In various transplantation therapies, many different immunosuppressants have been used. Tacrolimus, although used recently, has been known to cause numerous adverse sideeffects, including neuro-and nephrotoxicities. 1 In solid-organ transplantations it has been reported that tacrolimus is responsible for post-transplantation diabetes mellitus (PTDM). 2 There are few published reports on the incidence of diabetes after allogeneic stem cell transplantation (allo-SCT). It is speculated that the diabetes results from irradiation of endocrine gland or transfer by allo-SCT, although the details remain uncertain. 3 -5 Herein we describe a case of diabetes mellitus that may have been associated with tacrolimus after allo-SCT.
Case reportA 14-year-old boy was diagnosed with acute lymphoblastic leukemia. Blasts were morphologically L1 and divided into early B-cell lineage using heteroantisera and monoclonal antibodies. No chromosomal abnormality was detected. After receiving an induction regimen consisting of prednisolone (PSL), vincristine (VCR), daunorubicin (DNR), cyclophosphamide (CY), and L-asparaginase (L-ASP), he achieved complete remission (fi rst CR). He was given consolidation and maintenance therapies consisting (total dose) of 15 g/m 2 cytarabine (Ara-C), 1.5 g/m 2 etoposide (VP-16), 2.52 g/m 2 PSL, 9.45 g/m 2 methotrexate (MTX), 20 mg/m 2 VCR, 20.4 g/m 2 CY, 140 000 U/m 2 L-ASP, 160 mg/m 2 DNR, and 3.0 g/m 2 mercaptopurine (Fig. 1) . Despite these chemotherapies, his leukemia recurred in the bone marrow 14 months after the beginning of therapy. After receiving re-induction therapies consisting (total dose) of 5 g/m 2 Ara-C, 500 mg/m 2 VP-16, 1.8 g/m 2 PSL, 10 mg/m 2 VCR, 160 mg/m 2 DNR, 1 g/m 2 CY, and 40 000 U/m 2 L-ASP, he achieved second CR. Following preparation with total body irradiation (TBI) at 12 Gy divided into six fractions (days −9 to −7), Ara-C 3 g/m 2 daily for 4 days, and CY 60 mg/kg daily for 2 days, the patient underwent an allo-bone marrow transplantation (allo-BMT) from a human leukocyte antigenidentical (A 24/2601, B 54/3901, DR 0803/0405) unrelated female donor in September 2001. The cell count of the marrow allograft was 0.2 × 10 9 cells/kg. Tacrolimus (0.03 mg/m 2 per day, infused continuously since day -1) and a short-term MTX (10 mg/m 2 on day 1, and 7 mg/m 2 on day 3, 7) were used for graft-versus-host disease (GVHD) prophylaxis. The target trough level of tacrolimus was approximately 15 ng/mL. The neutrophil count reached >0.5 × 10 9 /L on day 28, a reticulocyte count >10 ‰ was achieved on day 17 and a platelet count >50 × 10 9 /L on day 25. Bone marrow analysis on day 28 showed normal marrow recovery with 99.6% female donorderived cells as demonstrated on fl uorescence in situ hybridization . Acute GVHD in the skin (grade I) and persistent fever became apparent after day 20 so the patient was treated with 1 mg/kg per day PSL. The trough levels of tacrolimus were maintained around 15 -20 ng/mL during the fi rst 2 months after BMT. The patient was discharged with mucositis due to chro...