Abstract: SA-PO837
Membranoproliferative Glomerulonephritis with Striated Ultrastructural Deposits: A New Pathological Entity? A Case Report and Literature Review
Session Information
- C3G, TMA, MGRS, Amyloidosis, and More
October 26, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Ishida, Manna, Kyoto Daigaku Igakubu Fuzoku Byoin, Kyoto, Kyoto, Japan
- Yamamoto, Shinya, Kyoto Daigaku Igakubu Fuzoku Byoin, Kyoto, Kyoto, Japan
- Iwashige, Yohei, Kyoto Daigaku Igakubu Fuzoku Byoin, Kyoto, Kyoto, Japan
- Mii, Akiko, Nihon Ika Daigaku, Bunkyo-ku, Tokyo, Japan
- Shimizu, Akira, Nihon Ika Daigaku, Bunkyo-ku, Tokyo, Japan
- Yanagita, Motoko, Kyoto Daigaku Igakubu Fuzoku Byoin, Kyoto, Kyoto, Japan
Introduction
Glomerular diseases with organized deposits can be classified into various etiologies. A diagnostic algorithm based on clinical and pathological findings has been proposed; however, some cases cannot be diagnosed using existing algorithms.
Case Description
A 77-year-old man presented to our hospital with proteinuria, hematuria, and lower leg edema that had developed 1 month prior. Renal biopsy revealed membranoproliferative glomerulonephritis (MPGN). Electron microscopy showed microfilament-like substructures with regularly stacked, straight bands arranged in parallel in the subendothelial space. The examinations and clinical findings were incompatible with known glomerular diseases with organized deposits with organized deposits . During 2 years without immunosuppressive drugs, he developed nephrotic syndrome, and renal impairment. A second renal biopsy revealed that the area occupied by the deposits was prominently extended (Figure). Hemodialysis was initiated 10 months after the second biopsy. We also performed mass spectrometry (MS) and estimated exponentially modified protein abundance index (emPAI) and, significant levels of fibrinogen and fibronectin were detected. Immunostaining for fibrinogen, fibrin, and fibronectin was also positive in the subendothelial space.
Discussion
Our case pathologically showed rare fibril structure mimicking striated fibrin bundles, and clinically showed progressive renal impairment. MS and emPAI analysis suggested the possibility of new disease entity which was associated with endothelial injury induced by fibril structure composed of a fibrin-fibronectin complex.Clinicians should be aware of the findings of glomerulonephritis with striated ultrastructural deposits because these patients do not respond to steroids and have a poor prognosis.