Evaluation of clinical and demographic characteristics of pediatric patients with persistent and chronic immune thrombocytopenia

Immune thrombocytopenia (ITP) is the most common cause of primary thrombocytopenia in childhood. Persistent ITP refers to thrombocytopenia lasting between 3 and 12 months after diagnosis, while chronic ITP refers to thrombocytopenia lasting longer than 12 months. In this study, we aimed to evaluate the clinical and demographic characteristics of pediatric patients with persistent and chronic ITP and to evaluate the factors affecting the long-term treatment responses, disease processes and determinants of remission. Methods: Patients with persistent and chronic ITP under the age of 18 years who were followed up in our department between December 1, 2014 and December 1, 2024 were included. The medical records of the patients were retrospectively reviewed through the hospital database. Demographic characteristics, baseline platelet counts, treatment responses and remission status were recorded. The treatments used at the time of diagnosis and during follow-up and the responses to these treatments were evaluated. Data were statistically compared between groups. Results: A total of 81 patients were included in the study. The median age of the patients was 5.4 years (9 months-16.5 years) and 56.8% were female. The median platelet count at diagnosis was 14 (1-93) x109/L and there was a significant correlation between higher platelet counts at diagnosis and the length of remission period (p=0.026). Remission duration was found to be longer in patients without a history of infection before admission (p=0.049). Patients with chronic ITP had higher platelet counts at diagnosis compared to patients with persistent ITP (p=0.037). The durable platelet response criterion used in eltrombopag treatment was found to be correlated with the platelet count during the last eight weeks of treatment (p=0.004). It was found that patients who were started on eltrombopag treatment in the persistent phase achieved remission earlier than patients who were started on eltrombopag treatment in the chronic phase (p=0.007). Moreover, patients who presented with clinically significant bleeding at diagnosis had a higher risk of presenting with bleeding during follow-up (p=0.037). Conclusion: Our study provided important data to understand the clinical and demographic characteristics as well as treatment responses in pediatric patients diagnosed with persistent and chronic ITP. Bleeding at presentation, platelet count at diagnosis, and the presence of previous infections are indicative for the follow-up of patients. Durable platelet response also indicates long-term response in patients receiving eltrombopag. Keywords: Persistent Immune Thrombocytopenia, Chronic Immune Thrombocytopenia, ITP, Eltrombopag, Romiplostim