title: Successful Mercaptopurine Usage despite Azathioprine-Induced Pancreatitis in Paediatric Crohn's Disease.
abstract: 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.
  
  
  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.
authors.affiliation: Pediatric Gastroenterology and Nutrition Unit, UGC de Pediatría, Hospital Regional Universitario de Málaga, Málaga, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Gallego-Gutiérrez
authors.affiliation: Pediatric Gastroenterology and Nutrition Unit, UGC de Pediatría, Hospital Regional Universitario de Málaga, Málaga, Spain Biomedical Institute of Malaga [IBIMA], Hopsital General de Málaga, Málaga, Spain victor.navas@gmail.com.
authors.forename: Víctor Manuel
authors.initials: VM
authors.lastname: Navas-López
authors.affiliation: Department of Human Pharmacology and Toxicology, Faculty of Pharmacy, UVPS Brno, Czech Republic Department of Clinical Pharmacy, Hospital Pharmacy, Faculty Hospital, Brno, Bohunice, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Kolorz
authors.affiliation: Department of Human Pharmacology and Toxicology, Faculty of Pharmacy, UVPS Brno, Czech Republic.
authors.forename: Ladislava
authors.initials: L
authors.lastname: Bartosova
authors.affiliation: Department of Human Pharmacology and Toxicology, Faculty of Pharmacy, UVPS Brno, Czech Republic.
authors.forename: Katerina
authors.initials: K
authors.lastname: Lukac
authors.affiliation: Pediatric Gastroenterology and Nutrition Unit, UGC de Pediatría, Hospital Regional Universitario de Málaga, Málaga, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Luque-Pérez
authors.affiliation: Pediatric Gastroenterology and Nutrition Unit, UGC de Pediatría, Hospital Regional Universitario de Málaga, Málaga, Spain.
authors.forename: Leticia
authors.initials: L
authors.lastname: Núñez-Caro
authors.affiliation: Pediatric Gastroenterology and Nutrition Unit, UGC de Pediatría, Hospital Regional Universitario de Málaga, Málaga, Spain.
authors.forename: Paloma
authors.initials: P
authors.lastname: García-Galán
authors.affiliation: Pediatric Gastroenterology and Nutrition Unit, UGC de Pediatría, Hospital Regional Universitario de Málaga, Málaga, Spain.
authors.forename: Francisco Girón
authors.initials: FG
authors.lastname: Fernández-Crehuet
authors.affiliation: Pediatric Gastroenterology and Nutrition Unit, UGC de Pediatría, Hospital Regional Universitario de Málaga, Málaga, Spain Biomedical Institute of Malaga [IBIMA], Hopsital General de Málaga, Málaga, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Blasco-Alonso
authors.affiliation: Pediatric Gastroenterology and Nutrition Unit, UGC de Pediatría, Hospital Regional Universitario de Málaga, Málaga, Spain.
authors.forename: María Juliana
authors.initials: MJ
authors.lastname: Serrano-Nieto
authors.affiliation: Pediatric Gastroenterology and Nutrition Unit, UGC de Pediatría, Hospital Regional Universitario de Málaga, Málaga, Spain Biomedical Institute of Malaga [IBIMA], Hopsital General de Málaga, Málaga, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Sierra-Salinas
mesh_terms: D000293:Adolescent; D001379:Azathioprine / Q000009:adverse effects* / Q000627:therapeutic use; D002648:Child; D003424:Crohn Disease / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008297:Male; D015122:Mercaptopurine / Q000627:therapeutic use*; D010195:Pancreatitis / Q000139:chemically induced*
chemical_list: D007166:Immunosuppressive Agents; D015122:Mercaptopurine; D001379:Azathioprine
keywords: Crohn′s disease; Thiopurines; azathioprine; children; mercaptopurine; pancreatitis