Some Points for the KDIGO 2021 Guideline for Prophylactic Anticoagulation in Membranous Nephropathy: Is It Clear Enough for Us to Follow?

Context: Patients with membranous nephropathy (MN) are recognized as individuals with high risk of thrombosis. However, prophylactic anticoagulant therapy in this population is still a controversial topic for a lack of high-quality evidence. Subject of Review: The Kidney Disease: Improving Global Outcomes (KDIGO) 2021 Clinical Practice Guideline for the Management of Glomerular Diseases was published in Kidney International in October 2021, and it was updated on the topic of prophylactic anticoagulant therapy in patients with MN. Differing from the previous main concern about the risk of venous thromboembolism (VTE) in MN, it paid attention to the risk of arterial thromboembolism (ATE) as well. Additionally, the risk of ATE was considered to be associated with hypoalbuminemia. A tool for evaluating the risk of bleeding in patients with MN was proposed in the KDIGO 2021 guideline, and individuals with low risk of bleeding as well as high risk of VTE were suggested to use warfarin or low-molecular-weight heparin (LMWH) combined with aspirin, as an alternative regimen for warfarin. Second Opinion: Our analysis shows that no consensuses have been reached on whether the prevention of ATE is necessary for patients with MN or whether the risk of ATE is associated with hypoalbuminemia. The proposed tool is not the only choice of tools for bleeding assessment, and the HAS-BLED risk score might be a better choice from the perspective of general applicability and availability. Furthermore, in our opinion, the suggestion for prophylaxis regimen of LMWH combined with aspirin showed a lack of consideration and might be inappropriate to some degree. In summary, there are still many controversies in the field of prophylactic anticoagulation for MN; as a consequence, more high-quality studies are required to provide guidance.