Immune Thrombocytopenia in Adults: Modern Approaches to Diagnosis and Treatment

Abstract

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder affecting approximately 1 in 20,000 people. Patients typically present with clinically benign mucocutaneous bleeding, but morbid internal bleeding can occur. Diagnosis remains clinical, possible only after ruling out other causes of thrombocytopenia through history and laboratory testing. Many adult patients do not require treatment. For those requiring intervention, initial treatment of adult ITP is with corticosteroids, intravenous immunoglobulin, or intravenous anti-RhD immune globulin. These agents are rapid-acting but do not result in durable remissions in most patients. No corticosteroid has demonstrated superiority to others for ITP treatment. Subsequent treatment of adult ITP is typically with thrombopoietin receptor agonists (TPO-RAs; romiplostim or eltrombopag), rituximab, or splenectomy. TPO-RAs are newer agents that offer an excellent response rate but may require prolonged treatment. The choice between subsequent treatments involves consideration of operative risk, risk of asplenia, drug side-effects, quality-of-life issues, and financial costs. Given the efficacy of medical therapies and the rate of spontaneous remission in the first year after diagnosis, splenectomy is frequently deferred in modern ITP treatment algorithms. Fostamatinib (a tyrosine kinase inhibitor recently approved by the U.S. Food and Drug Administration) and several older immunosuppressive agents (azathioprine, cyclophosphamide, cyclosporine, danazol, dapsone, mycophenolate mofetil, and the Vinca alkaloids) may be useful in patients with disease unresponsive to standard therapies or in specific clinical circumstances. This comprehensive review explores diagnostic considerations and surveys new and old treatment options for adults with ITP.