Why should intramuscular anti-D be different from intravenous anti-D?

Abstract

For reasons of safety the use of intravenous anti D to treat ITP has largely been abandoned because of the risk it incurs of intravascular haemolysis. Intramuscular delivery of anti-D could be a safer approach and deserves to be further evaluated. IV anti-D was a mainstay of ITP treatment in the United States in the 1990's until the development of intravascular hemolysis (IVH) and its serious even fatal consequences was appreciated. Subsequently, treatment of patients with ITP with IV anti-D has become very rare given other alternatives and the IVH risk. IM anti-D does not carry a risk for IVH and it should be re-evaluated and reconsidered as an option for D+ DAT-negative not splenectomized adults who do not have a long duration of ITP and require maintenance treatment. Commentary on: Lakhwani, et al. Intramuscular Anti-D treatment for immune thrombocytopenia: A single centre experience. Br J Haematol 2023;200:353-357.