Primary AL amyloid polyneuropathy successfully treated with high-dose melphalan followed by autologous stem cell transplantation.

We report 2 patients with polyneuropathy associated with amyloid derived from light chains (AL) who were treated successfully with high-dose melphalan followed by autologous peripheral blood stem cell transplantation (HDM/SCT). Neuropathic symptoms improved in conjunction with normalization of serum-free light chains. In addition to amyloid deposits in tissues, an amyloidogenic light chain itself produced by abnormal plasma cells might be harmful to peripheral nerve function, and thus HDM/SCT seems to be a promising therapy for primary AL amyloid polyneuropathy.