Utility of labile plasma iron and transferrin saturation in addition to serum ferritin as iron overload markers in different underlying anemias before and after deferasirox treatment

Abstract

OBJECTIVES: Plasma markers in addition to serum ferritin (SF) may be useful for the assessment of iron overload; however, predictive utility may differ depending on underlying, transfusion-dependent, anemias. METHODS: Data were collected before and after 1 year of deferasirox treatment (end of study; EOS) from the large, 1-year EPIC (Evaluation of Patients' Iron Chelation with Exjade(®) ) study. Trends were evaluated between liver iron concentration (LIC), transferrin saturation (TfSat), predose labile plasma iron (LPI) and their relationship to SF categories in 1530 patients: thalassemia major (TM; n = 1114), myelodysplastic syndromes (MDS, n = 336), and sickle-cell disease (SCD, n = 80). RESULTS: Baseline and EOS SF values showed a clear and similar relationship to LIC for all disease groups. TfSat also showed a relationship to SF, most clearly in patients with SCD, where TfSat was lowest in the lowest relative SF category. Unlike SF or LIC, TfSat did not decrease at EOS in any disease group. Baseline LPI was raised in TM and MDS, but not in patients with SCD, decreasing at EOS in both patient groups. After 1 year of chelation therapy, there was a significant trend for greater LPI reduction in patients with TM achieving LIC <7 mg Fe/g dw (P = 0.0137). CONCLUSIONS: Despite limitations, SF showed the clearest relationship, of the plasma markers evaluated, to LIC before and after 1 year of deferasirox in patients with TM, MDS, and SCD. In patients with TM, changes in LPI with chelation show a significant relationship to EOS LIC and may provide an additional indicator of chelation response (clinicaltrials.gov identifier: NCT00171821).