Clinical significance of serum cytokine levels and thrombopoietic markers in childhood idiopathic thrombocytopenic purpura

Background. Biological markers useful for defining children with newly diagnosed immune thrombocytopenic purpura (ITP) who are likely to develop the chronic form of the disease are partially lacking. The purpose of this study was to assess the clinical role of both immunological and thrombopoietic markers in children with ITP and correlate their levels with different disease stages. Materials and methods. We enrolled 28 children with ITP at the onset of their disease, who were followed-up for a whole year and divided according to whether their disease resolved within the 12 months (n=13) or became chronic (n=15), 11 subjects with chronic ITP off therapy for at least 1 month at the time of enrolment, and 30 healthy matched controls. Serum levels of T helper type 1 and 2 and T regulatory-associated cytokines, such as interferon γ, tumour necrosis factor α, interleukin (IL) 2, IL6, IL10, and thrombopoietin were measured in all children using quantitative immunoenzymatic assays, while reticulated platelets were evaluated by flow cytometric analysis. Results. Serum IL10 levels were significantly higher in patients with an acute evolution of ITP than in either healthy controls (p<0.001) or patients with chronic progression of ITP (p<0.05). Reticulated platelet count and thrombopoietin levels were significantly higher in ITP patients at the onset of their disease, whether with acute resolution or chronic progression, than in healthy subjects (p<0.01; p<0.001), but did not differ between the groups of patients. Conclusion. IL-10 seems to predict the clinical course of ITP, as it is significantly higher at the onset of disease in patients who obtain disease remission in less than 1 year.