Oral iron supplementation after blood donation: a randomized clinical trial

IMPORTANCE

Although blood donation is allowed every 8 weeks in the United States, recovery of hemoglobin to the currently accepted standard (12.5 g/dL) is frequently delayed, and some donors become anemic.

OBJECTIVE

To determine the effect of oral iron supplementation on hemoglobin recovery time (days to recovery of 80% of hemoglobin removed) and recovery of iron stores in iron-depleted ("low ferritin," ≤26 ng/mL) and iron-replete ("higher ferritin," >26 ng/mL) blood donors.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, nonblinded clinical trial of blood donors stratified by ferritin level, sex, and age conducted in 4 regional blood centers in the United States in 2012. Included were 215 eligible participants aged 18 to 79 years who had not donated whole blood or red blood cells within 4 months.

INTERVENTIONS

One tablet of ferrous gluconate (37.5 mg of elemental iron) daily or no iron for 24 weeks (168 days) after donating a unit of whole blood (500 mL).

MAIN OUTCOMES AND MEASURES

Time to recovery of 80% of the postdonation decrease in hemoglobin and recovery of ferritin level to baseline as a measure of iron stores.

RESULTS

The mean baseline hemoglobin levels were comparable in the iron and no-iron groups and declined from a mean (SD) of 13.4 (1.1) g/dL to 12.0 (1.2) g/dL after donation in the low-ferritin group and from 14.2 (1.1) g/dL to 12.9 (1.2) g/dL in the higher-ferritin group. Compared with participants who did not receive iron supplementation, those who received iron supplementation had shortened time to 80% hemoglobin recovery in both the low-ferritin (mean, 32 days, interquartile range [IQR], 30-34, vs 158 days, IQR, 126->168) and higher-ferritin groups (31 days, IQR, 29-33, vs 78 days, IQR, 66-95). Median time to recovery to baseline ferritin levels in the low-ferritin group taking iron was 21 days (IQR, 12-84). For participants not taking iron, recovery to baseline was longer than 168 days (IQR, 128->168). Median time to recovery to baseline in the higher-ferritin group taking iron was 107 days (IQR, 75-141), and for participants not taking iron, recovery to baseline was longer than 168 days (IQR, >168->168). Recovery of iron stores in all participants who received supplements took a median of 76 days (IQR, 20-126); for participants not taking iron, median recovery time was longer than 168 days (IQR, 147->168 days; P < .001). Without iron supplements, 67% of participants did not recover iron stores by 168 days.

CONCLUSIONS AND RELEVANCE

Among blood donors with normal hemoglobin levels, low-dose iron supplementation, compared with no supplementation, reduced time to 80% recovery of the postdonation decrease in hemoglobin concentration in donors with low ferritin (≤26 ng/mL) or higher ferritin (>26 ng/mL).

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01555060.

Estimates of SARS-CoV-2 Seroprevalence and Incidence of Primary SARS-CoV-2 Infections Among Blood Donors, by COVID-19 Vaccination Status - United States, April 2021-September 2022

Changes in testing behaviors and reporting requirements have hampered the ability to estimate the U.S. SARS-CoV-2 incidence (1). Hybrid immunity (immunity derived from both previous infection and vaccination) has been reported to provide better protection than that from infection or vaccination alone (2). To estimate the incidence of infection and the prevalence of infection- or vaccination-induced antibodies (or both), data from a nationwide, longitudinal cohort of blood donors were analyzed. During the second quarter of 2021 (April-June), an estimated 68.4% of persons aged ≥16 years had infection- or vaccination-induced SARS-CoV-2 antibodies, including 47.5% from vaccination alone, 12.0% from infection alone, and 8.9% from both. By the third quarter of 2022 (July-September), 96.4% had SARS-CoV-2 antibodies from previous infection or vaccination, including 22.6% from infection alone and 26.1% from vaccination alone; 47.7% had hybrid immunity. Prevalence of hybrid immunity was lowest among persons aged ≥65 years (36.9%), the group with the highest risk for severe disease if infected, and was highest among those aged 16-29 years (59.6%). Low prevalence of infection-induced and hybrid immunity among older adults reflects the success of public health infection prevention efforts while also highlighting the importance of older adults staying up to date with recommended COVID-19 vaccination, including at least 1 bivalent dose.*^,†.

Multiple-ancestry genome-wide association study identifies 27 loci associated with measures of hemolysis following blood storage

BackgroundThe evolutionary pressure of endemic malaria and other erythrocytic pathogens has shaped variation in genes encoding erythrocyte structural and functional proteins, influencing responses to hemolytic stress during transfusion and disease.MethodsWe sought to identify such genetic variants in blood donors by conducting a genome-wide association study (GWAS) of 12,353 volunteer donors, including 1,406 African Americans, 1,306 Asians, and 945 Hispanics, whose stored erythrocytes were characterized by quantitative assays of in vitro osmotic, oxidative, and cold-storage hemolysis.ResultsGWAS revealed 27 significant loci (P < 5 × 10-8), many in candidate genes known to modulate erythrocyte structure, metabolism, and ion channels, including SPTA1, ALDH2, ANK1, HK1, MAPKAPK5, AQP1, PIEZO1, and SLC4A1/band 3. GWAS of oxidative hemolysis identified variants in genes encoding antioxidant enzymes, including GLRX, GPX4, G6PD, and SEC14L4 (Golgi-transport protein). Genome-wide significant loci were also tested for association with the severity of steady-state (baseline) in vivo hemolytic anemia in patients with sickle cell disease, with confirmation of identified SNPs in HBA2, G6PD, PIEZO1, AQP1, and SEC14L4.ConclusionsMany of the identified variants, such as those in G6PD, have previously been shown to impair erythrocyte recovery after transfusion, associate with anemia, or cause rare Mendelian human hemolytic diseases. Candidate SNPs in these genes, especially in polygenic combinations, may affect RBC recovery after transfusion and modulate disease severity in hemolytic diseases, such as sickle cell disease and malaria.

Restless legs syndrome, pica, and iron status in blood donors

BACKGROUND

The association of blood donation-related iron deficiency with pica or restless legs syndrome (RLS) remains poorly elucidated. This study evaluated the prevalence of RLS and pica in blood donors completing the REDS-II Iron Status Evaluation (RISE) study.

STUDY DESIGN AND METHODS

RISE enrolled 2425 blood donors in a prospective cohort study; 1334 donors provided blood samples to characterize iron status and answered a questionnaire inquiring into symptoms of RLS and pica at a final visit after 15 to 24 months of follow-up. Associations between both conditions and iron status were evaluated.

RESULTS

There were 9 and 20% of donors reporting symptoms of probable or probable/possible RLS, respectively. Iron depletion and donation intensity were not predictive of RLS. Pica was reported by 65 donors (5.5%), half of whom reported daily cravings. Prevalence of pica increased with degree of iron depletion in women (2% in iron-replete females, 13% in those with ferritin < 12 ng/mL), but not in men. Probable RLS and pica coexpressed in eight individuals, but no more frequently than expected by chance.

CONCLUSION

RLS and pica have been associated with iron deficiency in nondonor populations. This study indicates a potentially high prevalence of RLS in frequent blood donors but shows no association with iron status or donation intensity. Low iron stores were associated with higher prevalence of pica, but only in females. Furthermore, the results are incompatible with RLS and pica sharing a common pathophysiology.

A randomized, blinded, placebo-controlled trial of education and iron supplementation for mitigation of iron deficiency in regular blood donors

BACKGROUND

The historical approach of offering dietary advice to donors with low hemoglobin (Hb) is ineffective for preventing iron deficiency in frequent donors. Alternative approaches to maintaining donor iron status were explored.

STUDY DESIGN AND METHODS

Frequent blood donors were randomly assigned into five arms for 2 years of follow-up. Three double-blinded arms provided 60 once-daily pills after each donation (38, 19, or 0 mg of iron). Two single-blinded arms provided iron status (ferritin) or no information letters after each donation. Ferritin, soluble transferrin receptor, and complete blood count were measured at each donation.

RESULTS

There were 692 subjects enrolled and 393 completed the study. Subjects in pill groups deenrolled more than those in letter groups (39% vs. 7%). Adverse events occurred equally in subjects receiving iron or placebo pills. Of those completing the study, the prevalence of ferritin of less than 12 or less than 26 ng/mL declined by more than 50% and was statistically indistinguishable in the three intervention groups (19 or 38 mg of iron; iron status letter). Longitudinal analyses of all subjects showed improved iron status in iron pill groups and worsening iron status in control groups (placebo; no information letter). The iron pill groups experienced a net increase of approximately 0.6 g/dL Hb compared to control groups. The iron status letter group had little change in Hb.

CONCLUSION

Providing 19 or 38 mg of daily iron or iron status information were effective and mostly equivalent interventions for mitigating iron deficiency in regular donors when compared at the end of the 2-year longitudinal phase of the study. Donors without intervention had worsened iron deficiency with continued donation.

Frequent blood donations alter susceptibility of red blood cells to storage- and stress-induced hemolysis

BACKGROUND

Frequent whole blood donations increase the prevalence of iron depletion in blood donors, which may subsequently interfere with normal erythropoiesis. The purpose of this study was to evaluate the associations between donation frequency and red blood cell (RBC) storage stability in a racially/ethnically diverse population of blood donors.

STUDY DESIGN

Leukoreduced RBC concentrate-derived samples from 13,403 donors were stored for 39 to 42 days (1-6°C) and then evaluated for storage, osmotic, and oxidative hemolysis. Iron status was evaluated by plasma ferritin measurement and self-reported intake of iron supplements. Donation history in the prior 2 years was obtained for each subject.

RESULTS

Frequent blood donors enrolled in this study were likely to be white, male, and of older age (56.1 ± 5.0 years). Prior donation intensity was negatively associated with oxidative hemolysis (p < 0.0001) in multivariate analyses correcting for age, sex, and race/ethnicity. Increased plasma ferritin concentration was associated with increased RBC susceptibility to each of the three measures of hemolysis (p < 0.0001 for all), whereas self-reported iron intake was associated with reduced susceptibility to osmotic and oxidative hemolysis (p < 0.0001 for both).

CONCLUSIONS

Frequent blood donations may alter the quality of blood components by modulating RBC predisposition to hemolysis. RBCs collected from frequent donors with low ferritin have altered susceptibility to hemolysis. Thus, frequent donation and associated iron loss may alter the quality of stored RBC components collected from iron-deficient donors. Further investigation is necessary to assess posttransfusion safety and efficacy in patients receiving these RBC products.

Intradonor reproducibility and changes in hemolytic variables during red blood cell storage: results of recall phase of the REDS-III RBC-Omics study

BACKGROUND

Genetic determinants may underlie the susceptibility of red blood cells (RBCs) to hemolyze in vivo and during routine storage. This study characterized the reproducibility and dynamics of in vitro hemolysis variables from a subset of the 13,403 blood donors enrolled in the RBC-Omics study.

STUDY DESIGN AND METHODS

RBC-Omics donors with either low or high hemolysis results on 4°C-stored leukoreduced (LR)-RBC samples from enrollment donations stored for 39 to 42 days were recalled 2 to 12 months later to donate LR-RBCs. Samples of stored LR-RBCs from the unit and from transfer bags were evaluated for spontaneous and stress-induced hemolysis at selected storage time points. Intradonor reproducibility of hemolysis variables was evaluated in transfer bags over two donations. Hemolysis data at serial storage time points were generated on LR-RBCs from parent bags and analyzed by site, sex, race/ethnicity, and donation frequency.

RESULTS

A total of 664 donors were successfully recalled. Analysis of intradonor reproducibility revealed that osmotic and oxidative hemolysis demonstrated good and moderate reproducibility (Pearson's r = 0.85 and r = 0.53, respectively), while spontaneous hemolysis reproducibility was poor (r = 0.40). Longitudinal hemolysis in parent bags showed large increases over time in spontaneous (508.6%) and oxidative hemolysis (399.8%) and smaller increases in osmotic (9.4%) and mechanical fragility (3.4%; all p < 0.0001).

CONCLUSION

Spontaneous hemolysis is poorly reproducible in donors over time and may depend on site processing methods, while oxidative and osmotic hemolysis were reproducible in donors and hence could reflect consistent heritable phenotypes attributable to genetic traits. Spontaneous and oxidative hemolysis increased over time of storage, whereas osmotic and mechanical hemolysis remained relatively stable.

Effect of iron supplementation on iron stores and total body iron after whole blood donation

BACKGROUND

Understanding the effect of blood donation and iron supplementation on iron balance will inform strategies to manage donor iron status.

STUDY DESIGN AND METHODS

A total of 215 donors were randomized to receive ferrous gluconate daily (37.5 mg iron) or no iron for 24 weeks after blood donation. Iron stores were assessed using ferritin and soluble transferrin receptor. Hemoglobin (Hb) iron was calculated from total body Hb. Total body iron (TBI) was estimated by summing iron stores and Hb iron.

RESULTS

At 24 weeks, TBI in donors taking iron increased by 281.0 mg (95% confidence interval [CI], 223.4-338.6 mg) compared to before donation, while TBI in donors not on iron decreased by 74.1 mg (95% CI, -112.3 to -35.9; p < 0.0001, iron vs. no iron). TBI increased rapidly after blood donation with iron supplementation, especially in iron-depleted donors. Supplementation increased TBI compared to controls during the first 8 weeks after donation: 367.8 mg (95% CI, 293.5-442.1) versus -24.1 mg (95% CI, -82.5 to 34.3) for donors with a baseline ferritin level of not more than 26 ng/mL and 167.8 mg (95% CI, 116.5-219.2) versus -68.1 mg (95% CI, -136.7 to 0.5) for donors with a baseline ferritin level of more than 26 ng/mL. A total of 88% of the benefit of iron supplementation occurred during the first 8 weeks after blood donation.

CONCLUSION

Donors on iron supplementation replaced donated iron while donors not on iron did not. Eight weeks of iron supplementation provided nearly all of the measured improvement in TBI. Daily iron supplementation after blood donation allows blood donors to recover the iron loss from blood donation and prevents sustained iron deficiency.

Elevated risk for iron depletion in high-school age blood donors

BACKGROUND

High school students 16 to 18 years-old contribute 10% of the US blood supply. Mitigating iron depletion in these donors is important because they continue to undergo physical and neurocognitive development.

STUDY DESIGN AND METHODS

Study objectives were to determine the prevalence of iron depletion in 16- to 18-year-old donors and whether their risk for iron depletion was greater than adult donors. Successful, age-eligible donors were enrolled from high school blood drives at two large US blood centers. Plasma ferritin testing was performed with ferritin less than 12 ng/mL as our primary measure of iron depletion and ferritin less than 26 ng/mL a secondary measure. Multivariable repeated-measures logistic regression models evaluated the role of age and other demographic/donation factors.

RESULTS

Ferritin was measured from 4265 enrollment donations September to November 2015 and 1954 follow-up donations through May 2016. At enrollment, prevalence of ferritin less than 12 ng/mL in teenagers was 1% in males and 18% in females making their first blood donation, and 8% in males and 33% in females with prior donations. Adjusted odds for ferritin less than 12 ng/mL were 2.1 to 2.8 times greater in 16- to 18-year-olds than in 19- to 49-year-olds, and for ferritin less than 26 ng/mL were 3.3- to 4.7-fold higher in 16- to 18-year-olds. Progression to hemoglobin deferral was twice as likely in 16- to 18-year-old versus 19- to 49-year-old females.

CONCLUSION

Age 16 to 18 years-old is an independent risk factor for iron deficiency in blood donors at any donation frequency. Blood centers should implement alternate eligibility criteria or additional safety measures to protect teenage donors from iron depletion.

Demographics of successful, unsuccessful and deferral visits at six blood centers over a 4-year period

BACKGROUND

Descriptions of donor demographics are of value in formulating recruitment and retention strategies. The demographics of successful (SV), unsuccessful (UV; meaning a nonuseable unit), and deferred (DV) donor visits over a 4-year period were investigated using Retrovirus Epidemiology Donor Study (REDS)-II databases.

STUDY DESIGN AND METHODS

Fourteen deferral categories were created that included low hematocrit (Hct) or hemoglobin (Hb), feeling unwell, malaria travel, malaria other, couldn't wait, blood pressure or pulse, medical diagnosis, medication, test results, higher-risk behavior, variant Creutzfeldt-Jakob disease (CJD), CJD, needle exposure or tattoo, and other. Rates per 10,000 donor presentations were determined for each category globally and for six subcategorizations (first-time or repeat donor status, sex, race/ethnicity, age, education, and fixed or mobile donation location). Deferral rates were also calculated on simultaneous stratifications of donor status, sex, and race/ethnicity.

RESULTS

Of 5,607,922 donor presentations there were 4,553,145 SVs (81.2%), 302,828 UVs (5.4%), and 751,381 DVs (13.4%). Overall rates of deferral ranged from 0.6 per 10,000 presentations for CJD, human growth hormone, or dura mater exposure to 777 per 10,000 presentations for low Hct or Hb. Deferral rates were remarkably different by first-time or repeat donor status, sex, race/ethnicity, and other demographics. The highest overall deferral rate was 3953 per 10,000 presentations, or nearly 40% in first-time, female, Asian donors, and the lowest rate was 5.6% in repeat, male, white donors.

CONCLUSION

Successful donation visits according to demographic characteristics need to be placed within the context of all donor visits. Deferral rates indicate that the burden of donor deferral is high. Efforts to expand the diversity of the donor base through recruitment of minority donors may bring additional challenges because certain deferral reasons were proportionally much higher in these groups.

Donor genetic and nongenetic factors affecting red blood cell transfusion effectiveness

BACKGROUNDRBC transfusion effectiveness varies due to donor, component, and recipient factors. Prior studies identified characteristics associated with variation in hemoglobin increments following transfusion. We extended these observations, examining donor genetic and nongenetic factors affecting transfusion effectiveness.METHODSThis is a multicenter retrospective study of 46,705 patients and 102,043 evaluable RBC transfusions from 2013 to 2016 across 12 hospitals. Transfusion effectiveness was defined as hemoglobin, bilirubin, or creatinine increments following single RBC unit transfusion. Models incorporated a subset of donors with data on single nucleotide polymorphisms associated with osmotic and oxidative hemolysis in vitro. Mixed modeling accounting for repeated transfusion episodes identified predictors of transfusion effectiveness.RESULTSBlood donor (sex, Rh status, fingerstick hemoglobin, smoking), component (storage duration, γ irradiation, leukoreduction, apheresis collection, storage solution), and recipient (sex, BMI, race and ethnicity, age) characteristics were associated with hemoglobin and bilirubin, but not creatinine, increments following RBC transfusions. Increased storage duration was associated with increased bilirubin and decreased hemoglobin increments, suggestive of in vivo hemolysis following transfusion. Donor G6PD deficiency and polymorphisms in SEC14L4, HBA2, and MYO9B genes were associated with decreased hemoglobin increments. Donor G6PD deficiency and polymorphisms in SEC14L4 were associated with increased transfusion requirements in the subsequent 48 hours.CONCLUSIONDonor genetic and other factors, such as RBC storage duration, affect transfusion effectiveness as defined by decreased hemoglobin or increased bilirubin increments. Addressing these factors will provide a precision medicine approach to improve patient outcomes, particularly for chronically transfused RBC recipients, who would most benefit from more effective transfusion products.FUNDINGFunding was provided by HHSN 75N92019D00032, HHSN 75N92019D00034, 75N92019D00035, HHSN 75N92019D00036, and HHSN 75N92019D00037; R01HL126130; and the National Institute of Child Health and Human Development (NICHD).

Prevalence and risk factors for RBC alloantibodies in blood donors in the Recipient Epidemiology and Donor Evaluation Study-III (REDS-III)

BACKGROUND

Little information exists on red blood cell (RBC) alloimmunization in healthy US blood donors, despite the potential significance for donors themselves, blood recipients, and the blood center.

STUDY DESIGN AND METHODS

Donor/donation data were sourced from the Recipient Epidemiology and Donor Evaluation Study-III, which contains information from four US blood centers during 2012 through 2016. Multivariable logistic regression was used to assess prevalence of positive antibody screen by donor demographics, blood type, parity, and transfusion history.

RESULTS

More than 2 million units were collected from 632,378 donors, with 0.51% of donations antibody screen positive and 0.77% of donors having at least one positive antibody screen. The most common antibody specificities were D (26.4%), E (23.8%), and K (21.6%). Regression analysis indicated that increasing age, female sex, D-negative status, and history of transfusion and pregnancy were positively associated with a positive antibody screen. Prior transfusion history was most strongly associated with a positive antibody screen, with donors reporting a prior transfusion having a higher adjusted odds ratio (3.9) of having a positive antibody screen compared to donors reporting prior pregnancy (adjusted odds ratio, 2.0). Though transfusion was a more potent immune stimulus for RBC alloantibody formation than pregnancy, the sheer number of previously pregnant donors contributed to pregnancy being a risk factor for the majority of clinically significant RBC alloantibodies detected in females.

CONCLUSION

These findings on prevalence of and risk factors for RBC antibodies may have implications for future medical care of donors and for operations at blood centers.

Blood Utilization and Transfusion Reactions in Pediatric Patients Transfused with Conventional or Pathogen Reduced Platelets

OBJECTIVES

To assess the safety and efficacy of a Food and Drug Administration-approved pathogen-reduced platelet (PLT) product in children, as ongoing questions regarding their use in this population remain.

STUDY DESIGN

We report findings from a quality assurance review of PLT utilization, associated red blood cell transfusion trends, and short-term safety of conventional vs pathogen-reduced PLTs over a 21-month period while transitioning from conventional to pathogen-reduced PLTs at a large, tertiary care hospital. We assessed utilization in neonatal intensive care unit (NICU) patients, infants 0-1 year not in the NICU, and children age 1-18 years (PED).

RESULTS

In the 48 hours after an index conventional or pathogen-reduced platelet transfusion, respectively, NICU patients received 1.0 ± 1.4 (n = 91 transfusions) compared with 1.2 ± 1.3 (n = 145) additional platelet doses (P = .29); infants 0-1 year not in the NICU received 2.8 ± 3.0 (n = 125) vs 2.6 ± 2.6 (n = 254) additional platelet doses (P = .57); and PEDs received 0.9 ± 1.6 (n = 644) vs 1.4 ± 2.2 (n = 673) additional doses (P < .001). Time to subsequent transfusion and red cell utilization were similar in every group (P > .05). The number and type of transfusion reactions did not significantly vary based on PLT type and no rashes were reported in NICU patients receiving phototherapy and pathogen-reduced PLTs.

CONCLUSIONS

Conventional and pathogen-reduced PLTs had similar utilization patterns in our pediatric populations. A small, but statistically significant, increase in transfusions was noted following pathogen-reduced PLT transfusion in PED patients, but not in other groups. Red cell utilization and transfusion reactions were similar for both products in all age groups.

Potential impact on blood availability and donor iron status of changes to donor hemoglobin cutoff and interdonation intervals

BACKGROUND

A minimum male hemoglobin (Hb) level of 13.0 g/dL becomes a Food and Drug Administration requirement effective May 2016. In addition, extending whole blood (WB) interdonation intervals (IDIs) beyond 8 weeks has been considered to reduce iron depletion in repeat blood donors. This study estimates the impact these changes might have on blood availability and donor iron status.

STUDY DESIGN AND METHODS

Six blood centers participating in Retrovirus Epidemiology Donor Study-II (REDS-II) collected information on all donation visits from 2006 to 2009. Simulations were developed from these data using a multistage approach that first sought to adequately reproduce the patterns of donor return, Hb and ferritin levels, and outcomes of a donor's visit (successful single- or double-red blood cell donation, deferral for low Hb) observed in REDS-II data sets. Modified simulations were used to predict the potential impact on the blood supply and donor iron status under different Hb cutoff and IDI qualification criteria.

RESULTS

More than 10% of WB donations might require replacement under many simulated scenarios. Longer IDIs would reduce the proportion of donors with iron depletion, but 80% of these donors may remain iron-depleted if minimal IDIs increased to 12 or 16 weeks.

CONCLUSION

Higher Hb cutoffs and longer IDIs are predicted to have a potentially large impact on collections but only a modest impact on donor iron depletion. Efforts to address iron depletion should be targeted to at-risk donors, such as iron supplementation programs for frequent donors, and policy makers should try to avoid broadly restrictive donation requirements that could substantially reduce blood availability.

The Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P): A research program striving to improve blood donor safety and optimize transfusion outcomes across the lifespan

BACKGROUND

The Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P) is a new iteration of prior National Heart, Lung, and Blood Institute (NHLBI) REDS programs that focus on improving transfusion recipient outcomes across the lifespan as well as the safety and availability of the blood supply.

STUDY DESIGN AND METHODS

The US program includes blood centers and hospitals (22 including 6 free-standing Children's hospitals) in four geographic regions. The Brazilian program has 5 participating hemocenters. A Center for Transfusion Laboratory Studies (CTLS) and a Data Coordinating Center (DCC) support synergistic studies and activities over the 7-year REDS-IV-P program.

RESULTS

The US is building a centralized, vein-to-vein (V2V) database, linking information collected from blood donors, their donations, the resulting manufactured components, and data extracts from hospital electronic medical records of transfused and non-transfused patients. Simultaneously, the Brazilian program is building a donor, donation, and component database. The databases will serve as the backbone for retrospective and prospective observational studies in transfusion epidemiology, transfusion recipient outcomes, blood component quality, and emerging blood safety issues. Special focus will be on preterm infants, patients with sickle cell disease, thalassemia or cancer, and the effect of donor biologic variability and component manufacturing on recipient outcomes. A rapid response capability to emerging safety threats has resulted in timely studies related to Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2).

CONCLUSIONS

The REDS-IV-P program endeavors to improve donor-recipient-linked research with a focus on children and special populations while also maintaining the flexibility to address emerging blood safety issues.

The strategies to reduce iron deficiency in blood donors randomized trial: design, enrolment and early retention

BACKGROUND AND OBJECTIVES

Repeated blood donation produces iron deficiency. Changes in dietary iron intake do not prevent donation-induced iron deficiency. Prolonging the interdonation interval or using oral iron supplements can mitigate donation-induced iron deficiency. The most effective operational methods for reducing iron deficiency in donors are unknown.

MATERIALS AND METHODS

'Strategies To Reduce Iron Deficiency' (STRIDE) was a two-year, randomized, placebo-controlled study in blood donors. 692 donors were randomized into one of two educational groups or one of three interventional groups. Donors randomized to educational groups either received letters thanking them for donating, or, suggesting iron supplements or delayed donation if they had low ferritin. Donors randomized to interventional groups either received placebo, 19-mg or 38-mg iron pills.

RESULTS

Iron deficient erythropoiesis was present in 52·7% of males and 74·6% of females at enrolment. Adverse events within 60 days of enrolment were primarily mild gastrointestinal symptoms (64%). The incidence of de-enrolment within 60 days was more common in the interventional groups than in the educational groups (P = 0·002), but not more common in those receiving iron than placebo (P = 0·68).

CONCLUSION

The prevalence of iron deficient erythropoiesis in donors enrolled in the STRIDE study is comparable to previously described cohorts of regular blood donors. De-enrolment within 60 days was higher for donors receiving tablets, although no more common in donors receiving iron than placebo.

The benefits of iron supplementation following blood donation vary with baseline iron status

Whole blood donation rapidly removes approximately 10% of a donor's blood volume and stimulates substantial changes in iron metabolism and erythropoiesis. We sought to identify donors who benefit from iron supplementation, describe the nature of the benefit, and define the time course for recovery from donation. Blood samples were collected over 24 weeks following whole blood donation from 193 participants, with 96 participants randomized to 37.5 mg daily oral iron. Changes in total body, red blood cell (RBC), and storage iron, hepcidin, erythropoietin, and reticulocyte count were modeled using semiparametric curves in a mixed model. and the changes were compared among six groups defined by baseline ferritin (<12; 12-50; ≥50 ng/mL) and iron supplementation. The effect of oral iron on storage and RBC iron recovery was minimal in donors with baseline ferritin ≥50 ng/mL, but sizeable when ferritin was <50 ng/mL. Iron initially absorbed went to RBC and storage iron pools when ferritin was <12 ng/mL but went mostly to RBCs when ferritin was ≥12 ng/mL. Donors with ferritin ≥12 ng/mL had a "ripple" increase in reticulocytes ~100 days after donation indicating physiological responses occur months following donation. Thus, iron supplements markedly enhance recovery from whole blood donation in donors with ferritin <50 ng/mL. However, full recovery from donation requires over 100 days when taking iron. The findings also highlight the value of the study of blood donors for understanding human hemoglobin and iron metabolism and their usefulness for future studies as additional biomarkers are discovered.

Therapeutic impact of red blood cell transfusion on anemic outpatients: the RETRO study

BACKGROUND

Patients with cancer or other diagnoses associated with chronic anemia often receive red blood cell (RBC) transfusion as outpatients, but the effect of transfusion on functional status is not well demonstrated.

STUDY DESIGN AND METHODS

To estimate the effect of transfusion on functional status and quality of life, we measured 6-minute walk test distance and fatigue- and dyspnea-related quality-of-life scores before and 1 week after RBC transfusion in 208 outpatients age ≥50 with at least one benign or malignant hematology/oncology diagnosis. To account for potential confounding effects of cancer treatment, patients were classified into two groups based on cancer treatment within 4 weeks of the study transfusion. Minimum clinically important improvements over baseline were 20 meters in walk test distance, 3 points in fatigue score, and 2 points in dyspnea score.

RESULTS

The median improvement in unadjusted walk test distance was 20 meters overall and 30 meters in patients not receiving recent cancer treatment. Fatigue scores improved overall by a median of 3 points and by 4 points in patients without cancer treatment. There was no clinically important change in dyspnea scores. In multiple linear regression analysis, patients who maintained hemoglobin (Hb) levels of 8 g/dL or greater at 1 week posttransfusion, who had not received recent cancer treatment, and who did not require hospitalization during the study showed clinically important increases in mean walk test distance.

CONCLUSIONS

Red blood cell transfusion is associated with a modest, but clinically important improvement in walk test distance and fatigue score outcomes in adult hematology/oncology outpatients.

Estimates of total body iron indicate 19 mg and 38 mg oral iron are equivalent for the mitigation of iron deficiency in individuals experiencing repeated phlebotomy

Iron deficiency anemia is a common clinical condition often treated with tablets containing 65 mg of elemental iron. Such doses can elicit gastrointestinal side effects lowering patient compliance. Oral iron supplements also increase hepcidin production causing decreased fractional absorption of subsequent doses. Frequent blood donors often become iron deficient. Therefore, they were enrolled in a two-year study involving continued blood donations and randomization to receive no pill, placebo, 19, or 38 mg ferrous gluconate for 60 days. Total body iron (TBI) did not change for the subset of donors in the no pill and placebo groups who completed both enrollment and final visits (P = .21 and P = .28, respectively). However, repeated measures regression analysis on the complete dataset estimated a significant decrease in TBI of 52 mg/year for the placebo and no pill groups (P = .001). The effects of 19 and 38 mg iron supplementation on TBI were indistinguishable (P = .54). TBI increased by 229 mg after the initial 60 days of iron supplementation (P < .0001) and was maintained at this higher level with continued iron supplementation following each subsequent donation. The TBI increase was apportioned 51 mg to red cell iron (P < .0001) and 174 mg to storage iron (P < .0001). Changes in storage iron were negatively impacted by 57 mg due to concurrent antacid use (P = .04). These findings in blood donors suggest that much lower doses of iron than are currently used will be effective for clinical treatment of iron deficiency anemia.

Frequent detection but lack of infectivity of SARS-CoV-2 RNA in presymptomatic, infected blood donor plasma

Respiratory viruses such as influenza do not typically cause viremia; however, SARS-CoV-2 has been detected in the blood of COVID-19 patients with mild and severe symptoms. Detection of SARS-CoV-2 in blood raises questions about its role in pathogenesis as well as transfusion safety concerns. Blood donor reports of symptoms or a diagnosis of COVID-19 after donation (post-donation information, PDI) preceded or coincided with increased general population COVID-19 mortality. Plasma samples from 2,250 blood donors who reported possible COVID-19-related PDI were tested for the presence of SARS-CoV-2 RNA. Detection of RNAemia peaked at 9%-15% of PDI donors in late 2020 to early 2021 and fell to approximately 4% after implementation of widespread vaccination in the population. RNAemic donors were 1.2- to 1.4-fold more likely to report cough or shortness of breath and 1.8-fold more likely to report change in taste or smell compared with infected donors without detectable RNAemia. No infectious virus was detected in plasma from RNAemic donors; inoculation of permissive cell lines produced less than 0.7-7 plaque-forming units (PFU)/mL and in susceptible mice less than 100 PFU/mL in RNA-positive plasma based on limits of detection in these models. These findings suggest that blood transfusions are highly unlikely to transmit SARS-CoV-2 infection.

The operational implications of donor behaviors following enrollment in STRIDE (Strategies to Reduce Iron Deficiency in blood donors)

BACKGROUND

Donor behaviors in STRIDE (Strategies to Reduce Iron Deficiency), a trial to reduce iron deficiency, were examined.

STUDY DESIGN AND METHODS

Six hundred ninety-two frequent donors were randomized to receive either 19 or 38 mg iron for 60 days or an educational letter based on their predonation ferritin. Compliance with assigned pills, response to written recommendations, change in donation frequency, and future willingness to take iron supplements were examined.

RESULTS

Donors who were randomized to receive iron pills had increased red blood cell donations and decreased hemoglobin deferrals compared with controls or with pre-STRIDE donations. Donors who were randomized to receive educational letters had fewer hemoglobin deferrals compared with controls. Of those who received a letter advising of low ferritin levels with recommendations to take iron supplements or delay future donations, 57% reported that they initiated iron supplementation, which was five times as many as those who received letters lacking a specific recommendation. The proportion reporting delayed donation was not statistically different (32% vs. 20%). Of donors who were assigned pills, 58% reported taking them "frequently," and forgetting was the primary reason for non-compliance. Approximately 80% of participants indicated that they would take iron supplements if provided by the center.

CONCLUSIONS

Donors who were assigned iron pills had acceptable compliance, producing increased red blood cell donations and decreased low hemoglobin deferrals compared with controls or with pre-STRIDE rates. The majority of donors assigned to an educational letter took action after receiving a low ferritin result, with more donors choosing to take iron than delay donation. Providing donors with information on iron status with personalized recommendations was an effective alternative to directly providing iron supplements.

Blood utilisation and transfusion reactions in adult patients transfused with conventional or pathogen-reduced platelets

Pathogen-reduced (PR) platelets are routinely used in many countries. Some studies reported changes in platelet and red blood cell (RBC) transfusion requirements in patients who received PR platelets when compared to conventional (CONV) platelets. Over a 28-month period we retrospectively analysed platelet utilisation, RBC transfusion trends, and transfusion reaction rates data from all transfused adult patients transfused at the Yale-New Haven Hospital, New Haven, CT, USA. We determined the number of RBC and platelet components administered between 2 and 24, 48, 72 or 96 h. A total of 3767 patients received 21 907 platelet components (CONV = 8912; PR = 12 995); 1,087 patients received only CONV platelets (1578 components) and 1,466 patients received only PR platelets (2604 components). The number of subsequently transfused platelet components was slightly higher following PR platelet components (P < 0·05); however, fewer RBCs were transfused following PR platelet administration (P < 0·05). The mean time-to-next platelet component transfusion was slightly shorter following PR platelet transfusion (P = 0·002). The rate of non-septic transfusion reactions did not differ (all P > 0·05). Septic transfusion reactions (N = 5) were seen only after CONV platelet transfusions (P = 0·011). These results provide evidence for comparable clinical efficacy of PR and CONV platelets. PR platelets eliminated septic transfusion reactions without increased risk of other types of transfusions with only slight increase in platelet utilisation.

Iron status and risk factors for iron depletion in a racially/ethnically diverse blood donor population

BACKGROUND

The optimal approach for reducing iron depletion (ID) in blood donors may vary depending on biologic or behavioral differences across donors.

STUDY DESIGN AND METHODS

More than 12,600 successful whole blood donors were enrolled from four US blood centers for ferritin testing. The study population was enriched for racial/ethnic minorities (1605 African American, 1616 Asian, 1023 Hispanic). Subjects completed questionnaires on ID risk factors. Logistic regression identified predictors of absent iron stores (AIS; ferritin <12 ng/mL) and low ferritin (LF; ferritin <26 ng/mL).

RESULTS

Across all subjects, 19% had AIS and 42% had LF, with a sharp increase in risk observed with increasing donation intensity and among women a large decrease in risk in those more than 50 years old. When other factors were controlled for, African American and Asian donors showed 20% to 25% decreased risk for AIS compared to non-Hispanic Caucasian donors, while Hispanic donors had 25% higher risk. Daily iron supplementation reduced risk for LF and AIS by 30% to 40%, respectively, while the benefit from less frequent use was lower (7%-19% protection). Regular antacid use was associated with at least 20% increment to risk. Use of oral contraceptives or estrogen in females reduced risk by 16% to 22%, while males who reported supplemental testosterone use had a 50% to 125% greater risk for LF and AIS.

CONCLUSIONS

This study confirms high prevalence of LF and AIS in US donors and the principal risk factors of age, sex, and donation frequency. Additional demographic and behavioral risk factors of secondary importance might allow for refinement of ID mitigation strategies.

Qualitative assessment of pica experienced by frequent blood donors

BACKGROUND

Pica, the compulsive consumption of ice or other nonnutritious substances, is associated with iron deficiency, a common negative consequence of frequent blood donation. Because of this, blood donors, such as those participating in the Strategies to Reduce Iron Deficiency (STRIDE) study, are an ideal population to explore pica and iron deficiency.

STUDY DESIGN AND METHODS

STRIDE was a 2-year intervention trial to assess the effectiveness of iron supplementation for mitigating iron deficiency in frequent blood donors. Subjects completed baseline and follow-up questionnaires that included questions about pica symptoms. In-depth telephone interviews were conducted with 14 of these subjects reporting pica symptoms and eight presumed controls (casual ice chewers) to gain a deeper understanding of pica symptoms and their impact on daily life and to make a final determination on the presence of pica.

RESULTS

Pica was confirmed in five of the 14 subjects reporting symptoms and in two of eight controls. Outcome misclassification based on the questionnaire was attributed to inadequate assessment of several pica symptoms identified during the interview. Comparison of subjects' repeated quantitative iron measurements taken throughout STRIDE with subjects' final adjudicated pica status revealed a positive relationship between development of pica and worsening iron status; the opposite was found in those whose pica symptoms resolved.

CONCLUSION

Continued refinement of pica symptom questions will allow for rapid and accurate detection of pica in frequent blood donors and confirmation of successful treatment with iron supplements.