Abstract 16175: Human Placental Growth Factor - a Novel Biomarker for Risk Assessment in Systemic Light-Chain Amyloidosis
Light-chain amyloidosis (AL) is a fatal systemic disease. Vascular amyloid deposition can be generally found in patients with AL. Human placental growth factor (PlGF), a member of the vascular endothelial growth factor family was found to be altered in pathological conditions (e.g. acute coronary syndrome, diabetes). PlGF has never been elucidated in patients with AL.
In 125 consecutive patients (70 male, 55 female; 60.2±0.9 years of age) with biopsy-proven systemic AL PlGF was analyzed. PlGF was measured by cobas PlGF, Roche Diagnostics, Mannheim, Germany. Organ involvement was defined according to the consensus criteria.
Predominant organ deposition was in kidneys (n=63) and heart (n=46). Mean thickness of IVS was 15.2±0.3mm, NYHA heart failure class was 1.6±0.1. Mean hs-TnT level was 75.5±9.7ng/L, NT-proBNP 7947±1531pg/mL, and PlGF was 35.2±3.8ng/L. PlGF increased with number of organs involved and with impairment of renal function. No correlation of PlGF was observed with indices of severity of cardiac involvement. A significant correlation of PlGF with hs-TnT (ρ=0.306; p=0.0007) and NT-proBNP (ρ=0.315; p=0.0006) was observed. PlGF increased with the probability of survival according to the staging system of Dispenzieri et al. (Dispenzieri et al., J Clin Oncol 2004) using troponin and NT-proBNP.
Thirty-eight patients (30.2%) died during follow-up of 24.1±1.2 months. PlGF was higher in deceased patients than in survivors (46.7±10.9 ng/L vs. 29.8±2.2 ng/L; p<0.01). The best cut-off discriminating survivors and non-survivors was 28.44 ng/L (sensitivity 66.7%; specificity 78.1%). A modified model risk model according to Dispenzieri et al. revealed a better discrimination if patients at intermediary risk for survival were additionally stratified by PlGF plasma levels. Net reclassification index was 37.2 % (p=0.002). The multivariate analysis revealed NT-proBNP, PlGF, and eligibility for stem cell transplantation as independent parameters of survival. In conclusion, plasma PlGF values in AL are invariably associated with the number of involved organs, but not with clinical, morphological, and functional parameters of cardiac involvement. PlGF provide useful information for risk stratification of patients at intermediary risk.
- © 2012 by American Heart Association, Inc.