Intravenous immunoglobulin anti-D treatment of chronic immune thrombocytopenic purpura in children

Eleven children with chronic immune thrombocytopenic purpura were treated with a 40 mg/kg dose of intravenous immunoglobulin anti-D (WinRho-SD). In 7 patients the results were regarded as very good (the platelet count increased by >100 Y 10(9)/1) and in 2 as good (>50 Y 10(9)/1); in 2 children the increase in platelet count was low (<50 Y 10(9)/1), despite repeated WinRho-SD administration. The increase in platelet count was achieved within 3 or 4 days and persisted for 2 to 36 weeks (median 8). In all patients mild red cell destruction occurred, reflected not only in routine tests but also in the elevated number of IgG molecules on patients' red cells (enzyme-linked antiglobulin test) and in their adherence and phagocytosis by patients' monocytes (monocyte monolayer assay). Additional observations concerning the interaction between patients' monocytes and donors' erythrocytes sensitized with a known amount of anti-D suggest that the mechanism of intravenous immuno-globulin anti-D action is not restricted to Fcg receptor blockade.