Presence of fluorescent in situ hybridization abnormalities is associated with plasma cell burden in light chain amyloidosis

Abstract

Objective/background: To assess abnormalities found on CD138-enriched fluorescent in situ hybridization (FISH) studies on pre-treatment bone marrow in systemic amyloid light-chain amyloidosis (AL) and correlate findings between these abnormalities with organ involvement and 1-year survival.

Methods: We reviewed 107 patients with systemic AL to identify the impact of a diagnostic FISH study done on plasma cell-enriched bone marrow in our institution between January 2010 and January 2015; 77 had pre-treatment testing performed.

Results: A total of 77 (61%) patients had abnormal FISH including: hyperdiploidy (29%), t(11;14), (20%), hypodiploidy (16%), t(4;14), (1%), del17p (5%), and+1q21 (5%). Abnormal FISH studies were more likely in those patients with plasma cell involvement≥10% (p=.002). FISH abnormalities were not shown to correlate with stage, cardiac involvement, or survival at 1year. One-year survival was significantly affected by stage at diagnosis and presence of cardiac and hepatic amyloid involvement.

Conclusion: We conclude that in AL, FISH abnormalities are associated with clonal burden. We found no impact of these markers on the type of organ involvement or 1-year survival.

Keywords: Amyloid; Fluorescent in situ hybridization; Light-chain amyloidosis; Myeloma.