New markers of bleeding risk among thrombocytopenic preterm neonates
BACKGROUND: Thrombocytopenic neonates and children have a higher incidence of bleeding than adults, and this observation has likely been a contributing factor to the liberal use of platelet (PLT) transfusions in neonatology. However, several recent studies found a poor correlation between the degree of thrombocytopenia and the incidence of bleeding in various patient populations (including neonates), highlighting the limitations of our current PLT count-based approach to transfusion decisions.
GAP: A better marker of bleeding risk suitable for use in thrombocytopenic preterm neonates could help physicians more accurately determine the risk/benefit of PLT transfusions, ultimately protecting vulnerable infants from exposure to unnecessary transfusion-related risks. Our recent study showed that the PFA-100 CT-ADP test was a significantly better marker of bleeding than the PLT count, particularly among the most preterm infants. However, the PFA-100 requires additional blood, which limits its usefulness in the smallest neonates. The Immature Platelet Fraction (IPF), which is provided as part of the complete blood count, measures the percentage of newly released platelets. Recent studies have shown its utility to assess bleeding risk in adult and pediatric patients.
HYPOTHESIS: We hypothesized that a higher IPF would be associated with less bleeding, and that the Immature Platelet Count (IPC, platelet count x IPF) would be a better predictor of bleeding in neonates with gestational age <32 weeks and severe thrombocytopenia than the PLT count alone.
METHODS: This is a prospective observational study designed to evaluate IPF/IPC and PFA-100 CT-ADP as markers of bleeding risk in thrombocytopenic neonates admitted to the Neonatal Intensive Care Unit (NICU). Infants will be eligible for study if they have a gestational age <32 weeks, a birth weight ≥500 grams, and PLT count <100 x 109/L.
IMPACT: This will be the first study evaluating the IPF and IPC in thrombocytopenic neonates as potential markers of bleeding risk. This study has the potential of leading to new approaches to PLT transfusion decisions in this high-risk population, with the goal of decreasing unnecessary transfusions.