Abstract

Immune thrombocytopenia (ITP) is an acquired bleeding disorder characterised by antibody-mediated destruction of platelets and impaired platelet production, often occurring in the absence of identifiable and specific precipitants. Most children with acute ITP do not require treatment, and thrombocytopenia resolves spontaneously. For paediatric patients requiring treatment, the guidelines recommends a single dose of IVIg (0.8 to 1 g/kg) if a more rapid increase in the platelet count is desired, or a short course of corticosteroids, as first-line treatment. However, for Rh(D)-positive patients with ITP and intact spleens, IV Rho immunoglobulin (RhIG) offers comparable efficacy, less toxicity, greater ease of administration, and a lower cost than IVIG. For children or adolescents with ITP who have significant ongoing bleeding despite treatment with IVIG, RhIG, or conventional doses of corticosteroids, the guidelines recommends considering rituximab or high-dose dexamethasone for second-line treatment. Rituximab or high-dose dexamethasone may also be considered as an alternative to splenectomy or as treatment for children and adolescents who do not respond favourably to splenectomy. In 2008, two thrombopoietin receptor agonists, romiplostin and eltrombopag, became available for adult patients with chronic ITP. In a phase 3 double-blind study of 62 symptomatic children with persistent or chronic ITP who were randomly assigned to receive weekly romiplostim or placebo for 24 weeks, durable platelet response was seen in 52% of patients receiving romiplostim vs. 10% of those in the placebo group (p=0.002, odds ratio 9.1) (Bussel JB, Blood 2011). Eltrombopag is approved by the Food and Drug Administration for children age 1 year old or older with chronic ITP who have not achieved an appropriate response by using other medications or with splenectomy. Approval was based on the placebo-controlled PETIT trials, which showed that 36% to 40% of eltrombopag-treated children maintained a platelet count of>50×10⁹/L for the majority of time on study compared with 0% to 3% who received placebo. (Bussel JB, Lancet 2015; Grainger JD, Lancet 2015). There are reports suggesting efficient results in childhood refractory ITP after sirolimus, mycophenolate mofetil, ciclosporine. Despite the new achievements in therapeutical approach, in the real practice it is very difficult to treat patients with new drugs due to limited financial resources and lack of regulatory rules for off-label use.