A dose of 75 μg/kg/d of i.v. anti-D increases the platelet count more rapidly and for a longer period of time than 50 μg/kg/d in adults with immune thrombocytopenic purpura

Treatment with 75 mug/kg/d intravenous (i.v.) anti-D was compared with 50 mug/kg/d in a prospective randomized study of 27 RhD-positive, human immunodeficiency virus-negative, adult, acute, non-splenectomized patients with immune thrombocytopenic purpura (ITP) and platelet counts less than or equal to 30 x 10(9)/l. The higher dose resulted in greater median d 1 (43 x 10(9)/l vs. 75 x 10(9)/l; P = 0.012) and d 7 (153 x 10(9)/l vs. 64.5 x 10(9)/l: P = 0.001) platelet increases despite no greater haemoglobin decrease. Children with acute ITP receiving 75 mug/kg/d had overnight platelet increases in seven out of nine cases. The duration of effect at the 75 mug/kg/d dose was 46 d vs. 21 d (P = 0.03). Adverse events were mild to moderate and ameliorated with prednisone and acetaminophen premedication.