Amyloid deposits in the bone marrow of patients with immunoglobulin light chain amyloidosis do not impact stem cell mobilization or engraftment.

Amyloid deposits are often found in the bone marrow in patients with Immunoglobulin light chain (AL) amyloidosis. We sought to determine whether this affects stem cell collection or engraftment after high-dose melphalan and autologous stem cell transplantation (HDM-SCT). We reviewed data on 361 patients with AL amyloidosis who had Congo red staining of pretreatment bone marrow biopsy specimens and underwent HDM-SCT between July 1994 and December 2011. We analyzed data on stem cell yield, days of stem cell collection, and days to neutrophil and platelet engraftment posttransplantation. Bone marrow amyloid deposits were found in 65% of patients (n = 233). There were no significant differences in median number of stem cells collected and days to neutrophil or platelet engraftment between patients with bone marrow amyloid deposits and those without these deposits. Thus, our data indicate that although amyloid involvement of the bone marrow is common, it does not negatively affect stem cell mobilization or neutrophil and platelet engraftment after HDM-SCT.