Predicting haemoglobin deferral using machine learning models: Can we use the same prediction model across countries?

BACKGROUND AND OBJECTIVES

Personalized donation strategies based on haemoglobin (Hb) prediction models may reduce Hb deferrals and hence costs of donation, meanwhile improving commitment of donors. We previously found that prediction models perform better in validation data with a high Hb deferral rate. We therefore investigate how Hb deferral prediction models perform when exchanged with other blood establishments.

MATERIALS AND METHODS

Donation data from the past 5 years from random samples of 10,000 donors from Australia, Belgium, Finland, the Netherlands and South Africa were used to fit random forest models for Hb deferral prediction. Trained models were exchanged between blood establishments. Model performance was evaluated using the area under the precision-recall curve (AUPR). Variable importance was assessed using SHapley Additive exPlanations (SHAP) values.

RESULTS

Across the validation datasets and exchanged models, the AUPR ranged from 0.05 to 0.43. Exchanged models performed similarly within validation datasets, irrespective of the origin of the training data. Apart from subtle differences, the importance of most predictor variables was similar in all trained models.

CONCLUSION

Our results suggest that Hb deferral prediction models trained in different blood establishments perform similarly within different validation datasets, regardless of the deferral rate of their training data. Models learn similar associations in different blood establishments.

Development and validation of a nomogram for predicting the risk of vasovagal reactions after plasma donation

BACKGROUND AND OBJECTIVES

Vasovagal reactions (VVRs) are the most common adverse reactions and are frequently associated with serious donor adverse events. Even mild VVRs can lead to a significant reduction in the likelihood of subsequent donations. The purpose of this study is to explore the factors related to the occurrence of VVRs after plasma donation and to construct a nomogram to identify individuals at risk for VVRs to improve the safety of plasma donors.

MATERIALS AND METHODS

We collected the donation data from July 2019 to June 2020 from a plasma center in Sichuan, China, to explore the independent risk factors for vasovagal reactions. From these data, we constructed and validated a predictive model for vasovagal reactions.

RESULTS

VVRs after plasma donation occurred 737 times in 120 448 plasma donations (0.66%). Gender, season, donor status, weight, pulse, duration of donation, and cycle were independent risk factors for VVRs (P< 0.05). The concordance index (C-index) of a logistic model in the derivation cohort was 0.916, with a Hosmer-Lemeshow goodness-of-fit probability of 0.795. The C-index of a logistic model in the validation cohort was 0.916, with a Hosmer-Lemeshow goodness-of-fit probability of 0.224. The calibration curve showed that the predicted results were in good agreement with the actual observed results.

CONCLUSION

This study preliminarily constructed and verified a prediction model for VVRs after plasma donation. The model nomogram is practical and can identify high-risk donors.

source plasma donor health

BACKGROUND

Plasma-derived medicinal products (PDMPs) are essential, life-saving medicines manufactured from plasma donated by healthy human volunteers. PDMPs are used to treat a range of rare, serious, and chronic conditions, often genetic in origin. Approximately 70% of the Source Plasma (SP) used for PDMP manufacturing comes from United States (US). The hypothesis of the study is that US donation frequency does not impair donor self-reported functional health and well-being.

STUDY DESIGN AND METHODS

A total of 5608 SP donors from 14 US SP centers were enrolled in a cross-sectional study to assess self-reported health related quality of life (HRQoL) and well-being. By sex, donors were assigned to one of four groups, according to their frequency of SP donation in the 12 months before enrollment. The SF-36v2® Health Survey (SF-36v2) and a survey assessing the frequency of various health conditions that may be associated with impaired immune function over different time periods were used.

RESULTS

There were no statistically significant differences in SF-36v2 scores between any of the donor frequency groups, compared with new donors after controlling for potential confounding and accounting for multiple comparisons among males and females. Cough, cold, occasional fatigue, and sore throat were the most reported health conditions or symptoms, but there was no clear difference among sex or frequency groups.

DISCUSSION

The self-reported data in this study support the hypothesis that compensated donations at US FDA permitted frequencies and volumes are consistent with maintaining donor health. Compared with the general population, SP donors have comparable or better health than the general population.

Simulated effects of ferritin screening on C-reactive protein levels in recruited blood donors

BACKGROUND AND OBJECTIVES

Ferritin is commonly measured to evaluate iron stores in the body. Some countries have added or considered adding ferritin lower bounds to donor eligibility criteria. Ferritin is also elevated by inflammation. The main goal of this study is to estimate how different ferritin cut-offs would affect the proportion of donors with a C-reactive protein (CRP) level over 3 mg/L, which is the decision limit of the highest chronic cardiovascular risk.

MATERIALS AND METHODS

To simulate recruitment of new blood donors, we selected participants from two Finnish general population cohorts, namely FINRISK 1997 (n = 5369) and Health 2000 (n = 3278), that would likely fulfil the selection criteria of blood donation. We then calculated the proportion of individuals with high-sensitivity CRP values above 3 mg/L, over a range of ferritin values.

RESULTS

We found that for several ferritin cut-offs the proportion of potential donors with CRP > 3 mg/L would rise by a statistically significant amount. The trend was significant and similar for all subgroups but weaker for non-menstruating women as well as men.

CONCLUSION

Our results show that screening a population of potential blood donors with ferritin cut-offs raises the number of people with CRP > 3 mg/L within the blood donor population.

An international comparison of haemoglobin deferral prediction models for blood banking

BACKGROUND AND OBJECTIVES

Blood banks use a haemoglobin (Hb) threshold before blood donation to minimize donors' risk of anaemia. Hb prediction models may guide decisions on which donors to invite, and should ideally also be generally applicable, thus in different countries and settings. In this paper, we compare the outcome of various prediction models in different settings and highlight differences and similarities.

MATERIALS AND METHODS

Donation data of repeat donors from the past 5 years of Australia, Belgium, Finland, the Netherlands and South Africa were used to fit five identical prediction models: logistic regression, random forest, support vector machine, linear mixed model and dynamic linear mixed model. Only donors with five or more donation attempts were included to ensure having informative data from all donors. Analyses were performed for men and women separately and outcomes compared.

RESULTS

Within countries and overall, different models perform similarly well. However, there are substantial differences in model performance between countries, and there is a positive association between the deferral rate in a country and the ability to predict donor deferral. Nonetheless, the importance of predictor variables across countries is similar and is highest for the previous Hb level.

CONCLUSION

The limited impact of model architecture and country indicates that all models show similar relationships between the predictor variables and donor deferral. Donor deferral is found to be better predictable in countries with high deferral rates. Therefore, such countries may benefit more from deferral prediction models than those with low deferral rates.

First donor haemovigilance system at a national level in China: Establishment and improvement

BACKGROUND AND OBJECTIVES

No systematic study has measured the incidence of adverse reactions (ARs) to blood donation at the national level in China before 2019. The objective of this study was to establish an effective reporting system to collect information on ARs to blood donation in China.

MATERIALS AND METHODS

The status of donor haemovigilance (DHV) in blood collection facilities in China was evaluated, and an online DHV system was established to collect data on ARs to blood donation in July 2019. The definitions of ARs were based on the International Society of Blood Transfusion (ISBT) standards. The prevalence and data quality of ARs from 2019 to 2021 were analysed.

RESULTS

A standard online reporting system has been established for ARs to blood donation. In total, 61, 62 and 81 participating sites were included in this pilot study in 2019, 2020 and 2021, respectively. From July 2019 to December 2021, 21,502 cases of whole-blood-related ARs and 1114 cases of apheresis platelet-related ARs were reported, with an incidence of 3.8‰ and 2.2‰, respectively. Data completeness for key reporting elements improved from 41.7% (15/36) in 2019 to 74.4% (29/39) in 2020. Data quality analysis for the year 2021 yielded similar results as for 2020.

CONCLUSION

The construction and continuous improvement of the blood donor safety monitoring system prompted the establishment of the DHV system. Improvements have been made to the DHV system in China, with a significant increase in sentinels and higher data quality.

A Danish national, multicentre evaluation of the new donor vigilance system among different staff groups

BACKGROUND AND OBJECTIVES

Two years after implementing a new national donor vigilance system, the Danish Haemovigilance Committee conducted a nationwide survey to evaluate the implementation among different staff groups. We present the results here.

MATERIALS AND METHODS

The study was designed as an anonymous online survey to evaluate the satisfaction with the new registration, understanding of the parameters used and the user-friendliness. The REDCap platform was used. The questionnaire consisted of 22 questions. Ordinal variables were answered using five-point Likert scale (1 = strongly disagree to 5 = strongly agree). The data were analysed using descriptive statistics. Successful implementation was defined as mean overall satisfaction ≥4 and mean understanding of the individual components (adverse reaction category, severity and imputability) in the registration ≥4.

RESULTS

In all, 104 staff members (77.9% donation staff) participated. The mean (SD) overall satisfaction among all participants was 3.96 (0.94), highest among medical doctors (4.43 (0.78)) and lowest for administrative or other personnel (2.78 (1.09)). The mean scores for understanding the adverse reaction categories, severity and imputability were 3.92 (0.94), 3.92 (0.94) and 3.88 (1.00), respectively. Experience with a previous donor vigilance system was associated with lower scores. The most successful implementation programme included a medical doctor for introduction and a contact person.

CONCLUSION

The goal for successful implementation was not met. However, the overall attitude towards the new registration was positive and indicates that the system is suitable for different staff groups. Our results suggest that implementation could benefit from special attention to administrative staff and those accustomed to another donor vigilance system.

Impact of donor ferritin testing on iron deficiency prevention and blood availability in France: A cohort simulation study

BACKGROUND AND OBJECTIVES

Implementing a ferritin testing policy for whole blood (WB) donors may prevent iron deficiency (ID, ferritin <26 ng/mL) and anaemia, but may induce donation losses. As part of a national prevention plan in France, we aimed to estimate its impact on ID, anaemias and WB donations among donors at high risk of ID.

MATERIALS AND METHODS

A micro-simulation model was developed to evaluate different scenarios compared to the current situation without ferritin testing as a reference scenario. The following scenarios were simulated: a minimum scenario with a 6-month deferral for donors with absent iron store (AIS, ferritinemia <15 ng/ml), a main scenario with additional delayed invitations for donors with ferritinemia 15-25 ng/ml and a supplementation scenario with additional iron supplementation for 50% of the donors with AIS.

RESULTS

In the main scenario, 52,699 WB donations per year were estimated to be lost after 1 year (-8%), falling to 27,687 (-4.7%) after 5 years. IDs and anaemias were reduced by 13.6% and 29.3%, respectively, after 1 year. The supplementation scenario increased the number of prevented IDs and anaemias to 24.1% and 35.4%, respectively, after 1 year, and halved the number of anaemias at 5 years. The latter scenario also had the least impact on the number of donations (-3.2% after 5 years).

CONCLUSION

A ferritin testing policy resulting in delayed donations for ID donors is effective in reducing IDs and anaemias, but significantly impacts the number of donations, thereby posing a self-sufficiency challenge.

The healthy donor effect and survey participation, becoming a donor and donor career

BACKGROUND

The healthy donor effect (HDE) is a selection bias caused by the health criteria blood donors must meet. It obscures investigations of beneficial/adverse health effects of blood donation and complicates the generalizability of findings from blood donor cohorts. To further characterize the HDE we investigated how self-reported health and lifestyle are associated with becoming a blood donor, lapsing, and donation intensity. Furthermore, we examined differences in mortality based on donor status.

STUDY DESIGN AND METHODS

The Danish National Health Survey was linked to the Scandinavian Donations and Transfusions (SCANDAT) database and Danish register data. Logistic- and normal regression was used to compare baseline characteristics and participation. Poisson regression was used to investigate future donation choices. Donation intensity was explored by the Anderson-Gill model and Poisson regression. Mortality was investigated using Poisson regression.

RESULTS

Blood donors were more likely to participate in the surveys, OR = 2.45 95% confidence interval (2.40-2.49) than non-donors. Among survey participants, better self-reported health and healthier lifestyle were associated with being or becoming a blood donor, donor retention, and to some extent donation intensity, for example, current smoking conveyed lower likelihood of becoming a donor, OR = 0.70 (0.66-0.75). We observed lower mortality for donors and survey participants, respectively, compared with non-participating non-donors.

CONCLUSION

We provide evidence that blood donation is associated with increased likelihood to participate in health surveys, possibly a manifestation of the HDE. Furthermore, becoming a blood donor, donor retention, and donation intensity was associated with better self-reported health and healthier lifestyles.

Explainable haemoglobin deferral predictions using machine learning models: Interpretation and consequences for the blood supply

BACKGROUND AND OBJECTIVES

Accurate predictions of haemoglobin (Hb) deferral for whole-blood donors could aid blood banks in reducing deferral rates and increasing efficiency and donor motivation. Complex models are needed to make accurate predictions, but predictions must also be explainable. Before the implementation of a prediction model, its impact on the blood supply should be estimated to avoid shortages.

MATERIALS AND METHODS

Donation visits between October 2017 and December 2021 were selected from Sanquin's database system. The following variables were available for each visit: donor sex, age, donation start time, month, number of donations in the last 24 months, most recent ferritin level, days since last ferritin measurement, Hb at nth previous visit (n between 1 and 5), days since the nth previous visit. Outcome Hb deferral has two classes: deferred and not deferred. Support vector machines were used as prediction models, and SHapley Additive exPlanations values were used to quantify the contribution of each variable to the model predictions. Performance was assessed using precision and recall. The potential impact on blood supply was estimated by predicting deferral at earlier or later donation dates.

RESULTS

We present a model that predicts Hb deferral in an explainable way. If used in practice, 64% of non-deferred donors would be invited on or before their original donation date, while 80% of deferred donors would be invited later.

CONCLUSION

By using this model to invite donors, the number of blood bank visits would increase by 15%, while deferral rates would decrease by 60% (currently 3% for women and 1% for men).

COVID-19 vaccine humoral response in frequent platelet donors with plateletpheresis-associated lymphopenia

BACKGROUND

Plateletpheresis involves platelet separation and collection from whole blood while other blood cells are returned to the donor. Because platelets are replaced faster than red blood cells, as many as 24 donations can be done annually. However, some frequent apheresis platelet donors (>20 donations annually) display severe plateletpheresis-associated lymphopenia; in particular, CD4⁺ T but not B cell numbers are decreased. COVID-19 vaccination thereby provides a model to assess whether lymphopenic platelet donors present compromised humoral immune responses.

STUDY DESIGN AND METHODS

We assessed vaccine responses following 2 doses of COVID-19 vaccination in a cohort of 43 plateletpheresis donors with a range of pre-vaccination CD4⁺ T cell counts (76-1537 cells/μl). In addition to baseline T cell measurements, antibody binding assays to full-length Spike and the Receptor Binding Domain (RBD) were performed pre- and post-vaccination. Furthermore, pseudo-particle neutralization and antibody-dependent cellular cytotoxicity assays were conducted to measure antibody functionality.

RESULTS

Participants were stratified into two groups: <400 CD4/μl (n = 27) and ≥ 400 CD4/μl (n = 16). Following the first dose, 79% seroconverted within the <400 CD4/μl group compared to 87% in the ≥400 CD4/μl group; all donors were seropositive post-second dose with significant increases in antibody levels. Importantly differences in CD4⁺ T cell levels minimally impacted neutralization, Spike recognition, and IgG Fc-mediated effector functions.

DISCUSSION

Overall, our results indicate that lymphopenic plateletpheresis donors do not exhibit significant immune dysfunction; they have retained the T and B cell functionality necessary for potent antibody responses after vaccination.

Impact of disasters on blood donation rates and blood safety: A systematic review and meta-analysis

Background and Objectives

Timely and adequate access to safe blood forms an integral part of universal health coverage, but it may be compromised by natural or man‐made disasters. This systematic review provides an overview of the best available scientific evidence on the impact of disasters on blood donation rates and safety outcomes.

Materials and Methods

Five databases (The Cochrane Library, MEDLINE, Embase, Web of Science and CINAHL) were searched until 27 March 2020 for (un)controlled studies investigating the impact of disasters on blood donation rates and/or safety. Risk of bias and overall certainty of the evidence were assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

Results

Eighteen observational studies were identified, providing very low certainty of evidence (due to high risk of bias, inconsistency and/or imprecision) on the impact of natural (12 studies) and man‐made/technological (6 studies) disasters. The available evidence did not enable us to form any generalizable conclusions on the impact on blood donation rates. Meta‐analyses could not detect any statistically significant changes in transfusion‐transmissible infection (TTI) rates [hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV)‐1/2, human T‐lymphotropic virus I and II (HTLV‐I/II) and syphilis] in donated blood after a disaster, either in first‐time or repeat donors, although the evidence is very uncertain.

Conclusion

The very low certainty of evidence synthetized in this systematic review indicates that it is very uncertain whether there is an association between disaster occurrence and changes in TTI rates in donated blood. The currently available evidence did not allow us to draw generalizable conclusions on the impact of disasters on blood donation rates.

Subjective donor deferral as a tool for increased blood transfusion safety: A cross-sectional observational study

OBJECTIVES

This study aims at evaluating whether subjective donor deferral (SDD) has the potential for increasing blood transfusion safety.

BACKGROUND

Appropriate donor selection via clinical and serologic screening is necessary to prevent transfusion-transmissible infections (TTIs). One additional strategy adopted by some Brazilian blood transfusion centers (BTCs) is the rejection of a donation by the pre-donation interviewer based on subjective factors.

METHODS/MATERIALS

We conducted a STROBE-guided cross-sectional study including 105 005 prospective donors who presented to our BTC between 1 January 2013, and 31 December 2015. Donors were evaluated for age, gender, education level, donation type and history, confidential unit exclusion, SDD, and results of serologic screening for TTIs.

RESULTS

Even after controlling for potential confounding variables, subjectively deferred donors were more likely to have at least one reactive serology in the standard screening (OR: 2.80; 95% CI: 2.13-3.69; P < .001). They also had a higher risk for testing positive for syphilis (OR: 4.47; 95% CI: 3.05-6.55; P < .001), hepatitis B (OR: 5.69; 95% CI: 2.48-13.08; P < .001), and HIV (OR: 6.14; 95% CI: 3.22-11.69; P < .001).

CONCLUSIONS

Routine implementation of SDD in donor selection may be an effective additional measure to avoid TTIs, highlighting the importance of interviewer experience, perspicacity, and face-to-face contact with donors for blood safety assurance.

Prediction and impact of personalized donation intervals

BACKGROUND AND OBJECTIVES

Deferral of blood donors due to low haemoglobin (Hb) is demotivating to donors, can be a sign for developing anaemia and incurs costs for blood establishments. The prediction of Hb deferral has been shown to be feasible in a number of studies based on demographic, Hb measurement and donation history data. The aim of this paper is to evaluate how state-of-the-art computational prediction tools can facilitate nationwide personalized donation intervals.

MATERIALS AND METHODS

Using donation history data from the last 20 years in Finland, FinDonor blood donor cohort data and blood service Biobank genotyping data, we built linear and non-linear predictors of Hb deferral. Based on financial data from the Finnish Red Cross Blood Service, we then estimated the economic impacts of deploying such predictors.

RESULTS

We discovered that while linear predictors generally predict Hb relatively well, they have difficulties in predicting low Hb values. Overall, we found that non-linear or linear predictors with or without genetic data performed only slightly better than a simple cutoff based on previous Hb. However, if any of our deferral prediction methods are used to assign temporary prolongations of donation intervals for females, then our calculations indicate cost savings while maintaining the blood supply.

CONCLUSION

We find that even though the prediction accuracy is not very high, the actual use of any of our predictors in blood collection is still likely to bring benefits to blood donors and blood establishments alike.

Active seeking of post-donation information to minimize a potential threat to transfusion safety: A pilot programme in the context of the COVID-19 pandemic

BACKGROUND AND OBJECTIVES

Early in the pandemic, the transmissibility of coronavirus disease-19 (COVID-19) by transfusion was unknown. We piloted a systematic, post-donation outreach programme to contact blood donors and inquired about symptoms post-donation.

MATERIALS AND METHODS

Persons who donated on on May 1 and 2, 2020 were contacted 3 days post-donation, by phone to assess COVID-19-related symptoms. Half of the donors were administered a short questionnaire, consisting of only three questions. Others were questioned using a longer, more specific questionnaire. If symptoms were reported, products were quarantined until donors were contacted again by a trained nurse who more thoroughly assessed the likelihood of COVID-19. Blood products were withdrawn if symptoms indicative of COVID-19 were identified.

RESULTS

Of 654 donors, 609 (93.1%) were successfully contacted. Of 310 donors who answered the short questionnaire and 299 who answered the long questionnaire, 19 (6.1%) and 8 (2.7%) had one or more symptoms, respectively. Based on the nurses' assessment, two donations (0.3%) had to be withdrawn.

CONCLUSION

These results suggest that actively seeking post-donation information might be feasible to mitigate emerging, unqualified transfusion risks.

The new donor vigilance system in Denmark reveals regional differences in adverse reactions supposedly caused by variation in the registration

BACKGROUND AND OBJECTIVES

In recent years, there has been an increased focus among blood bank professionals on the health and safety of blood donors. In 2019, the Danish Haemovigilance Committee designed a national donor vigilance system to improve the registration of adverse reactions (AR) in blood donors. The new donor vigilance system was implemented on 1 January 2020 and we here present the results from the first year of registration.

MATERIALS AND METHODS

AR categories, severity level and imputability score were defined based on the definitions from the International Society of Blood Transfusion, AABB and the European Commission directive 2005/61/EC, respectively.

RESULTS

Across all severity levels, AR in Danish blood donors were found to be rare (1498 per 100,000 donations). Only 0.2% of the registered reactions were classified as serious (2.7 per 100,000 donations). Large regional differences were seen in the registration of citrate reactions and haematomas.

CONCLUSION

Significant differences across regions in what to categorize as an AR were persistent even when including a severity score in the reporting. The Danish Haemovigilance Committee will commence a national work to align the definitions but suggests that this matter is raised to an international level as part of the current work to agree upon definitions for assessment of donor AR.

Use of plerixafor to mobilize haematopoietic progenitor cells in healthy donors

Increased transplant activity calls for improved stem cell collection, especially when peripheral blood is the preferred source of haematopoietic progenitor cells (HPCs). Plerixafor is a bicyclam molecule that mobilizes CD34+ cells by reversibly disrupting CXCR4-CXCL12-supported HPC retention. Plerixafor is given with granulocyte colony-stimulating factor (G-CSF) to help harvest autologous CD34+ cells for transplantation when mobilization with G-CSF fails. Mobilization protocols with the same doses of plerixafor and G-CSF have been used off-label in healthy allogeneic donors, with equal success and scarce side effects, both in adult and paediatric patients. Plerixafor has also been used as a sole mobilization agent. Plerixafor alone or coupled with G-CSF might lead to harvesting distinct cellular populations conferring improved engraftment properties and increased survival. Those characteristics might make plerixafor an especially attractive mobilization agent, particularly for non-related donations. However, available data are limited, and long-term follow-up is needed to clarify the best scenario for using plerixafor with or without G-CSF in healthy donors. In this review, we will summarize the evidence supporting this practice, highlighting the practical aspects and providing clues for an expanded use of plerixafor.

Low ferritin levels appear to be associated with worsened health in male repeat blood donors

BACKGROUND AND OBJECTIVES

Frequent blood donation depletes iron stores of blood donors. Iron depletion may lead to anaemia, but the health effects of iron depletion without anaemia in healthy blood donors are not well understood. We studied in the FinDonor cohort whether worsening of self-rated health of blood donors during the study period was associated with biomarkers for iron levels or other self-reported changes in lifestyle.

MATERIALS AND METHODS

We included 1416 participants from the cohort who answered an 89-item questionnaire on their health and lifestyle during their enrolment visit and again at the end of the study. We performed multivariate logistic regression to test if blood donation-related factors affected the probability of reporting worsened health. To set these findings into a more holistic context of health, we subsequently analysed all other questionnaire items with a data-driven exploratory analysis.

RESULTS

We found that donation frequency in men and post-menopausal women and ferritin level only in men was associated negatively with worsened health between questionnaires. In the exploratory analysis, stable physical condition was the only questionnaire item that was associated negatively with worsened health in both women and men.

CONCLUSION

Our results suggest that low ferritin level is associated with worsened health even in non-anaemic repeat donors, although we find that when health is analysed more holistically, ferritin and other factors primarily related to blood donation lose their importance.

Characterization of health issues in young first-time blood donors

BACKGROUND AND OBJECTIVES

Blood donors, especially young donors, are considered a healthy segment of the population. We sought to identify medical issues that may warrant medical referral in young first-time blood donors.

MATERIALS AND METHODS

A retrospective cohort study was performed in first-time donors ages 16-22 who presented in a system of nineteen regional United States blood centres over 10 years. Donor health attributes characterized include body mass index, blood pressure, total cholesterol and pre-donation haemoglobin. Using standardized definitions, overweight and obese body mass, hypertension, elevated cholesterol and anaemia were identified and characterized in this donor population.

RESULTS

Among 825 041 young first-time donors presenting between January 2009 and December 2018, with available measurements, 46·9% were either overweight or obese, 59·8% demonstrated high blood pressure (22·2% elevated blood pressure, 37·6% stage 1 or 2 hypertension), elevated cholesterol was identified among 6·3% of males and 8·8% of females, and anaemia was present in 3·5% of males and 5·2% of females. During the study period, all unfavourable health outcomes significantly increased in prevalence (P < 0·0001) when comparing 2009 vs. 2018 rates.

CONCLUSION

Elevated weight and obesity are common in young first-time allogeneic United States blood donors, with fewer donors having elevated total cholesterol or anaemia. Such medical issues may have significant importance for future health and well-being as well as continued donor eligibility. Blood centres may be able to help support the identification and mitigation of important medical issues in donors and provide a public health benefit.

Complications of blood donation reported to haemovigilance systems: analysis of eleven years of international surveillance

BACKGROUND AND OBJECTIVES

The International Haemovigilance Network collects aggregate data on complications of blood donation from member haemovigilance systems (HVS). We analysed the data collected in 2006-2016 in order to learn from it and consider future improvements.

MATERIALS AND METHODS

National HVS entered annual data on donation complications and on annual whole blood and apheresis donations in the 'ISTARE' (International Surveillance of Transfusion Adverse Reactions and Events) online database. We calculated national and aggregate donation complication rates.

RESULTS

Twenty-four HVS provided data for 138 country years (CY; median 7 CY, IQR 2-8), covering 155 M donations. The overall complication rate was 6·3/1000 donations and the median country rate 3·2/1000 (IQR 1·1-10·1). Overall and severe complication rates varied considerably between HVS. Vasovagal reactions (VVR) were most commonly reported: 4·6/1000 donations, median country rate 3·1/1000 donations (IQR 0·6-7·7). Rare complications included generalized allergic reaction (0·10/100 000) and major blood vessel injury (category available since 2015; 0·12/100 000). Eighteen HVS reported complications of whole blood donation (WBD) and apheresis separately (89 CY, 101·6 M WBD and 26·3 M apheresis donations). The median country VVR rate was 3·4/1000 WBD (IQR 1·0-9·1) and 1·5/1000 apheresis donations (1·0-4·2). Rates of venepuncture-related complications tended to be higher for apheresis: the median country rate of reported haematomas was 0·39/1000 WBD (IQR 0·31-1·2) vs. 4·2/1000 apheresis donations (0·69-5·6).

CONCLUSION

International reporting allows HVS to study rates of blood donation complications and capture information about very rare events. The present variability of reporting and severity assessment hampers comparisons between HVS and requires further work.

How donor selection criteria can be evaluated with limited scientific evidence: lessons learned from the TRANSPOSE project

BACKGROUND AND OBJECTIVE

Donor selection criteria (DSC) are a vital link in the chain of supply of Substances of Human Origin (SoHO) but are also subject to controversy and differences of opinion. Traditionally, DSC have been based on application of the precautionary principle.

MATERIALS AND METHODS

From 2017 to 2020, TRANSPOSE (TRANSfusion and transplantation PrOtection and SElection of donors), a European research project, aimed to identify discrepancies between current DSC by proposing a standardized risk assessment method for all SoHO (solid organs excluded) and all levels of evidence.

RESULTS

The current DSC were assessed using a modified risk assessment method based on the Alliance of Blood Operators' Risk-based decision-making framework for blood safety. It was found that with limited or diverging scientific evidence, it was difficult to reach consensus and an international standardized method for decision-making was lacking. Furthermore, participants found it hard to disregard their local guidelines when providing expert opinion, which resulted in substantial influence on the consensus-based decision-making process.

CONCLUSIONS

While the field of donation-safety research is expanding rapidly, there is an urgent need to formalize the decision-making process regarding DSC. This includes the need for standardized methods to increase transparency in the international decision-making process and to ensure that this is performed consistently. Our framework provides an easy-to-implement approach for standardizing risk assessments, especially in the context of limited scientific evidence.

Putting the spotlight on donation-related risks and donor safety - are we succeeding in protecting donors?

BACKGROUND AND OBJECTIVE

The European consortium project TRANSPOSE (TRANSfusion and transplantation: PrOtection and SElection of donors) aimed to assess and evaluate the risks to donors of Substances of Human Origin (SoHO), and to identify gaps between current donor vigilance systems and perceived risks.

MATERIALS AND METHODS

National and local data from participating organizations on serious and non-serious adverse reactions in donors were collected from 2014 to 2017. Following this, a survey was performed among participants to identify risks not included in the data sets. Finally, participants rated the risks according to severity, level of evidence and prevalence.

RESULTS

Significant discrepancies between anticipated donor risks and the collected data were found. Furthermore, many participants reported that national data on adverse reactions in donors of stem cells, gametes, embryos and tissues were not routinely collected and/or available.

CONCLUSIONS

These findings indicate that there is a need to further develop and standardize donor vigilance in Europe and to include long-term risks to donors, which are currently underreported, ensuring donor health and securing the future supply of SoHO.

Effectiveness of the post-donation instruction sheet in conveying information to repeat blood donors

BACKGROUND AND OBJECTIVES

Written materials are commonly used for blood donor education. While pre-donation materials are largely standardized across US blood collectors, the post-donation instruction sheet (PDIS) is variable and few have been evaluated to assess their effectiveness in conveying information as reflected by donors' attention, understanding and recall.

METHODS

An online survey was sent to two independent randomly selected samples of repeat donors, before and after implementation of the enhanced PDIS.

RESULTS

A total of 12 935 blood donors responded (33·4% response rate). Most donors did not read the entire PDIS - 34·3% less than half and 18·1% none. Of the 10 593 donors who reported reading any of the PDIS, 97·8% recalled instructions about immediate post-donation care (e.g. extra fluids/no exercise) and 88·0% to call with questions/problems. However, only 50·1% remembered reading about what to do if you felt dizzy/faint and 32·4% about care for bruises. Recall rates in every area were similar before and after revision; except after revision, more donors remembered seeing information about maintaining iron and fewer that you should call the centre back with additional health information (P < 0·0001).

DISCUSSION

Blood collectors rely heavily on written materials to convey instructions to donors. Most repeat donors do not read the entire PDIS, and many do not recall important information. More donors recalled seeing how to maintain iron with the enhanced PDIS, but recall deficits remained on how to care for adverse reactions. Written materials alone appear to be insufficient to educate some donors about new or updated topics.

Venous sample is superior to repeated skin-prick testing in blood donor haemoglobin second-line screening

BACKGROUND

Blood donor haemoglobin concentration (Hb) is commonly measured from a skin-prick sample. However, the skin-prick sample is prone to preanalytical error and variation, which may lead to false deferrals due to low Hb.

STUDY DESIGN AND METHODS

We assessed the efficacy of two second-line screening models for the evaluation of blood donors failing the initial skin-prick test. In the venous model (n = 305), Hb was measured from a venous sample at the donation site. In the skin-prick model (n = 331), two additional skin-prick samples were measured. All on-site Hb measurements were performed with HemoCue Hb201+ (HemoCue AB) point-of-care (POC) device. Hb in the venous samples was later also determined with a hematology analyzer (Sysmex XN, Sysmex Co.) to obtain the donor's correct Hb. A questionnaire evaluated Blood Service nurses' preferences regarding Hb assessment.

RESULTS

Significantly less donors were deferred from donation with venous model (40%) than with skin-prick model (51%; chi-square test P = 0·004). Only two donors (0·7%) were incorrectly accepted in the venous model. Further, Blood Service nurses preferred venous model over skin-prick model. After the study, the venous model was implemented nationwide, and in the first two months after implementation, the deferral rate due to low Hb decreased from 2·7% to 1·9%.

CONCLUSION

A venous sample for blood donor Hb second-line screening significantly decreased low Hb deferrals compared to repeated skin-prick testing without compromising donor safety. Valuable donations can be recovered by implementing a practical second-line screening model based on venous sampling.

Is sexual risk behaviour associated with an increased risk of transfusion-transmissible infections in blood donors from Western and Pacific countries? A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

The donor medical questionnaire is designed to aid blood establishments in supporting a safe blood supply. According to blood donor deferral policies, sexual risk behaviour (SRB) leads to a (temporary) deferral from blood donation. This systematic review aimed to scientifically underpin these policies by identifying the best available evidence on the association between SRB and the risk of transfusion transmissible infections (TTIs).

MATERIALS & METHODS

Studies from three databases investigating the link between SRB (excluding men who have sex with men (MSM)) and TTIs (HBV, HCV, HIV, Treponema pallidum) in donors from Western and Pacific countries were obtained and assessed on eligibility by two reviewers independently. The association between SRB and TTIs was expressed by calculating pooled effect measures via meta-analyses. The GRADE methodology (Grades of Recommendation, Assessment, Development and Evaluation) was used to assess the quality of evidence.

RESULTS

We identified 3750 references and finally included 15 observational studies. Meta-analyses showed that there is a significant (P < 0·05) positive association between the following SRB and HBV and/or HCV infection: having sex with an intravenous drug user (high-certainty evidence), receiving money or goods for sex (moderate-high certainty evidence), having a sex partner with hepatitis/HIV (moderate-certainty evidence) and paid for sex or anal sex (low-certainty evidence).

CONCLUSION

Sexual risk behaviour (including having sex with an intravenous drug user, receiving money or goods for sex or having a sex partner with hepatitis/HIV) is probably associated with an increased risk of HBV/HCV infection in blood donors from Western and Pacific countries.

Informed consent for whole blood donation

BACKGROUND AND OBJECTIVES

It is recognized that blood transfusion services have an ethical duty to obtain informed consent from their voluntary, non-remunerated donors. This right was most recently affirmed by the 2017 revision of the International Society of Blood Transfusion (ISBT) Code of Ethics. However, the constituent elements necessary to adequately inform such consent have not been definitively established.

MATERIALS AND METHODS

This review evaluates the historical background to informed consent in medicine and as it has been applied to blood donation. The question of what information should be disclosed is then considered with regard to existing statutory requirements in both the United States and EU as well guidance from relevant international organizations. The emerging ethical issues around repurposing of donated blood for sale as recovered plasma and use in research are included in this analysis.

RESULTS

A reasonable basis is found in the literature to advocate that valid informed consent of blood donors should encompass: the donation process itself and potential adverse effects, the need for pre-donation transfusion-transmissible infection (TTI) screening, potential non-transfusion uses of derived products, requirements to obtain and store personal information, the consequences that non-disclosure of such information may have for both the donor and the recipient and reassurance as to the confidentiality of this information.

CONCLUSION

Informed consent is a key component of the duty of care between a blood service and its donor. We identify essential elements that should be present for such consent to be considered valid.

Is there a risk of transfusion-transmissible infections after percutaneous needle treatments in blood donors? A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

The donor medical questionnaire identifies a blood donor's history of known blood safety risks. Current Australian, Canadian, European and USA legislation temporarily defers blood donors who received different percutaneous needle treatments (i.e. tattooing, acupuncture and piercing) from blood donation. This systematic review aimed to scientifically underpin these deferrals by identifying the best available evidence on the association between percutaneous needle treatments and the risk of transfusion-transmissible infections (TTIs).

MATERIALS AND METHODS

Studies from three databases investigating the link between percutaneous needle treatments and TTIs (HBV, HCV and HIV infection) in blood donors were retained and assessed on eligibility by two reviewers independently. The association between percutaneous needle treatments and TTIs was expressed by conducting meta-analyses and calculating pooled effect measures (odds ratios (ORs) and 95% CIs). The GRADE methodology (Grades of Recommendation, Assessment, Development and Evaluation) was used to assess the quality of evidence.

RESULTS

We identified 1242 references and finally included 21 observational studies. Twenty studies assessed the link between percutaneous needle treatments and HCV infection and found that blood donors receiving these treatments had an increased risk of HCV infection (tattooing: pooled OR 5·28, 95% CI [4·33, 6·44], P < 0·00001 (low-quality evidence); acupuncture: pooled OR 1·56, 95% CI [1·17, 2·08], P = 0·03 (very low-quality evidence); and piercing: pooled OR 3·25, 95% CI [1·68, 6·30], P = 0·0005 (low-quality evidence)).

CONCLUSION

Percutaneous needle treatments may be associated with an increased HCV infection risk. Further high-quality studies are required to formulate stronger evidence-based recommendations on percutaneous needle treatments as a blood donor deferral criterion.

Recipient sepsis caused by Lactococcus garvieae contamination of platelets from a donor with colon cancer

Lactococcus garvieae is a well-known fish pathogen that has low virulence in humans and is rarely isolated from the blood cultures of endocarditis patients. We describe herein the first reported case of transfusion-transmitted L. garvieae sepsis caused by a contaminated platelet concentrate from a donor who consumed raw octopus before blood donation. Retrospective examination of the laboratory results of the index donor revealed that his haemoglobin levels had been steadily decreasing, which led to the detection of a latent colon cancer. The donors with colon lesions involving a latent cancer may relate an asymptomatic bacteremia.

Donor InSight: characteristics and representativeness of a Dutch cohort study on blood and plasma donors

Background and Objectives

More insight into donor health and behaviour may contribute to more efficient and focused strategies regarding donor care and management. Donor InSight (DIS) is a Dutch cohort study of blood and plasma donors. We aimed to outline the objectives and methods of DIS, describe the cohort, and compare it to the active Dutch donor population.

Materials and Methods

In 2007‐2009 (DIS‐I, n = 31 338) and 2012‐2013 (DIS‐II, 34 826, of whom 22 132 also participated in DIS‐I) questionnaire data on demographics, donation, lifestyle, family composition, health and disease were collected. A second follow‐up (DIS‐III, n = 3046), including donors with differing haemoglobin trajectories, was completed in 2015‐2016. DIS‐III includes data on genetic determinants, iron and red cell indices. Representativeness of the DIS‐I sample for the entire Dutch donor population was assessed by comparing characteristics of both.

Results

Donor InSight was initially set up because of a need for more detailed information and evidence as a basis for decision‐making in blood banks. DIS‐I sample is comparable to the total Dutch donor population in terms of age, body mass index, haemoglobin level, blood pressure, blood type and donation behaviour.

Conclusion

Donor InSight is a cohort study representative of the Dutch donor population. It provides evidence to support evidence‐based decision making.

Failure of bacterial screening to detect Staphylococcus aureus: the English experience of donor follow-up

BACKGROUND AND OBJECTIVES

Between February 2011 and December 2016, over 1·6 million platelet units, 36% pooled platelets, underwent bacterial screening prior to issue. Contamination rates for apheresis and pooled platelets were 0·02% and 0·07%, respectively. Staphylococcus aureus accounted for 21 contaminations, including four pooled platelets, one confirmed transfusion-transmitted infection (TTI) and three 'near-miss' incidents detected on visual inspection which were negative on screening. We describe follow-up investigations of 16 donors for skin carriage of S. aureus and molecular characterisation of donor and pack isolates.

MATERIALS AND METHODS

Units were screened by the BacT/ALERT 3D detection system. Contributing donors were interviewed and consent requested for skin and nasal swabbing. S. aureus isolates were referred for spa gene type and DNA macrorestriction profile to determine identity between carriage strains and packs.

RESULTS

Donors of 10 apheresis and two pooled packs screen positive for S. aureus were confirmed as the source of contamination; seven had a history of skin conditions, predominantly eczema; 11 were nasal carriers. The 'near-miss' incidents were associated with apheresis donors, two donors harboured strains indistinguishable from the pack strain. The TTI was due to a screen-negative pooled unit, and a nasal isolate of one donor was indistinguishable from that in the unit.

CONCLUSION

Staphylococcus aureus contamination is rare but potentially harmful in platelet units. Donor isolates showed almost universal correspondence in molecular type with pack isolates, thus confirming the source of contamination. The importance of visual inspection of packs prior to transfusion is underlined by the 'near-miss' incidents.

Epidemiology of donors and recipients: lessons from the SCANDAT database

With the development of several 'vein-to-vein' databases, which capture data on the entire donor-recipient continuum and link this data to health outcomes, there has been an increasing number of studies investigating the health effects of all aspects of the practice of transfusion medicine. The Scandinavian Donations and Transfusions (SCANDAT) database is one of several such databases, which includes all electronically available data on blood donors, donations and transfusions since the late 1960s in Sweden and the early 1980s in Denmark. The SCANDAT database has been used to characterise disease occurrence among blood donors and transfused patients, as well as to investigate possible health effects of blood donations, aspects of transfusion care and possible transfusion transmission of disease. Recent publications include studies on recipient mortality associated with the storage lesion, studies on the effects of donor demographics on patient mortality and health effects of frequent blood donation. Although this research approach is clearly very powerful, the appropriate analysis of such real-world data is complex and requires close methodological attention. The purpose of this review is to present some of the research conducted within the SCANDAT collaboration. We hope more international collaboration may help improve our understanding of the important remaining questions about donor and recipient health.

QTc prolongation during peripheral stem cell apheresis in healthy volunteers

BACKGROUND AND AIM

Today, voluntary donation of peripheral blood stem cells by healthy donors for allogeneic hemopoietic cell transplantation is common worldwide. Such donations are associated with small but measurable risks of morbidity and mortality. Most complications are associated with citrate infusion during cell collection. We studied the effects of citrate infusion on the QTc and other vital parameters during and after peripheral stem cell apheresis in volunteers.

METHOD

To ensure that donors were healthy, screening included taking a detailed medical history, physical examination, and laboratory measurements of plasma calcium and magnesium. Corrected QT (QTc) values were assessed using a 12-lead electrocardiographic platform that derived QTc values automatically.

RESULTS

In all, 141 apheresis procedures were performed. The mean QTc values at baseline, at 2 and 4 h during the procedure, and at 30 min after the procedure, were 347.6 ± 59.5, 349.9 ± 52.8, 391.8 ± 54.0, and 404.8 ± 59.2 ms, respectively. The baseline and 2 h QTcs did not differ significantly, but the baseline QTc did differ significantly from the 4 h and 30 min after the procedure values. The plasma levels of calcium and magnesium did not significantly differ before and after the procedure.

CONCLUSION

QTc prolongation may develop during leukopheresis, particularly if the procedure takes more than 2 h. Thus, to enhance donor safety, QTc measurement should be standard for all donors. In addition, any family history of sudden death should be noted, to prevent the development of possible fatal arrhythmia in susceptible donors.

Predonation finger lancet punctures: a potential risk factor for interdonor pathogen transmission in the blood donor clinic

BACKGROUND AND OBJECTIVES

Point-of-care testing using capillary blood from a finger prick is widely used for predonation haemoglobin testing of blood donors. It is common practice to cover the finger prick with a cotton swab and to instruct the donor to press for few minutes. The finger prick can cause blood contamination of surfaces in contact with the lanced finger, especially door handles, risking infectious disease transmission, particularly if another person touching the contaminated door handle also has a punctured fingertip.

MATERIALS AND METHODS

First, we investigated contamination by blood (benzidine assay) of the door handles of our blood donor clinic, taking 175 samples 3 h after opening of the donation centre (baseline). We then introduced band-aids to cover the finger prick and started an information campaign using educational flyers to sensitize blood donors and staff to this problem (period-1). Thereafter, the staff was instructed to use the non-dominant hand for blood sampling and mandated to replace any discarded band-aids immediately (period-2).

RESULTS

At baseline, 82% of the nurse room door handles showed contamination with blood. This decreased somewhat (10-40%) after period-1, but only after immediate mandatory band-aid replacement on any donor finger without a band-aid (period-2), no further blood contaminations were detected.

CONCLUSION

Blood contamination of shared surfaces can occur after finger prick for capillary blood sampling. Application of a band-aid and use of the non-dominant hand for fingertip incision are easy to apply and effective in reducing this iatrogenic health hazard.

Development of standard definitions for surveillance of complications related to blood donation

Standard definitions of donor reactions allow each blood establishment to monitor donor adverse events and compare with other organizations to develop best practices. The ISBT Haemovigilance Working Party leads a multi-organizational effort to update the 2008 ISBT standard for surveillance of complications related to blood donation. Revised definitions have been developed and endorsed by the ISBT, AABB, International Haemovigilance Network (IHN) and other international organizations.