[High-dose melphalan treatment followed by hematopoietic progenitor cell rescue in primary amyloidosis]

Primary systemic amyloidosis (AL) is a plasma cell dyscrasia characterized by the extracellular deposition of immunoglobulins light chains in different organs and systems. Median survival with current standard treatment is less than 2 years. Intensive chemotherapy followed by hematopoietic stem cell rescue has been used in AL for the last five years. The reported results are encouraging, with a high response rate (65%). Nonetheless, this procedure is associated to an important toxicity, with high transplant related mortality (about 25%). In patients with advanced AL (more than two involved organs) and/or complicated cardiac disease, the mortality is particularly high. In the current report we describe the outcome of the first five patients who received high dose therapy for AL at our institution.

This treatment was administered to patients up to the age of 70 years, who met the standard eligibility criteria for an autologous bone marrow transplantation. Intensive treatment consisted of melphalan 200 mg/m2 in all patients but one who received 140 mg/m2.

Two patients died during the first month after the transplant (arrhythmia: 1, multiorganic failure: 1). Both patients had a poor performance status and advanced disease, with more than two organs involved. The response in the remaining three was of stabilization of the nephrotic syndrome in one and objective response in all the involved organs in the remaining two.

High dose therapy (HDT) with stem cell rescue in AL produces a high response rate. Nevertheless, this treatment approach is associated to a high toxicity.