Relative risk of post-transplant renal thrombosis in patients with antiphospholipid antibodies

Introduction. Antiphospholipid antibody syndrome (APAS) is a condition associated with recurrent arterial and venous thrombosis, recurrent abortions, and thrombocytopenia either with or without lupus. In this study we have evaluated the impact of APAS on the renal transplant outcome of 174 patients. Method. Patients' APAS status was determined by the presence of anticardiolipin antibodies (ACA) and a history of clotting disorders. Serum samples from each patient were tested for the presence of ACA by the ELISA method. Transplant outcomes were monitored for ≤ 1 yr. Results. Of 174 patients, 78 received renal transplants. Six of these 78 patients had APAS as evidenced by either recurrent microrenal angiopathy (2 patients), thrombocytopenia (1 patient) or frequent A-V shunt thrombosis (3 patients) along with high titers of ACA of IgM, IgG, or both subtypes at the time of their transplants. Each of these 6 patients thrombosed their renal allografts within a week of their transplants. The other 72 transplanted patients with no APAS were all doing well 1 yr post-transplant. The association between APAS and post-transplant renal thrombosis among these patients is highly significant (p < 0.0001). In contrast, no association was discerned between post-transplant thrombosis and prior sensitization to HLA. Conclusion. Our data demonstrates that patients with APAS are at high risk for development of post-transplant renal thrombosis.