Treatment outcomes and chronicity predictors for primary immune thrombocytopenia: 10-year data from an academic center

Primary immune thrombocytopenia (ITP) is an intriguing autoimmune disease characterized by autoantibodies against platelets and megakaryocytes. Clinical outcomes, response to treatment, and chronicity predictors were investigated. Patients with newly diagnosed primary ITP treated at a hematology referral center from 2008 to 2018 with complete medical and recent medication history were stratified by age as children < 16 years and adults > 16 years. Responses to treatment including steroids, splenectomy, rituximab, and eltrombopag were classified as response (R) and complete (CR). Factors for developing chronic ITP were determined by multiple regression with uni- and multivariate analysis.p< 0.05 was considered significant. A total of 175 patients were included, 52 children and 123 adults; women predominated with 57.7%. Response to first-line treatment in the whole cohort was 86.18%, CR 43.42% and R 42.76%. The initial response to steroids alone was 83.9% (n= 52/62), rituximab plus high-dose dexamethasone (HDD) 87.2% (n= 34/39), eltrombopag plus HDD 90.9% (n= 10/11), and children receiving IVIG alone 100% (n= 8/8); 9 children were under clinical observation and achieved spontaneous response; loss of response was documented in 15.21% children and 28.3% adults with a median time of 15.95 and 4.07 months respectively; 37.39% of adults and 30.76% of children progressed to a chronic course. Platelets >= 20 x 10(9)/L and age >= 6 years were risk factors for chronic ITP in the univariate analysis in the adult and children groups, respectively. Clinical course and treatment outcomes for ITP are considerably heterogeneous. Higher platelet counts at diagnosis in adults and age >= 6 years in children were associated with an increased risk of chronicity.