Temporal trends in disparities in COVID-19 seropositivity among Canadian blood donors.

BACKGROUND: In Canada's largest COVID-19 serological study, SARS-CoV-2 antibodies in blood donors have been monitored since 2020. No study has analysed changes in the association between anti-N seropositivity (a marker of recent infection) and geographic and sociodemographic characteristics over the pandemic. METHODS: Using Bayesian multi-level models with spatial effects at the census division level, we analysed changes in correlates of SARS-CoV-2 anti-N seropositivity across three periods in which different variants predominated (pre-Delta, Delta and Omicron). We analysed disparities by geographic area, individual traits (age, sex, race) and neighbourhood factors (urbanicity, material deprivation and social deprivation). Data were from 420 319 blood donations across four regions (Ontario, British Columbia [BC], the Prairies and the Atlantic region) from December 2020 to November 2022. RESULTS: Seropositivity was higher for racialized minorities, males and individuals in more materially deprived neighbourhoods in the pre-Delta and Delta waves. These subgroup differences dissipated in the Omicron wave as large swaths of the population became infected. Across all waves, seropositivity was higher in younger individuals and those with lower neighbourhood social deprivation. Rural residents had high seropositivity in the Prairies, but not other regions. Compared to generalized linear models, multi-level models with spatial effects had better fit and lower error when predicting SARS-CoV-2 anti-N seropositivity by geographic region. CONCLUSIONS: Correlates of recent COVID-19 infection have evolved over the pandemic. Many disparities lessened during the Omicron wave, but public health intervention may be warranted to address persistently higher burden among young people and those with less social deprivation.

Gene expression profiling of p53 and c-myc in HTLV-1 positive blood donors in Congo.

OBJECTIVES: The HTLV-1 infection persists for life, remaining as asymptomatic viral reservoirs in most patients, ensuring the chain of transmission, but around 4% develop adult T-cell leukemia/lymphoma (ATLL). HTLV-1 is an oncogenic retrovirus that transforms CD4+ T lymphocytes and deregulates the lymphoproliferative pathways that contribute to the development of ATLL. To achieve cell transformation, most oncogenic retroviruses use proto-oncogene capture transduction, with proviral integration disrupting the expression of tumor suppressors or proto-oncogenes. THE AIM: We conducted this study on the prevalence of HTLV-1 infection in blood donors to expand the HTLV-1 database, assess the risk of transmission via blood products, as well as evaluate the risk of persistent infection or development of neoplastic diseases in HTLV-1 carriers. MATERIALS AND METHODS: This is a cross-sectional study of blood donors of all categories. For this study, 265 blood donors were recruited at the Centre National de Transfusion Sanguine in Brazzaville. After testing for HTLV-1 antibodies by ELISA, proviral DNA was extracted from all ELISA-positive samples for detection by nested PCR, followed by RT qPCR using specific primers p53 and c-myc for gene expression. RESULTS: 20/265 were positive for anti-HTLV-1 antibody, 5 donors were positive for proviral DNA. The prevalence of HTLV-1 was 1.8%. All HTLV-1-positive donors were male (1.8%), with a positive correlation (p = 0.05); the 1.1% of positive donors were regular, with the majority aged between 31 and 45 years (1.5%), and concubine donors were the most frequent (1.1%). All samples showed normal expression of the p53 and c-myc genes. CONCLUSION: The prevalence, though low, remains a serious problem. No abnormal p53 or c-myc gene expression was detected in HTLV-1-positive donors, which could mean that none of the T lymphocytes in these donors had been transformed by HTLV-1.

Screening blood donors for malaria, can we increase the number of eligible donors? An observational retrospective study.

BACKGROUND: In non-endemic countries, malaria can be transmitted through blood donations from imported cases. To ensure standards of quality and safety of human blood, the European Union and Spanish national law, requires a deferral period, or a screening by immunological or genomic test among those donors with potential risk of malaria. Scientific societies, European Committee on Blood Transfusion, and Spanish Society of Haematology and Haemotherapy, refer only to the result of the immunological test. METHODS: An observational retrospective study was performed in potential donors with a positive immunological test for malaria done in the Regional Transfusion Center in Madrid and referred to the National Reference Unit for Tropical Diseases in Madrid between 2015-2020. At consultation a Polymerase Chain Reaction (PCR) for malaria was performed. RESULTS: During the study period, 121 possible donors attended for consultation at NRU-Trop. Median age: 38.5 (IQR:33-48); median time to consultation was 32 months (IQR:12.5-110). Eighty-two (67.8%) donors were migrants and thirty-nine were travellers (32.2%). ELISA values were available for 109 subjects (90.1%), 56 individual left malaria endemic area > 3 years before. All donors tested negative for Plasmodium spp PCR test (n = 121, 100%). CONCLUSIONS: None of the subjects with a positive immunologic test deferred as blood donors had a positive genomic test. The presence of Plasmodium spp in collected blood was not detected by molecular techniques. To avoid the loss of potential blood donors, especially those with low incidence red blood cell antigens, as more precise microbiology techniques become available, updating the existing legislation becomes necessary to increase the availability of donated blood.

Identification of the novel HLA-DQB1*06:466 allele by next-generation sequencing in a Chinese cord blood donor.

HLA-DQB1*06:466 differs from HLA-DQB1*06:01:01:01 by a single nucleotide substitution at position 571G→A.

Screening and Analysis of SARS-CoV-2 Antibody Among Unvaccinated Blood Donors in Chongqing, China.

OBJECTIVE: To investigate the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody among unvaccinated voluntary blood donors in Chongqing, and to provide evidence for epidemic surveillance. METHODS: A total of 10,208 voluntary blood donors from January 5 to January 20, 2021, in the Chongqing area were collected, and the SARS-CoV-2 immunoglobulin (Ig) G and IgM antibodies were detected by chemiluminescence, and the differences of antibody-positive rate in different gender, age, ABO blood group, and different risk areas were analyzed. RESULTS: Among 10208 blood donors, 10 were found to be positive for SARS-COV-2 IgG antibody, giving a positivity rate of SARS-COV-2 IgG at 0.10%, and 29 were positive for SARS-CoV-2 IgM antibody, with a positivity rate of SARS-CoV-2 IgM at 0.28%. There was no statistical difference in the positive rate of antibody among different genders, ages, and ABO blood types, but it was related to the number of confirmed coronavirus disease 2019 (COVID-19) cases in each city. CONCLUSIONS: The SARS-CoV-2 seroprevalence rate in Chongqing was low and correlated with the number of confirmed COVID-19 cases.

A virtual reality paradigm simulating blood donation serves as a platform to test interventions to promote donation.

Effective interventions that support blood donor retention are needed. Yet, integrating an intervention into the time-pressed and operationally sensitive context of a blood donation center requires justification for disruptions to an optimized process. This research provides evidence that virtual reality (VR) paradigms can serve as a research environment in which interventions can be tested prior to being delivered in blood donation centers. Study 1 (N = 48) demonstrated that 360°-video VR blood donation environments elicit a similar profile of emotional experience to a live donor center. Presence and immersion were high, and cybersickness symptoms low. Study 2 (N = 134) was an experiment deploying the 360°-video VR environments to test the impact of an intervention on emotional experience and intentions to donate. Participants in the intervention condition who engaged in a suite of tasks drawn from the process model of emotion regulation (including attentional deployment, positive reappraisal, and response modulation) reported more positive emotion than participants in a control condition, which in turn increased intentions to donate blood. By showing the promise for benefitting donor experience via a relatively low-cost and low-resource methodology, this research supports the use of VR paradigms to trial interventions prior to deployment in operationally-context field settings.

Influence of Gender and Previous Blood Donation Status on Attitude Toward Blood Donation: a Cross-Sectional Study.

BACKGROUND: Blood supply shortage may affect the health of patients who are transfusion-dependent. Consequently, blood donation plays an important role in the community as it can provide sufficient blood supply at blood bank centers. Medical sciences students can help promote blood donation. The current study aimed to assess the knowledge on, attitude toward, and barriers on blood donation among medical sciences students at the Faculty of Applied Medical Sciences of Jazan University, Saudi Arabia. METHODS: An online questionnaire with 23 knowledge and attitude questions was established using Google Forms. Statistical analysis was performed based on gender and blood donation status (never donated, unable to donate, and donated blood). RESULTS: In total, 601 participants from six different departments responded to the questionnaire. Interestingly, female students had a higher rate of accurate responses toward the knowledge and attitude questions than male students (p < 0.01). Furthermore, students who previously donated had a higher rate of accurate responses to the questions than those who were not able to or never donated blood (p < 0.01). CONCLUSIONS: The questionnaire was designed to assess the general knowledge and attitude of medical sciences students and barriers on blood donation. Female gender and a history of blood donation had a significant impact on responses. Therefore, more efforts are required to educate students regarding the importance of blood donation among patients who are transfusion-dependent.

Exploring the determinants of risk behavior for transfusion transmissible infections among first-time blood donors in Mandalay General Hospital, Myanmar.

INTRODUCTION: Blood donation is vital to healthcare, but it must be kept safe by mitigating the risk of transfusion transmissible infections (TTIs). The objective of this study was to investigate the factors that influence risk behavior for transfusion transmissible infections among first-time blood donors at Mandalay General Hospital, Myanmar. METHODS: This study utilized a cross-sectional study design using secondary data. Mandalay city and Mandalay Blood Bank in Mandalay General Hospital were purposely selected and a total of 406 first-time blood donors participated. A structured questionnaire administered by an interviewer was used. The questionnaire contained background characteristics, knowledge on TTIs, attitude toward TTIs, and TTIs risk behaviors. To examine the determinants (background characteristics, knowledge, and attitude) that affect risk behavior, inferential statistics techniques that included the chi-squared test, bivariable logistic regression, and multivariable logistic regression were applied. A p-value of less than 0.05 signified statistical significance. RESULTS: Among 406 first-time blood donors, 52.9% were under 20 years old, and 53.7% were male. Most had undergraduate education (77.6%), were married (84.2%), and were students (55.7%). Additionally, 76.8% hadn't received the hepatitis B vaccine. Blood groups were distributed as follows: B (40.0%), O (33.8%), A (23.4%), AB (8.9%). About 15.8% showed high knowledge level, and 63.6% had high attitude. Notably, 29.3% exhibited high-risk behavior for TTIs. Age was associated with lower risk behavior (OR = 1.54, 95% CI: 0.99, 2.38, p = 0.049), but lost significance in multivariable regression (p = 0.214). Knowledge on TTIs didn't show significance. However, high attitudes were significantly associated with lower risk behavior (OR = 11.4, 95% CI: 1.25, 103.83, p = 0.017, retained in multivariable regression, p = 0.012). CONCLUSION: Findings of this study contribute in the development of programs that ensure a safe and reliable blood supply chain. To improve blood safety standards among first-time blood donors, this study highlights the value of targeted education and screening processes, placing particular emphasis on acquiring knowledge and positive attitude toward blood donation and risk behavior.

New atypical epidemiological profile of parvovirus B19 revealed by molecular screening of blood donations, France, winter 2023/24.

In France, blood donations are tested in pools of 96 samples for parvovirus B19 (B19V) DNA to discard plasma for fractionation when it contains high viral loads. Between January 2015 and March 2024, B19V-positive donations decreased during the COVID-19 pandemic, followed by a strong rebound in 2023 and unusually high circulation during winter 2023/24 (ca 10 times higher December 2023-March 2024 vs the pre-pandemic period). Variations over time are probably related to measures implemented to limit SARS-CoV-2 spread.

Dengue virus transmission risk in blood donation: Evidence from Thailand.

Individuals infected with dengue virus (DENV) often show no symptoms, which raises the risk of DENV transfusion transmission (TT-DENV) in areas where the virus is prevalent. This study aimed to determine the evidence of DENV infection in blood donors from different geographic regions of Thailand. A cross-sectional study was conducted on blood donor samples collected from the Thai Red Cross National Blood Center and four regional blood centers between March and September 2020. Screening for DENV nonstructural protein 1 (NS1), anti-DENV immunoglobulin G (IgG), and IgM antibodies was performed on residual blood from 1053 donors using enzyme-linked immunosorbent assay kits. Positive NS1 and IgM samples indicating acute infection were verified using four different techniques, including quantitative real-time (q) RT-PCR, nested PCR, virus isolation in C6/36 cells, and mosquito amplification. DENV IgG seropositivity was identified in 89% (938/1053) of blood donors. Additionally, 0.4% (4/1053) and 2.1% (22/1053) of Thai blood donors tested positive for NS1 and IgM, respectively. The presence of asymptomatic dengue virus infection in healthy blood donors suggests a potential risk of transmission through blood transfusion, posing a concern for blood safety.

Future Blood Debt: Projecting Blood Supply and Demand of Korea Based on Subnational Population Projections (2021-2050).

BACKGROUND: South Korea faces a critical challenge with its rapidly declining fertility rates and an increasingly aging population, which significantly impacts the country's blood supply and demand. Despite these nationwide trends, regional disparities in blood supply and demand have not been thoroughly studied. METHODS: This research utilized blood donation data from the Korean Red Cross and blood transfusion data from the Health Insurance Review and Assessment Service. We analyzed these datasets in conjunction with regional population projections to simulate blood supply and demand from 2021 to 2050 across South Korea. Sensitivity analyses were conducted to assess the impact of various factors, including the number of donors, age eligibility criteria for donations, frequency of donations, and blood discard rates. RESULTS: Our projections indicate a decreasing trend in blood supply, from 2.6 million units in 2021 to 1.4 million units by 2050, while demand is expected to peak at 5.1 million units by 2045 before declining. Metropolitan areas, particularly Gyeonggi Province, are projected to experience the most severe shortages. Sensitivity analyses suggest that increasing the donation frequency of existing donors and relaxing age eligibility criteria are more effective strategies in addressing these imbalances than merely increasing the number of new donors. Blood discard rates showed minimal impact on the overall blood shortage. CONCLUSION: The findings emphasize the urgent need for targeted strategies to mitigate national and regional blood supply shortages in South Korea. Encouraging frequent donations from experienced donors and broadening eligibility criteria are critical steps toward stabilizing the blood supply amidst demographic shifts. These strategies must be prioritized to address the impending regional disparities in blood availability.

Rational or altruistic: the impact of social media information exposure on Chinese youth's willingness to donate blood.

Background: Non-remunerated blood donation is the main approach for various medical institutions to get the source of blood supply, but the blood supply shortage is still a problem in today's society. Social media has become the main approach of information acquisition for youth groups nowadays, and the information on social media will have an impact on people's behavioral decisions. The objective of this study was therefore to investigate the correlation between social media exposure to relevant information about blood donation and the willingness of youths to donate blood. Methods: We collected data from 455 questionnaires through an online questionnaire and structural equation modeling was constructed for validation. Data were analyzed for reliability, validity, and demographic differences using IBM-SPSS 26.0, and IBM-SPSS-AMOS 26.0 was used for model fit analysis and path analysis. Results: The results of the study showed that there was a positive correlation between social media exposure to relevant blood donation information and willingness to donate blood (ß = 0.262, p < 0.001), altruism (ß = 0.203, p < 0.001) and self-efficacy (ß = 0.170, p < 0.001). While there was also a positive correlation between attitude toward blood donation and self-efficacy (ß = 0.560, p < 0.001), there was no positive correlation between it and willingness to donate blood (ß = -0.180, p = 0.786). There was also a positive correlation between altruism and willingness to donate blood (ß = 0.150, p < 0.05) and attitude toward blood donation (ß = 0.150, p < 0.001). Similarly, there was a positive correlation between self-efficacy and willingness to donate blood (ß = 0.371, p < 0.001). Conclusion: Exposure to more information related to blood donation on social media can increase the willingness of the youth population to donate blood, while exposure to information related to altruism and self-efficacy on social media can also enhance young people's attitudes toward blood donation, while further strengthening their willingness to donate.

Survival of transfused red blood cells from a donor with alpha-thalassemia trait in a recipient with sickle cell disease.

BACKGROUND: Post-transfusion survival of donor red blood cells (RBCs) is important for effective chronic transfusion therapy in conditions including sickle cell disease (SCD). Biotin labeling RBCs allows direct in vivo measurement of multiple donor RBC units simultaneously post-transfusion. STUDY DESIGN AND METHODS: In an observational trial of patients with SCD receiving monthly chronic transfusion therapy, aliquots of RBCs from one transfusion episode were biotin-labeled and infused along with the unlabeled RBC units. Serial blood samples were obtained to measure RBC survival. Donor units were tested for RBC indices, hemoglobin fractionation, and glucose-6-phosphate dehydrogenase (G6PD) enzyme activity. For microcytic donor RBCs (MCV < 70 fL), HBA1 and HBA2 genetic testing was performed on whole blood. RESULTS: We present one recipient, a pediatric patient with SCD and splenectomy who received two RBC units with aliquots from each unit labeled at distinct biotin densities (2 and 18 µg/mL biotin). One donor unit was identified to have microcytosis (MCV 68.5 fL after biotinylation); whole blood sample obtained at a subsequent donation showed 2-gene deletion alpha-thalassemia trait (ɑ-3.7kb/ɑ-3.7kb) and normal serum ferritin. G6PD activity was >60% of normal mean for both. The RBCs with alpha-thalassemia RBC had accelerated clearance and increased surface phosphatidylserine post-transfusion, as compared with the normocytic RBC (half life 65 vs. 86 days, respectively). DISCUSSION: Post-transfusion RBC survival may be lower for units from donors with alpha-thalassemia trait, although the impact of thalassemia trait donors on transfusion efficacy requires further study.

Measuring the effectiveness of online search ads on blood donor recruitment and donation.

BACKGROUND: Acutely highlighted during the COVID-19 pandemic, the tenuousness of the blood supply continues to be a lynchpin of the most important medical procedures. Online advertisements have become a mainstay in donor recruitment. We set out to determine the effectiveness of online search ads and variations thereof on blood donations with an emphasis on first-time donors. STUDY DESIGN AND METHODS: From September 01, 2022 through March 31, 2023, we performed a campaign comparison experiment through a major search-ads platform with two distinct messages: one altruistic ("Altruistic") and one with a prospect of rewards ("Promotion"). We developed a method to track donation outcomes and associated them with impressions, click-throughs, and conversions. We compared the performance of the Altruistic and Promotion arms to a control group that was not associated with any search-ads ("Baseline"). RESULTS: Analyzing 34,157 donations during the study period, the Promotion group, and not Altruistic, had a significant difference of first-time donors over Baseline (24% vs. 12%, p = 7e-6). We analyzed 49,305 appointments and discovered that appointments made from the Altruistic arm resulted in a significantly higher percentage of donations when compared to Baseline (57% vs. 53%, p = .009); however, the Promotion group had a higher percentage of donations from first-time donors when compared to Baseline (12% vs. 8%, p = .006). CONCLUSION: We developed a method for determining the effectiveness of online search ads on donation outcomes. Rewards/promotions messaging was most effective at recruiting first-time donors. Our methodology is generalizable to different blood centers to explore messaging effectiveness among their unique communities.

Prevalence of Acute Hepatitis E Virus Infections in Swiss Blood Donors 2018-2020.

INTRODUCTION: Hepatitis E virus (HEV) genotype 3 is the major cause of acute viral hepatitis in several European countries. It is acquired mainly by ingesting contaminated pork, but has also been reported to be transmitted through blood transfusion. Although most HEV infections, including those via blood products, are usually self-limiting, they may become chronic in immunocompromised persons. It is thus essential to identify HEV-infected blood donations to prevent transmission to vulnerable recipients. AIMS: Prior to the decision whether to introduce HEV RNA screening for all Swiss blood donations, a 2-year nationwide prevalence study was conducted. METHODS: All blood donations were screened in pools of 12-24 samples at five regional blood donation services, and HEV RNA-positive pools were subsequently resolved to the individual donation index donation (X). The viral load, HEV IgG and IgM serology, and HEV genotype were determined. Follow-up investigations were conducted on future control donations (X + 1) and previous archived donations of the donor (X - 1) where available. RESULTS: Between October 2018 and September 2020, 541,349 blood donations were screened and 125 confirmed positive donations were identified (prevalence 1:4331 donations). At the time of blood donation, the HEV RNA-positive individuals were symptom-free. The median viral load was 554 IU/mL (range: 2.01-2,500,000 IU/mL). Men (88; 70%) were more frequently infected than women (37; 30%), as compared with the sex distribution in the Swiss donor population (57% male/43% female, p < 0.01). Of the 106 genotyped cases (85%), all belonged to genotype 3. Two HEV sub-genotypes predominated; 3h3 (formerly 3s) and 3c. The remaining sub-genotypes are all known to circulate in Europe. Five 3ra genotypes were identified, this being a variant associated with rabbits. In total, 85 (68%) X donations were negative for HEV IgM and IgG. The remaining 40 (32%) were positive for HEV IgG and/or IgM, and consistent with an active infection. We found no markers of previous HEV in 87 of the 89 available and analyzed archive samples (X - 1). Two donors were HEV IgG-positive in the X - 1 donation suggesting insufficient immunity to prevent HEV reinfection. Time of collection of the 90 (72%) analyzed X + 1 donations varied between 2.9 and 101.9 weeks (median of 35 weeks) after X donation. As expected, none of those tested were positive for HEV RNA. Most donors (89; 99%) were positive for anti-HEV lgG/lgM (i.e., seroconversion). HEV lgM-positivity (23; 26%) indicates an often-long persistence of lgM antibodies post-HEV infection. CONCLUSION: The data collected during the first year of the study provided the basis for the decision to establish mandatory HEV RNA universal screening of all Swiss blood donations in minipools, a vital step in providing safer blood for all recipients, especially those who are immunosuppressed.

Finger photopletysmography detects early acute blood loss in compensated blood donors: a pilot study.

Objective.Diagnosis of incipient acute hypovolemia is challenging as vital signs are typically normal and patients remain asymptomatic at early stages. The early identification of this entity would affect patients' outcome if physicians were able to treat it precociously. Thus, the development of a noninvasive, continuous bedside monitoring tool to detect occult hypovolemia before patients become hemodynamically unstable is clinically relevant. We hypothesize that pulse oximeter's alternant (AC) and continuous (DC) components of the infrared light are sensitive to acute and small changes in patient's volemia. We aimed to test this hypothesis in a cohort of healthy blood donors as a model of slight hypovolemia.Approach.We planned to prospectively study blood donor volunteers removing 450 ml of blood in supine position. Noninvasive arterial blood pressure, heart rate, and finger pulse oximetry were recorded. Data was analyzed before donation, after donation and during blood auto-transfusion generated by the passive leg-rising (PLR) maneuver.Main results.Sixty-six volunteers (44% women) accomplished the protocol successfully. No clinical symptoms of hypovolemia, arterial hypotension (systolic pressure < 90 mmHg), brady-tachycardia (heart rate <60 and >100 beats-per-minute) or hypoxemia (SpO2< 90%) were observed during donation. The AC signal before donation (median 0.21 and interquartile range 0.17 a.u.) increased after donation [0.26(0.19) a.u;p< 0.001]. The DC signal before donation [94.05(3.63) a.u] increased after blood extraction [94.65(3.49) a.u;p< 0.001]. When the legs' blood was auto-transfused during the PLR, the AC [0.21(0.13) a.u.;p= 0.54] and the DC [94.25(3.94) a.u.;p= 0.19] returned to pre-donation levels.Significance.The AC and DC components of finger pulse oximetry changed during blood donation in asymptomatic volunteers. The continuous monitoring of these signals could be helpful in detecting occult acute hypovolemia. New pulse oximeters should be developed combining the AC/DC signals with a functional hemodynamic monitoring of fluid responsiveness to define which patient needs fluid administration.

Factors Influencing Blood Donation among Young Saudi Arabian Adults: A Cross-Sectional Study to Inform Donor Recruitment and Retention Programs.

OBJECTIVE: Blood donation is critical in Saudi Arabia due to high rates of sickle cell disease and thalassemia. Recent trends show a decline in the number of blood donors, threatening blood supplies for medical treatments. This study aims to identify factors that influence blood donation decisions and behaviors among young Saudi Arabian adults to develop strategies to enhance donation rates. METHODS: A cross-sectional study was conducted with 407 university students in Riyadh Province (Shaqra, Riyadh City, Al-Majmaah and Al-Duwadimi) and occurred from December 2022 to May 2023, using convenience sampling. Data were collected via online questionnaires and analyzed using logistic regression. RESULTS: Findings revealed a significant gender disparity in donation rates with males more likely to donate. Knowledge gaps were prevalent, especially regarding eligibility criteria. Support for organ donation, prior experience of receiving blood, and high levels of self-determined motivation positively associated with donation likelihood. Conversely, amotivation was a strong negative predictor of donation. CONCLUSION: This study highlights the importance of educational interventions to address misconceptions about blood donation and tailor campaigns to enhance donor motivation. Strategies focusing on these aspects could improve the donor pool and ensure a stable blood supply for patients with blood disorders in Saudi Arabia.

Genome-wide association study reveals a locus in ADARB2 for complete freedom from headache in Danish Blood Donors.

Headache disorders are the most common disorders of the nervous system. The lifetime prevalence of headache disorders show that some individuals never experience headache. The etiology of complete freedom from headache is not known. To assess genetic variants associated with complete freedom from headache, we performed a genome-wide association study of individuals who have never experienced a headache. We included 63,992 individuals (2,998 individuals with complete freedom from headache and 60,994 controls) from the Danish Blood Donor Study Genomic Cohort. Participants were included in two rounds, from 2015 to 2018 and in 2020. We discovered a genome-wide significant association, with the lead variant rs7904615[G] in ADARB2 (EAF = 27%, OR = 1.20 [1.13-1.27], p = 3.92 × 10-9). The genomic locus was replicated in a non-overlapping cohort of 13,032 individuals (539 individuals with complete freedom from headache and 12,493 controls) from the Danish Blood Donor Study Genomic Cohort (p < 0.05, two-sided). Participants for the replication were included from 2015 to 2020. In conclusion, we show that complete freedom from headache has a genetic component, and we suggest that ADARB2 is involved in complete freedom from headache. The genomic locus was specific for complete freedom from headache and was not associated with any primary headache disorders.