Clinical outcome of childhood chronic immune thrombocytopenia: A 38-year experience from a single tertiary center in Thailand.

BACKGROUND: There is limited information on long-term follow-up and prognostic factors for remission among children diagnosed with chronic immune thrombocytopenia (ITP). The aim of this study was to determine clinical outcomes and factors influencing remission in childhood chronic ITP.

STUDY DESIGN: The hospital records of children aged 0-15 years diagnosed with chronic ITP were retrospectively reviewed. Kaplan-Meier curves were fit to estimate the median time to complete remission with 95% confidence intervals (CIs). Multivariate Cox proportional hazards regression models were used to identify independent factors for remission.

RESULTS: A total of 113 patients were included in the analysis. The number of children achieving complete remission was 49 (46%) and the median time to remission was 7.1 years (95% CI: 4.8-11.0). The remission rates at 3, 5, 10, and 20 years were 25, 43, 60, and 75%, respectively. Factors influencing remission were platelets >60 × 109 /L at the onset of chronic ITP (hazard ratio [HR]: 7.24, 95% CI: 3.0-17.5) and treatment with intravenous immunoglobulin (HR: 0.37, 95% CI: 0.16-0.84). Age, gender, and clinical factors at the time of newly diagnosed ITP including bleeding manifestations, onset of symptoms, and history of preceding infection and vaccination were not predictive of remission.

CONCLUSION: The spontaneous complete remission rates of chronic ITP were 43 and 60% at 5 and 10 years, respectively, and reached 75% at 20 years. A higher platelet level at diagnosis of chronic ITP and form of treatment were statistically significant indicators for achieving complete remission.