{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,6,12]],"date-time":"2025-06-12T22:21:13Z","timestamp":1749766873866,"version":"3.40.4"},"reference-count":6,"publisher":"BMJ","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["BMJ Case Reports"],"abstract":"<jats:p>A 47-year-old woman with a 36-month history of Crohn's disease with one previous bowel resection treated with azathioprine was found to have a persistently raised mean corpuscular volume (MCV) on routine complete blood count testing. Despite vitamin B<jats:sub>12<\/jats:sub>replacement, her MCV remained elevated. A bone marrow biopsy was performed, which demonstrated myelodysplastic syndrome. Macrocytosis is a common abnormality in patients with Crohn's disease, most commonly due to vitamin B<jats:sub>12<\/jats:sub>deficiency and secondarily due to bacterial overgrowth. However, it is important to recognise that myelodysplastic syndrome is a common under-reported complication of azathioprine therapy. One-third of cases progress to acute myeloid leukaemia with poor prognosis. In patients with suspected myelodysplastic syndrome, azathioprine therapy should be immediately discontinued.<\/jats:p>","DOI":"10.1136\/bcr-2013-200287","type":"journal-article","created":{"date-parts":[[2013,8,7]],"date-time":"2013-08-07T12:58:17Z","timestamp":1375880297000},"page":"bcr2013200287","source":"Crossref","is-referenced-by-count":2,"title":["Macrocytosis in Crohn's disease: a devastating blast"],"prefix":"10.1136","volume":"2013","author":[{"given":"Lennard Y W","family":"Lee","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vidya","family":"Santharam","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"George","family":"Macfaul","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2013,8,7]]},"reference":[{"key":"2025042709004284000_2013.aug07_1.bcr2013200287.1","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1097\/00054725-199905000-00005","article-title":"Concurrent inflammatory bowel disease and myelodysplastic syndromes","volume":"2013","author":"Harewood","year":"1999","journal-title":"Inflamm Bowel Dis"},{"key":"2025042709004284000_2013.aug07_1.bcr2013200287.2","unstructured":"International Agency for Research on Cancer (IARC)\u2014Summaries & Evaluations. Azathioprine [Internet]. http:\/\/www.inchem.org\/documents\/iarc\/suppl7\/azathioprine.html ."},{"key":"2025042709004284000_2013.aug07_1.bcr2013200287.3","first-page":"691","article-title":"Secondary myelodysplastic syndromes following treatment with azathioprine are associated with aberrations of chromosome 7","volume":"2013","author":"Knipp","year":"2005","journal-title":"Haematologica"},{"key":"2025042709004284000_2013.aug07_1.bcr2013200287.4","doi-asserted-by":"crossref","first-page":"485","DOI":"10.3899\/jrheum.090834","article-title":"Azathioprine: association with therapy-related myelodysplastic syndrome and acute myeloid leukemia","volume":"2013","author":"Kwong","year":"2010","journal-title":"J Rheumatol"},{"key":"2025042709004284000_2013.aug07_1.bcr2013200287.5","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1182\/blood-2002-11-3343","article-title":"Clinical-cytogenetic associations in 306 patients with therapy-related myelodysplasia and myeloid leukemia: the University of Chicago series","volume":"2013","author":"Smith","year":"2003","journal-title":"Blood"},{"key":"2025042709004284000_2013.aug07_1.bcr2013200287.6","doi-asserted-by":"crossref","first-page":"696","DOI":"10.1046\/j.1365-2141.1996.00400.x","article-title":"Spontaneous remission in a patient with therapy-related myelodysplastic syndrome (t-MDS) with monosomy 7","volume":"2013","author":"Renneboog","year":"1996","journal-title":"Br J Haematol"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2013-200287","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,27]],"date-time":"2025-04-27T16:00:48Z","timestamp":1745769648000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2013-200287"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,8,7]]},"references-count":6,"alternative-id":["10.1136\/bcr-2013-200287"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2013-200287","relation":{},"ISSN":["1757-790X"],"issn-type":[{"type":"electronic","value":"1757-790X"}],"subject":[],"published":{"date-parts":[[2013,8,7]]}}}