Safety of Oral Thrombopoietin Receptor Agonist in Pediatric Chronic ITP

Assessment of Response Rate and Safety of Oral Thrombopoietin Receptor Agonist in Pediatric Chronic ITP in Assiut.

This study aimed to evaluate the response rate and safety of oral thrombopoietin receptor agonist (Eltrombopag drug) used for children with chronic immune thrombocytopenia in patients attending Assiut university children's hospital.

Immune thrombocytopenic purpura (ITP) is an autoimmune disease characterized by decrease number of the platelets due to destruction of the platelets by antiplatelet antibodies. Also, platelet production can be reduced because the antiplatelet antibodies can also damage megakaryocytes . Its prevalence being approximately 8 per 100,000 children It is characterized by temporary or persistent reduction of the platelet number to less than 100 × 109/liter.

All new cases at diagnosis are defined as acute ITP. While, Persistent ITP is defined as ITP lasting between 3 and 12 months from diagnosis while chronic ITP is defined as the presence of ITP for more than one-year ITP Patients have an increased hazard of bleeding that may have no effect on patient's life or have life-threatening danger the goal of treatment in chronic ITP is to increase and then keep platelets in a sufficient number to prevent bleeding

. Meanwhile most life-threatening bleeding occurs with platelet number less than 30 × 109/liter.

New guideline recommend that treatment constricted on symptomatic patients with number lower than 30 × 109/liter (3,6) new Guidelines recommended that corticosteroids as first-line therapy and splenectomy considered as one of several second-line therapies. Other choices exist for ITP patients with insufficient response or who do not undergo to splenectomy including IVIg, IV anti-D, Rituximab, danazol, azathioprine, Vinca alkaloids and cyclophosphamide New consensus statements and guidelines recommend thrombopoietin-receptor (TPO-R) agonists as second and third line of treatment Eltrombopag consider the first oral, nonpeptide TPO-R agonist accepted for the treatment of chronic ITP in patients with insufficient response to at least one other therapy It rises platelet number by increase platelet production by binding to the transmembrane domain of the TPO-R. It does not compete with endogenous TPO in vitro and it enhance production and differentiation of BM progenitor cells in the megakaryocytic lineage

Inclusion Criteria:

• Subjects between 2 year and <18 years of age in both sex
• Confirmed diagnosis of chronic ITP
• all patient received oral thrombopoietin receptor agonist (Eltrombopag) for 6 months or more

Exclusion Criteria:

• age of the patient < 2years and >18 years
• secondary thrombocytopenia
• Concurrent or past malignant disease, including myeloproliferative disorder
• patient with platelet agglutination abnormality that prevents reliable measurement of platelet counts
• patient with bone marrow aplasia