Lee Lennard Y W, Santharam Vidya, Macfaul George
Department of Gastroenterology, Milton Keynes NHS Foundation Trust, Milton Keynes, UK.
BMJ Case Rep. 2013 Aug 7;2013:bcr2013200287. doi: 10.1136/bcr-2013-200287.
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 B12 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 B12 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.
一名47岁女性，有36个月克罗恩病病史，曾接受过一次肠道切除术，一直使用硫唑嘌呤治疗，在常规全血细胞计数检测中发现平均红细胞体积（MCV）持续升高。尽管补充了维生素B12，其MCV仍居高不下。遂进行了骨髓活检，结果显示为骨髓增生异常综合征。大细胞性贫血在克罗恩病患者中是一种常见异常，最常见原因是维生素B12缺乏，其次是细菌过度生长。然而，必须认识到骨髓增生异常综合征是硫唑嘌呤治疗一种常见但报告不足的并发症。三分之一的病例会进展为预后不良的急性髓系白血病。对于疑似骨髓增生异常综合征的患者，应立即停用硫唑嘌呤治疗。
