Iron deficiency in blood donors: the REDS‐II Donor Iron Status Evaluation (RISE) study

Abstract

Background Blood donors are at risk of iron deficiency. We evaluated the effects of blood donation intensity on iron and hemoglobin in a prospective study. Methods Four cohorts of frequent and first time or reactivated blood donors (no donation in 2 years), female and male, totaling 2425 were characterized and followed as they donated blood frequently. At enrollment and the final visit, ferritin, soluble transferrin receptor (sTfR), and hemoglobin were determined. Models to predict iron deficiency and hemoglobin deferral were developed. Iron depletion was defined at two levels: Iron Deficient Erythropoiesis (IDE) [log (soluble transferrin receptor/ferritin ≥ 2.07)] and Absent Iron Stores (AIS) (ferritin < 12 ng/mL). Results Among returning female first time/reactivated donors, 20% and 51% had AIS and IDE at their final visit, respectively; corresponding proportions for males were 8% and 20%. Among female frequent donors who returned, 27% and 62% had AIS and IDE, respectively, while corresponding proportions for males were 18% and 47%. Predictors of IDE and/or AIS included a higher frequency of blood donation in the last 2 years, a shorter interdonation interval, and being female and young; conversely, taking iron supplements reduced the risk of iron depletion. Predictors of hemoglobin deferral included female gender, Black race and a shorter interdonation interval. Conclusions There is a high prevalence of iron depletion in frequent blood donors. Increasing the interdonation interval would reduce the prevalence of iron depletion and hemoglobin deferral. Alternatively, replacement with iron supplements may allow frequent donation without the adverse outcome of iron depletion.

Iron Status in Blood Donor Dogs

“…Iron concentration in serum and %SAT (percentage of available sites bound to iron) were higher in the BD canine population when compared with C. These results differ from those in human transfusion medicine studies, where iron deficiency anemia is common in regular donors (defined by low SI and %SAT, along with low iron stores) 3. %SAT in a healthy individual should be ~33% (range 20–60%),4 and all values in our study were within normal reference intervals.…”

“…Because of the importance of the welfare of BD, iron status and safety of blood donation frequency have been recently assessed through a large study called RISE (REDS‐II Donor Iron Status Evaluation) 3. This study concluded that there is a high prevalence of iron deficiency among the BD population, particularly in young women, and that there is a strong association between iron depletion and prior donation intensity/time since last donation.…”

Hepcidin level predicts hemoglobin concentration in individuals undergoing repeated phlebotomy

“…9,10 Institutional Review Boards from all sites approved the study protocol. A subset of subjects was selected from the RISE cohort to examine the relationship between plasma hepcidin, plasma ferritin and venous hemoglobin levels.…”

“…The enrollment and longitudinal phases of the RISE study have been described in detail previously. 9,10 During routine volunteer blood donation in the United States, approximately 500 mL of whole blood containing between 200 and 250 mg of iron is removed from the donor. This amount of iron is approximately equal to the total available iron stores in females and one-fourth of the available iron stores in males.…”

“…Consequently, many individuals who frequently donate blood become iron deficient. [10][11][12] Dietary iron absorption is regulated by hepcidin, an iron regulatory protein produced by the liver. Hepcidin production is regulated by iron stores, erythropoiesis and inflammation, but its physiology when repeated blood loss occurs has not been characterized.…”