[Asymmetric peripheral neuropathy following reduced-intensity cord blood transplantation]

A 57-year-old male patient in the first remission of acute erythroid leukemia underwent reduced-intensity umbilical cord blood transplantation. He developed grade III acute graft-versus-host disease (GVHD) on day 29. Although the acute GVHD was resolved with tacrolimus and steroid therapy, weakness developed in the left upper extremity on day 59. Neurological examination demonstrated asymmetric muscular weakness of the extremities with the proximal part of the left upper extremity being markedly affected. Neurophysiological studies suggested that this was due to immune-mediated demyelinating neuropathy. Intravenous immunoglobulin (IVIG) therapy was administered at a dose of 0.4 g/kg/day for 5 days and worsening of clinical symptoms ceased. While the patient developed diarrhea and chronic GVHD of the skin and cytomegalovirus (CMV) antigenemia was repeatedly positive, neurological exacerbation was stabilized. Neurological symptoms did not immediately improve after the second and third dose of IVIG. Approximately 50 days after the third dose of IVIG, neurological symptoms improved with the gradual resolution of diarrhea and CMV reactivation. Although the pathophysiology of polyneuropathies after allo-SCT is not well understood, some reports suggest an association with GVHD or alloreactive T cell expansion following antecedent infection. This case provides valuable information regarding the pathophysiology of peripheral neuropathy following allo-SCT.