Diagnosis of platelet dysfunction in children: clinical predictors and test methods

Evaluation for platelet function disorders (PFD) in children is complicated by their limited exposure to hemostatic challenges, large volumes needed for light transmission aggregometry (LTA) testing, and limited data on the performance characteristics of whole-blood methods such as whole-blood impedance lumiaggregometry (WBILA). The objective of this study was to determine the clinical variables associated with the diagnosis of a PFD. A single-center, retrospective, cohort study of children evaluated for PFD was conducted. Medical charts were abstracted for demographics, medications, testing indications, bleeding sites and severity, and laboratory results. Univariate odds ratios (OR) and multivariable modeling were conducted for association of clinical variables with PFD diagnosis in children tested by LTA or WBILA. Of 667 patients, 20.5% were diagnosed with a PFD. The PFD cohort was more likely male (OR, 1.54; P = .025) and younger (8.8 vs 10.1 years; P = .026). Neither mucocutaneous bleeding (most common presenting indication) nor bleeding severity scores correlated with increased odds of PFD diagnosis. Both LTA and WBILA showed sensitivity of >91% and specificity of >84% for PFD diagnosis. A multivariable model identified younger age, male sex, thrombocytopenia, genetic disorders, and gastrointestinal bleeding with PFD diagnosis in the WBILA cohort. In conclusion, younger, male patients have a higher incidence of PFD. These data support that WBILA can effectively rule out PFD in a pediatric population.