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

P>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.