What is your approach to treating antibody-mediated rejection in a pregnant patient with a kidney transplant?

This is a very difficult situation. Presumably, this is late AMR, and to begin with, we would have very few treatment options. I would first optimize immunosuppression and consider IVIG and solumedrol, and defer further treatment until after delivery. We have not used rituximab in pregnancy. Rituximab can cross the placenta, and evidence for safety in pregnancy is limited. PLEX has limited efficacy in late AMR; although this can be considered in life-threatening conditions in pregnancy (e.g., TTP), we have also not used this in a pregnant patient with AMR.