High levels of serum angiogenic growth factors in patients with AL amyloidosis: comparisons with normal individuals and multiple myeloma patients

Summary Serum levels of five angiogenic cytokines were evaluated in 82 patients with primary systemic amyloidosis (AL). Angiopoietin‐1, vascular endothelial growth factor, basic fibroblast growth factor and angiogenin were higher in AL patients than in controls ( n = 35) and newly‐diagnosed, symptomatic, myeloma patients ( n = 35). Angiopoetin‐1/Angiopoetin‐2 ratio was lower in AL compared to controls but higher than in myeloma patients. Angiopoetin‐2 correlated with cardiac dysfunction indices; however, none of the angiogenic growth factors was prognostically significant. The increased angiogenic cytokine levels observed in AL seem to represent either a toxic effect of amyloid fibrils or light chains, or a compensatory response to organ dysfunction.