Treatments for Primary Immune Thrombocytopenia: A Review

Immune thrombocytopenic purpura (ITP) is an autoimmune condition that affects nearly 1:10,000 people in the world. It is traditionally defined by a platelet count of less than 100 x 10⁹L, but treatment typically depends on symptomology rather than on the platelet count itself. For primary idiopathic ITP, corticosteroids have been the standard first-line of treatment for symptomatic patients, with the addition of intravenous immune globulin (IVIG) or Rh_o(D) immune globulin (anti-RhD) for steroid-resistant cases. In cases of refractory or non-responsive ITP, second-line therapy includes splenectomy or rituximab, a monoclonal antibody against the CD20 antigen (anti-CD20). In patients who continue to have severe thrombocytopenia and symptomatic bleeding despite first- and second-line treatments, the diagnosis of "chronic refractory ITP" is appropriate, and third-line treatments are evaluated. This manuscript describes the efficacy of different treatment options for primary ITP and introduces the reader to various third-line options that are emerging as a means of treating chronic refractory ITP.