Low EBV, youth, and first-time donor status are major risk factors for IRs and DRs. Women are more likely than men to report DRs. Delayed and off-site reactions lead to potentially preventable morbidity. Understanding the physiologic basis of DRs may lead to the development of appropriate interventions to reduce their likelihood.

BACKGROUND  Whole blood (WB) donation encompasses several periods during which some donors faint. Identification of factors associated with fainting during each period should guide intervention strategies. Reducing faint reactions may reduce donor injuries and disability. METHODS  Blood donation was divided into three periods: Period 1 - registration; Period 2 - phlebotomy; and Period 3 - post-phlebotomy. Period 3 consists of two sub-periods (3A - on-site and 3B - off-site). For each Period, stratified rates of fainting in relation to various donor and donation characteristics were calculated and multivariable logistic regression analyses to identify factors associated with fainting were conducted. Donor injuries in each period were also analysed. RESULTS  Of the 956 766 donors registered in 2007, 554 534 (58%) donated WB. There were 43 fainting episodes and two injuries in Period 1 and 1520 faints and 73 injuries in Periods 2 and 3. Regression analyses showed that youth and donor first-time status are associated with fainting in all periods; but most significantly in Period 1. Small estimated blood volume is notably not a factor in Period 1 but is significant in Periods 2 and 3. The highest injury rate is seen in Period 3A (0·07 and 0·09/1000 donations) for male and female donors, respectively. CONCLUSIONS  Variability in factors associated with fainting across defined periods of the donation process suggest differing underlying mechanisms and the possibility that interventions for the reactions most associated with injury during each time period can be designed. The highest rate of injury per donation occurred in ambulating donors.

The interventions to reduce vasovagal reactions in whole blood donors were effective. Future efforts to reduce reactions in blood donors can build on the strengths and avoid the weaknesses identified while conducting and analyzing the data from this study.

BACKGROUND Previous reports of WNV RNA persistence in blood compartments have raised concerns around the remaining risk of WNV transfusion-transmission. This study characterized the dynamics of WNV viremia in blood compartments in a longitudinal cohort of 54 WNV-infected blood donors. STUDY DESIGN AND METHODS Blood samples were collected throughout the year after WNV RNA+ blood donation (index) and characterized for anti-WNV IgM and IgG antibodies and for WNV RNA by real-time reverse-transcription polymerase chain reaction. WNV viral loads were compared in plasma and whole blood samples and correlated with blood groups and clinical outcomes. RESULTS WNV RNA persisted in the red blood cell (RBC) compartment up to three months post-index in 42% of the donors. Donors with the highest WNV RNA levels in plasma at index maintained the highest WNV RNA levels in whole blood over the three months post-index. Blood group A donors maintained higher post-index WNV viral load in whole blood than blood group O individuals (P=0.027). Despite a trend for WNV RNA to persist longer in whole blood from symptomatic subjects, no significant association was found between WNV RNA levels in whole blood and disease outcome. CONCLUSION This study confirmed that WNV RNA persists in the RBC fraction in whole blood and further suggested that the level of persistence in whole blood may be a reflection of initial viral burden in plasma. The association with blood groups suggests that WNV adherence to RBCs may be mediated by molecules overrepresented at the surface of blood group A RBCs.

The HTLV-1 and HTLV-2 prevalences among US blood donors has declined since the early 1990s. A higher prevalence of HTLV-2 in the west and southwest may be attributed to endemic foci among Amerindians.

BACKGROUND Some countries impose an upper age limit on whole blood and double RBC donation while others do not. We evaluated the safety of blood donation in older individuals (≥71 years), and their contribution to the blood supply of five countries. STUDY DESIGN AND METHODS Twelve blood center members of the Biomedical Excellence for Safer Transfusion (BEST) Collaborative from four countries with no upper age limit for whole blood and double RBC donation (Canada, New Zealand, England, and the United States) or an upper age limit of 80 (Australia) provided 2016 data on donors and donations, deferral rates, and vasovagal reactions by donor age and sex. Donors under age 24 were included in the number of total donors and donations, but not in deferral and reaction rate comparisons. RESULTS Older donors accounted for 1.0% (New Zealand) to 4.3% (United States) of donors, and 1.5% (New Zealand) to 5.6% (United States) of donations; most were between ages 71 and 76. The deferral rate was higher in older compared to 24‐ to 70‐year‐old males, but very similar between older and younger females. In contrast, vasovagal reaction rates were either lower (male donors) or similar (female donor for reactions with loss of consciousness) in older compared to 24‐ to 70‐year‐old donors. CONCLUSIONS Exclusion solely based on older age appears to be unwarranted based on safety concerns such as donor reactions. Healthy older individuals can continue to safely donate and make a significant contribution to the blood supply past arbitrary age limits.

Background Improving the safety of the donation experience will reduce donor injuries and increase donations, donation frequency and donor satisfaction. Understanding the physiology of donor reactions supports selection of effective interventions to reduce risk.Aims The examination of the time course of donor vasovagal syncopal reactions (VVS) to determine when most reactions occur supports the development of appropriate theories about cause of the majority of the reactions and the application of interventions to reduce the risk of a significant number of reactions.Materials and Methods A database of more than 900 000 donor registrations and more than 500 000 whole blood donation events was examined for the time course of VVS reactions by reviewing the onset time of the reactions. The donor experience was divided into three periods based on the theory that the risk of reaction depends on different factors in each of the periods. The time course was analyzed using frequency distribution counts stratified by donation status and separately by gender.Results There were 956 766 registrations, 554 513 attempted whole blood donations, 536 907 complete donations and 17 606 incomplete donations. The mean draw time of a complete donation was 8.21 (95% CI, 8.2-8.21) min and for an incomplete donation was 8.91 (95% CI, 8.8-9.01) min. The reaction rate for Period 1 (before venipuncture) was 0.045 ⁄ 1000 registrations; for Period 2 (venipuncture to 4 min post-venipuncture) and Period 3 (4 min post venipuncture to last reported VVS reaction -265 min), the reaction rate was 3.5 ⁄ 1000 for women and 1.5 ⁄ 1000 for men. There was a steady increase in the reaction rate during phlebotomy and the rate peaked at the time of needle removal. After needle removal there were peaks in the VVS rate at 5 and 9 min. The reaction rate declined steadily thereafter.Discussion The peak reaction rates occur within a time period of 10 min beginning 1 min before needle removal. The reactions which have the most significant risk of donor injury occur later than this and often occur after the donor leaves the donation site. Approximately 10% of VVS reactions in male donors and 25% of VVS reactions in female donors occur more than 15 min after the needle is removed. The latest VVS reaction was reported to have begun at about 4.5 h after needle withdrawal.Conclusion It is our thought that preventive interventions for reactions which occur during phlebotomy might be slightly different from the preventive measure aimed at reducing risk to donors after assuming upright posture. Once the donor stands up, relative hypovolemia plays a greater role and interventions should be aimed at preventing changes in blood pressure due to hypovolemia during this period.

Background Obesity is a global pandemic characterized by multiple comorbidities, including cardiovascular and metabolic diseases. The aim of this study was to define the associations between blood donor body mass index (BMI) and RBC measurements of metabolic stress and hemolysis. Study Design and Methods The associations between donor BMI (<25 kg/m2, normal weight; 25‐29.9 kg/m2, overweight; and ≥30 kg/m2, obese) and hemolysis (storage, osmotic, and oxidative; n = 18 donors) or posttransfusion recovery (n = 14 donors) in immunodeficient mice were determined in stored leukocyte‐reduced RBC units. Further evaluations were conducted using the National Heart, Lung, and Blood Institute RBC‐Omics blood donor databases of hemolysis (n = 13 317) and metabolomics (n = 203). Results Evaluations in 18 donors revealed that BMI was significantly (P < 0.05) and positively associated with storage and osmotic hemolysis. A BMI of 30 kg/m2 or greater was also associated with lower posttransfusion recovery in mice 10 minutes after transfusion (P = 0.026). Multivariable linear regression analyses in RBC‐Omics revealed that BMI was a significant modifier for all hemolysis measurements, explaining 4.5%, 4.2%, and 0.2% of the variance in osmotic, oxidative, and storage hemolysis, respectively. In this cohort, obesity was positively associated (P < 0.001) with plasma ferritin (inflammation marker). Metabolomic analyses on RBCs from obese donors (44.1 ± 5.1 kg/m2) had altered membrane lipid composition, dysregulation of antioxidant pathways (eg, increased oxidized lipids, methionine sulfoxide, and xanthine), and dysregulation of nitric oxide metabolism, as compared to RBCs from nonobese (20.5 ± 1.0 kg/m2) donors. Conclusions Obesity is associated with significant changes in RBC metabolism and increased susceptibility to hemolysis under routine storage of RBC units. The impact on transfusion efficacy warrants further evaluation.