tailieunhanh - Chapter 109. Disorders of Platelets and Vessel Wall (Part 6)

Immune Thrombocytopenic Purpura: Treatment The treatment of ITP utilizes drugs that decrease reticuloendothelial uptake of the antibody-bound platelet and/or decrease antibody production. However, the diagnosis of ITP does not necessarily mean that treatment must be instituted. Patients with platelet counts 30,000/µL appear not to have increased mortality related to the thrombocytopenia. | Chapter 109. Disorders of Platelets and Vessel Wall Part 6 Immune Thrombocytopenic Purpura Treatment The treatment of ITP utilizes drugs that decrease reticuloendothelial uptake of the antibody-bound platelet and or decrease antibody production. However the diagnosis of ITP does not necessarily mean that treatment must be instituted. Patients with platelet counts 30 000 pL appear not to have increased mortality related to the thrombocytopenia. Initial treatment in patients without significant bleeding symptoms severe thrombocytopenia 5000 pL or signs of impending bleeding such as retinal hemorrhage or large oral mucosal hemorrhages can be instituted as an outpatient using single agents. Traditionally this has been prednisone at 1 mg kg although Rh0 D immune globulin therapy WinRho SDF at 50-75 pg kg is also being used in this setting. Rh0 D immune globulin must be used only in Rh patients as the mechanism of action is production of limited hemolysis with antibody-coated cells saturating the Fc receptors inhibiting Fc receptor function. Hemoglobin levels usually decrease mean g dL although severe intravascular hemolysis is a rare complication. Doses are reduced if given to anemic patients. Intravenous gamma globulin IVIgG which is pooled primarily IgG antibodies also blocks the Fc receptor system but appears to work primarily through different mechanism s . IVIgG has more efficacy than anti-Rh0 D in post-splenectomized patients. IVIgG is dosed at 2 g kg total given in divided doses over 2-5 days. Side effects are usually related to the volume of infusion and infrequently include aseptic meningitis and renal failure. All immunoglobulin preparations are derived from human plasma and undergo treatment for viral inactivation. For patients with severe ITP and or symptoms of bleeding hospital admission and combined modality therapy are given using high-dose glucocorticoids with IVIgG or anti-Rh0D therapy and as needed additional immunosuppressive agents. Rituximab an