Chronic myeloid leukemia within a year of kidney transplant with elevated alkaline phosphatase correlated with imatinib therapy

The incidence of certain malignancies is significantly higher after organ transplant. However, there are rare reports of chronic myeloid leukemia in the posttransplant setting. The average reported interval between a transplant and the diagnosis of chronic myeloid leukemia is 44 months (range, 10- 96 mo). We report 2 patients with chronic myeloid leukemia within 1 year of a kidney transplant, which is significantly shorter than those previously reported. Both patients were receiving mycophenolate mofetil and tacrolimus for immunosuppression. They were treated with imatinib for chronic myeloid leukemia, and both patients demonstrated an isolated elevation of serum alkaline phosphatase that was directly correlated with imatinib. Despite a potential interaction between the 2 drugs, blood levels of tacrolimus and imatinib were not elevated during the course of treatment. Isolated elevation of alkaline phosphatase in this particular setting has not been reported previously.