Abstract
A 4-year-old boy with juvenile chronic myelogenous leukemia (JCML) received an unrelated donor allogeneic bone marrow transplantation. While cyclosporine A (CsA) and short-term methotrexate were given for GVHD prophylaxis, an acute GVHD of grade III and disturbance of consciousness occurred on day 40. The latter was recovered soon after conventional treatments without any abnormality as shown by brain magnetic resonance imaging (MRI). However, the GVHD worsened further, and thus tacrolimus (FK506) was substituted for CsA and methylprednisolone pulse therapy was administered on day 53. His consciousness again began to deteriorate. A brain MRI disclosed a scattered, abnormally high signal intensity on T2-weighted image in his cortex and subcortical white matter areas. On day 93, he suddenly had a convulsion and became unconscious and oliguric. Considering that the condition was an encephalopathy side effect due to FK506, it was dis-continued and CsA was again administered. Thereafter, his condition improved and finally recovered without leaving any abnormality in neurological and MRI findings. It should be stressed that FK506 may have an adverse effect not only on renal function but on the central nervous system as well.
