Immune thrombocytopenia (ITP) in childhood spontaneously remits in up to 80% of affected children. Predictors of remission are not well understood and identifying them could be useful for treatment decisions that impact outcomes.
Data from a large prospective cohort of pediatric patients with ITP (Registry II of Intercontinental Cooperative ITP Study Group [ICIS]) was analyzed to investigate factors that might predict remission. Included children were >4 months and 20 years of age with newly diagnosed ITP based on standard criteria. Therapy was classified as no systemic pharmacologic therapy, IVIG alone, corticosteroids alone, anti-D Ig alone, IVIG, and steroids in combination, and other.
1,239 patients were analyzed, 705 had follow-up data and came from 45 different institutions. Data collected through 12 months or through 12 and 24 months. More than half of the patients had no or mild bleeding. Patients were managed with observation alone (28%), IVIG alone (25%), corticosteroids alone (13%), and anti-D Ig (3%). Remission was achieved in 419/705 (59%) at 12 months and 211/383 (55%) at 24 months. Younger age (especially patients 1 year and 1 to 6 years) was associated with highest remission rates at both 12 and 24 months. Significant bleeding at diagnosis and pharmacologic treatment at diagnosis were statistically associated with remission at both 12 and 24 months. Highest remission rate at both 12 and 24 months occurred in the group treated with combination of corticosteroids and IVIG at diagnosis (76% and 77% respectively). Gender and platelet count at diagnosis were not significantly associated with ITP remission rates. Lower platelet count at diagnosis was not predictive of remission (contrary to previous reports).
Large numbers of patients were lost to follow-up, management decisions were at the discretion of the treating provider at multiple different institutions, and other lab studies that can impact disease course (such as ANA and red cell antibodies) were not collected.