Immunoglobulins As a Predictor of Chronicity in Pediatric Immune Thrombocytopenia

Introduction: Immune thrombocytopenia (ITP) is the most common acquired bleeding disorder in children, but predictors of chronicity at the time of diagnosis remain largely unknown. Small studies have previously indicated predictive value of baseline immunoglobulin levels, but without definitive clinically applicable conclusions. We aim to further investigate the utility of immunoglobulin levels obtained at the time of diagnosis in predicting the development of chronic ITP (cITP) in children. Methods: We completed a retrospective review of patients aged 6 months - 21 years diagnosed with ITP at tertiary referral centers from 2015 - 2022 in accordance with IRB-approved protocols. Patients with immunoglobulin levels obtained within 3 months of ITP diagnosis and prior to any treatment were included in the study. cITP was defined as ITP duration >12 months. ITP resolution was defined as achieving a platelet count > 150 x 10 9/L on 2 occasions, or on 1 occasion in the presence of normalized MPV, absent of therapy. Patients who were lost to follow-up or had ongoing disease