Acyclovir encephalopathy developed after autologous peripheral blood stem cell transplantation in a patient with multiple myeloma

Abstract

A 50-year-old woman was diagnosed as having multiple myeloma (MM) (IgM- κ type, urinary Bence-Jones Protein positive). She received bortezomib plus dexamethasone chemotherapy and achieved partial response. After autologous peripheral blood stem cells were collected, she underwent autologous peripheral blood stem cell transplantation by conditioning with high-dose melphalan chemotherapy. On the 10th day, her consciousness level worsened with the renal failure. Since she was administered acyclovir (ACV) for herpes simplex virus (HSV) prophylaxis, we suspected her consciousness disturbance to be ACV encephalopathy. ACV was discontinued and she underwent hemodialysis, resulting in improved consciousness and renal function. The diagnosis of ACV encephalopathy was based on very high ACV concentrations in the serum and cerebrospinal fluid when her consciousness level worsened. As hematopoietic stem cell transplantation is accompanied by severe immunodeficiency, ACV for HSV prophylaxis is required. The possibility of ACV encephalopathy should be considered in patients following stem cell transplantation who develop acute encephalopathy, especially in the cases of MM patients, who are prone to develop renal dysfunction.