PT  - JOURNAL ARTICLE
AU  - YOK-LAM KWONG
TI  - Azathioprine: Association with Therapy-related Myelodysplastic Syndrome and Acute Myeloid Leukemia
AID  - 10.3899/jrheum.090834
DP  - 2010 Mar 01
TA  - The Journal of Rheumatology
PG  - 485--490
VI  - 37
IP  - 3
4099  - http://www.jrheum.org/content/37/3/485.short
4100  - http://www.jrheum.org/content/37/3/485.full
SO  - J Rheumatol2010 Mar 01; 37
AB  - Objective. Azathioprine is widely used in patients with autoimmune diseases and after organ allografting. A recognized carcinogen, azathioprine is also associated with the development of therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML). Methods. In 56 reported cases, azathioprine had been administered for a median of 65 months (range 6–192) to a median cumulative dose of 146 g (range 19–750) before t-MDS/AML developed. Results. In 11 patients, repeated episodes of cytopenias developed during azathioprine therapy, ante-dating the development of t-MDS/AML. In 33 cases with successful karyotypic analysis, 26 cases (79%) showed monosomy 7, deletion of the long arm of chromosomes 7 and 5, and rearrangement of chromosome 11q23. These changes were cytogenetic hallmarks of MDS/AML secondary to known leukemogenic agents and radiotherapy. Conclusion. The observations implicate azathioprine as a leukemogenic agent. It will be prudent to review the need for azathioprine therapy when unexpected cytopenias occur and prescription has been prolonged.