among patients exposed to infliximab vs patients not exposed to a biologic agent, even when patients were stratified by thiopurine exposure.
Dr Thayu's team concludes, "In determination of age-, sex-, and race-adjusted standardized incidence ratios using data from a large clinical study and the SEER database, we found that infliximab exposure did not associate with increased risk of malignancy or hemophagocytic lymphohistiocytosis in pediatric patients with IBD."
"Thiopurine exposure is an important precedent event for the development of malignancy or hemophagocytic lymphohistiocytosis in pediatric patients with IBD."