Successful Mercaptopurine Usage despite Azathioprine-Induced Pancreatitis in Paediatric Crohn’s Disease

• Published in: Journal of Crohn's and colitis Vol. 9; no. 8; pp. 676 - 679
• Main Authors: Gallego-Gutiérrez, Silvia, Navas-López, Víctor Manuel, Kolorz, Michal, Bartosova, Ladislava, Lukac, Katerina, Luque-Pérez, Silvia, Núñez-Caro, Leticia, García-Galán, Paloma, Fernández-Crehuet, Francisco Girón, Blasco-Alonso, Javier, Serrano-Nieto, María Juliana, Sierra-Salinas, Carlos
• Format: Journal Article
• Language: English
• Published: UK Oxford University Press 01-08-2015
• Subjects: Adolescent; Azathioprine - adverse effects; Azathioprine - therapeutic use; Child; Crohn Disease - complications; Crohn Disease - drug therapy; Humans; Immunosuppressive Agents - therapeutic use; Male; Mercaptopurine - therapeutic use; Pancreatitis - chemically induced; azathioprine; pancreatitis; Thiopurines; mercaptopurine; Crohn′s disease; children
• ISSN: 1873-9946; 1876-4479
• DOI: 10.1093/ecco-jcc/jjv086

Background:
Azathioprine [AZA] and mercaptopurine [MP] are recommended for maintenance of steroid-free remission in children with Crohn`s disease [CD]. Azathioprine-induced pancreatitis, an idiosyncratic and major side effect, has been considered as an absolute contraindication for the use of a second thiopurine in IBD patients.
Materials and Methods:
We describe two children with CD in whom MP were successfully trialled after a confirmed azathioprine-induced pancreatitis, being well tolerated in both cases.
Results:
Two boys [13 and 10 years old] started exclusive enteral nutrition after diagnosis of moderate (Pediatric Crohn′s Disease Activity Index [wPCDAI] = 45) and mild [wPCDAI = 35] CD. Both developed an acute mild to moderate pancreatitis after 2 and 3 weeks, respectively, of AZA treatment but recovered fully in hospital after AZA withdrawal. They started on MP treatment without any adverse effect. They were tested for the presence of polymorphisms 238G>C, 460G>A, and 719A>G in the TPMT gene and 94C>A and 21>C in the ITPase. Both patients were wild-type for all tested polymorphisms.
Conclusions:
Azathioprine-induced acute pancreatitis should not be considered as an absolute contraindication for the use of MP. Further investigation is required to create a better understanding of the mechanism underlying the adverse events and to allow more possibilities for personalised therapy.