Immune suppressant medications such as thiopurines and anti-tumor necrosis factor agents are important for maintaining disease control in most patients with inflammatory bowel diseases (IBDs).
However, their use has been associated with the development of malignant lymphoma.
Dr Hommes and colleagues from the Netherlands performed a Dutch nationwide study to estimate the relative risk of malignant lymphoma in IBD patients.
IBD patients who developed a lymphoma between 1997 and 2004 were identified using the Dutch National Database of PALGA.
|Only 43% of patients were exposed to azathioprine/mercaptopurine|
|Inflammatory Bowel Disease|
Data from confirmed cases were collected from individual hospitals, including data on Epstein–Barr virus.
The age-adjusted 8-year incidence of malignant lymphoma in the Netherlands was retrieved from the Central Bureau of Statistics.
The research team found that 42 hospitals were visited, and 285 matches evaluated in the total cohort of 17,834 IBD patients.
The team observed 44 lymphomas, resulting in a relative risk of 1.3.
Only 43% of patients were exposed to azathioprine/mercaptopurine.
Remarkably, 92% of patients with Epstein–Barr virus-positive lymphoma used azathioprine/mercaptopurine, in contrast to only 19% patients with Epstein–Barr virus-negative lymphoma, suggesting a strong relation between Epstein–Barr virus-positive lymphoma and thiopurine use.
Dr Hommes' team concludes, "This nationwide study does not suggest a significant overall increased risk for lymphoma in IBD patients."
"A distinct correlation between Epstein–Barr virus-positive lymphoma and azathioprine/mercaptopurine use was observed."