Platelet Transfusion Outcomes Linked to Blood Donor & Product Traits?

Purpose in Exploring Platelet Transfusion Outcomes

Investigators in Blood Advances sought to, “understand the impact of blood donor and product characteristics on platelet transfusion outcomes.” Specifically, the paper described how the authors, “leverage[d] a vein-to-vein database of platelet transfusions to evaluate associations between blood donor and product processing characteristics [with] posttransfusion platelet increments and subsequent red blood cell (RBC) transfusion requirements.” The researchers performed a retrospective cohort study of electronic health record data which included, “blood donor demographics (e.g., age, sex, BMI, ABO/Rh), collection date, platelet processing characteristics (e.g., number of platelet splits, pathogen reduction, storage in platelet additive solution (PAS), storage duration, and irradiation) [for] each platelet unit. All [were] stored at room temperature, and all split units met the minimal approved dose of 300 × 10⁹ platelets per unit.” The study took place from June 2020 to March 2022 and included inpatients and outpatients, “who received a single unit of platelets during ≥1 transfusion episodes at 21 medical centers.” The investigators considered a platelet transfusion episode to be, “any single unit platelet transfusion linked to a donor with both pretransfusion and posttransfusion platelet counts.” The primary outcome was, “platelet increment of >20 × 10⁹/L based on previous studies of platelet transfusion. Secondary outcomes were the incidence and number of RBC transfusions in the 24 hours after platelet transfusion.”

Findings

The study found, “increasing donor BMI, platelet unit concentration, and high SARS-CoV-2 anti-N Ab levels were associated with higher odds of a platelet increment of >20 × 10⁹/L. Conversely, pathogen reduction, storage in PAS, and prolonged storage were associated with reduced odds of achieving increased platelet increments. Findings complementary to those of platelet increments were that increasing donor BMI and high SARS-CoV-2 anti-N Ab levels were associated with lower odds of subsequent RBC transfusion and that pathogen reduction was associated with increased odds of RBC transfusion.” The researchers explained that the results suggest that, “alterations of platelet function in patients with obesity or previous SARS-CoV-2 infection affect outcomes in the recipients of platelet products from donors with these characteristics.” They also discovered that, “platelet transfusions from donors with high anti-N Ab levels were associated with increased platelet increments and reductions in 24-hour RBC transfusion requirements. Increased anti-N Ab levels have been correlated with the COVID-19 severity and recognized to rise with SARS-CoV-2 reinfection,” they noted. Additionally, the investigators found that pathogen reduction and storage in PAS, “were associated with reduced odds of posttransfusion platelet increments of >20 × 10⁹/L. Prolonged storage of platelets was also associated with reduced platelet increments.

[Despite] reduced platelet increments, [they discovered] that prolonged storage and use of PAS did not affect the odds of 24-hour RBC transfusion events. [Splitting] platelet donations into three or four units did result in lower platelet increments but did not affect the odds of 24-hour RBC transfusion events.” The explained that, “[t]hese findings support that the current practice of splitting platelet units to ensure the availability and efficient use of blood products is not compromising patient outcomes. Collectively, [the] results also suggest that donor biology and processing factors, rather than platelet dose alone, may be more relevant to platelet quality and outcomes. [Although the researchers] did see differences in posttransfusion platelet increments in ABO-mismatched donors and recipients, this finding did not translate to differences in 24-hour RBC requirements.”

Conclusion

The paper concluded that, “[p]roinflammatory conditions such as donor obesity and previous SARS-CoV-2 infection may enhance platelet function, thereby reducing subsequent RBC transfusion requirements. In contrast, platelet processing methods such as pathogen reduction and storage in PAS may adversely affect platelet transfusion outcomes. These insights underscore the potential utility of vein-to-vein analysis to inform platelet transfusion practice. Further research is needed to explore mechanisms underlying these findings and evaluate outcomes of platelet transfusions in different clinical contexts.” Limitations of the study acknowledge by the authors included: “analysis of only single-unit platelet transfusions in which the exact timing of posttransfusion platelet counts could not be standardized; [they] were not able to reliably assess the incidence or severity of bleeding in [this] retrospective study; [t]he use of SARS-CoV-2 anti-N Ab levels as a proxy for immune response to infection is another limitation, because this measure may not fully capture the complexity of SARS-CoV-2 infection on platelet function; [and] the study’s reliance on RBC transfusion events as an indirect measure of platelet effectiveness may introduce bias, despite adjustments for various donor, product, and recipient factors.” A commentary titled “Vein-to-vein data: what predicts platelet response?” is also available in Blood Advances and explained that the findings of the study, “may leave readers wondering: are the results credible? An important next step will involve attempts to replicate findings in other data sets with additional statistical models and methods. This can be difficult given the many factors that influence the outcomes, but reproducing the key findings will increase reader confidence and potentially set the stage for targeted donor recruitment for better transfusion outcomes. The role of donor characteristics could ultimately be tested directly through randomization of platelet units from donors across BMI categories.”

Citation: Roubinian, N.H., Plimier, C., Thomas, K.A.,et al. “Associations of blood donor and product characteristics with platelet transfusion outcomes.” Blood Advances. 2026.