Background

Platelet transfusions are frequently given to preterm neonates. However, observational and randomized studies have reported higher morbidity and mortality associated with increased numbers of transfusions. We hypothesized that this was related to pro-inflammatory effects of transfused platelets. This study assessed the effects of platelet transfusions on bleeding, plasma cytokines, and neutrophil extracellular trap (NET) levels in neonates.

Methods

This was a prospective cohort study of thrombocytopenic neonates conducted from 2020 to 2024. Bleeding was assessed with each platelet count. Blood was collected before and 2 h or 4 h after platelet transfusion for evaluation of a plasma cytokine panel and NETs. Aliquots from transfused units were also collected.

Results

Forty-two infants with severe thrombocytopenia received 68 platelet transfusions. Transfusion increased the platelet count by 15 ± 3 × 10⁹/L but had no significant effect on bleeding. Four hours post-transfusion, RANTES levels increased 6.5-fold (p = 0.03) and were higher than expected based on the quantity in the units. Plasma NETs increased 1.24-fold (p = 0.007) post-transfusion. The transfused platelet units’ storage time and free mtDNA concentrations correlated with RANTES increases (p = 0.04 and 0.03, respectively).

Conclusions

Platelet transfusions are associated with increases in inflammatory cytokines and NET in neonates, which may contribute to the negative outcomes associated with platelet transfusions.