Regional
Building the evidence base to protect plasma donors: Why Europe needs a large, multicentre randomised controlled trial on plasma donation frequency
Christian Erikstrup
Department of Clinical Medicine, Aarhus University, Aarhus Denmark
Peter O’Leary
European Blood Alliance, Brussels, Belgium.
Katja van den Hurk
Sanquin / Amsterdam UMC, Amsterdam, Netherlands
The growing plasma imperative
Worldwide, the demand for plasma-derived medicinal products is rising steeply. To keep pace, public blood centres in many European countries are expanding plasmapheresis programmes and recruiting more donors, while also encouraging existing donors to donate more often. Yet the scientific foundation for setting safe upper limits on donation frequency remains surprisingly thin.
The EU-funded project Strengthening voluntary non-remunerated plasma collection capacity in Europe (SUPPLY) recently reviewed the literature on frequent plasmapheresis. Only a few studies met basic standards of rigour, and none were large enough or long enough to capture serious outcomes. The small-scale randomised controlled trials conducted thus far were not designed to assess clinical endpoints or long-term effects. Observational studies are often compromised by the “Healthy Donor Effect”, where healthier individuals are more likely to donate and to continue donating for longer and/or at higher frequencies, potentially masking the true impact of frequent donations on health. Meanwhile, in the United States, authorities continue to allow up to 104 donations per year, despite insufficient evidence to confirm the safety of such practices. The absence of high-quality evidence prevents the establishment of safe donation thresholds, thereby posing a risk to donor health.
According to the European Directorate for the Quality of Medicines & HealthCare’s Guide to the preparation, use and quality assurance of blood components (Blood Guide), a maximum of two donations per month is recommended, with donations at weekly intervals allowed only if enhanced monitoring is in place. However, even the safety of donating every two weeks is not well established. A survey conducted within SUPPLY also showed that current national guidelines diverge widely. Without solid evidence, raising donation frequency may inadvertently expose donors to unforeseen risks. As guardians of donor health, we must do better.
According to the European Directorate for the Quality of Medicines & HealthCare’s Guide to the preparation, use and quality assurance of blood components (Blood Guide), a maximum of two donations per month is recommended, with donations at weekly intervals allowed only if enhanced monitoring is in place. However, even the safety of donating every two weeks is not well established. A survey conducted within SUPPLY also showed that current national guidelines diverge widely. Without solid evidence, raising donation frequency may inadvertently expose donors to unforeseen risks. As guardians of donor health, we must do better.
Why a continent-wide RCT is essential
We need a trial large enough and with sufficient follow-up to capture not only biochemical changes, such as declines in immunoglobulins, but also harder clinical endpoints. Such a geographically diverse, multicentre randomised controlled trial (RCT) would:
- Define a truly safe ceiling for donation frequency by tracking immunoglobulin, plasma-protein and haemoglobin levels, including in those who stopped or were deferred from donating, as well as donors’ self-reported wellbeing.
- Detect clinical outcomes, such as infections facilitated by the decline in immunoglobulins, and other clinical endpoints that smaller studies inevitably miss.
- Provide generalisable evidence for future guidelines. Strengthen public trust by demonstrating an unwavering commitment to evidence-based safeguards for donors.
A call to action Within the ISBT community we excel when we collaborate. A pan-European RCT on plasmapheresis frequency is our next collective challenge.
