Prevalence and clinical significance of antiphospholipid antibodies in renal transplant recipients

Background. The prevalence and clinical significance of antiphospholipid an tibodies (APAs) have not been extensively studied in non-systemic lupus ery thematosus (non-SLE) renal transplant recipients. Methods. To further define the prevalence and clinical significance of APAs in non-SLE renal transplant recipients and the appearance of dialysis-rela ted APAs after renal transplantation, we conducted a retrospective study on 178 renal transplant recipients. Documentation of anticardiolipin antibodi es (ACAs) and lupus anticoagulant in non-SLE renal transplant recipients, r etrospective documentation of ACAs on pretransplant frozen plasma and stand ardized collection of demographic characteristics and posttransplant histor y of thrombosis were assessed. Results, Fifty of 178 patients (28.1%) had APAs, Transplant duration was sh orter and hemodialysis duration was longer in patients with APAs, A posttra nsplant history of both venous and arterial thrombosis was more frequent in patients with posttransplant APAs (respectively, 18% vs. 6.2% [P<0.001] an d 8% vs. 2.3% [P<0.001]). Pretransplant sera were available from 55 patient s. Most of patients with posttransplant ACAs had ACAs in the pretransplant period (85%). Pretransplant ACAs were associated with a posttransplant hist ory of venous thrombosis (P<0.001). Conclusions. Our study demonstrates a high prevalence of APAs in non-SLE re nal transplant recipients. Most of them have been acquired in the pretransp lant period. Both pretransplant ACAs and posttransplant APAs are associated with posttransplant episodes of thrombosis. Further studies are required t o determine the interest of prophylactic measures.