Rituximab Treatment in Childhood Chronic Immune Thrombocytopenic Purpura (ITP).

Immune thrombocytopenic purpura (ITP) is characterized by mucocutaneous purpura and thrombocytopenia caused by circulating anti-platelet auto-antibodies. ITP is usually self-limited in children, but around 20% of patients will develop chronic ITP. The conventional treatments for children chronic ITP include intravenous immunoglobulin (IVIG), corticosteroid therapy, anti-D immune globulin, or splenectomy. Some children with chronic ITP are refractory to these treatments and nowadays begun to try new treatment agents such as rituximab. Rituximab as a monoclonal antibody to CD-20, has shown promising reports to these patients with refractory chronic ITP in adults groups and a few children groups. We investigated this study to evaluate the efficacy of rituximab for childhood chronic ITP in Korea.

We reviewed the questionnaires and medical records about the clinical progresses and results in thirteen children from eight clinical institutes, retrospectively. Complete response (CR) was considered if the platelet count was > 100,000/uL.

Thirteen patients with chronic thrombocytopenia who had been treated with rituximab were investigated. Two patients were lost to follow-up after rituximab. Finally eleven patients were evaluated including one patient with Evans syndrome. Median age was 6.5 year (range, 0.5 ∼ 15.4). Median platelet count at baseline was 13,700/uL (3,000∼46,000). All patients had been treated with conventional therapy including IVIG and steroids. One had done splenectomy. Median follow-up duration was 2.8 years (1.1-5.9). Among 11 patients, CR was achieved in 3 patients (27%). Their platelet count prior to rituximab were < 10,000/uL. They were treated as the regimen of 375 mg/m²/dose weekly for 4 doses. Time from the first rituximab dose to achievement of complete response was 3.9, 4.9 and 5.7 weeks respectively. One patient who was relapsed 6months after the first course of rituximab was received second course of rituximab using the same regimen and achieved a new CR at 9.3 weeks after. There were no reports about severe complication or interruption of medication.

Therefore, we suggest that rituximab is effective treatment choice in childhood refractory chronic ITP and well tolerated.

No relevant conflicts of interest to declare.