R. Kalla, N. Ventham, and J. Satsangi, Crohn's disease, BMJ, vol.349, issue.nov19 13, p.6670, 2014.
DOI : 10.1136/bmj.g6670

D. Baumgart and W. Sandborn, Inflammatory bowel disease: clinical aspects and established and evolving therapies, The Lancet, vol.369, issue.9573, pp.1641-1657, 2007.
DOI : 10.1016/S0140-6736(07)60751-X

J. Cosnes, S. Cattan, and A. Blain, Long-Term Evolution of Disease Behavior of Crohn's Disease, Inflammatory Bowel Diseases, vol.8, issue.4, pp.244-250, 2002.
DOI : 10.1097/00054725-200207000-00002

J. Cosnes, C. Gower-rousseau, and P. Seksik, Epidemiology and Natural History of Inflammatory Bowel Diseases, Gastroenterology, vol.140, issue.6, pp.1785-1794, 2011.
DOI : 10.1053/j.gastro.2011.01.055

URL : https://hal.archives-ouvertes.fr/hal-00631553

E. Prefontaine, L. Sutherland, and J. Macdonald, Azathioprine or 6-mercaptopurine for maintenance of remission in Crohn's disease, Cochrane Database Syst. Rev, vol.122, issue.4, p.67, 2009.
DOI : 10.1002/14651858.CD000067.pub2

D. Pearson, G. May, and G. Fick, Azathioprine and 6-Mercaptopurine in Crohn Disease, Annals of Internal Medicine, vol.123, issue.2, pp.132-142, 1995.
DOI : 10.7326/0003-4819-123-2-199507150-00009

C. López-martín, M. Chaparro, and L. Espinosa, Adverse events of thiopurine immunomodulators in patients with inflammatory bowel disease, Gastroenterolog??a y Hepatolog??a, vol.34, issue.6, pp.385-392, 2011.
DOI : 10.1016/j.gastrohep.2011.03.023

L. Beaugerie, N. Brousse, and A. Bouvier, Lymphoproliferative disorders in patients receiving thiopurines for inflammatory bowel disease: a prospective observational cohort study, The Lancet, vol.374, issue.9701, pp.1617-1625, 2009.
DOI : 10.1016/S0140-6736(09)61302-7

URL : https://hal.archives-ouvertes.fr/hal-00466312

M. Camus, P. Seksik, and A. Bourrier, Long-term Outcome of Patients With Crohn's Disease Who Respond to Azathioprine, Clinical Gastroenterology and Hepatology, vol.11, issue.4, pp.389-394, 2013.
DOI : 10.1016/j.cgh.2012.10.038

L. Peyrin-biroulet, K. Khosrotehrani, and F. Carrat, Increased Risk for Nonmelanoma Skin Cancers in Patients Who Receive Thiopurines for Inflammatory Bowel Disease, Gastroenterology, vol.141, issue.5, pp.1621-1628, 2011.
DOI : 10.1053/j.gastro.2011.06.050

URL : https://hal.archives-ouvertes.fr/hal-00631539

M. Toruner, E. Loftus, and W. Harmsen, Risk Factors for Opportunistic Infections in Patients With Inflammatory Bowel Disease, Gastroenterology, vol.134, issue.4, pp.929-936, 2008.
DOI : 10.1053/j.gastro.2008.01.012

S. Chatu, V. Subramanian, and S. Saxena, The Role of Thiopurines in Reducing the Need for Surgical Resection in Crohn's Disease: A Systematic Review and Meta-Analysis, The American Journal of Gastroenterology, vol.17, issue.1, pp.23-34, 2014.
DOI : 10.1038/ajg.2013.402

L. Beaugerie and H. Sokol, Clinical, serological and genetic predictors of inflammatory bowel disease course, World Journal of Gastroenterology, vol.18, issue.29, pp.3806-3813, 2012.
DOI : 10.3748/wjg.v18.i29.3806

URL : https://hal.archives-ouvertes.fr/hal-00724458

W. Blonski, A. Buchner, and G. Lichtenstein, Clinical Predictors of Aggressive/Disabling Disease: Ulcerative Colitis and Crohn Disease, Gastroenterology Clinics of North America, vol.41, issue.2, pp.443-462, 2012.
DOI : 10.1016/j.gtc.2012.01.008

J. Willoughby, J. Beckett, and P. Kumar, CONTROLLED TRIAL OF AZATHIOPRINE IN CROHN'S DISEASE, The Lancet, vol.298, issue.7731, pp.944-947, 1971.
DOI : 10.1016/S0140-6736(71)90268-6

O. Donoghue, D. Dawson, A. Powell-tuck, and J. , Double-blind withdrawal trial of azathioprine as maintenance treatment for Crohn's disease, Lancet, vol.2, pp.955-957, 1978.

A. Fraser, T. Orchard, and D. Jewell, The efficacy of azathioprine for the treatment of inflammatory bowel disease: a 30 year review, Gut, vol.50, issue.4, pp.485-489, 2002.
DOI : 10.1136/gut.50.4.485

P. Kozuch and S. Hanauer, Treatment of inflammatory bowel disease: A review of medical therapy, World Journal of Gastroenterology, vol.14, issue.3, pp.354-377, 2008.
DOI : 10.3748/wjg.14.354

G. Mantzaris, A. Christidou, and M. Sfakianakis, Azathioprine Is Superior to Budesonide in Achieving and Maintaining Mucosal Healing and Histologic Remission in Steroid-Dependent Crohn??s Disease, Inflammatory Bowel Diseases, vol.15, issue.3, pp.375-382, 2009.
DOI : 10.1002/ibd.20777

D. Laharie, A. Reffet, and G. Belleannée, Mucosal healing with methotrexate in Crohn???s disease: a prospective comparative study with azathioprine and infliximab, Alimentary Pharmacology & Therapeutics, vol.50, issue.Suppl. 3, pp.714-721, 2011.
DOI : 10.1111/j.1365-2036.2010.04569.x

S. Hanauer, B. Korelitz, and P. Rutgeerts, Postoperative maintenance of Crohn???s disease remission with 6-mercaptopurine, mesalamine, or placebo: A 2-year trial, Gastroenterology, vol.127, issue.3, pp.723-729, 2004.
DOI : 10.1053/j.gastro.2004.06.002

G. Assche, . Van, A. Dignass, and W. Reinisch, The second European evidence-based Consensus on the diagnosis and management of Crohn's disease: Special situations, Journal of Crohn's and Colitis, vol.4, issue.1, pp.63-101, 2010.
DOI : 10.1016/j.crohns.2009.09.009

C. Su, R. Stein, and J. Lewis, Azathioprine or 6-mercaptopurine for inflammatory bowel disease: do risks outweigh benefits?, Digestive and Liver Disease, vol.32, issue.6, pp.518-531, 2000.
DOI : 10.1016/S1590-8658(00)80010-9

U. Hindorf, M. Lindqvist, and H. Hildebrand, Adverse events leading to modification of therapy in a large cohort of patients with inflammatory bowel disease, Alimentary Pharmacology and Therapeutics, vol.122, issue.2, pp.331-342, 2006.
DOI : 10.1373/clinchem.2005.057158

W. Connell, M. Kamm, and J. Ritchie, Bone marrow toxicity caused by azathioprine in inflammatory bowel disease: 27 years of experience., Gut, vol.34, issue.8, pp.1081-1085, 1993.
DOI : 10.1136/gut.34.8.1081

M. Holtmann, O. Schreiner, and H. Köhler, Veno-occlusive disease (VOD) in Crohn's disease (CD) treated with azathioprine, Digestive Diseases and Sciences, vol.48, issue.8, pp.1503-1505, 2003.
DOI : 10.1023/A:1024755521423

J. Cosnes, I. Nion-larmurier, and L. Beaugerie, Impact of the increasing use of immunosuppressants in Crohn's disease on the need for intestinal surgery, Gut, vol.54, issue.2, pp.237-241, 2005.
DOI : 10.1136/gut.2004.045294

S. Chatu, S. Saxena, and V. Subramanian, The Impact of Timing and Duration of Thiopurine Treatment on First Intestinal Resection in Crohn's Disease: National UK Population-Based Study 1989???2010, The American Journal of Gastroenterology, vol.54, issue.3, pp.409-416, 2014.
DOI : 10.1111/ijcp.12039

E. Loo, . Van, N. Vosseberg, and H. F. Van-der, Thiopurines are associated with a reduction in surgical re-resections in patients with Crohn's disease: a long-term followup study in a regional and academic cohort, Inflamm. Bowel Dis, vol.19, pp.2801-2808, 2013.

J. Cosnes, A. Bourrier, and D. Laharie, Early Administration of Azathioprine vs Conventional Management of Crohn's Disease: A Randomized Controlled Trial, Gastroenterology, vol.145, issue.4, pp.758-765, 2013.
DOI : 10.1053/j.gastro.2013.04.048

J. Panés, A. López-sanromán, and F. Bermejo, Early Azathioprine Therapy Is No More Effective Than Placebo for Newly Diagnosed Crohn's Disease, Gastroenterology, vol.145, issue.4, pp.766-774, 2013.
DOI : 10.1053/j.gastro.2013.06.009