Phospholipase A2 Receptor-Positive Membranous Nephropathy Associated with Polycythemia Presenting with Recurrent Venous Thrombosis

Abstract

Background: Nephrotic syndrome with concomitant polycythemia is exceedingly rare, and its association with phospholipase A2 receptor (PLA2R)-positive membranous nephropathy is even more uncommon.
Case Presentation: We report the case of a 29-year-old male who presented with recurrent venous thromboembolic
events, including pulmonary embolism and renal vein thrombosis, and was subsequently found to have PLA2Rpositive membranous nephropathy with secondary polycythemia. Despite anticoagulation and immunosuppressive
therapy, the patient continued to have recurrent thrombotic episodes and persistent proteinuria, ultimately requiring escalation to a modified Ponticelli regimen. This case underscores several important learning points. First, polycythemia as a manifestation of membranous nephropathy is an extremely rare phenomenon, with only a handful of
cases described in the literature. Second, the presence of recurrent thromboembolism in young patients warrants
careful evaluation for underlying glomerular disease, particularly when associated with heavy proteinuria and hypoalbuminemia. Third, the pathophysiological link between nephrotic syndrome and secondary polycythemia remains
unclear, highlighting the need for ongoing clinical vigilance and further research.
Conclusion: This report adds to the limited literature on the coexistence of membranous nephropathy and polycythemia, while emphasizing the importance of early recognition, combined immunosuppressive and anticoagulant
strategies, and close follow-up to reduce morbidity from thrombotic complications.