Perioperative Use of Efgartigimod Alfa, a Neonatal Fc Receptor Antagonist, to Reduce Antiphospholipid Antibody Titers and Thrombotic Risk in a Kidney Transplant Recipient.

Antiphospholipid syndrome (APS) is associated with an increased risk of thrombotic complications after kidney transplantation, particularly in patients with persistently elevated and triple-positive antiphospholipid antibodies (aPLs). Management of APS in kidney transplantation relies primarily on perioperative anticoagulation; however, thrombotic events may still occur despite appropriate therapy in patients with high-risk aPLs. We report the case of a 49-year-old woman with systemic lupus erythematosus-associated APS and persistently triple-positive aPLs who underwent living donor kidney transplantation. Because of her high thrombotic risk, perioperative immunoglobulin G--lowering therapy with the neonatal Fc receptor antagonist efgartigimod alfa was administered in addition to therapeutic anticoagulation. Treatment with efgartigimod alfa was associated with marked reductions in anticardiolipin and anti-β2-glycoprotein I antibody levels before transplantation, conversion of lupus anticoagulant to negative after transplantation, and sustained suppression of aPLs during the early posttransplant period. Kidney transplantation was successful with stable graft function during follow-up. To our knowledge, this represents the first reported use of efgartigimod alfa to reduce aPLs in the perioperative management of APS in kidney transplantation.