Efficacy, safety, and dose response of intravenous anti-D immune globulin (WinRho SDF) for the treatment of idiopathic thrombocytopenic purpura in children

Abstract

We analyzed data from 20 children treated for acute or chronic idiopathic (immune) thrombocytopenic purpura (ITP) at a single institution to determine the relationship between dose of intravenous anti-D immune globulin (WinRho SDF; Nabi, Boca Raton, FL), increase in platelet count, and decrease in hemoglobin in the therapy of ITP. Higher doses of anti-D were clearly associated with a greater therapeutic response in the platelet count, with no increase in hemolysis for both acute and chronic ITP. A significant correlation was found between dose and peak increase in platelet count measured in the 14 days following administration. This effect was present for both acute ITP (17 infusions, P = .0001) and chronic ITP (30 infusions, P = .038). Although hemolysis was seen in nearly all infusions, with a median hemoglobin fall of 1.9 g/dL (range, 0 to 4.2), the decrease in hemoglobin was greater than 2.5 for only three infusions, and the largest fall in hemoglobin (4.2) was in a child with an underlying hemolytic anemia. Furthermore, for both acute and chronic ITP there was no relationship between the decrease in hemoglobin and the dose given (P = .22), nor between the increase in platelet count and fall in hemoglobin (P = .27). This analysis supports the use of higher doses of anti-D for the treatment of ITP, and demonstrates the need for a trial of high-dose anti-D (>100 microg/kg) in acute and chronic ITP.