The case described by Mariette and associates further supports the idea that therapy for disorders associated with plasma cell dyscrasia and abnormal immunoglobulin deposits—such as AL amyloidosis, light-chain deposition disease, and probably also heavy-chain disease—should be aimed at completely eliminating the proliferation of clonal plasma cells.

We previously described one patient [1] and treated two others who had generalized AL amyloidosis using high-dose chemoradiotherapy supported by peripheral blood stem-cell transplantation. Of these two, one remains unevaluable because of insufficient treatment duration. In the other patient, who was refractory to intermediate-dose melphalan (70 mg/m² body surface area), evaluation 1 year after stem-cell transplantation showed that monoclonal plasma cell and light-chain excretion was no longer detectable. Furthermore, symptoms associated with amyloid deposits, such as the nephrotic syndrome and orthostatic hypotension, had greatly improved. Amyloid deposits, present in repeated bone marrow biopsies before stem-cell transplantation, had cleared completely.

We agree with Mariette and colleagues that high-dose chemoradiotherapy supported by stem-cell transplantation should be strongly considered in patients with immunoglobulin deposition disease, unless the patient is eligible for an allogeneic transplant. The effect of grafts against myeloma, which has recently been shown (unpublished data), might result in more complete and endurable remissions in fatal plasma-cell disorders.