Pooling, room temperature, and extended storage time increase the release of adult‐specific biologic response modifiers in platelet concentrates: a hidden transfusion risk for neonates?

Abstract

BACKGROUNDAdult donor platelets (PLTs) are frequently transfused to prevent or stop bleeding in neonates with thrombocytopenia. There is evidence for PLT transfusion–related morbidity and mortality, leading to the hypothesis on immunomodulatory effects of transfusing adult PLTs into neonates. Candidate factors are biologic response modifiers (BRMs) that are expressed at higher rates in adult than in neonatal PLTs. This study investigated whether storage conditions or preparation methods impact on the release of those differentially expressed BRMs.STUDY DESIGN AND METHODSPooled PLT concentrates (PCs) and apheresis PCs (APCs) were stored under agitation for up to 7 days at room temperature (RT) or at 2 to 8°C. The BRMs CCL5/RANTES, TGFβ1, TSP1, and DKK1 were measured in PCsʼ supernatant, lysate, and corresponding plasma. PLT function was assessed by light transmission aggregometry.RESULTSConcerning the preparation method, higher concentrations of DKK1 were found in pooled PCs compared to APCs. In supernatants, the concentrations of CCL5, TGFβ1, TSP1, and DKK1 significantly increased, both over standard (≤4 days) and over extended storage times (7 days). Each of the four BRMs showed an up to twofold increase in concentration after storage at RT compared to cold storage (CS). There was no difference in the aggregation capacity.CONCLUSIONThis analysis shows that the release of adult‐specific BRMs during storage is lowest in short‐ and CS APCs. Our study points to strategies for reducing the exposure of sick neonates to BRMs that can be specifically associated to PLT transfusion–related morbidity.

Survey of transfusion practices in preterm infants in Europe

“…The use of thresholds lower than those tested in trials may be an acceptable practice for platelet transfusions, given the evidence in favour of the restrictive versus liberal threshold, but again this needs to be tested in a clinical trial. Possible explanations for platelet transfusion-mediated adverse effects include the role of platelets in inflammatory and immunoregulatory responses,24 a developmental mismatch between adult donor platelets and neonatal platelets25 26 and volume-mediated effects, since platelet transfusions are given at relatively high volumes and rates compared with adult transfusions 27…”

Aberrant Hematopoiesis and Morbidity in Extremely Preterm Infants With Intrauterine Growth Restriction

“…PLTs have an immunologic function and transfusions of adult PLT might cause a proinflammatory response in preterm infants ( 14 ). The pathophysiology could include the release of biological response modifiers from stored adult PLTs, claimed to worsen inflammatory injury and BPD ( 62 , 63 ).…”