[A case of rapidly progressive HTLV-I associated myelopathy that developed after a ‍living donor kidney transplantation].

Case Male in his 40s. Due to end-stage renal failure, a living donor kidney transplantation was performed in September 2019 from his mother, who was positive for anti-HTLV-1 antibodies, to this case, who was negative for anti-HTLV-1. He was admitted in September 2021 due to progressive lower limb muscle weakness since March 2021. The patient was unable to stand or walk due to spastic paraplegia. Spinal cord MRI T2-weighted image showed continuous high signal and myelopathy from the cervical to thoracic spinal cord. Serum and spinal fluid anti-HTLV-1 antibodies were positive. The diagnosis of rapidly progressive HTLV-1-associated myelopathy (HAM) was made, which was problematic because kidney transplantation from an HTLV-1-positive donor to a negative recipient was performed in this case, even though it had already been noted that living donor-negative recipients are at high risk of developing HAM.