Comparative evaluation of red blood cell storage lesion in red cell concentrates (RCCs) prepared from regular and first-time blood donors

Iron status, body mass index (BMI) and blood pressure (BP) are all important health indicators. In this study, ferritin and transferrin saturation levels and their correlations with BMI and BP were investigated in first-time and regular male blood donors in Taiwan. Serum ferritin and transferrin saturation values represented iron status of blood donors. Serum ferritin, serum iron, and total iron binding capacity (TIBC) were determined by chemiluminescent immunoassay sandwich method, timed-endpoint method, and turbidimetric method, respectively. Transferrin saturation was calculated as 100× serum iron/TIBC. Statistical analyses included 2-sample t test, chi-square test, Pearson correlation coefficient, and multiple linear regression. Comparisons of ferritin and transferrin saturation mean values with BMI, age, systolic blood pressure (SBP), diastolic blood pressure (DBP), and occupation were conducted. A total of 111 first-time donors and 1249 regular blood donors participated in this study. The ferritin and transferrin saturation mean values of regular male blood donors were lower than those of first-time male blood donors, but remained within the safe range. BMI was positively correlated with serum log ferritin, but not with transferrin saturation value in first-time and regular blood donors. First-time donors with BMI ≥24 kg/m2 and aged more than 40 years demonstrated 1.37-fold higher serum ferritin on average. Among regular donors, significant effects of BMI ≥24 kg/m2 and age >40 years were observed with 1.25- and 1.18-fold higher serum ferritin levels, respectively. First-time donors with SBP ≥120/DBP ≥80, ≥120/<80, and <120/≥80 mm Hg had on average 1.65-, 1.54-, and 2.59-fold higher serum ferritin levels than those with normal BP. Ferritin level was higher in BMI ≥24 kg/m2 subgroup than in BMI <24 kg/m2 subgroup among first time and regular male donors, but no difference was found in transferrin saturation values.Abnormal SBP/DBP was associated with increased ferritin level only in first-time male blood donors.

BackgroundBlood banks have been suffering a shortage of blood worldwide due to limited donations. By and large, it is widely believed that blood donation has multiple health benefits. However, there are limited studies that support it. As a result, assessing the biochemical profiles of the regular blood donors is indispensable to evaluating an individual’s risk for chronic inflammation.ObjectiveWe strived to compare lipid and haematological profiles of the regular and first-time blood donors in the National Blood Bank Service of Ethiopia.Materials and MethodsA comparative cross-sectional study, involving 104 blood samples (52 each of regular and first-time donors), was designed to analyze lipid and haematological profiles and anthropometric parameters were measured. Data were analyzed using SPSS version 25, Chi-square (χ2) was used to compare the relationship between categorical variables and an independent Student’s t-test was used to compare the mean of the two groups. A p-value <0.05 was considered statistically significant.ResultsRegular blood donors had lower mean TC (144.3 ± 28 mg/dL), TG (159.3 ± 88.2 mg/dL), LDL-c (75.9 ± 25.9 mg/dL) than the first-time blood donors with values of TC (158.1 ± 38.94 mg/dL), TG (163.9 ± 82.7 mg/dL), LDL-c (93.1 ± 31.5 mg/dL), respectively. The ratio of LDL-c/HDL-c and TC/HDL-c was found to be lower in regular blood donors when compared to the first-time donors (P < 0.05). Even though the level of HDL-c was higher (39.8 ± 8.8 mg/dL) in regular blood donors compared to first-time blood donors (36.8 ± 7.7 mg/dL), it was not statistically significant. The mean of some haematologic parameters like a platelet, RDW, lymphocyte, and MCH was significantly lower in regular blood donors than in first-time blood donors. BMI and WHR in regular donors were less than the first-time donors, albeit statistically insignificant.ConclusionInterestingly, blood donation has a significant health benefit by lowering TC, TG and LDL-c, which have the potential risk of developing chronic inflammation.

Background: Regular blood donation which decreases blood iron levels may protect against cardiovascular diseases (CVD). This protection against atherosclerosis can be assessed by Carotid Intima-Media Thickness (CIMT) a biomarker for atherosclerosis. This study sought to determine and compare the mean and maximum CIMT, the serum level of iron and plaque prevalence among regular and first-time blood donors in Lagos University Teaching Hospital (LUTH), Lagos. Methods: A comparative, cross-sectional study involving 214 randomly-selected blood donors (107 regular and first-time blood donors each). Using a structured proforma, sociodemographic, anthropometric, radiological and laboratory data were collected from blood donors in the two groups. high frequency linear probe was used to assess CIMT, and presence of plaque in both extra-cranial carotid arteries. CIMT was the distance between the intima–blood interface and the adventitia–media junction and iron study included serum total iron, ferritin, transferrin and total iron binding capacity. Comparison between the study groups was done by Chi-square test and Student t-test/Mann-Whitney U-test for categorical and continuous variables respectively. Level of significance was set at p&lt;0.05. Results: The mean and maximum CIMT of both carotid arteries in regular blood donors (mean right CIMT-0.49+/-0.11mm, maximum right CIMT-0.58+/-0.14mm, mean left CIMT-0.51+/-0.16mm, maximum left CIMT-0.60+/-0.27mm) were significantly(p&lt;0.05) lower than those of the first-time blood donors(Mean right CIMT-0.79+/-0.17mm, maximum right CIMT-0.93+/-0.25mm, mean left CIMT-0.83+/-0.31mm, maximum left CIMT-0.96+/-0.27mm). Median serum iron(10.5µmol/L; IQR:8.8-13.5µmol/L), ferritin(30.50µg/ml; IQR:16.2-600µg/ml) and transferrin(2.1g/L;IQR:0.9-2.3g/L) in regular blood donors were significantly lower(p&lt;0.05) than serum iron (16.1µmol/L; IQR:13.7-18.6µmol/L), ferritin(158.0µg/ml; IQR:115-365.2µg/ml) and transferrin(2.3g/L; IQR:2.1-2.4g/L) in first-time donors. Plaque prevalence was significantly higher (ꭓ2=5.81; p – 0.016) in first-time (11.2%) than regular (2.8%) donors. Conclusion: Regular blood donation significantly lower CIMT values, and iron parameters. Regular blood donation may offer protection against atherosclerosis.

Background: Low iron stores are a key complication of frequent blood donation. The effects of repeated donation on lipid levels and Glycated hemoglobin (HbA1c) are not well understood. This study aims to assess how repeated blood donation affects various health markers, including hematological parameters, lipid profile, iron status, and HbA1c, with the main goal of ensuring donor safety and well-being. Materials and Methods: A prospective study involved the examination of 299 regular and 204 first-time voluntary blood donors. Regular donors were divided into three categories: Category I (blood donated 1–5 times), Category II (blood donated 6–10 times), and Category III (blood donated 10 times and above). Venous blood was drawn from donors for hematological parameters, HbA1c, iron indices, and lipid profile measurement. Results: There was a significant decrease in mean corpuscular volume (MCV) ( P = 0.02) and mean corpuscular hemoglobin (Hb) value in regular blood donors than in 1 st -time donors ( P ≤ 0.01). Among the categories of regular donors, a significant decrease in MCV was observed ( P = 0.046). Mean serum ferritin levels exhibited a significant decrease in regular donors as compared to first-time donors ( P = 0.02). There was a significant decrease in mean serum ferritin concentrations with an increase in the frequency of blood donation ( P = 0.04). The values for triglyceride and very low-density lipoprotein significantly decreased in regular blood donors ( P &lt; 0.01 and 0.02). Total cholesterol and Low Density Lipoprotein (LDL) revealed a significant decrease among the categories of regular blood donors ( P = 0.02 and &lt; 0.01). No significant decrease in HbA1c was observed. Conclusions: Our study indicates that solely assessing Hb in blood donors is inadequate for determining donation eligibility. It is imperative to also evaluate serum ferritin levels in regular blood donors.

Background & Objective:Trapped cell population in leukoreduction filters (LRFs) contains such a significant number of CD34+ hematopoietic stem cells that can be recovered to be used in research studies. Methods:Samples (n=20) were obtained from 10 first-time donors and 10 regular blood donors with more than 30 times blood donation. After separating leukocytes from LRFs by backflushing, total leukocyte number and differential count were determined in both groups using an automated haemocytometer. Then cell viability and CD34+ cell quantification were assessed using 7- amino-actinomycin D and fluorescent-labeled monoclonal antibodies using flow cytometry, respectively.Results:Total leukocyte count was 665±164.92×106 in the first-time blood donors and 883±233.89×106 in the regular donors, which were not significantly different (P=0.08). While the number of CD34+ cells was significantly reduced in the regular donors compared to the first-time donors (0.58±0.20×106/µL vs. 0.36±0.22×106/µL; P=0.034). There was no significant difference in terms of absolute neutrophil count (10.58±3.66×06 vs. 13.17±6.45×106/µL; P=0.349), lymphocytes (7.75±3.11×106 vs. 10.38±3.77×106 /µL; P=0.917), and monocytes (2.31±0.88×106 vs. 2.59±1.09×106/µL; P=0.591) between the first-time and regular donor groups, respectively. Based on the correlation coefficients, the participants’ age had no significant effect on these variables. Conclusion:The results of this study depicted that regular blood donation reduces the number of CD34+ cells in the peripheral blood (PB) of regular donors while it has no significant effect on the ratio of myeloid to lymphoid cells of the two groups.

Regular blood donation can lead to iron deficiency. Screening donors' serum ferritin levels at the time of first donation and subsequently once every year is a very rational way to pick up iron deficiency in a voluntary blood donor population. The aim of this study was to determine the effect of blood donation and the prevalence of erythropoiesis with iron deficiency (sideropenia) in Saudi male blood donors. The study was prospectively conducted, between December 2008 and March 2009, on 182 male native Saudi blood donors at King Fahd Central Hospital in Jazan region, Saudi Arabia. Each donor gave 450 ± 50 mL of whole blood. Following the donation, samples were removed into 2.5 mL EDTA tubes for measurement of mean cell volume (MCV) and mean corpuscular haemoglobin (MCH) and into 7.5 mL plain tubes for estimation of iron and serum ferritin concentrations. The blood donors were divided into five groups, according to the number of donations they had given in the preceding 3 years. The blood donors in group I were first-time donors, with no previous history of blood donation. Group II donors had donated once in the last 3 years. Subjects in groups III, IV and V had donated more than once in the preceding 3 years and were considered regular donors. The mean serum iron was significantly higher among subjects with no previous history of blood donation (group I) than among regular donors who had donated twice or more. The difference in serum ferritin concentration was statistically significant (p<0.05) when comparing regular donors in group III (72.4 μg/L), group IV (67.4 μg/L) and group V (26.2 μg/L) with first-time blood donors (131.4 μg/L). In contrast, the difference in the concentration of serum ferritin between subjects in group II (98.9 μg/L), who had donated once in the last 3 years, and in first-time blood donors (131.4 μg/L) was not statistically significant (p<0.131). None of the group I donors suffered from iron deficiency, whereas 2.8% of the donors who had donated between two to five times had iron deficiency. The prevalence of erythropoiesis with iron deficiency in regular blood donors was 4.3%. The results of this study show that an increase in the number of donations results in an increase in the frequency of depleted iron stores and subsequently in erythropoiesis with iron deficiency, although the level of haemoglobin remained acceptable for blood donation. This result may indicate the need to review the guidelines on acceptance of donors.

Objective:First-time blood donors are the most common group of blood donors. They usually have different motivations for blood donation, some of which provoke the donors to hide risk factors of transfusion-transmissible infections (TTIs). Therefore, detection of TTIs among first-time donors is crucial and can decrease the rate of TTIs among blood recipients. This study aimed to evaluate the prevalence of TTIs among first-time donors in the transfusion center of Kohgiluyeh and Boyer-Ahmad Province (KBTC), Iran.Materials and Methods:This retrospective study was conducted with volunteer blood donors in 2004-2014 in the KBTC. Various data, including sex, confidential unit exclusion (CUE), previous donation history, and the laboratory findings of confirmatory tests, were extracted from blood donor software. Data were analyzed by SPSS using the chi-square test.Results:Among 198,501 blood donors, 52,527 (26.46%) were first-time donors, while 145,974 donors (73.54%) were repeat and regular donors. Most of the donors (94.5%) were male, while a minority (5.5%) were female. The CUE option was chosen by 2,237 (1.13%) donors. The incidence of hepatitis B surface antigen (HBsAg) and hepatitis C virus (HCV) was 247 (0.13%) and 134 (0.07%) among the entire study population, respectively. Three donors (0.002%) had confirmed human immunodeficiency virus (HIV), while none of the blood donors were positive for syphilis. Most of the donors with positive HBsAg (95.8%), HCV (86.6%), and HIV (100%) infection were first-time donors.Conclusion:Since TTIs are more common among first-time blood donors than regular and repeat donors, special considerations should be taken into account for this common group of blood donors.

Oxidative stress orchestrates a significant part of the red blood cell (RBC) storage lesion. Considering the tremendous interdonor variability observed in the "storability," namely, the capacity of RBCs to sustain the storage lesion, this study aimed at the elucidation of donor-specific factors that affect the redox homeostasis during the storage of RBCs in standard systems. The hematologic profile of regular blood donors (n = 78) was evaluated by biochemical analysis of 48 different variables, including in vivo hemolysis and plasma oxidant and antioxidant factors and statistical analysis of the results. The possible effect of the uric acid (UA) variable on RBC storability was investigated in leukoreduced CPD/SAGM RBC units (n = 8) collected from donors exhibiting high or low prestorage levels of UA, throughout the storage period. Among the hematologic variables examined in vivo, cluster analysis grouped the donors according to their serum UA levels. Plasma antioxidant capacity, iron indexes, and protein carbonylation represented covariants of UA factor. RBCs prepared by low- or high-UA donors exhibited significant differences between them in spheroechinocytosis, supernatant antioxidant activity, and other RBC storage lesion-associated variables. UA exhibits a storability biomarker potential. Intrinsic variability in plasma UA levels might be related to the interdonor variability observed in the storage capacity of RBCs. A model for the antioxidant effect of UA during the RBC storage is currently proposed.

Abstract: INTRODUCTION: Due to rapid technological advancements, several new methods such as telephone (TP), e-mail, social media, WhatsApp (WA), and Short Message Services are being used as effectively among blood centers worldwide for postdonation communication with blood donors’ education and motivation to recruit and retain them as repeat and regular voluntary nonremunerated blood donors. The present study was aimed at determining the effectiveness of WA, TP, and personal communications (PCs) as modes of communication to recruit and retain first-time replacement blood donors to become repeat and regular voluntary blood donors. MATERIALS AND METHODS: This 1-year observational prospective study was conducted in the Post Graduate Department of Immunohematology and Blood Transfusion in Government Medical College and Hospital, Jammu. Three hundred first-time blood donors selected for the study were divided into three groups comprising 100 blood donors each as per the mode of communication strategy adopted, namely postdonation PC, TP, and WA groups. RESULTS: The repeat donation rate was highest in the TP group (61%), followed by the WA group (47%) and PC group (37%). The mean repeat donation was found to be significant in the TP group (P = 0.007) and WA group (P = 0.021) as compared PC group while there was no significant difference between the TP group and WA groups (0.751). CONCLUSION: In our study, it was found that of the three communication modes, namely personal, TP, and WA, telephonic communication with a repeat donation rate of 61% was the most effective mode of communication in for motivating and converting first-time blood donors into repeat regular voluntary blood donors.

IntroductionIt has been suggested that blood donation reduces risks of developing cardiovascular diseases such as heart failure, atherosclerosis, and stroke. Although there are known benefits of blood donation, the inclination of people of the Kurdistan Region of Iraq to donate blood is not known. Therefore, the aim of this study was to determine demograpic and blood biochemical profiles of regular and first-time blood donors in the Sulaimani province of North Iraq.MethodsA cross-sectional study was conducted at the Sulaimani Blood Bank, during the period of April 1, 2016 to March 28, 2017, on convenient samples of 100 regular and 100 first-time blood donors. Donor particulars were obtained from blood bank records. The cholesterol, triglyceride, low-density lipoprotein, ferritin, vitamin D3, and uric acid concentrations of blood samples were determined.ResultsThe main reason for blood donation by regular blood donors was headache (45%), while for the first-timers it was to help relatives (31%). The low-density lipoprotein and ferritin concentrations were significantly (p=0.001) lower in the blood of regular donors than first-timers.ConclusionThe study shows that regular blood donation is beneficial for the maintenance of health of donors.

Iron deficiency is a common problem in regular blood donors which can be prevented by timely iron supplementation. Consequently, these donors should be supplied with oral iron in good time. We evaluated the need to use ferritin rather than or in addition to haemoglobin to screen iron deficiency in blood donors. To this end, serum ferritin was measured routinely every 10th donation in 632 long-term and 171 first-time donors. Furthermore, donors with ferritin < 15 microg L-1 were supplemented with iron. The supplementation efficiency was assessed by follow-up haemoglobin levels over the course of five donations in blood donors with high donation frequency. Our results showed that ferritin decreases after 10 donations and with the increase of donation frequency. In 26% of regular donors, ferritin levels were < 15 microg L-1 and 12% of them were anaemic due to low haemoglobin. After iron supplementation, haemoglobin was raised rapidly in donors with initially low haemoglobin, and thus donor deferment was never indicated. In conclusion, regular ferritin measurement is a useful indicator for iron depletion in blood donors. Our data suggested the usefulness of ferritin screening in first-time donors and regular donors with low haemoglobin levels within the normal range.

Genotype Screening for Hereditary Hemochromatosis among Voluntary Blood Donors in Hungary

For it is not enough to possess a good mind; the most important thing is to apply it correctly. Whether transfusion of "older" blood is as beneficial as transfusion of "fresher" blood is a topic of active debate. Considering the sheer volume of recent publications including some excellent reviews2,3 and a meta-analysis4 on the issue, one may wonder why there is a need for yet another editorial5,6 addressing one more observational study on the subject.7 Distinctively, this editorial strives to 1) examine how a well-conducted observational study can intelligently inform a scientific debate, 2) demonstrate the benefit of evaluating an issue from a variety of angles using different study methods, and 3) illustrate how research in transfusion medicine can impact and promote scientific knowledge in other fields. Several studies have reported an association between transfusion of older blood and highly clinically significant outcomes, including an increase in length of hospital stay, postoperative infections, prolonged mechanical ventilation, multiple organ failure, and mortality (see Lelubre et al.3 and Zimrin and Hess2 for in-depth reviews of the literature). Two mechanisms could be conjectured to explain these potential detrimental outcomes if a "cause-and-effect" relationship between duration of red blood cell (RBC) storage and morbidity/mortality is present; note that this is purely speculative since such a causal link has not been demonstrated. One hypothesis proposes that the RBC storage lesion defects that occur in stored blood components cause immunomodulatory and inflammatory complications in transfusion recipients including changes in vasoregulation. The second hypothesis, which could coexist with the first, proposes that susceptibility factors predispose certain patient populations to the clinical-pathologic side effects of older RBC transfusion. This problem if present (meaning if a causal relationship exists) would represent a major public health impediment considering the 5 million US patients who, every year, rely on RBC transfusions for their care. A shortened RBC storage time would have a major impact on the availability of blood. Blood banks would need to adapt recruitment practices to ensure a steady supply of fresher cells and/or develop storage procedures that prevented the development of lesions which contribute to significant adverse clinical outcomes. Faced with this specter, it behooves us to evaluate this problem in a scientifically rigorous and rational manner. Scientific objectivity is crucial because the consequences of misinterpreting the data are significant. As discussed, incorrectly concluding that blood storage duration is causally related to increased morbidity and mortality would severely impact blood availability and put patient care at risk. On the other hand, erroneously concluding that storage duration does not impact morbidity and mortality, if indeed it does, would have appalling consequences. Just under 400 years ago, Descartes put forward four methods in Part II of the Discourse1 which, to this day, can guide our approach to research and scientific discoveries. In his words, "the first [method] was never to accept anything as true that I did not incontrovertibly know to be so; that is to say, carefully to avoid both prejudice and premature conclusions; . . . "; "the second [method] was to divide all the difficulties under examination into as many parts as possible, and as many as were required to solve them in the best way"; "the third [method] was to conduct my thoughts in a given order, beginning with the simplest and most easily understood objects, and gradually ascending, . . . to the knowledge of the most complex"; and "the last [method] was to undertake such complete enumerations and such general surveys that I would be sure to have left nothing out." In other terms, we should refrain from jumping to conclusions when there is insufficient evidence (sounds familiar?); evaluate the issue from different perspectives using several study methods to collect a comprehensive set of data points; resolve simplest issues first; be comprehensive and systematic in our approach; check for consistency; double check our results; and use our "good sense," that is, "the power of judging correctly and of distinguishing the true from the false"1 when conducting data analysis and interpreting results (as a side note, some philosophers argue that truth is never attainable). Armed with these principles and the desire to fund research that will most rapidly advance our understanding of this issue, the National Heart, Lung, and Blood Institute (NHLBI) undertook a review of the studies conducted in this area starting with the clinical literature. We concluded that it is extremely difficult to interpret existing data. Many of the studies are observational in nature and suffer from lack of adjustment, a small sample size, and/or the inability to generalize results (only a few small randomized clinical trials [RCTs] have been conducted so far). In particular, the frequently observed imbalance in baseline characteristics of the comparison groups renders adjustment for confounders (characteristics that are associated with both the outcome and the main independent variable) a critical requirement for interpretation. For example, the "number of transfusions," which is linked to both severity of disease and increased RBC storage duration, is a major confounder in all RBC storage analyses.8 It is therefore crucial to carefully scrutinize these reports to evaluate how data were analyzed and interpreted and note that adjustment can still be problematic because not all confounders may be known and the assumptions underlying the statistical method that was used may not hold. Some studies suggest that transfusion of older blood is associated with increased morbidity and/or mortality while others suggest a lack of association or even the converse.2-4 A cause-and-effect relationship was not demonstrated and equipoise was present—meaning that there is genuine uncertainty as to whether transfusing fresher blood is more, less, or equally beneficial as transfusion of older blood. These observations begged for the conduct of studies evaluating comparable patient groups (e.g., RCTs) and, possibly, observational studies that were sufficiently powered and adequately analyzed to better inform the debate. NHLBI decided to pursue support of a RCT using the Transfusion Medicine and Hemostasis Clinical Trials (TMH) Network infrastructure (see below) and an observational study which is the subject of the report by Edgren and colleagues7 in this issue of TRANSFUSION. Using the Scandinavian Donations and Transfusions (SCANDAT) database, a powerful tool that merges data from population and migration, death and inpatient care, and blood donations and transfusion registries in Sweden and Denmark, Edgren and colleagues conducted a retrospective cohort study aimed at evaluating mortality among transfused patients receiving RBC units stored in a saline-adenosine-glucose-mannitol solution for 0 to 9 days (25.5% of transfusion episodes), 10 to 19 days (34.7%), 20 to 29 days (15.7%), or 30 to 42 days (8.1%); 15.9% of the transfusion episodes involved RBC units of mixed ages. They included data from more than 350,000 patients, 15 to 90 years old, who were transfused with RBCs between 1995 and 2002. Data on a little more than 400,000 transfusion episodes were analyzed using a variety of sophisticated methods and adjusted, at a minimum, for number of transfusions, age, sex, blood group, calendar period, season, weekday, hospital, and transfusion indication. Several other subanalyses were conducted to evaluate cause-specific risks of death as well as the effect of leukoreduction. This study evaluated a robust outcome (mortality) and included a large number of patient transfusion exposures allowing for adjustment of major known confounders. There was unbiased ascertainment of both exposure and outcome because the data were compiled from national registers. The investigators evaluated the data through a variety of approaches and still reached similar conclusions: that the 1-week risk of death after transfusion did not significantly differ between recipients of RBCs stored for different periods. Conversely, there was a significant increase in the 2-year mortality risk in recipients of 30- to 42-day-stored RBCs (5% increase) and mixed-age (3% increase) RBCs compared to the risk of recipients receiving RBCs stored for 10 to 19 days. The hazard ratios for patients receiving blood stored for 0 to 9 days and 20 to 29 days were 1.01 and 0.99, respectively (neither value was significant). Observing a significant increase in risk of death at 2 years but not at 1 week for recipients of 30- to 42-day-old or mixed-age blood is contrary to the expectation that the effects of an acute harmful event usually decrease over time. This observation, along with the absence of a clear dose-response effect and not finding that any particular cause(s) of death explained the excess risk, led the authors to attribute these findings to residual confounding by severity of disease, for which they were not able to directly adjust. One may also wonder if these two significant findings could just have occurred by chance considering the number of comparisons made. However, adjustment for multiple comparisons can be problematic and the authors would probably have been criticized for using such an adjustment to "get rid of" significant associations. Subset analyses did not reveal significant associations. In particular, looking at patients undergoing coronary artery bypass graft (CABG) surgery, the hazard ratios were similar, 1.09 and 1.10 (both nonsignificant) among patients receiving either blood stored for less than 10 days or blood stored for 30 to 42 days, respectively. The results of this well-conducted observational study are reassuring in the sense that 1) these investigators did not detect associations of the magnitude observed in other studies such as the study by Koch and colleagues9 and 2) the two significant findings can be reasonably explained by residual confounding and/or a multiple comparison effect. However, uncertainty still remains. What if these findings really reflect a cause-and-effect relationship (although it would be difficult to explain biologically why recipients of mixed-age blood would be at higher risk)? What if the subset analyses were insufficiently powered and patients undergoing CABG are at greater risk of complications if they receive fresh (<10 days) or old (>30 days) RBC units rather than blood that has been stored for 10 to 29 days? Clearly, RCTs are needed in a setting of equipoise because the ramifications for patient care and blood banking practices are profound. While RCTs can provide the strongest clinical evidence of whether RBC storage duration does or does not affect morbidity and mortality (the random allocation of patients to treatment arms provides for balance of baseline characteristics between comparison groups), RCTs are logistically difficult, lengthy, and expensive to conduct. Four large RCTs are now planned or under way in three different patient populations, highlighting the importance of this issue. The Age of Blood Evaluation (ABLE) study10 supported by the Canadian Institutes of Health Research (CIHR) is randomizing about 2500 intensive care unit patients at 25 or more Canadian sites to receive, if transfused, either less than 8-day RBCs or standard-issue RBCs (2-42 days); their primary outcome is 90-day all-cause mortality. The Age of Red Blood Cells in Premature Infants (ARIPI),11 also funded by CIHR, plans to randomize 450 premature infants (≤1250 g) to receive either less than 8-day RBCs or 2- to 42-day RBC aliquots (the standard practice is to take aliquots from the same unit of RBCs until its expiration); the primary endpoint is a 90-day composite measure of all-cause mortality and organ dysfunction. The Red Cell Storage Duration and Outcomes in Cardiac Surgery, which is being conducted at one center, the Cleveland Clinic (Ohio), is randomizing cardiac surgery patients who are 18 years and older to receive, if transfused, either less than 14- or more than 20-day RBC transfusions; their target is 2800 patients and their primary outcome is postoperative morbidity.12 Finally, the NHLBI TMH Network Red Cell Storage Duration Study (RECESS) currently plans to randomize approximately 1800 cardiac surgery patients at an estimated 15 centers across the United States to receive either 10-day-or-less or 21-day-or-more RBC units if transfused. Patients randomized to receive RBCs stored for 21 days or more will receive units from the hospital's existing blood bank inventory using the standard inventory management practice of releasing the oldest RBC units first. The primary outcome for RECESS is the change in the composite multiple organ dysfunction score (MODS) from baseline.13 Although results will not be known for several years, these clinical trials will be key to our understanding of whether the RBC storage lesion produces a clinically important phenomenon. Let us now turn our attention to the RBC storage lesion itself.14,15 What biologic and/or pathologic mechanisms could underlie some of the adverse clinical findings observed in transfused recipients? Can RBC products be optimized to increase oxygen delivery? The latter question should be considered independently of the first. Indeed, since about 1 in 60 individuals receive RBC transfusions in the United States every year, transfusion therapies should not only be safe but, importantly, as effective as possible. While some elements of the RBC storage lesion are well known (e.g., increase in free hemoglobin [Hb] and potassium; decrease in pH, adenosine triphosphate, and 2,3-diphosphoglycerate; and increased RBC morphologic changes leading to loss of deformability),14,15 less is known about other components such as the shed microparticles (MPs), RBC-dependent vasoregulatory compounds, and immune and inflammatory mediators that may be accumulating during storage. Further, surprisingly little current research has been performed to evaluate the effects of these elements on host cells, the vessel wall, and tissue microoxygenation. To begin rectifying this gap in knowledge, NHLBI recently established a targeted research program titled "Immunomodulatory, Inflammatory, and Vasoregulatory Properties of Transfused Red Blood Cell Units as a Function of Preparation and Storage." Eight teams of investigators around the country are conducting basic and translational research including animal models and/or basic human physiologic studies aimed at further characterizing the storage lesion and understanding the interaction between the storage lesion components and recipient/host cells such as endothelial and hematopoietic cells. As shown in Table 1, several of these teams (Gladwin and Kim-Shapiro; Patel, Barnum, and Weinberg; Roback; and Stamler) propose that transfusion damage from stored blood can be traced to suboptimal tissue oxygenation engendered by a loss of proper control of blood flow. These investigators will evaluate the role of nitric oxide (NO), nitrite, ATP, and/or S-nitrosohemoglobin (SNO-Hb) in this context. For example, consideration will be given to whether loss of vasoregulation could be secondary to increased levels of Hb and MPs in the plasma which scavenge NO and inhibit beneficial NO signaling and/or due to a loss of RBC-mediated hypoxic vasodilation (see Table 1 for each group-specific aim). Blumberg and Phipps will investigate the RBC units' supernatant including Hb, MPs, and fats and its effect (as well as that of RBCs) on patients' platelets (PLTs). Jy's group will explore the role of MPs in transfused products by studying their potential procoagulant, proinflammatory, immunosuppressive, and endothelial activities. Norris' team will focus on the potential inflammatory and immune effects of stored RBCs by characterizing immune and inflammatory mediators in fresher and older RBC units, evaluating RBC-endothelial cell adhesion as a function of RBC storage, determining if novel storage solutions or pathogen reduction can ameliorate the "storage lesion," and determining how RBC unit storage affects immunomodulation and inflammation in transfusion recipients enrolled in ABLE. Finally, the team led by Spitalnik will evaluate whether transfusion of older stored RBCs can produce a proinflammatory cytokine response due to delivery of substantial amounts of Hb iron to the monocyte-macrophage (reticuloendothelial) system and its consequent pro-oxidant effects (see Table 1 for additional descriptions of each of these eight projects). This research is expected to significantly increase our understanding of the RBC storage lesion and its potential clinical effects, as well as optimize methods and further development of assays to detect biomarkers of clinical relevance. New storage solutions could be developed. For example, identification of components in RBC units that may be potentially harmful to a specific patient population could lead to either development of improved RBC therapies that do not contain the harmful component or personalization of RBC therapy with transfusion of biomarker-negative units only in the patient population(s) at risk. Further studies may identify elements that are missing or in suboptimal concentrations because of preparation, manipulations, and storage time; RBC units may benefit from addition of such elements during component manufacturing or storage or before infusion. This multifaceted research could also have important ramifications for other fields. There are many examples of how research in transfusion medicine has positively impacted other scientific domains. For example, research conducted on infectious (e.g., human immunodeficiency virus, hepatitis B and C, West Nile virus) and immunologic complications of transfusions (e.g., transfusion-related acute lung injury) has not only helped advance the field of transfusion medicine by improving the safety of the blood supply, but has also been hypothesis generating. Thus, this work has fostered additional research to understand the pathogenesis of a wide variety of infectious and noninfectious diseases, including underlying host genetic and immunologic mechanisms involved in responding to and controlling infections and allogeneic immunologic challenges. The latter studies are critical to advancing the development of vaccines, for example. Similarly, we can anticipate that research on NO bioavailability, blood flow, tissue microoxygenation, interactions with the endothelium, PLT biology, immune and inflammatory modulators, and iron metabolism will be highly informative to the fields of vascular biology, hematology, immunology, and cellular therapies. It is hoped that this systematic and rational approach will lead to a better understanding of the RBC storage lesion and its clinical effects as well as to the development of enhanced transfusion therapies and strategies. These discoveries will help us achieve our mission, which is to improve and optimize patient care. The author declares no conflict of interest.

Previous studies have shown that baseline hematologic characteristics concerning or influencing red blood cell (RBC) properties might affect storage lesion development in individual donors. This study was conducted to evaluate whether variation in hemolysis, microparticle accumulation, phosphatidylserine (PS) exposure, and other storage lesion-associated variables might be a function of the prestorage hematologic and biologic profiles of the donor. Ten eligible, regular blood donors were paired and studied before donation (fresh blood) and during storage of RBCs in standard blood banking conditions. Plasma and cellular characteristics and modifications were evaluated by standard laboratory and biochemical or biologic analyses as well as by statistical and network analysis tools. Nitrate/nitrite and other bioactive factors exhibited high interdonor variability, which further increased during storage in a donor-specific manner. Storage lesion evaluators, including RBC fragility and PS exposure, fluctuated throughout the storage period in proportion to their values in fresh blood. Donors' levels of phosphatidylserine exposure and hemoglobin F correlated with stored cells' mean cell (RBC) Hb concentration, oxidative stress markers, and cellular fragility. Storage lesion indicators change in an orderly fashion, namely, by following donor-related prestorage attributes. These correlations are illustrated for the first time in "prestorage versus storage" biologic networks, which might help determine the best candidates for in vivo biomarkers of storage quality and provide deeper insight into the apparently complex donor variation effect on the RBC storage lesion.

Dear Editor, Blood donations saves the lives of millions of people worldwide, and blood transfusion is essential to the effectiveness of the health care system by supporting modern medicine as its pivotal role in patient interventions [1][2]. New, more sophisticated medical and surgical procedures such as transplant, heart surgery, and trauma or cancer treatment depend highly on blood transfusions in each country. Moreover, blood samples improve the quality of life of multitransfused patients. In developing countries transfusion-transmitted infections (TTIs) often threaten the safety of patients requiring blood transfusion, and medical providers face serious challenges with blood availability, safety, and affordability. It is estimated that 45% of the 80 million blood donations across the globe are collected each year in developing countries that comprised roughly 80% of the world’s population [3][4]. On a national level, countries should secure the safety of patients requiring blood transfusion by creating standard blood-transfusion establishments with solid support from policy makers and adequate and consistent government funding. One of the most prominent factors in ensuring safe blood samples is to have a national program for donor selection, recruitment, retention, and education to minimize donations from donors who might transmit diseases to recipients [2][4]. In addition, to ensure blood safety it is important to monitor and evaluate TTIs, including hepatitis B virus (HBV) and hepatitis C virus (HCV), among blood donors and in the general population. The prevalence of transfusion transmitted infections among blood donors in well-structured health care system with a well-organized blood establishment can be used as a reliable tool for statistical estimations of those infectious agent that can be transmitted through blood products including Hepatitis B and C. Indeed, the prevalence size of HCV or HBV among blood donors in such countries can contribute to statistical estimation of those viruses in the general population[5]. In Petrovic’s study, the prevalence rates of chronic HBV and HCV in the general populations of the Tuzla Canton in Bosnia and Herzegovina have been estimated by the adjusted prevalence of HBs-Ag and anti-HCV seropositive samples among first-time blood donors. In the current study the statistical analysis of prevalence rates has been performed based on incidence calculation of the estimated ratio between the two populations (the first-time blood donors and general population) using Poisson distribution method through reviewing published papers[6]. However, epidemiological studies of HBV and HCV in general populations have faced difficulties in obtaining sufficient sample sizes, gender and age distributions, and financial support. Nevertheless, the process of blood-donor selection aims to identify and recruit nonremunerated, apparently healthy people willing to donate blood. The donated blood should be free of bloodborne infectious agents that can be transmitted to recipients, and this depends highly on the structure of the country’s health care system [6][7]. In addition, blood-transfusion establishments should meet the international requirements for standard operating procedures that play a pivotal role in protecting the safety of both donors and recipients. Especially after the AIDS epidemic, the concern about blood safety in multitransfused patients has increased greatly. As the authors have explained, recruited blood donors are usually healthier because they are from people in the community who tend to exhibit healthier behaviors and safer life styles[8]. In conclusion, the accuracy of estimating TTI prevalence in the general population by surveying first-time blood donors depends on how similar the demographic characteristics of the two populations are. What we perceive from this study are significant differences in TTI prevalence rates between first-time and regular blood donors (data not shown here but available upon request), particularly in terms of demographic characteristics (e.g., cultural-economic issues), the structure of regional or country health care systems, blood transfusion service structures, blood donation incentives, blood type of donors (paid-donors, family replacement donors, or volunteer nonremunerated blood donors). Indeed, it seems that the populations of the countries or regions in which the reviewed studies were conducted are not demographically compatible or similar enough for valid inferences to be made.