Past exposure to immunosuppressive drugs called thiopurines has been found to increase the risk of myeloid disorders, such as acute myeloid leukemia and myelodysplastic syndrome, among patients with inflammatory bowel disease (IBD). The findings were reported by Lopez et al in Clinical Gastroenterology and Hepatology. Thiopurines are an established treatment for IBD patients, used to reduce inflammation and provide symptom relief.
“In order to make appropriate, informed decisions about thiopurines, patients and providers need to be well-educated about the risks and benefits of this treatment,” said study author Laurent Peyrin-Biroulet, MD, PhD, of the Department of Hepato-Gastroenterology, University Hospital of Nancy-Brabois in France. “According to our research, the risk of myeloid disorders was not increased among the overall IBD population, compared with the general population…. We hope these findings encourage other researchers to investigate more about the drug and its potentially harmful effects.”
Study Details
Researchers conducted a prospective observational study to determine the trends of IBD patients exposed to thiopurines. The researchers studied 19,486 patients enrolled in the CESAME (Cancers et Surrisque Associé aux Maladies Inflammatoires Intestinales en France) study from May 2004 through June 2005. After 3 years of follow-up, five patients were diagnosed with incident myeloid disorders, four of whom had been previously exposed to thiopurines.
Past exposure to thiopurines was associated with a sevenfold increased risk of myeloid disorders among patients with IBD (standardized incidence ratio [SIR] = 6.98, 95% confidence interval [CI] = 1.44–20.36). However, compared to the general population, the risk of myeloid disorders was not increased among the overall IBD population (SIR = 1.80, 95% CI = 0.58–4.20), nor was it increased among IBD patients receiving ongoing thiopurine treatment (SIR = 1.54, 95% CI = 0.05–8.54).
While these findings provide evidence of the connection between thiopurines and myeloid disorders in IBD patients, the absolute risk to an individual patient is only 1 in 10,000. The link between IBD patients receiving thiopurines and myeloid disorders remains complex. Physicians need to balance this risk against the known benefits of thiopurines in the management of IBD.
Dr. Peyrin-Biroulet is the corresponding author for the Clinical Gastroenterology and Hepatology article.
The study was supported by grants from Programme Hospitalier de Recherche Clinique National, Association François Aupetit, Délégation Interrégionale de la Recherche Clinique Ile de France-AP-HP, Ligue Contre le Cancer, and Fonds de Recherche de la Société Nationale Française de Gastro-entérologie. For full disclosures of the study authors, visit www.cghjournal.org.
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