Kidney transplantation in catastrophic antiphospholipid syndrome survivors: Results from a nationwide series of 12 cases.

Catastrophic antiphospholipid syndrome (CAPS) is a rare, life-threatening subtype of APS that may progress to end-stage kidney disease. CAPS survivors may have limited access to kidney transplantation (KT). We conducted a retrospective nationwide study including all French KTs performed in recipients with a history of CAPS between 2008 and 2024. Twelve KTs were performed in 10 patients (median age, 45 [interquartile range {IQR}, 41-56] years), all from deceased donors. Anticoagulation therapy was resumed 4 (IQR, 0-5) hours after KT and reached therapeutic levels at 12 (IQR, 6-28) hours. Preventive strategies included perioperative anti-C5 therapy in 5 KTs and plasma exchange in 6, including 1 transplant performed with both approaches. No CAPS recurrences or deaths occurred. We observed 5 early microangiopathic events: 2 cases of microangiopathic hemolytic anemia with thrombocytopenia, 2 cases of cortical necrosis with microangiopathic hemolytic anemia and thrombocytopenia, and 2 segmental renal infarctions. One case of cortical necrosis led to early graft loss. After a median follow-up of 21 (IQR, 17-46) months, 9 of 12 (75%) kidney allografts remained functional (2 graft losses at 55 and 71 months). In this series, no CAPS recurrence or death was observed; however, allograft complications were frequent, highlighting the need for tailored preventive strategies.