Impacto da sobrecarga de ferro no tecido hepático, miocárdico e ósseo de pacientes em hemodiálise

Abstract

NUNES LLA. Impact of iron overload and on hepatic, myocardial and bone tissue of hemodialysis patients. [thesis] "Faculdade de Medicina da Universidade de São Paulo"; 2019. INTRODUCTION: Chronic kidney disease (CKD) is associated with several comorbidities, including anemia, since with decreased renal function there is a decrease in erythropoietin (EPO) production and changes in iron (Fe) metabolism. In hemodialysis patients, prescription of Fe is indicated to supplement the needs of this element by maintaining ferritin levels above 100 mg/dl and transferrin saturation greater than 20%. However, the excess of Fe can generate free Fe not bound to transferrin, and deposit in organs such as liver, heart, and bone marrow, with consequent impairment of their function. In hemodialysis patients, the diagnosis of Fe overload, its clinical significance and therapeutic decision have been poorly studied, unlike thalassemia patients. OBJECTIVES: To assess whether hemodialysis patients with ferritin levels equal to or greater than 1000 mg/l also have Fe overload in liver, heart, and bone marrow, as well as compromise bone density and remodeling. RESULTS: We evaluated 28 hemodialysis patients with a mean age of 55.8±13.1, hemodialysis time of 42.5±26.5 and iron use in the year prior to study enrollment of 311.5±179.8 mg/month. Biochemical analysis showed 3 patients with Hb below 9.0 mg/dl and 14 with values above 11.5 mg/dl; 6 patients with SatFe <30% and 12 patients with ferritin >1500mg/dl; 16 patients with PTH <300pg/ml and eight with >600pg/dl. MRI revealed Fe overload in the liver and bone tissue of all patients but not in the heart. Serum ferritin levels correlated with liver and bone overload. Densitometry and bone biopsy results were not affected by Fe overload; however, serum Fe levels were associated with lower bone remodeling suggesting an effect of this element on osteoblast activity. CONCLUSIONS: Elevated serum ferritin levels correlate with liver and bone marrow deposit, but not heart.