Role of therapeutic anticoagulation in kidney transplant recipients with thrombophilia: A systematic review

Abstract

Abstract Background: Renal allograft thrombosis, though commonly attributed to surgical or anatomical causes, is increasingly linked to inherited thrombophilia, including Factor V Leiden, prothrombin gene mutations, and deficiencies in protein C, protein S, or antithrombin III. These conditions raise the risk of early graft thrombosis and may impair graft survival. While therapeutic anticoagulation has been proposed as a preventive strategy, there are no established guidelines to direct its use in transplant recipients with thrombophilia. Methods: We systematically searched PubMed, Embase, and the Cochrane Library from inception to July 2025 to assess the role of therapeutic anticoagulation in kidney transplant recipients with thrombophilia. Two reviewers independently screened 275 titles and abstracts, as well as 35 full-text articles, using Covidence. Eligible studies included observational cohorts and case series (with≥2 patients) that reported anticoagulation outcomes in adult transplant recipients with thrombophilia. Case reports (n=1), reviews, pediatric studies were excluded. No randomized controlled trials were identified. Eleven observational studies met our inclusion criteria. Results: Type of anticoagulation medication, timing of use, and outcome reporting were heterogeneous. Only one retrospective cohort study directly compared anticoagulated and non-anticoagulated patients, reporting no thrombotic events in the anticoagulated group versus two in the control group. Several studies suggested benefits of anticoagulation, particularly in patients with antiphospholipid syndrome or lupus anticoagulant. Bleeding complications were reported in some of the studies, with major bleeding rates ranging from 20% to 30% in some cohorts. One study noted a 30% rate of perinephric hematomas in patients receiving perioperative heparin. Due to significant heterogeneity in study design, anticoagulation protocols, thrombophilia, and outcomes reported, meta-analysis was not feasible. Conclusion: Therapeutic anticoagulation may reduce thrombotic risk in kidney transplant recipients with thrombophilia, but bleeding complications and limited comparative evidence preclude general recommendations. Randomized and controlled studies are needed to better define indications and safety. Until then, anticoagulation decisions should be individualized based on patient risk factors and clinical context.