RESUMEN
AIM: Anemia of chronic disease is considered the most common extra-articular manifestation of rheumatoid arthritis (RA). The present study aimed to investigate the effect of etanercept (anti-tumor necrosis factor) on anemia and hepcidin gene expression in a rat model of RA. METHOD: Rheumatoid arthritis was induced in rats by Freund Complete Adjuvant (FCA; 1 mg/0.1 ml paraffin oil, subcutaneously) on days (0, 30 and 40). Etanercept was administered subcutaneously at a dose of (0.3 mg/kg 3 times/week). Arthritis parameters, erythrocytic indices, iron profile, serum TNF-α, serum IL-6 and hepatic RT-PCR hepcidin expression were assessed. RESULTS: FCA-rats developed arthritis and anemia, with significant increase of serum TNFα and IL-6 levels, and of hepcidin gene expression. In RA-rats, etanercept administration improved arthritis, corrected the erythrocyte indices and restored serum iron and ferritin with significant reduction in TNF-α, IL-6 and hepcidin gene expression. Hepcidin expression was negatively correlated to erythrocytic indices and iron profile, while it was positively correlated to serum TNF-α and IL-6 levels. CONCLUSION: Etanercept improved anemia in this animal model of RA, which could be explained in part by the reduction in hepcidin gene expression.
