Diagnoses, Outcomes, and Chronicity Predictors of Patients with Secondary Immune Thrombocytopenia: Ten-Year Data from a Hematology Referral Center

Abstract

BACKGROUND: Secondary immune thrombocytopenia (ITP) is a heterogeneous and unpredictable disease associated with various underlying conditions. OBJECTIVE: The objective of the study was to investigate clinical evolution and chronicity predictors in secondary ITP. METHODS: Patients treated at an academic medical center during 2008-2019 were stratified by age as children <16 years and adults <16 years. Responses to steroids, intravenous immunoglobulin G (IVIG), rituximab, and eltrombopag were classified as response (R) and complete response (CR). Risk factors for chronic ITP were determined by multiple regression with uni- and multi-variate analysis. RESULTS: Eighty-three patients were included, 37 children and 46 adults. The most frequent associated conditions were infections 53%, systemic lupus erythematosus (SLE) 24%, thyroid disease 9.6%, and Evans syndrome 3.6%. Response to first-line treatment in the whole cohort was 94%; CR 45.7%; and R 50.6%. Initial response to steroids alone was 91.3% (n = 21/23), rituximab plus high-dose dexamethasone (HDD) 93.3% (n = 14/15); children receiving IVIG alone 100% (n=12/12); and eltrombopag in adults 100% (n = 3/3). Relapse was documented in 19.4% of children and 34% of adults, at a median time of 15 and 2 months, respectively; 30.4% of adults (15.2% from the miscellaneous group, 10.9% SLE-associated, and 4.3% infection-associated) and 18.9% of children followed a chronic course; age ≥10 years and platelets ≥20 × 109/L were risk factors for chronic ITP in children. CONCLUSION: Evolution was heterogeneous: a better and more sustained response was documented in the infections group compared to SLE or the miscellaneous group.