Severe autologous GVHD after hematopoietic progenitor cell transplantation for multiple myeloma.

GVHD is a recognized complication of autologous hematopoietic progenitor cell transplantation (HPCT), but has typically been reported to respond well to primary therapy with corticosteroids. In this study, we report the development of severe autologous GVHD in five patients who underwent HPCT for multiple myeloma. In all cases, response to corticosteroids was unsatisfactory and three of these patients ultimately died from complications that ensued from prolonged immunosuppressive therapy. Severe autologous GVHD occurred only in patients transplanted for multiple myeloma and was observed at a much higher frequency in patients undergoing their second HPCT. The severity of this syndrome primarily in patients undergoing second HPCTs suggests that repetitive exposure to high-dose therapy may compromise endogenous peripheral regulatory mechanisms and predispose these patients to autoimmunity. Given the evolving role of second autologous transplantations in the therapeutic armamentarium for multiple myeloma, consideration of this potential toxicity may be appropriate when considering treatment options for these patients.