Influence of blood donation time intervals on ferritin and hemoglobin concentration

Identify possible significant hemoglobin level variations between blood donations, and observe the effect of periodic donations on iron store.

Seventy-seven subjects were monitored in the course of 1 year to evaluate if repetitive blood donations had an effect on hemoglobin and ferritin concentrations. Furthermore, we determined if hemoglobin concentration variation, detected by the cyanmethemoglobin method, could be used as an early marker for decreased ferritin concentration, quantified by ELISA.

No association between hemoglobin and ferritin variations was observed, as evidenced from our results. Ferritin variations were greater than 50% between donations; in contrast, hemoglobin remained unchanged within intra-individual biological fluctuations. We observed decreased ferritin values during the first blood donation in 15% of the men and 14% of the women evaluated. During the second blood donation 22% of men and 23% of women had decreased ferritin levels. During the third blood donation 43% of men and 50% of women had decreased ferritin values. Only men donated blood four times during the course of the year with all men having decreased ferritin levels. Decrease in ferritin was conditioned both by the number of blood donations as well as the periodicity between them. Spans greater than 6 months between blood donations reduced the risk of iron store reduction.

We determined hemoglobin is not a sensitive marker for monitoring repetitive blood donor follow-up, since hemoglobin did not vary significantly between donations despite having very low or nil ferritin concentration values.