Abstract: PUB391
Decoding the Kidney Conundrum: Dive into the Glomerulonephritis Mystery!
Session Information
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Mirchandani, Sonakshi, Texas Health Resources, HEB/Denton, Texas, United States
- Chavez Velasquez, Ana, Texas Health Resources, HEB/Denton, Texas, United States
- Paryani, Rahul, Texas Christian University, Fort Worth, Texas, United States
Introduction
ANCA-associated glomerulonephritis (GN) comprises over half of RPGN cases, Typically, patients present with acute kidney injury (AKI) and active urinary sediment. Kidney biopsies often reveal necrotizing and crescentic glomerulonephritis with minimal (pauci immune) complex deposits and normal serum complements. Here, we describe a rare case of myeloperoxidase (MPO)-ANCA glomerulonephritis with concurrent immune complex deposition and low complement levels.
Case Description
A 77-year-old female with a medical history of OA, gout, hypertension, and type 2 diabetes presented in 2019 with AKI Cr 2.34 Baseline(0.9-1.1), hematuria (65 RBC), and significant proteinuria (Urine Protein Creatinine UP/C 3g). Biopsy indicated IgA nephropathy with acute crescentic changes. Serology showed MPO pANCA positivity and low C4. Treatment involved IV Solumedrol and cyclophosphamide which were later transitioned to oral immunosuppressants once creatinine stabilised.
In 2021, she experienced an intestinal angioedema due to ACE inhibitor(c1 esterase), leading to treatment discontinuation. A relapse occurred in 2022, necessitating oral immunosuppressants. In August 2023, she had another AKI episode(Cr 3.1 UP/C 6g) and underwent a second biopsy, revealing MPO-ANCA mediated focal necrotizing and focal sclerosing glomerulonephritis with concurrent immune complex and crescent formation, IF with granular capillary wall staining for IgG, IgA, IgM, C3, C1Q, kappa and lambda chains and electron Microscopy (EM) with immune complex dense deposits with 90% epithelial foot process effacement. Serology -MPO ANCA positive 1:40. low C4 <2.9, normal complement C3 at 95, Anti ds DNA negative, ANA negative, HIV negative. Treatment involved IV Rituximab and steroids with significant improvement for Cr to 1.7 She developed facial angioedema and AKI, prompting a third biopsy(April 2024) pending results showing improvement with Rituximab and planned avacopan therapy.
Discussion
Immune complex deposition in ANCA-associated vasculitis (AAV) GN is atypical, as AAV is typically "pauci-immune." Recent studies classify AAV/GN into "pauci-immune" (PI) and "immune complex" (IC) groups, with IC deposits potentially exacerbating ANCA effects and role of complement activation causing worsened proteinuria. Early recognition is crucial for preserving renal function, with rituximab and avacopan showing promise in treatment.