A lower threshold for platelet transfusions in preterm infants with severe thrombocytopenia is associated with significantly lower incidence of death and major bleeding, compared with a higher threshold, a new study suggests.
A new major bleeding episode or death occurred in 26% of infants in the high-threshold group, compared with 19% in the low-threshold group, representing a 57% higher risk of poor outcomes even after researchers adjusted for gestational age and intrauterine growth restriction (odds ratio, 1.57; P = .02).
Researchers reported the results of a trial in 660 infants with a mean gestational age of 26.6 weeks, who were randomized to a platelet infusion either at a high platelet–count threshold of 50,000/mm3 or a low threshold of 25,000/mm3.
“Although retrospective studies have suggested that platelet transfusions may cause harm in neonates independently of the disease process, data from randomized controlled trials to support this are lacking,” Anna Curley, MD, of the National Maternity Hospital in Dublin and her coauthors reported in the New England Journal of Medicine.
The rates of minor or worse bleeding were similar between the two groups, and the percentage of infants surviving with bronchopulmonary dysplasia at 36 weeks of corrected age was higher in the high-threshold group (63% vs. 54%; OR, 1.54).
The rates of serious adverse events, not including major bleeding, were similar between the high- and low-threshold groups.
The outcomes of transfusions were not influenced by other factors such as intrauterine growth restriction, gestational age, or postnatal age at randomization.
“Our trial highlights the importance of trials of platelet transfusion involving patients with conditions other than haematological malignancies,” the authors wrote.
However they acknowledged that the reasons for the differences in mortality and outcomes between the two study groups were unknown.
“Platelets have recognized immunological and inflammatory effects, outside of effects on hemostasis,” they wrote. “The effect of transfusing adult platelets to a delicately balance neonatal hemostatic system with relatively hypofunctional platelets is also poorly understood.”
The study was supported by the National Health Service Blood and Transplant Research and Development Committee and other foundations. Authors reported financial disclosures related to Sanquin and Cerus.
SOURCE: Curley A et al. N Engl J Med. 2018 Nov 2. doi: 10.1056/NEJMoa1807320.