Heterogenic donors

Frequent whole blood donations may carry the risk of iron depletion and subsequent hemoglobin (Hb) level decrease. A low Hb level may lead to deferral for donation, which results in unnecessary costs for the blood bank and an increased risk of donor lapse.

There are large differences in Hb levels and Hb recovery after donation between donors. Several factors are known to influence Hb, for example sex, age and season. However, genetic loci associated with red cell parameters may also play a role, but this has never been studied. Therefore, the aim of this study is to investigate genetic factors associated with declining versus stable Hb levels in blood donors. Furthermore, it will be assessed whether genetic factors can improve existing prediction models. Last, health effects of iron deficiency in blood donors will be examined.

Blood donors with a known Hb level of their first donor screening, who have already participated in Donor InSight 2 and gave permission to be recontacted will be eligible to participate in this study. From this group we will select donors who represent the extreme ends of four groups of donors with different Hb trajectories:

1. 1. Donors with high naïve Hb levels that decline over time
2. 2. Donors with high naïve Hb levels that remain stable over time
3. 3. Donors with low naïve Hb levels that decline over time
4. 4. Donors with low naïve Hb levels that remain stable over time

This list of potential participants will be complemented with a group randomly selected donors, in order to also enable analyses on a representative sample of the donor population. We expect that 3,000 blood donors will participate in this study.

Increased knowledge on genetic factors that distinguish between donors with different Hb trajectories after repeated blood donations will help to select donors and tailor their donation intervals in order to prevent iron deficiency, deferral for donation and unnecessary costs.