Acute polymyositis after donor lymphocyte infusion.

Polymyositis usually occurred along with other manifestations of chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT) had been reported. However, polymyositis with a sole manifestation of acute GVHD following donor lymphocyte infusion (DLI) is rare. We reported a 45-yr-old man of acute lymphoid leukemia post-allogeneic HSCT 6 months developed acute polymyositis after DLI. He did not develop any symptoms, signs of acute or chronic GVHD following allogeneic HSCT, despite withdraw of immuosuppresive agents, cyclosporin A (CsA). As the DNA-STR of bone marrow analysis showed mixed chimerism, he received the DLI for remission on May 16, 2002. Acute polymyositis developed following DLI 22 d later. The clinical presentation of polymyositis is compatible with a manifestation of acute GVHD following DLI. It also responds to the treatment of steroid and CsA.