The effect of iron balance on platelet counts in blood donors.

BACKGROUND: Thrombocytosis (or, less commonly, thrombocytopenia) is associated with iron-deficiency anemia and resolves with iron therapy. Many volunteer blood donors have low iron stores, with or without anemia. Iron balance could affect platelet counts in blood donors. STUDY DESIGN AND METHODS: Whole blood donors deferred for finger-stick hemoglobin levels less than 12.5 g/dL were evaluated by complete blood count and serum iron panel before and after oral iron treatment. Group assignment for iron depletion was based on serum ferritin cutoffs of less than 20 µg/L for women and less than 30 µg/L for men or was based on changes in serum ferritin levels after iron replacement. RESULTS: Among 1273 Hb-deferred whole blood donors, 55% (619 of 1128) of the women and 70% (102 of 145) of the men were iron depleted. Iron-depleted donors had higher platelet counts compared with donors who had normal ferritin levels (women: 286 vs. 268 × 103 /µL; p < 0.0001; men: 246 vs. 222 × 103 /µL; p = 0.0454). Only 4.4% of iron-depleted donors had thrombocytosis (> 400 × 103 /µL) compared with 2.0% of donors who had normal ferritin levels (p = 0.017). Iron replacement decreased platelet counts in iron-depleted female donors (mean, -19,800/µL; interquartile range, 8000 to -45,000/µL), but not in donors who had normal or stable ferritin levels. The same trends were observed in male donors. CONCLUSION: Iron-depleted donors had higher platelet counts than donors who had adequate iron stores. Oral iron replacement decreased platelet counts on average by about 20,000/µL in iron-depleted donors but had no effect on platelet counts in donors who had normal or stable ferritin levels.

An international survey of pediatric apheresis practice.

INTRODUCTION: Pediatric apheresis (PA) has distinct characteristics compared to adult apheresis, and requires specialized knowledge and experience to perform safely, particularly in low-weight patients. As evidence-based medicine advances the field of therapeutic apheresis, increased attention must be paid to pediatric patients with conditions for which apheresis is indicated. METHODS: An electronic survey of >5,000 potential participants throughout the world was conducted to ascertain the scope and the current state of practice. RESULTS: The survey elicited 159 responses from 12 countries; 107 of the responses provided sufficient information for analysis. Participants performed an average of 176 PA procedures/year (range: 1-2,000). The types of PA procedures were therapeutic plasma exchange (92% of centers), red cell exchange (86%), leukocyte depletion (87%) and peripheral blood hematopoietic progenitor cell collection (72%). More than 65% of the centers had treated children older than 5 years with PA. Many centers had also performed PA on younger children; 40% have treated patients <12 months of age; 61% had treated patients 1-5 years old. 36% of centers reported that they would perform apheresis regardless of patient weight; 18% used a 5 kg threshold, 11% used 5-10 kg, and 17% used 10 kg as their weight threshold. CONCLUSION: This report is the largest single survey of centers performing PA. The results provide information about the scope and diversity of PA and identify areas where considerable variability in practice exists. Further exploration of these differences could establish best practices in PA through international research and collaboration.

Donor survey to assess facial flushing during automated red cell collections and medication use.

BACKGROUND: We conducted a donor survey to assess the occurrence of facial flushing and other symptoms during automated 2-U red cell collections (2RBC) and plateletpheresis (PLT) procedures and evaluated the possible association of the reactions with angiotensin-converting enzyme (ACE) inhibitors or with the collection technology. METHODS: An online survey was developed using Zoomerang to capture details of the donors' experience and medication use after 2RBC or PLT donations in regional blood centers of the American Red Cross. RESULTS: Between 12/16/09 and 4/19/10, 1,299 donors in five American Red Cross blood center regions completed an online survey (739 2RBC, 4.2% total registrations; 560 PLT, 2.3% total registrations). Facial flushing was reported by 29 donors, and was more likely associated with 2RBC than PLT procedures (3.0% vs. 1.3%, P = 0.03). Facial flushing with 2RBC donation was reported by eight of 72 (11%) donors on ACE inhibitors; and 14 of 667 (2%) donors who were not taking ACE inhibitors (P = 0.001). The incidence of facial flushing reactions with PLT donation was less than 2% whether donors reported ACEI inhibitor use or not. More than 95% of the donors reported their intent to donate again, regardless of symptoms. CONCLUSION: Facial flushing was more often reported by 2RBC donors taking ACE inhibitors than other donors [11% vs. 2%; P = 0.001]; and was uncommon among PLT donors, irrespective of ACE inhibitor use (<2%). All blood donors should be informed of the potential for common, minor side effects of the collection procedure and the possible but rare occurrence of more medically serious complications.

Evidence-based practice guidelines for plasma transfusion.

BACKGROUND: There is little systematically derived evidence-based guidance to inform plasma transfusion decisions. To address this issue, the AABB commissioned the development of clinical practice guidelines to help direct appropriate transfusion of plasma. STUDY DESIGN AND METHODS: A systematic review (SR) and meta-analysis of randomized and observational studies was performed to quantify known benefits and harms of plasma transfusion in common clinical scenarios (see accompanying article). A multidisciplinary guidelines panel then used the SR and the GRADE methodology to develop evidence-based plasma transfusion guidelines as well as identify areas for future investigation. RESULTS: Based on evidence ranging primarily from moderate to very low in quality, the panel developed the following guidelines: 1) The panel suggested that plasma be transfused to patients requiring massive transfusion. However, 2) the panel could not recommend for or against transfusion of plasma at a plasma : red blood cell ratio of 1:3 or more during massive transfusion, 3) nor could the panel recommend for or against transfusion of plasma to patients undergoing surgery in the absence of massive transfusion. 4) The panel suggested that plasma be transfused in patients with warfarin therapy-related intracranial hemorrhage, 5) but could not recommend for or against transfusion of plasma to reverse warfarin anticoagulation in patients without intracranial hemorrhage. 6) The panel suggested against plasma transfusion for other selected groups of patients. CONCLUSION: We have systematically developed evidence-based guidance to inform plasma transfusion decisions in common clinical scenarios. Data from additional randomized studies will be required to establish more comprehensive and definitive guidelines for plasma transfusion.

The potential impact of selective donor deferrals based on estimated blood volume on vasovagal reactions and donor deferral rates.

BACKGROUND: Whole blood donation in the United States is restricted in volume to 10.5 mL/kg or less in an effort to prevent hypovolemic reactions, but still may exceed more than 15% of a donor's estimated blood volume (EBV). We analyzed the association of EBV with prefaint and systemic vasovagal reactions (SVRs) among whole blood donors and the potential impact of an EBV-based deferral policy. STUDY DESIGN AND METHODS: Independent predictors for prefaint reactions and SVRs were assessed by multivariate logistic regression analysis on 591,177 unique donors participating in the Retrovirus Epidemiology Donor Study-II study. RESULTS: Young age (16 years old odds ratio [OR], 3.70; 95% confidence interval [CI], 2.78-4.94), low EBV (<3.5 L OR, 3.30; 95% CI, 2.57-4.23), and first-time donation status (OR, 2.33; 95% CI, 2.03-2.67) were the strongest predictors for SVRs, with similar trends seen for prefaint reactions. Sex, height, race, blood center, and donation site were weakly associated predictors. A total of 5.6% of all donors had an EBV of less than 3.5 L and experienced 12.5% of all prefaint reactions and 14.5% of SVRs. The highest reaction rates were seen in donors less than 23 years old with an EBV of less than 3.5 L who comprised 2.7% of all donors, who were mostly female (99.9%), and who experienced 8.8% of prefaint reactions and 11.0% of SVRs. CONCLUSION: Young age, low EBV, and first-time donation status are the major correlates of prefaint reactions and SVRs, suggesting that high school and college donors are at particular risk. Deferral of donors with low EBV who are less than 23 years old may offer a rational approach to protecting donors at greater risk of reactions without jeopardizing the adequacy of the blood supply.

TRALI risk reduction: donor and component management strategies.

Transfusion-related lung injury (TRALI) occurs in approximately 1 in 5,000 transfusions and may cause considerably more morbidity and mortality that is not recognized in clinical practice. Based on the current understanding of the etiology of TRALI, blood centers have implemented or are evaluating various donor and component management strategies in an effort to mitigate the risk of TRALI. Many cases of TRALI are likely caused by antibodies to leukocyte antigens (HLA or HNA) in blood components. Approximately 10 to 20% of female blood donors with a history of pregnancy and 1 to 5% of male blood donors harbor these antibodies. Alternatively, TRALI may be mediated by other bioactive lipids or substances that accumulate during storage and cause a reaction when transfused to susceptible patients. The complex interplay among various donor-, component-, and patient-related factors underlying TRALI guarantees that effective prevention will not be a single or simple intervention but rather will require a multifaceted approach. Perhaps, the most important risk reduction strategy is the effort to ensure appropriate use of blood products and eliminate unnecessary transfusions. Blood collection agencies, however, have more proximate control over donor selection and component management than transfusion practice. AABB has provided some guidance on deferring donors implicated in TRALI and minimizing the preparation of high plasma volume components from donors who have anti-leukocyte antibodies or are at increased risk of leukocyte alloimmunization. Blood centers have taken various approaches to mitigate the risk of TRALI, and the possible benefit and the inherent limitations of the current strategies will be reviewed.