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 status in Dutch and Finnish blood donor and general populations: A cross-cohort comparison study

BACKGROUND AND OBJECTIVES

Blood donors are at risk of developing iron deficiency (ID) (ferritin <15 μg/L, World Health Organization definition). Blood services implement different strategies to mitigate this risk. Although in Finland risk group-based iron supplementation is in place, no iron supplementation is provided in the Netherlands. We aim to describe differences in ferritin levels and ID prevalence in donor and general populations in these countries.

MATERIALS AND METHODS

Six cohorts, stratified based on sex, and for women age, in the Netherlands and Finland were used to evaluate differences in ferritin levels and ID between donor populations (Donor InSight-III and FinDonor 10,000) and general populations (Prevention of Renal and Vascular End-Stage Disease [PREVEND], FinRisk 1997 and Health 2000) and newly registered Dutch donors. Multivariable logistic regression was used to quantify associations of various explanatory factors with ID.

RESULTS

In total, 13,443 Dutch and 13,933 Finnish subjects were included. Donors, except for women aged ≤50 years old in Finland, had lower median ferritin levels compared with the general population and new donors. Dutch regular blood donors had higher or similar prevalence of ID as compared with the Dutch general population, including new donors. In contrast, Finnish donors showed similar prevalence of ID compared with the general population, except for a markedly lower prevalence in ≤50-year-old women who routinely receive iron supplements when donating.

CONCLUSION

Iron status in blood donors differs from that in the general population. The Finnish blood service donor management policy, for example, iron supplementation for risk groups, seemingly protects young female blood donors from developing ID.

High Ferritin Is Not Needed in Hemodialysis Patients: A Retrospective Study of Total Body Iron and Oral Iron Replacement Therapy

In vivo iron levels can be adjusted through intestinal iron absorption to be maintained at a suitable level; however, optimal iron levels in hemodialysis (HD) patients are unclear. In this study, we investigated total body iron (TBI), calculated as the sum of red blood cell (RBC) iron and iron stores, during courses of low-dose oral iron replacement therapy, and evaluated in vivo iron sufficiency and its indicators in HD patients. We analyzed data on 105 courses of low-dose iron replacement therapy administered to 83 patients on maintenance HD over 7 months. We evaluated changes in TBI, RBC iron, and iron stores from the initiation of treatment to month 7 in two groups of patients, namely, iron-therapy responders and non-responders. TBI showed significant increases until month 4 and plateaued thereafter in iron-therapy responders, and tended to increase and then reached a similar plateau in non-responders (month 7: 1900 ± 447 vs. 1900 ± 408 mg). Steady-state TBI was strongly correlated with body surface area (y = 1628.6x - 791.91, R2 = 0.88, p < 0.001). We observed constant TBI during oral iron replacement therapy suggesting the activation of a "mucosal block". The results suggest that body surface area has utility for estimating the required TBI with regression equations.

Iron supplementation: A qualitative study on the perception of blood donors, blood collection staff and donor physicians

BACKGROUND AND OBJECTIVES

Iron supplementation is an effective strategy to mitigate donation-induced iron deficiency in blood donors. However, evidence on the perception of individuals involved in blood donation on iron supplementation as a blood service policy is lacking. This study aimed to evaluate the knowledge and perception of whole blood donors (donors), blood collection staff (collection staff) and donor physicians (physicians) regarding donation-induced iron loss and iron supplementation.

MATERIALS AND METHODS

Online focus group discussions had four to six participants and followed a structured questioning approach. All participants had to be fluent in Dutch to participate, and donors had donated at least five times. Sixteen donors, eight collection staff members and four physicians participated in this study. Recordings were transcribed, coded and analysed using a grounded theory approach.

RESULTS

Awareness of donation-induced iron loss was limited in donors. Donors and physicians were predominantly positive towards iron supplementation; the primary motivator for donors was to prevent deferral and reduce iron-deficiency-related symptoms. Improving donor health was the main argument for physicians to advocate iron supplementation. Staff had a critical view on iron supplementation as a policy, as they perceived it as unethical and possibly ineffective. A knowledge gap might underlie their concerns.

CONCLUSION

Most individuals involved in blood donation are positive towards iron supplementation as a blood service policy. If implemented, guidance and monitoring is desired and adequate education of all stakeholders is required.

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.

[Effect of iron deficiency level on oral iron absorption]

Objective: To study the effect of iron deficiency level for oral iron absorption in iron deficient patients. Methods: 37 non-pregnant female patients who were diagnosed with iron deficiency and 13 healthy females who completed their physical examination at the outpatient department of the Anemia Center of the Institute of Hematology & Blood Diseases Hospital from July 2018 to June 2020 were included. Hepcidin and C2-C0 of oral iron absorption test were analyzed in different iron deficiency and serum ferritin level. Results: The median of Hepcidin in IDA, ID/IDE and healthy control group were 4.9 (2.17-32.86) , 26.98 (11.02-49.71) and 69.89 (42.23-138.96) μg/L (P<0.001) , respectively. Hepcidin level of IDA group was lower than that of ID/IDE group (adjusted P=0.005) and healthy control (adjusted P<0.001) . Hepcidin level of ID/IDE group had no significant difference compared with healthy control (adjusted P=0.22) . The mean of C2-C0 in IDA, ID/IDE and healthy control group were (35.30±21.68) , (37.90±14.06) and (23.57±10.14) μmol/L (P=0.130) , respectively. Multilinear regression analysis showed C0, SF, sTFR and HGB were independent factors for Hepcidin in iron deficient patients, with an equation of Hepcidin=-31.842-0.642*C0+2.239*SF+1.778*sTFR+0.365*HGB-0.274*RET-HB. We didn't find independent factor of C2-C0. Conclusion: The degree of iron deficiency had an effect on oral iron absorption. Patients of ID/IDE group absorbed iron more slowly than patients of IDA group. Iron deficient patients with normal gastrointestinal function absorbed more iron by oral administration when they were in a more serious iron deficient stage. Hepcidin was a better parameter to distinguish iron absorption level among different iron deficient patients than C2-C0 of oral iron absorption test.

Association of proton pump inhibitor and histamine H2-receptor antagonists with restless legs syndrome

Restless legs syndrome (RLS) is a common sensorimotor disorder, which can disrupt sleep and is thought to be caused in part by low cellular iron stores. Proton pump inhibitors (PPI) and histamine H₂-receptor antagonists (H₂A) are among the most commonly used drugs worldwide and show evidence of causing iron deficiency. We conducted a case/non-case observational study of blood donors in the United States (N = 13,403; REDS-III) and Denmark (N = 50,323; Danish Blood Donor Study, DBDS), both of which had complete blood count measures and a completed RLS assessment via the Cambridge–Hopkins RLS questionnaire. After adjusting for age, sex, race, BMI, blood donation frequency, smoking, hormone use, and iron supplement use, PPI/H₂A use was associated with RLS (odds ratio [OR] = 1.41; 95% confidence interval [CI], 1.13–1.76; p = 0.002) in REDS-III for both PPI (OR = 1.43; CI, 1.03–1.95; p = 0.03) and H₂A (OR = 1.56; CI, 1.10–2.16; p = 0.01). DBDS exhibited a similar association with PPIs/H₂As (OR = 1.29; CI, 1.20–1.40; p < 0.001), and for PPIs alone (OR = 1.27; CI, 1.17–1.38; p < 0.001), but not H₂As alone (OR = 1.18; CI, 0.92–1.53; p = 0.2). We found no evidence of blood iron stores mediating this association. The association of PPI, and possibly H₂A, consumption with RLS independent of blood iron status and other factors which contribute to RLS risk suggest the need to re-evaluate use of PPI/H₂A in populations at particular risk for RLS.

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.

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.

Genetic and behavioral modification of hemoglobin and iron status among first-time and high-intensity blood donors

BACKGROUND

Some people rapidly develop iron deficiency anemia following blood donation, while others can repeatedly donate without becoming anemic.

METHODS

Two cohorts of blood donors were studied. Participants (775) selected from a 2-year longitudinal study were classified into six analysis groups based on sex, donation intensity, and low hemoglobin deferral. Associations with iron supplement use, cigarette smoking, and four genetic variants of iron metabolism were examined at enrollment and with longitudinal regression models. An unbiased assessment of genetic variability and ability to repeatedly donate blood without experiencing low hemoglobin deferral was conducted on participants (13,403) in a cross-sectional study who were examined by genome wide association (GWA).

RESULTS

Behaviors and genetic variants were associated with differences in hemoglobin and ferritin change following repeated donation. At least weekly iron supplement use was associated with improved status in first-time donors, while daily use was associated with improved status in high-intensity donors. Cigarette smoking was associated with 0.5 g/dL increased hemoglobin in high-intensity donors. A736V in TMPRSS6 was associated with a rapid drop in hemoglobin and ferritin in first-time females following repeated donation. Conversely, the protective TMPRSS6 genotype was not enriched among high-intensity donors. H63D in HFE was associated with increased hemoglobin in female high-intensity donors. However, no differences in genotype between first-time and high-intensity donors were found in GWA analyses.

CONCLUSION

Behavioral and genetic modifiers contributed to first-time donor hemoglobin and iron status, while iron supplement use was more important than underlying genetics in high-intensity donors.

The effect of donation activity dwarfs the effect of lifestyle, diet and targeted iron supplementation on blood donor iron stores

The iron status of blood donors is a subject of concern for blood establishments. The Finnish Red Cross Blood Service addresses iron loss in blood donors by proposing systematic iron supplementation for demographic at-risk donor groups. We measured blood count, ferritin and soluble transferrin receptor (sTfR) and acquired lifestyle and health information from 2200 blood donors of the FinDonor 10000 cohort. We used modern data analysis methods to estimate iron status and factors affecting it with a special focus on the effects of the blood service's iron supplementation policy. Low ferritin (< 15 μg/L), an indicator of low iron stores, was present in 20.6% of pre-menopausal women, 10.6% of post-menopausal women and 6% of men. Anemia co-occurred with iron deficiency more frequently in pre-menopausal women (21 out of 25 cases) than in men (3/6) or post-menopausal women (1/2). In multivariable regression analyses, lifestyle, dietary, and blood donation factors explained up to 38% of the variance in ferritin levels but only ~10% of the variance in sTfR levels. Days since previous donation were positively associated with ferritin levels in all groups while the number of donations during the past 2 years was negatively associated with ferritin levels in pre-menopausal women and men. FRCBS-provided iron supplementation was negatively associated with ferritin levels in men only. Relative importance analyses showed that donation activity accounted for most of the explained variance in ferritin levels while iron supplementation explained less than 1%. Variation in ferritin levels was not significantly associated with variation in self-reported health. Donation activity was the most important factor affecting blood donor iron levels, far ahead of e.g. red-meat consumption or iron supplementation. Importantly, self-reported health of donors with lower iron stores was not lower than self-reported health of donors with higher iron stores.

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.

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.

Whole Blood Transfusion

Whole blood is the preferred product for resuscitation of severe traumatic hemorrhage. It contains all the elements of blood that are necessary for oxygen delivery and hemostasis, in nearly physiologic ratios and concentrations. Group O whole blood that contains low titers of anti-A and anti-B antibodies (low titer group O whole blood) can be safely transfused as a universal blood product to patients of unknown blood group, facilitating rapid treatment of exsanguinating patients. Whole blood can be stored under refrigeration for up to 35 days, during which it retains acceptable hemostatic function, though supplementation with specific blood components, coagulation factors or other adjuncts may be necessary in some patients. Fresh whole blood can be collected from pre-screened donors in a walking blood bank to provide effective resuscitation when fully tested stored whole blood or blood components are unavailable and the need for transfusion is urgent. Available clinical data suggest that whole blood is at least equivalent if not superior to component therapy in the resuscitation of life-threatening hemorrhage. Low titer group O whole blood can be considered the standard of care in resuscitation of major hemorrhage.