Kidney Week

Abstract: SA-PO0371

Severe Obstructive AKI from Biopsy-Precluded Retroperitoneal Fibrosis in Quiescent Systemic Lupus Erythematosus

Session Information

• AKI: Case Reports - Drug/Toxin Injury, Crystals, Obstruction, and Unusual Presentations
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 102 AKI: Clinical, Outcomes, and Trials

Authors

• Muralidharan, Suchitra, University of Cincinnati, Cincinnati, Ohio, United States

Suchitra Muralidharan, MD

• Hasan, Mohammed Mustafa, University of Cincinnati, Cincinnati, Ohio, United States

Mohammed Mustafa Hasan, MD

• Andrews, Trisha, University of Cincinnati, Cincinnati, Ohio, United States

Trisha Andrews, MD

• McGraw, Gregory, University of Cincinnati, Cincinnati, Ohio, United States

Gregory McGraw, DO

• Gudsoorkar, Prakash Shashikant, University of Cincinnati, Cincinnati, Ohio, United States

Prakash Shashikant Gudsoorkar, MD, FASN

Introduction

Retroperitoneal fibrosis (RPF) rarely occurs in quiescent systemic lupus erythematosus (SLE). We describe obstructive acute kidney injury (AKI) from RPF where biopsy was anatomically precluded and non-lupus etiologies remained possible.

Case Description

A 36-year-old male with SLE (class IV/G lupus nephritis, MMF maintenance) and hypertension (lisinopril/HCTZ) presented with fatigue and weight loss. Creatinine rose from 0.9 to 12.37 mg/dL (RI 0.6-1.2 mg/dL) with bland urine and low UPC 0.06 (RI <0.2). Inflammatory markers were elevated (CRP 58.9 [RI <1.0 mg/dL], ESR 105 [RI <15 mm/hr]); C3, C4, and dsDNA were normal, excluding flare. IgG4 was normal (18 mg/dL). CT showed a retroperitoneal mass at the aortic/IVC bifurcation, causing bilateral hydroureteronephrosis. Biopsy was deferred as the mass abutted major vessels. Lisinopril/HCTZ (potential RPF triggers) were stopped; MMF continued. Bilateral stents were placed without steroids. Creatinine improved to 1.55 mg/dL in 1 month. PET/CT showed active periaortic tissue concerning for RPF vs. lymphoma; bone marrow biopsy was negative.

Discussion

Obstructive AKI from RPF in quiescent SLE poses a dilemma when biopsy is unsafe. While 70% of RPF is idiopathic, it is rarely linked to SLE. A conservative strategy—ureteral decompression, stopping trigger drugs, and maintaining background immunosuppression—can successfully recover kidney function even when empiric high-dose steroids are withheld due to diagnostic uncertainty.