Kidney Week

Abstract: FR-PO0793

Pauci-Immune Crescentic Glomerulonephritis with Diffuse Alveolar Hemorrhage and Serologic Overlap: Navigating Myeloperoxidase (MPO)-ANCA Vasculitis with Concurrent Antinuclear Antibody (ANA) and Anti-Sjogren Syndrome-Related Antigen A (Anti-SSA) Positivity

Session Information

• Glomerular Diseases: ANCA Vasculitis, Anti-GBM Disease, and Crescentic GN
  October 23, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Sweis, Jaleel Jerry, Southern Illinois University School of Medicine, Springfield, Illinois, United States

Jaleel Jerry Sweis, MD

• Carey, Austin L., Southern Illinois University School of Medicine, Springfield, Illinois, United States

Austin L. Carey, MD

• Rich, Trent E., Southern Illinois University School of Medicine, Springfield, Illinois, United States

Trent E. Rich, MD

• Chen, Xueguang (Gary), Southern Illinois University School of Medicine, Springfield, Illinois, United States

Xueguang (Gary) Chen, MD, PhD

Introduction

MPO-ANCA–associated vasculitis (AAV) presenting with diffuse alveolar hemorrhage (DAH) requiring mechanical ventilation is associated with high mortality. Concurrent high-titer ANA and anti-SSA positivity in MPO-AAV raises important diagnostic considerations, including autoimmune overlap syndromes and drug-induced vasculitis.

Case Description

75-year-old female with renal artery stenosis status post left renal artery stent, hypertension, chronic kidney disease (baseline creatinine 2.5–2.7 mg/dL), presented with progressive dyspnea and severe hypoxemia (oxygen saturation in the 50s). Hemoglobin was 6.7 g/dL and creatinine 7.7 mg/dL. CT chest showed diffuse bilateral alveolar infiltrates, and bronchoscopy confirmed diffuse alveolar hemorrhage (DAH). Hospital course was complicated by oliguric acute kidney injury requiring emergent hemodialysis. Serologic workup revealed MPO antibody 222.4 U/mL, p-ANCA 1:640, ANA 1:1280, anti-SSA 140 U/mL, and low C3. Anti-GBM, anti-dsDNA, PR3-ANCA, and cryoglobulins were negative. Renal biopsy demonstrated pauci-immune crescentic glomerulonephritis consistent with ANCA-associated vasculitis. She required mechanical ventilation and Treatment included pulse-dose methylprednisolone, plasmapheresis, and rituximab. Plasmapheresis was initiated for life-threatening DAH. MPO antibody titers declined to 14 U/mL after 3 months. Subsequently she demonstrated marked pulmonary recovery and her creatinine improved to 2.7 mg/dL with preserved urine output, though intermittent hemodialysis remained necessary.

Discussion

This case highlights two teaching points. First, concurrent high-titer ANA and anti-SSA positivity with MPO-ANCA requires careful evaluation. Drug-induced ANCA vasculitis commonly presents with multiple autoantibodies; however, absence of culprit drug exposure supported primary ANCA-associated vasculitis. Whether SSA positivity reflects evolving overlap autoimmunity warrants longitudinal follow-up. Second, although PEXIVAS showed no overall mortality benefit of plasma exchange in severe AAV, subgroup analyses suggested possible benefit in DAH. Rapid pulmonary improvement likely reflected glucocorticoid and plasmaphersis effect, whereas sustained serologic remission reflected rituximab-mediated B-cell depletion suggesting potential for continued renal recovery over 6-12 months.