Iron Replacement in Blood Donors

在研究的前16个月，473名因筛查手指血红蛋白低于12.5 g/dL而推迟献血的献血者（“低血红蛋白”献血者）和395名同时进行的“对照”献血者，其筛查手指血红蛋白等于或超过12.5 g/dL。与对照组相比，低血红蛋白组的女性献血者（84对35%）和首次献血者（26对12%）的比例更高。在男性供体中，铁蛋白在19-29微克/升之间的缺铁率在“低血红蛋白”组中为9%，在对照组中为18%。低血红蛋白组中缺铁（铁蛋白小于19）的发生率为58%，对照组中为22%。相比之下，31%的低血红蛋白组和对照组女性供体缺铁（铁蛋白9-19微克/升），而25%和10%的低血红蛋白组和对照组女性供体缺铁（铁蛋白低于9微克/升）。总体而言，在低血红蛋白组中，67%的男性和56%的女性缺铁或缺铁，而在对照组中，40%的男性和41%的女性缺铁或缺铁。缺铁通常会引起疲劳和注意力难以集中的症状，这两种症状很难与这些疾病的高背景发生率区分开来。然而，缺铁会带来一些独特的症状，包括异食癖，一种像上瘾一样渴望吃非营养物质，如冰、淀粉、粉笔和灰尘，以及不宁腿综合征。在我们的研究中发现异食癖和不宁腿综合征的发病率很高，9%的缺铁或缺铁供者表现出食癖，14%的供者患有不宁腿。相比之下，异食癖的发生率只有2%，不宁腿的发生率只有6%。供体对每日一次硫酸亚铁的耐受性很好，只有12%的供体出现轻度胃肠道不适症状，将口服药片改为葡萄糖酸亚铁后症状消失。由于严重的急性胃部不适，只有4%的供体不能耐受任何口服铁制剂。每天口服一次硫酸亚铁或葡萄糖酸盐60天导致平均血红蛋白、MCV、铁蛋白和转铁蛋白饱和度显著增加，平均RDW降低，尽管连续献血的平均间隔为94天。口头筛查及实验室监测发现胃肠出血2例，子宫出血6例，原发性血小板增多症1例，糖尿病7例，甲状腺毒症1例，地中海贫血特征26例。未发现胃肠道恶性肿瘤，未发现遗传性血色素沉着症。献血者对口服补铁后症状和化验值的改善表示感谢和满意，并对献血对其血球计数的影响正受到密切监测感到高兴。铁替代对低血红蛋白水平供体延迟发生率的影响仍在调查中。

In the first 16 months of the study, 473 donors who were deferred from blood donation due to a screening fingerstick hemoglobin of less than 12.5 g/dL ("low hemoglobin" donors) and 395 concurrent "control" donors whose screening fingerstick hemoglobin equalled or exceeded 12.5 g/dL were enrolled. The low hemoglobin group contained a greater proportion of female (84 vs 35%) and first time (26 vs 12%) donors compared to the control group. The prevalence of iron deficiency in male donors, defined as a ferritin between 19-29 mcg/L, was 9% in the "low hemoglobin" and 18% in the control men. The prevalence of iron depletion (ferritin less than 19) was 58% in the low hemoglobin and 22% in the control males. In contrast, iron deficiency in female donors (ferritin 9-19 mcg/L) was seen in 31% of both the low hemoglobin and the control groups, whereas iron depletion (ferritin less than 9) was found in 25% and 10% of the low hemoglobin and control women, respectively. Overall, in the low hemoglobin group, 67% of males and 56% of females were either iron depleted or deficient, and in the control group, 40% of males and 41% of females were either iron depleted or deficient. Iron deficiency commonly causes symptoms of fatigue and difficulty concentrating, both of which are difficult to differentiate from high background rates of these complaints. However, several unique symptoms can accompany iron deficiency, including pica, an addictive-like craving to eat non-nutritional substances such as ice, starch, chaulk, and dirt, and restless legs syndrome. A high incidence of both pica and restless legs syndrome was found in our study, with 9% of all iron deficient or depleted donors exhibiting pagophagia and 14% having restless legs. In contrast, pica was seen in only 2% and restless legs in only 6% of the control group. Donors tolerated the once daily dose of ferrous sulfate very well, with only 12% having symptoms of mild gastrointestinal upset which resolved upon changing the oral tablet to ferrous gluconate. Only 4% of donors were unable to tolerate any oral formulation of iron due to severe acute gastric discomfort. Sixty days of oral once-daily ferrous sulfate or gluconate resulted in signficant increases in mean hemoglobin, MCV, ferritin, and transferrin saturation, and decreases in mean RDW, despite continued blood donation at a mean of 94 days between successive donations. Verbal screening and laboratory monitoring detected two cases of gastrointestinal blood loss, six cases of uterine bleeding, one case of essential thrombocythemia, seven cases of diabetes, one case of thyrotoxicosis, and 26 cases of thalassemia trait. No GI malignances were found, and no subjects had genetic hemochromatosis. Donors expressed gratitude and satisfaction at the improvement in symptoms and laboratory values produced by oral iron replacement, and were generally pleased to know that the effect of donation on their blood counts was being closely monitored. The effect of iron replacement on the incidence of donor deferral for low fingerstick hemoglobin levels remains under investigation. Iron replacement therapy is a cheap, safe, and effective method of preventing iron deficiency in blood donors, and has added advantages of decreasing donor deferrals and enhancing donor well-being, thereby increasing overall donor satisafaction and retention. A cost-benefit analysis and analysis of the effect of iron intervention on successful donation outcomes as a percentage of donor visits will be performed when the study is completed.