Associations and prognostic interactions between circulating levels of hepcidin, ferritin and inflammatory cytokines in primary myelofibrosis

Abstract

Iron homeostasis is dysregulated in primary myelofibrosis (PMF), given the high prevalence of anemia, need for red blood cell (RBC) transfusions, and disease-associated inflammatory state. We measured plasma hepcidin levels in 203 consecutive PMF patients at the time of first referral; hepcidin levels were significantly higher as compared to healthy controls (P < 0.0001), and were correlated with hemoglobin of <10 g/dL, RBC transfusion requirement, serum ferritin of >500 µg/L, higher dynamic international prognostic scoring system (DIPSS)-plus risk category, the presence of circulating blasts, age of >65 years, and leukocyte count of <4 × 10(9) /L. Increased hepcidin levels predicted for inferior survival independent of six out of the eight DIPSS-plus prognostic parameters (hazard ratio [HR] = 1.8; P = 0.02), but not when RBC transfusion requirement, hemoglobin of <10 g/dL, or increased serum ferritin were included in the Cox model. Multivariable analysis that considered the four overlapping prognostic variables revealed that increased hepcidin (HR = 1.9; P = 0.03) and increased ferritin (HR = 2.3; P = 0.04), but not hemoglobin of <10 g/dL or RBC transfusion requirement, independently retained their significance for predicting survival. Accordingly, increased levels of both hepcidin and serum ferritin (seen in 29% of patients) predicted inferior survival independent of DIPSS-plus or increased inflammatory cytokine levels (HR = 2.4; P = 0.002), and could be considered in future prognostic models for PMF.