Abstract: SA-PO829
Infection-Related Glomerulonephritis with Thrombotic Microangiopathy following Treatment for Streptococcal Bacteremia: A Case Report
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
- Onishi, Keisuke, Kagawa Daigaku, Takamatsu, Kagawa, Japan
- Sofue, Tadashi, Kagawa Daigaku, Takamatsu, Kagawa, Japan
- Minamino, Tetsuo, Kagawa Daigaku, Takamatsu, Kagawa, Japan
Introduction
Post-streptococcal acute glomerulonephritis (PSAGN) occurs 1-3 weeks after infections of the upper respiratory tract or skin. Infection-related glomerulonephritis can be accompanied by anemia and thrombocytopenia; however, the detailed mechanism remains unknown. Here, we report a case of PSAGN complicated by thrombotic microangiopathy (TMA) after treatment for streptococcal bacteremia.
Case Description
A 64-year-old woman with no relevant medical history was admitted to our hospital with fever and abdominal pain. Antibiotics were administered because a blood culture revealed group A Streptococcus, although the fever and right-sided chest pain persisted. Surgical thoracic drainage was performed after a diagnosis of pyothorax based on CT and pleural fluid analysis. Postoperative fever persisted, and 14 days after admission, serum Cr was 1.2 mg/dL and urinalysis results were normal; however, low C3 and CH50 levels were observed. On day 21 after admission, gross hematuria developed, and urinalysis revealed proteinuria. Based on the patient’s medical history and positive ASO findings, she was clinically diagnosed with PSAGN. Progressive thrombocytopenia and hemolytic anemia were also observed, requiring differentiation from TMA. One month after PSAGN onset, serum Cr level had elevated to 1.8 mg/dL. Renal biopsy was performed, and light microscopy revealed membranoproliferative glomerulonephritis with tubulointerstitial nephritis. Immunofluorescence revealed C3 and IgG deposition in the glomerular tuft, and electron microscopy showed dense subepithelial deposits, leading to the diagnosis of PSAGN. Six weeks after the onset of PSAGN, 30 mg prednisolone was administered because her renal function, anemia, and complement levels did not improve. Renal function and hemolytic anemia improved rapidly after treatment initiation, followed by steroid tapering and complete remission of proteinuria after 3 months.
Discussion
There have been few reports of cases of secondary TMA after severe streptococcal infection or of TMA complicated by PSAGN. In this report, we captured the natural history of PSAGN development by observing gross hematuria followed by a drop in complement levels after streptococcal infection. Because TMA occurred simultaneously with PSAGN, a common underlying pathogenesis is hypothesized for both diseases.