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.

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.

The impact of analytical variation of hemoglobin measurement on blood donors' hemoglobin and deferral rates.

BACKGROUND: Donors' hemoglobin (Hb) level must be tested before blood donation. Low Hb is the leading reason for donor deferral. Many donor-related and external factors associated with low Hb are known, but no studies have been conducted concerning the effects of analytical variation on donor Hb measurements and deferrals. STUDY DESIGN AND METHODS: The effects of donors' age, the seasonal and daily distribution of donations, and batch-to-batch variation in HemoCue Hb 201+ cuvettes on donors' capillary Hb (cHb) measurements and deferrals were analyzed for more than 1.7 million donor visits in 2010 to 2016 at a national blood establishment. Furthermore, approximately 3.1 million cHb measurements from the years 2000 to 2009 were included in analyses to correlate measured cHb value and Hb deferral rate. RESULTS: A significant correlation between the mean annual cHb and Hb deferral rate was observed in both women and men. The season of the donation was the strongest explanatory factor for the monthly variation of predonation cHb (explaining 25 and 31% of the variation in women and men, respectively). Batch-to-batch variation in HemoCue cuvettes explained 6.8% of monthly variation in women and 7.4% in men. Monthly changes in donors' age distribution explained 2.5% of monthly variation in women and 2.4% in men. CONCLUSION: Small and, in most clinical settings, negligible analytical variation in Hb measurement methods can have significant consequences when used for Hb screening of blood donors. This should be minimized by using methods in which analytical variation is under control and kept as low as possible.