Blood donation, blood supply, iron deficiency and anemia - It is time to shift attention back to donor health

Abstract

Since the 1980s blood collectors worldwide have focused on two central themes: blood product safety and an adequate blood supply. From the standpoint of safety, specifically the reduction of transfusion-transmitted diseases, the achievements over the past quarter century are remarkable. With respect to the adequacy of the blood supply, the past decade has witnessed major gains in some countries of Europe, Canada and the US and less than had been expected in others, including Brazil, where the challenge of having a more stable blood supply, in which supply and demand are in better balance remains an important issue(1). On the other hand, the aforementioned achievement has come at a price: iron depletion of the repeat blood donor. Blood centers have long recognized that it is more effective and less expensive to collect blood from existing donors than to recruit new donors. While first-time donors, particularly the young and minorities, have been more successfully recruited, 70% of US and 40-70% (depending on the region) of Brazilian donors are repeat donors(1,2). The only known significant disadvantage of blood donation is the potential risk of iron deficiency (ID). Iron is a vitally important element in the human metabolism. It plays a central role in erythropoiesis and is also involved in many other intracellular processes in all the tissues of the body. The potentiality of the individual donor to give blood without developing ID and iron deficiency anemia (IDA) varies widely, probably due to differences in nutritional iron intake, the differences in prevalences of ID in each study population, menstrual iron loss in females, the frequency of blood donation and the use of supplemental iron(2). The frequency of ID is high in blood donors (1.8% to 8.4% in males and 4.5% to 34.8% in females), and more dependent on the frequency of donations than on the cumulated number of donations(2,4). In addition to this, ID is a significant problem and its prevalence is increasing in many countries around the world. The prevalence has been reported to be 9-40% in women, depending on age and menstrual status and 2-5% in men(1,2). Because menstruating females begin their blood donation careers from a lower starting point, subsequent donations pose a risk for greater clinical harm. Females have much higher rates of both ID and IDA.The clinical implications of ID and IDA are not insignificant, including fatigue, reduced work performance and intellectual capacity, reduced endurance, restless leg syndrome, pica, and cognitive and immune function changes. The degree of symptomatology is proportionate to the severity of the anemia(1,2). Moreover, low hemoglobin (Hb) accounts for 4-10% of total deferrals, with the vast majority occurring in women. Therefore it seems reasonable to secure adequate iron reserves in the donor population in order to maintain an appropriate donation potentiality and to avoid possible hematological and non-hematological complications related to ID(1,2). The question that arises is whether this practice is in the best interest of donor health. In this issue of Revista Brasileira de Hematologia e Hemoterapia, Silva et al., representing the Hemocentro Regional de Uberaba, Minas Gerais, Brazil, have brought this issue to light(5). Given the findings in this and other studies, what measures can blood collectors pursue to address iron depletion? There is no single answer, but several approaches should be considered: 1) modifying the donor Hb requirements and measurement of Hb, 2) changing the interdonation interval, 3) testing for serum ferritin, and 4) iron supplementation.