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
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.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.