[Autoimmune thrombopenic purpura. Therapeutic modalities]

TOP PRIORITY: Preventing hemorrhage is the number one priority in the treatment of idiopathic thrombocytopenic purpura. There are three main treatments: corticosteroids, intravenous immunoglobulins and splenectomy.

The main effects of corticosteroids are to reduce platelet phagocytosis, counteract mechanisms leading to inhibited thrombopoiesis, limit vascular fenestration and endothelial fragility, and immuno-depression. Corticosteroids are usually started at 1 to 2 mg/kg/day for 2 or 3 weeks before rapidly tapering off to final withdrawal after 3 or 4 weeks.

Administered by intravenous injections, immunoglobulins saturate the Fc fragment of the IgGs on the surface of the macrophages, neutralize antiplatelet antibodies, and inhibits synthesis of antiplatelet autoantibodies. Treatment cost is high as is the risk of adverse effects.

The most effective long-term treatment, splenectomy is particularly useful when platelet sequestration, as identified by radiolabeling occurs mainly in the spleen.

Anti-D immunoglobulins (limited availability), danazol or immuno-suppressors have a beneficial effect which disappears after withdrawal.

Essential elements are the risk of hemorrhage (low or nil above 30000 platelets/mm3), its severity, patients status (childhood cases usually resolve spontaneously) and prognosis factors (idiopathic thrombocytopenic purpura is a benign disorder).