Stem cell transplantation for the management of primary systemic amyloidosis

Purpose To review the characteristics and outcomes of amyloidosis patients treated with high-dose chemotherapy and stem cell reconstitution. Subjects and methods Sixty-six patients with biopsy-proven amyloidosis received transplants between March 1996 and January 2001. All patients had evidence of a clonal plasma cell dyscrasia; those with nonimmunoglobulin forms of amyloidosis were excluded, as were those who had no symptoms of amyloidosis, purpura, carpal tunnel syndrome, or symptomatic multiple myeloma. Results Amyloid was seen clinically in the kidneys (n = 45 patients), heart (n = 32), peripheral nerves (n = 11), and liver (n = 11). A monoclonal protein was found in the serum in 46 patients and in the urine in 57 patients. The median daily urinary protein loss was 4.1 g. Septal thickness, measured by echocardiography, ranged from 7 to 24 mm (median, 12 mm); 8 patients had a septal thickness ≥16 mm. Ten patients received transplants 1 year or more after diagnosis. All patients received melphalan-based chemotherapy; 17 patients were conditioned with total body irradiation. Nine patients required dialysis, 7 of whom died. Treatment-related mortality for stem cell transplantation was 14% (9/66). After a median of 25 months of follow-up after transplantation, the percentage of patients alive with one organ involved was 91% (31 of 34); two organs, 82% (18 of 22); three organs, 33% (3 of 9); and four organs, 0% (0 of 1). Hematologic responses were seen in 33 patients and organ responses in 32 patients. The 2-year actuarial survival of all patients was 70%. Conclusion The number of organs involved before stem cell transplantation for amyloidosis is the most important factor in predicting subsequent survival. Stem cell transplantation should be considered as a treatment option for selected patients with amyloidosis.