[Peripheral neuropathy occurring soon after cord blood transplantation]

We experienced two cases of peripheral neuropathy in the early phase following cord blood transplantation. Case 1 was a 66-year-old man with recurrent T-ALL. On day 8, he experienced a sharp pain originating in both the palms and the soles, which worsened spreading to the knees, and was accompanied by muscle weakness. The neurological symptom progressed to the point of being unable to walk. A nerve conduction velocity test showed demyelination and axonopathy. In the CSF analysis, albuminocytologic dissociation and a rise in myelin basic protein were detected. These findings met the diagnostic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP). The symptoms improved with intravenous immunoglobulin (IVIG). He is now able to walk and continues to visit our department. Case 2 was a 42-year-old man with primary mediastinal large B-cell lymphoma. As the disease was refractory, he underwent reduced intensity cord blood transplantation (RICBT). Flare and numbness started in the palms and soles on day 26, with the symptoms progressing thereafter. A nerve conduction velocity test showed demyelination and axonopathy. The symptoms improved after IVIG administration. The diagnosis of peripheral neuropathy after transplantation is often difficult, but when an immunologic disorder is suspected to be the cause, early administration of IVIG may be effective.