In our study, an important proportion of subjects (12%) abandoned 2RBC donation on medical advice because of low SF levels (generally below 30 ng/mL), even in the absence of anaemia and of symptoms of iron deficiency. This practice largely reflects the uncertainty about the course of Hb and SF levels in repeated 2RBC donors, with a perceived greater risk for iron deficiency anaemia associated with this procedure compared to conventional WB donation. Although only very few donors of our cohort were excluded from 2RBC apheresis because of inadequate Hb levels, it is possible that in a larger number of subjects the decrease in Hb values below critical levels was prevented by an earlier deferral due to low SF. Interestingly, 25 cases already had low SF levels at their first apheresis. To our knowledge, there are no published data on the effects of 2RBC collection in subjects with low base-line iron stores. Such evaluations, as well as a comparison of different 2RBC donation frequencies on the course of Hb and SF levels, would be extremely valuable in order to optimise donation strategies targeted at preventing iron deficiency anaemia and thus avoiding donor loss.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5016297/