Abstract: PO1754
Coexisting Proteinase 3 Antineutrophil Cytoplasmic Antibody-Associated Crescentic Glomerulonephritis, Immunoglobulin A Nephropathy, and Lambda Light Chains
Session Information
- Glomerular Diseases: Vasculitis and TMA
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Report
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Kalaria, Arjun Lalit, UPMC, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
- Puli, Amoghavarsha, UPMC, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
- Bastacky, Sheldon, UPMC, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
Introduction
Rapidly progressive glomerulonephritis (RPGN) is a clinical syndrome that develops within weeks and is manifested by glomerular disease that is histologically delineated by crescent formation and progressively worsening renal function. The most common causes of RPGN include anti-neutrophil cytoplasmic antibody (ANCA) vasculitis, immune complex-mediated injury, and anti-glomerular basement membrane disease. We report a case of proteinase-3 (PR-3) ANCA associated crescentic glomerulonephritis with concurrent immunoglobulin A (IgA) nephropathy and lambda light chain. The co-existence of ANCA associated crescentic GN, IgA nephropathy and lambda light chain is rare.
Case Description
A previously healthy 53-year-old Caucasian woman with newly diagnosed Granulomatosis with Polyangiitis (PR-3 ANCA positive) presented with tachycardia, cough and congestion over the past 2 months. Physical examination was notable for sinus tachycardia and tenderness to palpation over maxillary sinuses. Urinalysis revealed active sediment with dysmorphic red blood cells.
Initial workup was significant for serum creatinine of 1.35 mg/dl (baseline of 0.7 mg/dl ), positive C-ANCA 1:160, anti-Proteinase-3 antibody 28.4 (normal <1) and 24-hour urine protein of 576 mg. Preliminary native kidney biopsy light microscopy showed active and organizing crescentic glomerulonephritis involving 15 of 34 (44%) non-globally sclerotic glomeruli. Immunofluorescence and electron microscopy were significant for granular mesangial staining for IgA and lambda light chain and presence of few mesangial electron-dense deposits. The patient was empirically pulsed with intravenous steroids for three days. She was given one dose of Rituximab with a planned second dose two weeks after discharge.
Discussion
Rapidly progressive ANCA associated crescentic GN along with mesangial staining for IgA and lambda light chain is extremely uncommon with limited literature. By presenting this case, we highlight the significance of a renal biopsy as an essential tool for diagnostic purposes and the need to have a low threshold to biopsy in otherwise clinically straight forward cases given unexpected histologic and immunologic findings that could affect therapy and consequently patient’s morbidity and mortality.