Investigation of clinical and laboratory parameters affecting treatment response in immune thrombocytopenia (ITP) patients receiving intravenous immunoglobulin (IVIG) therapy

Immune Thrombocytopenia (ITP) is an acquired autoimmune hematologic disorder characterized by isolated thrombocytopenia without a clinically apparent cause. ITP can be observed in both pediatric and adult populations and is classified as either primary or secondary depending on the presence of an associated underlying condition. In adults, it typically has an insidious onset, follows a chronic course, and is observed more frequently in women than in men. However, in elderly individuals, the gender distribution tends to be more balanced. Spontaneous remission is rare, and the disease generally requires treatment (5, 6). The pathogenesis of the disease involves IgG-class autoantibodies produced by B lymphocytes against platelet surface antigens. These antibodies suppress platelet production by megakaryocytes and accelerate the destruction of circulating platelets. In some patients, T cell-mediated immune dysregulation may predominate. In this subgroup, the response to standard immunosuppressive agents—particularly treatments like intravenous immunoglobulin (IVIG) or rituximab—may be lower (7, 13, 19). The diagnosis of ITP is based on the demonstration of thrombocytopenia and the exclusion of other causes of low platelet count. Clinical findings are directly related to the degree of thrombocytopenia. Aside from bleeding symptoms, most patients typically have normal physical examinations and systemic evaluations. A platelet count below 30,000/μL is generally considered critical in terms of bleeding risk; however, the need for treatment may arise even in patients with higher counts if significant bleeding is present (6, 28). The primary goal in the management of ITP is to maintain a platelet count sufficient to prevent clinically significant and life-threatening bleeding. Accordingly, the treatment goal is not to restore the platelet count to the normal reference range in all patients. The decision to initiate treatment is mainly based on the patient's symptomatology and bleeding tendency. The most common clinical manifestations include purpura, menorrhagia, epistaxis, and gingival bleeding; gastrointestinal bleeding and hematuria are less frequently observed. Intracerebral hemorrhage occurs in approximately 1% of patients and is one of the leading causes of mortality (6, 29). The aim of this study is to retrospectively evaluate the response to intravenous immunoglobulin (IVIG) treatment in patients diagnosed with ITP, assess the sustainability of this response, and determine whether the treatment response is associated with various clinical and laboratory parameters. The response criterion was defined as an increase in platelet count to >30,000/μL, remission as a count reaching >100,000/μL, and relapse as a decrease below these thresholds.