Incidence and impact of light chain associated (AL) amyloidosis on the prognosis of patients with multiple myeloma treated with autologous transplantation.

Little is known about the incidence of clinically occult AL amyloid in patients with multiple myeloma and its impact on prognosis of these patients. To address these issues, subcutaneous fat pad aspirates (SAFA) and bone marrow biopsies were evaluated for the presence of amyloid in a cohort of newly diagnosed patients with multiple myeloma prior to enrollment on a phase II study including tandem transplants. Organ directed biopsies were performed when clinically indicated. Presence of amyloid at > or = 1 site was noted in 32 patients (38%). SAFA was positive in 25 (31%), bone marrow in 8 patients (10%) and other organ sites in 7 patients. Patients with and without amyloid did not differ in disease characteristics, in particular no lambda predominance was observed in patients with amyloid. Event free survival (59+ vs 52 months; p = .9) and overall survival (59+ vs 66+ months; p = .9) were similar in both groups. Even the seven patients with symptomatic organ involvement with AL amyloid had a median overall survival of 38+ months. In conclusion, AL amyloidosis occurs more often than previously reported, but its presence does not influence the outcome of these patients after transplantation.