First-line therapies for immune thrombocytopenic purpura: re-evaluating the need to treat.

Immune thrombocytopenic purpura (ITP) can be challenging to both diagnose and treat: despite the ability to detect anti-platelet antibodies, the diagnosis of ITP remains one of exclusion. Management of ITP is similarly difficult as many therapies pose potential risks that may be worse than the disease. It has been generally agreed that bleeding - not platelet count - should be the rationale for treatment. Despite the absence of prospective, controlled studies, there is consensus that bleeding risks are significantly greater in patients with platelet counts <20 x 10(9)-30 x 10(9)/L, and therefore treatment is indicated for these patients; for those with platelet counts that are higher, but still <50 x 10(9)/L, treatment is also indicated if accompanied by substantial mucous membrane bleeding. The standard initial treatment for ITP is oral corticosteroids to increase platelet counts. Intravenous immunoglobulin or anti-D immunoglobulin can also increase platelet counts and are particularly useful for stimulating rapid platelet increases before planned procedures. Splenectomy, which produces a long-lasting response in a majority of patients, is still commonly used for those who do not have long-term responses to steroid therapy and it should remain the gold standard therapy. However, splenectomy is an invasive procedure with some patients relapsing even after several years. Very rare cases of life-threatening or lethal infections may also occur at any time after splenectomy and thus physicians and patients are increasingly reluctant to advise or agree to this treatment approach. Other treatments have been evaluated to prevent or delay splenectomy, including high-dose dexamethasone, intermittent anti-D immunoglobulin infusions, and rituximab. There have been few randomized, placebo-controlled studies of these approaches, and they cannot currently be recommended as their efficacy and safety remain unclear. Thrombopoietin receptor agonists are currently under clinical investigation for the treatment of ITP and may represent an alternative treatment option in the future. The criteria for treating ITP and the benefits and risks of therapies are discussed here. Ongoing and future studies will help define the best strategies for increasing platelet counts and reducing the risk of bleeding in ITP patients.