Ferritin testing to characterize and address iron deficiency in young donors

The effect of ferritin-guided iron supplementation among Danish female first-time blood donors

BACKGROUND

The identification of blood donors at risk of developing low hemoglobin (Hb) and subsequent intervention is expected to reduce donation-induced iron deficiency and low Hb among blood donors. This study explores the effects of ferritin-guided iron supplementation for female first-time donors implemented in four of five administrative regions in Denmark.

STUDY DESIGN AND METHODS

We included 45,919 female first-time donors in this study. Hb values were determined in donations of included donors during a 2-year follow-up period. For each region, an intervention group (after implementation) and a control group (before implementation) were defined. The primary outcome was Hb below the donation threshold (7.8 mmol/L ~ 12.5 g/dL) at the time of donation, in the control group, and the intervention group, using logistic regression. The secondary outcome was the number of donations per donor given during the follow-up period.

RESULTS

We observed a statistically significant decrease in the risk of female first-time donors experiencing a donation with low Hb after ferritin-guided iron supplementation was introduced: Odds ratio, 0.82; 95% confidence interval (CI), 0.71-0.95. We found a statistically significant increase in the number of donations per donor during the follow-up period after intervention; rate ratio: 1.05, 95% CI: 1.02-1.08.

DISCUSSION

Ferritin-guided iron supplementation led to a significant reduction in the occurrence of low hemoglobin (Hb) levels among Danish female first-time blood donors. The intervention was additionally associated with an increase in the number of donations per donor.

Research partnerships between blood services and public health authorities: An international, cross-sectional survey

BACKGROUND AND OBJECTIVES

The COVID-19 pandemic has brought to the fore how blood services can partner with public health (PH) authorities to inform decisions. Yet the scope of partnerships between blood services and PH authorities is inadequately documented. We explored how blood services partner with PH authorities outside the scope of COVID-19.

MATERIALS AND METHODS

On 19 January 2022, survey was sent to employees of blood services located throughout the world. Survey questions mainly pertained to partnerships with PH authorities, including how blood specimens are used and collected.

RESULTS

Twenty-seven recipients-4 (14.8%) in Africa, 3 (11.1%) in Asia, 9 (33.3%) in Europe, 6 (22.2%) in North America, 2 (7.4%) in Oceania and 3 (11.1%) in South America-completed the survey. Fifteen recipients (55.6%) indicated their blood service was directly or indirectly supervised by PH authorities. Twenty-four recipients (88.9%) indicated currently using or planning to use blood donor data or samples for PH research or pathogen surveillance. A substantial proportion of respondents reported using samples or results from non-routine tests for the surveillance of non-transfusion-transmitted infectious disease pathogens (n = 13 [48.1%]); samples or results of non-routine tests for PH research unrelated to pathogens (n = 10 [37.0%]); donor data for PH research unrelated to pathogens (n = 12 [44.4%]) and donor data for PH research unrelated to transfusion safety (n = 11 [40.7%]). Fourteen (51.9%) had established (or planned to establish) longitudinal cohorts and 19 (70.4%) biobanks.

CONCLUSION

The majority of responding blood services were already involved in or planned to be involved in PH research or pathogen surveillance.

Iron status of blood donors

PURPOSE OF REVIEW

This review examines recent research on the prevalence and importance of iron deficiency in blood donors, and on efforts to mitigate it.

RECENT FINDINGS

Premenopausal females, teenagers, and high-frequency donors are at the highest risk for donation-induced iron deficiency, in both high-resource and low-resource settings. The physiology relating iron stores to hemoglobin levels and low hemoglobin deferral is well elucidated in blood donor populations, yet the clinical effects attributable to iron loss in the absence of anemia are challenging to identify. Expanded adoption of ferritin testing is improving donor management but may cause decreases in the blood supply from temporary donor loss. The potential for personalized donor management is emerging with development of computational models that predict individual interdonation intervals that aim to optimize blood collected from each donor while minimizing low hemoglobin deferrals.

SUMMARY

Measures to reduce iron deficiency are available that can be deployed on a standardized or, increasingly, personalized basis. Blood centers, regulators, and donors should continue to evaluate different tactics for addressing this problem, to obtain a balanced approach that is optimal for maintaining adequate collections while safeguarding donor health.

Factors associated with first-time and repeat blood donation: Adverse reactions and effects on donor behavior

BACKGROUND

Blood centers have a dual mission to protect donors and patients; donor safety is paramount to maintaining an adequate blood supply. Elucidating donor factors associated with adverse reactions (AR) is critical to this mission.

STUDY DESIGN/METHODS

A retrospective cohort analysis of whole blood donors from 2003 to 2020 was conducted at a single blood center in northern California. Adjusted odds ratios (AORs) with 95% CIs for ARs were estimated via multivariable logistic regression on demographics, donation history, and physical examination data. Where appropriate, Wilcoxon-Rank Sum and chi-squared tests were used to determine significance.

RESULTS

First-time blood donors (FTD) exhibited a higher AR rate than repeat donors (4.4% vs. 1.9% p < .0001). When compared with FTDs without AR, FTDs with ARs (FT-AR) were less likely to return (30.0% vs. 47.3%, p < .0001), and, of those who returned, had a higher rate of reaction 20.2% versus 2.8% (p < .001). Factors found to be associated with FT-AR (younger age, increased heart rate, and higher diastolic blood pressure) still correlated positively with AR on return donation, but to a lower degree. FTD who potentially witnessed an AR had a lower return rate (44.6% vs. 47.3%, p = <.001) and donated fewer units (2.38 vs. 3.37, p < .001) when compared to FTD who did not witness an AR.

CONCLUSION

The AR on FTD increases the AR likelihood of return donation. Longitudinal analysis shows that a time-based deferral policy targeted at FT-AR young donors can reduce the number of ARs while not dramatically impacting the blood supply.

Cost-effectiveness of alternative minimum recall intervals between whole blood donations

BACKGROUND

The INTERVAL trial showed shorter inter-donation intervals could safely increase the frequency of whole-blood donation. We extended the INTERVAL trial to consider the relative cost-effectiveness of reduced inter-donation intervals.

METHODS

Our within-trial cost-effectiveness analysis (CEA) used data from 44,863 whole-blood donors randomly assigned to 12, 10 or 8 week (males), and 16, 14 or 12 week inter-donation intervals (females). The CEA analysed the number of whole-blood donations, deferrals including low- haemoglobin deferrals, and donors' health-related quality of life (QoL) to report costs and cost-effectiveness over two years.

FINDINGS

The mean number of blood donation visits over two years was higher for the reduced interval strategies, for males (7.76, 6.60 and 5.68 average donations in the 8-, 10- and 12- week arms) and for females (5.10, 4.60 and 4.01 donations in the 12-, 14- and 16- week arms). For males, the average rate of deferral for low haemoglobin per session attended, was 5.71% (8- week arm), 3.73% (10- week), and 2.55% (12- week), and for females the rates were: 7.92% (12-week), 6.63% (14- week), and 5.05% (16- week). Donors' QoL was similar across strategies, although self-reported symptoms were increased with shorter donation intervals. The shorter interval strategies increased average cost, with incremental cost-effectiveness ratios of £9.51 (95% CI 9.33 to 9.69) per additional whole-blood donation for the 8- versus 12- week interval for males, and £10.17 (95% CI 9.80 to 10.54) for the 12- versus 16- week interval arm for females.

CONCLUSIONS

Over two years, reducing the minimum donation interval could provide additional units of whole-blood at a small additional cost, including for those donor subgroups whose blood type is in relatively high demand. However, the significance of self-reported symptoms needs to be investigated further before these policies are expanded.

Iron deficiency among French whole-blood donors: first assessment and identification of predictive factors

BACKGROUND

The objectives of this study are to estimate the prevalence of iron deficiency (ID) among French whole-blood (WB) donors to identify factors associated with ID and to generate decision trees.

STUDY DESIGN AND METHODS

A prospective National multicentre study was performed on WB donors from March 11, to April 5th, 2019. Samples were selected randomly to perform serum ferritin. ID was defined as ferritin value under 26 ng/ml. All results were stratified by sex. Factors associated with ID were analysed using multivariate logistic regression model. CART algorithm was used for decision trees.

RESULTS

Eleven thousand two hundred fifty eight WB donors were included. ID was more frequent in women (39·5%) than in men (18·0%). Among 7200 repeated donors, women below 50 yo had a higher risk (OR = 2·37; [1·97-2·85] IC95) than those above 50 yo. Factors associated with ID were: haemoglobin level under the threshold at donation n-1 except for women and n-2 donation; a low mean corpuscular haemoglobin at n-1 and n-2 donations; a shorter interval since n-1 donation and between n-1 and n-2 donations except for women; and women who had given three or four times in the last year. CART algorithm defined high risk of ID subgroups within three populations of donors, new female donors, repeated male donors and repeated female donors. In these identified subgroups, prevalence of ID was up to 72·1%.

CONCLUSIONS

Our study showed the high prevalence of ID among French WB donors, identified well-known and new factors associated with ID and defined algorithms predicting ID in three populations.

Recovery of Iron Stores After Adolescents Donate Blood

BACKGROUND

Teenagers aged 16 to 18 are at increased risk for iron deficiency, exacerbated by losses with whole blood (WB) or double red blood cell (2RBC) donations. Required 56-day (WB) or 112-day (2RBC) interdonation intervals (IDIs) are too short for many to replace lost iron without supplements.

METHODS

Teenagers donating WB or 2RBCs at Vitalant, a national blood provider, had serum ferritin measured at their first and immediately subsequent successful donation from December 2016 to 2018. We modeled postindex log-ferritin as a function of IDI to estimate the shortest intervals that corresponded with 50% to 95% prevalence of adequate donor iron stores (ferritin ≥20 ng/mL female donors, ≥30 ng/mL male donors) at the subsequent donation.

RESULTS

Among 30 806 teenagers, 11.4% of female and 9.7% of male donors had inadequate iron stores at index donation. Overall, 92.6% had follow-up ferritin values within 13 months. Approximately 12 months after WB index donations, >60% of female and >80% of male donors had adequate iron stores (>50% and >70% after 2RBC donations). Follow-up-donation iron stores were highly dependent on index ferritin. Less than half of WB donors with low ferritin at index achieved adequate stores within 12 months. Achieving a ≥90% prevalence of adequate ferritin at 12 months required index values >50 ng/mL.

CONCLUSIONS

These findings suggest that postdonation low-dose iron supplements should be strongly encouraged in teenagers with borderline or low iron stores to permit donation without increased risk for symptoms of mild iron depletion. Increasing the minimum recommended IDI to allow time for replacing donation-related iron losses may be desirable for teenagers.

Longer-term efficiency and safety of increasing the frequency of whole blood donation (INTERVAL): extension study of a randomised trial of 20 757 blood donors

BACKGROUND

The INTERVAL trial showed that, over a 2-year period, inter-donation intervals for whole blood donation can be safely reduced to meet blood shortages. We extended the INTERVAL trial for a further 2 years to evaluate the longer-term risks and benefits of varying inter-donation intervals, and to compare routine versus more intensive reminders to help donors keep appointments.

METHODS

The INTERVAL trial was a parallel group, pragmatic, randomised trial that recruited blood donors aged 18 years or older from 25 static donor centres of NHS Blood and Transplant across England, UK. Here we report on the prespecified analyses after 4 years of follow-up. Participants were whole blood donors who agreed to continue trial participation on their originally allocated inter-donation intervals (men: 12, 10, and 8 weeks; women: 16, 14, and 12 weeks). They were further block-randomised (1:1) to routine versus more intensive reminders using computer-generated random sequences. The prespecified primary outcome was units of blood collected per year analysed in the intention-to-treat population. Secondary outcomes related to safety were quality of life, self-reported symptoms potentially related to donation, haemoglobin and ferritin concentrations, and deferrals because of low haemoglobin and other factors. This trial is registered with ISRCTN, number ISRCTN24760606, and has completed.

FINDINGS

Between Oct 19, 2014, and May 3, 2016, 20 757 of the 38 035 invited blood donors (10 843 [58%] men, 9914 [51%] women) participated in the extension study. 10 378 (50%) were randomly assigned to routine reminders and 10 379 (50%) were randomly assigned to more intensive reminders. Median follow-up was 1·1 years (IQR 0·7-1·3). Compared with routine reminders, more intensive reminders increased blood collection by a mean of 0·11 units per year (95% CI 0·04-0·17; p=0·0003) in men and 0·06 units per year (0·01-0·11; p=0·0094) in women. During the extension study, each week shorter inter-donation interval increased blood collection by a mean of 0·23 units per year (0·21-0·25) in men and 0·14 units per year (0·12-0·15) in women (both p<0·0001). More frequent donation resulted in more deferrals for low haemoglobin (odds ratio per week shorter inter-donation interval 1·19 [95% CI 1·15-1·22] in men and 1·10 [1·06-1·14] in women), and lower mean haemoglobin (difference per week shorter inter-donation interval -0·84 g/L [95% CI -0·99 to -0·70] in men and -0·45 g/L [-0·59 to -0·31] in women) and ferritin concentrations (percentage difference per week shorter inter-donation interval -6·5% [95% CI -7·6 to -5·5] in men and -5·3% [-6·5 to -4·2] in women; all p<0·0001). No differences were observed in quality of life, serious adverse events, or self-reported symptoms (p>0.0001 for tests of linear trend by inter-donation intervals) other than a higher reported frequency of doctor-diagnosed low iron concentrations and prescription of iron supplements in men (p<0·0001).

INTERPRETATION

During a period of up to 4 years, shorter inter-donation intervals and more intensive reminders resulted in more blood being collected without a detectable effect on donors' mental and physical wellbeing. However, donors had decreased haemoglobin concentrations and more self-reported symptoms compared with the initial 2 years of the trial. Our findings suggest that blood collection services could safely use shorter donation intervals and more intensive reminders to meet shortages, for donors who maintain adequate haemoglobin concentrations and iron stores.

FUNDING

NHS Blood and Transplant, UK National Institute for Health Research, UK Medical Research Council, and British Heart Foundation.

Expanded feasibility of ferritin testing: stability of ferritin stored as whole blood and validation of plastic tubes

BACKGROUND

Ferritin testing is a recommended strategy to mitigate iron depletion in blood donors. A barrier for some testing platforms is a requirement to complete sample management and testing within a temporal window incompatible with the logistics of many blood collectors. The ability to delay separation of plasma/serum from red cells and subsequent testing would enhance the feasibility of ferritin testing on a broader scale.

STUDY DESIGN AND METHODS

Thirty blood donors provided a research donation of 12, 4-mL sample tubes of whole blood. Six pairs of serum and K₂ -EDTA-plasma tubes were centrifuged and samples tested in triplicate on day of collection and on each of the next 5 days following storage at 4°C. Comparison of ferritin values for serum versus K₂ -EDTA-plasma at baseline was performed to validate plastic EDTA-containing tubes. Variation of ferritin values during storage was assessed for direction and strength of any detectable changes.

RESULTS

Ferritin values were comparable between EDTA-plasma and serum, with baseline values from EDTA-plasma samples 7% lower on average than serum (p < 0.0001 by paired t-test). Variability over five storage days was within approved parameters in the manufacturer's instructions. Within-run precision averaged 2% to 3% for each test day and within-subject precision across all samples averaged less than 5% for both serum and EDTA-plasma. Repeated measures showed no difference in changes during storage by tube type or day of testing.

CONCLUSION

These results support flexible testing procedures, expanding the opportunity for blood centers to adopt this measure for assessing donor iron status.

Iron Depletion in Adult and Teenage Blood Donors: Prevalence, Clinical Impact, and Options for Mitigation

Iron depletion is a known risk for adult blood donors, but recent studies indicate the prevalence of iron depletion is higher in teenage blood donors. Teenage donors account for more than 10% of the blood collected in the United States and are important for maintaining component availability. Evidence of harm from iron depletion has not been demonstrated, but the area would benefit from further scientific inquiry. Options to protect against iron depletion exist, but each has limitations including cost, logistics, and potential negative impact on blood supply. Blood centers should communicate with donors and make efforts to mitigate these risks.

Association of blood donation with iron deficiency among adolescent and adult females in the United States: a nationally representative study

BACKGROUND

Blood donation results in a loss of iron stores, which is particularly concerning for young female blood donors. This study examines the association of blood donation and iron deficiency among adolescent and adult females in the United States.

STUDY DESIGN AND METHODS

A cross-sectional analysis was performed using data from the 1999-2010 National Health and Nutrition Examination Survey (NHANES). Females who reported their blood donation history in the preceding year and had serum ferritin (SF) measurements were included. Analyses were weighted and stratified by adolescents (16-19 years; n = 2419) and adults (20-49 years; n = 7228). Adjusted prevalence ratios (aPRs) were estimated by multivariable Poisson regression. Standard errors were estimated by Taylor series linearization.

RESULTS

Geometric mean SF levels (ng/mL) were lower in blood donors compared to nondonors among adolescents (21.2 vs. 31.4; p < 0.001) and among adults (26.2 vs. 43.7; p < 0.001). The prevalence of absent iron stores (SF < 12 ng/mL) was higher in blood donors compared to nondonors among adolescents (22.6% vs. 12.2%; aPR = 2.03 [95% confidence interval (CI) = 1.45-2.85]) and among adults (18.3% vs. 9.8%; aPR = 2.06 [95% CI = 1.48-2.88]). Additionally, the prevalence of iron deficiency anemia (SF < 26 ng/mL and hemoglobin < 12.0 g/dL) was also higher in blood donors compared to nondonors among adolescents (9.5% vs. 6.1%; aPR = 2.10 [95% CI = 1.13-3.90]) and among adults (7.9% vs. 6.1%; aPR = 1.74 [95% CI = 1.06-2.85]). Similar results were observed in a sensitivity analysis restricted to adolescents aged 16 to 18 years.

CONCLUSIONS

Blood donation is associated with iron deficiency among adolescent and adult females in the United States. These national data call for further development and implementation of blood donation practices aimed toward mitigating iron deficiency.