Kidney Week

Abstract: FR-PO0457

Severe Small-Bowel Hemorrhage Preceding Pauci-Immune Crescentic Glomerulonephritis in PR3/c-ANCA-Associated Vasculitis

Session Information

• AKI: Case Reports - TMA, Vasculitis, Immune-Mediated Injury, and Systemic Disease
  October 23, 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

• Brady, Clayton, Mayo Clinic Minnesota, Rochester, Minnesota, United States

Clayton Brady, MD, PhD

• Wexler, Jade, Mayo Clinic Minnesota, Rochester, Minnesota, United States

Jade Wexler, MD

• Agrawal, Upasana, Mayo Clinic Minnesota, Rochester, Minnesota, United States

Upasana Agrawal, MBBS

• Kamalumpundi, Vijayvardhan, Mayo Clinic Minnesota, Rochester, Minnesota, United States

Vijayvardhan Kamalumpundi, MD

• Hassan, Hatim A., Mayo Clinic Minnesota, Rochester, Minnesota, United States

Hatim A. Hassan, MD, PhD, FASN

• Weyand, Cornelia, Mayo Clinic Minnesota, Rochester, Minnesota, United States

Cornelia Weyand, MD, PhD

Introduction

PR3/c-ANCA-associated vasculitis (PR3-AAV) classically causes granulomatosis with polyangiitis affecting the upper and lower respiratory tracts and kidneys. Gastrointestinal involvement is rare but may be severe. We report a case of PR3-AAV with life-threatening small bowel hemorrhage prior to the development of pauci-immune crescentic glomerulonephritis.

Case Description

A 60-year-old man developed a purpuric rash that improved with prednisone. One month later he developed abdominal pain with massive melena and hematochezia requiring ICU admission and seven units transfusion, with hemoglobin nadir of 5.6 g/dL. CT imaging showed jejunal wall thickening, mesenteric edema, and luminal dilation. Capsule endoscopy demonstrated distal small bowel bleeding with jejunal erosions and mucosal erythema.

Symptoms self-resolved and he was discharged. Shortly after, abdominal pain recurred and he underwent expedited rheumatology work up. Skin biopsy revealed leukocytoclastic vasculitis without IgA deposition. Serologic evaluation demonstrated strongly positive PR3 antibodies (>8.0 U) and c-ANCA titer (1:64). Treatment with methylprednisolone and rituximab was initiated for active PR3-AAV.

Kidney function remained preserved with serum creatinine 0.86 mg/dL, though there was persistent microscopic hematuria. Despite treatment, over the following weeks he developed acute kidney injury with serum creatinine rising to 2.3 mg/dL, nephritic urine sediment, and nephrotic-range proteinuria. Kidney biopsy demonstrated pauci-immune necrotizing and crescentic glomerulonephritis with fibrinoid necrosis, segmental cellular crescents, and negative immunofluorescence microscopy. Avacopan was added but discontinued due to myalgias. Renal function gradually improved over 6 months but then declined, ultimately prompting another cycle of methylprednisolone and rituximab.

Discussion

This case highlights an uncommon presentation PR3-AAV with gastrointestinal hemorrhage preceding overt kidney involvement. Progressive hematuria and proteinuria in this patient ultimately culminated in biopsy-proven pauci-immune crescentic glomerulonephritis. Although renal disease is a classic feature of PR3-AAV, early kidney manifestations may be subtle despite active systemic vasculitis. Awareness of gastrointestinal manifestations is critical in atypical presentations of PR3-AAV to avoid delaying diagnosis and treatment.