May Intravenous Immune Globulin Revert Steroid-Resistant State in Immune Thrombocytopenic Purpura

Immune thrombocytopenic purpura (ITP) is characterized by immune-mediated platelet destruction. The modulating effect of intravenous immune globulin (IVIg) was first recognized in ITP treatment and IVIg is currently considered a second-line (first-line in selected conditions) therapy for ITP according to American Society of Hematology guidelines. Three acute ITP patients (mean age 63.3±14.4 years; M:F=1:2) with severe thrombocytopenia and bleeding symptoms have been observed. After the failure of high doses of intravenous corticosteroids and platelet transfusions in controlling bleeding symptoms, a single infusion cycle of IVIg was used as add-on therapy (0.4 mg/kg/day for 5 days). Circulating platelet counts and presence of bleeding symptoms were estimated. An increase of circulating platelet counts associated to complete symptom resolution was promptly obtained in all three patients. The mean platelet count increased from 6x103/μl at baseline to 184x103/μl by the 12th day, but with different time dynamics, the slowest (12 days) being observed in patient 1 versus 6 and 9 days in patients 2 and 3, respectively. Although IVIg efficacy has been largely demonstrated in ITP treatment, its main mechanism of action can not be easily determined, however, it may include its capacity to revert the steroid-resistant state in these three patients.