Levels of non-transferrin-bound iron as an index of iron overload in patients with thalassaemia intermedia.

Non-transferrin-bound iron (NTBI) was evaluated as an index of iron overload in a cross-sectional randomised study in 74 non-transfused patients with thalassaemia intermedia (TI). Mean NTBI (2.92 +/- 3.43 micromol/l), serum ferritin (1023 +/- 780 ng/ml) and liver iron concentration (LIC; 9.0 +/- 7.4 mg Fe/g dry weight) were increased above reference-range levels. Significant positive correlations occurred between mean NTBI and LIC (Pearson correlation 0.36; P = 0.002) and serum ferritin (Pearson correlation 0.421; P < 0.0001); with higher levels observed in splenectomised patients. NTBI assessment has potential as a simple reliable approach to determining iron status in TI.