Comparison of bleomycin-detectable iron and labile plasma iron assays

To the Editor: Non-transferrin-bound iron (NTBI)1 is detected in the plasma of pa- tients with diseases in which the transferrin-binding capacity for iron is exceeded by a massive iron overload, such as in certain forms of thalassemia and hemochroma- tosis, repeated blood transfu- sions, or bone marrow failure. Excess iron is harmful because it causes oxidative stress, accumu- lates in and damages tissues, and enhances the growth of patho- gens. [...]the measure- ment of NTBI is of clinical im- portance, because NTBI may be used as an indicator of systemic iron overload and iron toxicity (1,2).