Anuria as an Unusual Presentation of Recurrent FSGS Following Kidney Transplant: A Case Report

Introduction: Recurrent focal segmental glomerulosclerosis (FSGS) after kidney transplantation presents a significant challenge that can cause graft failure.This report highlights an unusal case where recurrent FSGS led to early anuria shortly after transplantation. Case Description: A 24-year-old male, diagnosed with primary FSGS since 2017 and end stage renal disease (ESRD) of two years, underwent a living donor kidney transplant from his mother in 2024. Pre-transplant evaluation showed no donor-specific antibodies (DSAs), negative crossmatches, and a CMV mismatch (D+/R-),So he started Valacyclovir as a prophylaxis. Post-operatively, the graft function was excellent initially. Patient urine output was 600-800 mL/hr with improving creatinine levels. By postoperative day 2 (POD 2), Urine output began to decline till the patient became anuric by POD 3. Renal Doppler and ultrasound were normal. Renal biopsy performed on POD 3 revealed acute tubular injury (ATI) with no signs of rejection or C4d positivity. Despite initial management with plasmapheresis and antithymocyteglobulin (ATG), the patient remained anuric. A second biopsy on POD 9 confirmed ATI. So, his immunosuppression was adjusted by reducing tacrolimus, initiating sirolimus, and switching valacyclovir to valganciclovir. On POD 16,Urine output began to increase. Electron microscopy (EM) revealed diffuse podocyte foot process effacement, confirming the diagnosis of recurrent FSGS.12 sessions of plasmapheresis were done and a single dose of obinutuzumab was given. At the last follow-up, he maintained stable graft function with a serum creatinine 1.05 mg/dL, though urine protein/creatinine ratio (1.5 g/day). Discussion: Recurrent FSGS remains a diagnostic and theraputic challenge in kidney transplantation. This case is unique due to its early, atypical presentation with anuric graft dysfunction. It shows the diagnostic challenges associated with early recurrence of primary FSGS post-transplant, where anuria may be the sole presenting feature. Electron microscopy plays an important role in confirming the diagnosis, particularly in cases where light microscopy fails to reveal glomerular pathology.