Inflammation triggered by platelet transfusions may influence outcomes in infants affected by or vulnerable to fetal and neonatal alloimmune thrombocytopenia (FNAIT), according to research published recently in Pediatric Research.
These results show that transfusions provoke immune activity without clearly reducing bleeding. Because FNAIT already involves maternal antibodies that destroy fetal platelets, any transfusion-related immune surge could compound existing risks for these newborns.
This prospective cohort study, conducted from 2020 to 2024, followed thrombocytopenic neonates, including those whose clinical course resembled complications often seen in FNAIT. Investigators found that although platelet transfusions increased platelet counts by 15 ± 3 × 10⁹/L, they did not ease bleeding severity.
“[W]e identified novel inflammatory responses to platelet transfusions in neonates and an association between storage time and free mtDNA [mitochondrial DNA] in the transfused units and RANTES elevations in the recipient,” stated this study’s authors.
Read more about causes and risk factors of FNAIT
Among 42 infants who received 68 transfusions, bleeding scores stayed consistent regardless of transfusion, and major or severe bleeding episodes appeared only in infants with other medical risk factors. The lack of bleeding improvement is especially relevant in FNAIT, where clinicians frequently weigh whether transfusions will meaningfully change bleeding risk.
The team next evaluated inflammatory responses in 20 infants using blood samples drawn before and after transfusion. Four hours after transfusion, concentrations of RANTES rose 6.5-fold, far above what was expected based solely on the content of the platelet units. NETs increased 1.24-fold.
Both findings show immune activation that could be particularly concerning for infants with FNAIT, who may already have heightened inflammatory vulnerability due to antibody-mediated platelet destruction.
Researchers explored whether donor, recipient, or platelet unit factors influenced these reactions. Only platelet storage time and the concentration of free mitochondrial DNA were linked to larger RANTES increases. Birth weight correlated with NET changes, suggesting that the smallest infants, including those with severe FNAIT, may respond more intensely.
For families navigating FNAIT, this study helps explain why clinicians often use platelet transfusions cautiously. While transfusions remain essential for infants with dangerously low platelet counts or active bleeding, this research shows that they may also introduce inflammatory stress. These results support more refined transfusion strategies for infants with or at risk for FNAIT and highlight the importance of ongoing monitoring and individualized care.
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