Abstract: SA-PO728
Glomerulonephritis Following a Streptococcal Infection: Deciding Whether It's Poststreptococcal Glomerulonephritis
Session Information
- Glomerular Diseases: Clinical, Outcomes, Trials - III
November 05, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1303 Glomerular Diseases: Clinical‚ Outcomes‚ and Trials
Authors
- Gayle, Latoya N., NewYork-Presbyterian Hospital/Weill Cornell Medical Center, New York, New York, United States
- Weinstein, Alan Mark, NewYork-Presbyterian Hospital/Weill Cornell Medical Center, New York, New York, United States
- Salvatore, Steven, NewYork-Presbyterian Hospital/Weill Cornell Medical Center, New York, New York, United States
Introduction
Infection related glomerulonephritis (IRGN) was described in children as poststreptococcal glomerulonephritis (PSGN). Diagnostic kidney biopsy findings are subepithelial humps, which stain for C3 and IgG. IRGN is increasingly diagnosed in adults presenting for treatment of other infections. Ambiguity may arise when the biopsy does not display classic findings. We present a case of PSGN in an adult
Case Description
A 64-year-old female with hypertension and type 2 diabetes, presented to hospital with dyspnea for 1-2 days. She had a strep throat a week prior and received amoxicillin. She was saturating 86% on room air, with BP 182/90 and leg edema. Serum creatinine (Cr) = 4.68, up from 1.06 a month prior. Urine protein:Cr = 6.2, and urine sediment showed >50 RBC, >50 WBC, and RBC casts. On hospital day 1, urine output was less than 100 ml, despite bumetanide. CXR showed patchy consolidation and edema. She had worsening dyspnea with elevated systolic BP to 200 mmHg. CVVHD was started, and after net removal of 9L, systolic BP improved to 130 and BIPAP was no longer needed.
Serologies included C3 = 54 (90-180mg/dl), C4 = 46.8 (12-36mg/dl), antistreptolysin O (ASLO) titre = 544 (</=200iu/mol), ANA positive 1:180, rheumatoid factor positive, ESR 83 and CRP 10. ANCA, dsDNA, MPO, PR3, hepatitis B and C were negative. Renal biopsy on day 4 revealed an exudative GN with no crescents, and IF showing only C3 and no IgG; there was widespread acute tubular injury of moderate severity. The patient received dialysis twice (days 5 and 7), as urine output reached 1.25 L on day 8. She was discharged on day 10 with Cr = 3.4. One-week later Cr = 2.9, with C3 = 118 and ASLO = 198.
Discussion
IRGN is often diagnosed in children based on presentation, while in adults biopsy confirmation is recommended. The finding of C3 only on our patient’s kidney biopsy suggested possible C3GN. With her history, positive ASLO, and normalization of C3 within 2-3 weeks of presentation, this case was a true IRGN. However, at the time of biopsy there was ambiguity, between true PSGN and C3GN in someone who had a recent strep infection. Further studies into the evolution of IRGN in adults, with respect to the processing of glomerular immune deposits, may help address this ambiguity.