Abstract: FR-PO0792
A Rare Case of Immune Complex Glomerular Nephritis with Associated Chronic Eosinophilic Pneumonia
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
- Szendrey, John Alexander, Penn Medicine, Philadelphia, Pennsylvania, United States
- Galgano, Joseph, Penn Medicine, Philadelphia, Pennsylvania, United States
- Nader, Ralph, Penn Medicine, Philadelphia, Pennsylvania, United States
Introduction
Membranoproliferative glomerular nephritis (MPGN) is a pattern of glomerular injury which can be seen on kidney biopsy with a broad differential diagnosis. Diagnosis is critical to guide management. We present a case of MPGN associated with chronic eosinophilic pneumonia.
Case Description
A 68-year-old male was transferred to our institution for management of new interstitial lung disease and nephrotic range proteinuria. He had presented to hospital with fatigue and dyspnea where he was treated for pneumonia, and had an exudative pleural effusion managed with video-assisted thoracoscopic surgery. Pleural biopsy demonstrated rare mesothelial cells, chronic inflammation with lymphocytes and rare plasma cells.
On arrival, he had normal hemodynamics and was euvolemic on exam. Creatinine was at baseline 0.86 mg/dL, serum albumin was 2 g/dL. Blood count had a eosinophil count of 2,000 cells/uL. Computed tomography-chest found bilateral peripheral consolidative and ground glass opacities. Urinalysis and microscopy were negative other than heavy protein. He had no proteinuria 3 months prior. Urine protein/creatinine was 7.31 g/g. He had a positive ANA (1:320, speckled pattern), but serology including ANCA, anti-dsDNA, anti-PLA2R was otherwise negative. Viral and paraprotein studies were negative. Complement 3 (C3) level was normal, but C4 was reduced at 3 mg/dL (16-47 mg/dL). Kidney biopsy showed mild immunocomplex glomerulopathy with membranous and membranoproliferative features. Immunofluorescence (IF) had +1 polytypic IgG and negative complement staining, but was limited by a paraffin sample. Electron microscopy (EM) showed scattered subepithelial and trace subendothelial immune-type deposits, and diffuse foot process effacement. Transbronchial biopsy of lymph nodes was negative for carcinoma, granulomas, or clonal process. He was diagnosed with chronic eosinophilic pneumonia (CEP) and immune-complex glomerulonephritis (ICGN) and started on prednisone and mycophenolate.
Discussion
The finding of ICGN with MPGN pattern on biopsy has a broad differential including autoimmune, malignant, clonal, and infectious causes. No monoclonal process was seen on IF, and viral causes were ruled out. Lupus nephritis is possible as tubuloreticular inclusions were seen on EM, however serology for lupus was negative. Tissue biopsies did not demonstrate IgG4 related disease. Occult malignancy remains a differential.