Modified antibody in fetal alloimmunization.

In this issue of Blood, Ghevaert et al propose to develop a therapeutic antibody for fetal and neonatal alloimmune thrombocytopenia (FNAIT) that would block the actual antibody in sensitized mothers from binding and therefore prevent, or at least ameliorate, fetal and neonatal thrombocytopenia in fetuses who would otherwise be affected.1 The goal of the group is to engineer an antibody reagent that would on the one hand not engage conventional activating Fc receptors and on the other hand interact normally with FcRn, allowing transplacental passage.