Safety and protection of plasma donors: A scoping review and evidence gap map

Abstract

Background and ObjectivesAs part of a large‐scale project to safely increase plasma collection in Europe, the current scoping review identifies the existing evidence (gaps) on adverse events (AEs) and other health effects in plasmapheresis donors, as well as factors that may be associated with such events/effects.Materials and MethodsWe searched six databases and three registries. Study characteristics (publication type, language, study design, population, outcomes, associated factors, time of assessment, duration of follow‐up, number and frequency of donations, convalescent plasma [y/n], setting and location) were synthesized narratively and in an interactive evidence gap map (EGM).ResultsNinety‐four research articles and five registrations were identified. Around 90% were observational studies (57 controlled and 33 uncontrolled), and most of them were performed in Europe (55%) or the United States (20%). Factors studied in association with donor health included donor characteristics (e.g., sex, age) (n = 27), cumulative number of donations (n = 21), donation frequency (n = 11), plasma collection device or programme (n = 11), donor status (first time vs. repeat) (n = 10), donation volume per session (n = 8), time in donation programme (n = 3), preventive measures (n = 2) or other (n = 9).ConclusionThe current scoping review provides an accessible tool for researchers and policymakers to identify the available evidence (gaps) concerning plasmapheresis donation safety. Controlled prospective studies with long‐term donor follow‐up are scarce. Furthermore, additional experimental studies comparing the health effects of different donation frequencies are required to inform a safe upper limit for donation frequency.

Balancing donor health and plasma collection: a systematic review of the impact of plasmapheresis frequency

“…For the initial scoping review [5], 17810 records were identified from databases and registers. After removal of duplicates, 7209 records were screened, resulting in the inclusion of 97 papers and registrations.…”

“…We did not include studies that compared the health of first-time or new donors to that of repeat donors [42,43] or investigated health effects in donors with different cumulative numbers of plasma donations [44,45]. We did, however, identify these studies systematically in the framework of our scoping review [5]. Several retrospective studies found no effect of the number of donations made in the previous 12 months on iron levels, protein levels, immunity markers, red cell and iron metabolism, cardiovascular risk, or risk of (osteoporotic) fractures [41,46,47].…”

“…A scoping review [5] preceded the current systematic review. For this scoping review, an initial search for eligible studies was performed on 10 October 2022.…”

Very‐high frequency plasmapheresis and donor health–absence of evidence is not equal to evidence of absence

“…To avoid selective outcome reporting, evidence on donor-reported or staff-reported adverse events, and objectively measured physiological parameters, hematological parameters, iron metabolism parameters, coagulation factors, and protein levels should also be considered when formulating overall conclusions. 10 For example, evidence from a RCT (submitted for publication), 11 and two cohort studies 12,13 showed that very-high frequency plasma donation (up to two times per week) may result in significant and clinically relevant reductions in IgG levels. Moreover, 12.4% of donors in the first SIPLA study, which was conducted in Germany, were deferred because of low levels of IgG investigating the impact of intensive plasmapheresis with up to 60 donations per year.…”

“…We agree that self‐perceived health (via the SF‐36 4 ) is important but it is only one indicator/dimension of donor health. To avoid selective outcome reporting, evidence on donor‐reported or staff‐reported adverse events, and objectively measured physiological parameters, hematological parameters, iron metabolism parameters, coagulation factors, and protein levels should also be considered when formulating overall conclusions 10 . For example, evidence from a RCT (submitted for publication), 11 and two cohort studies 12,13 showed that very‐high frequency plasma donation (up to two times per week) may result in significant and clinically relevant reductions in IgG levels.…”