Abstract: TH-PO682
Infection-Related ANCA-Negative Pauci-Immune Glomerulonephritis
Session Information
- Glomerular Diseases: Epidemiology and Case Reports
November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Sohail, Mohammad Ahsan, Cleveland Clinic Glickman Urological and Kidney Institute, Cleveland, Ohio, United States
- Taliercio, Jonathan J., Cleveland Clinic Glickman Urological and Kidney Institute, Cleveland, Ohio, United States
- Tomaszewski, Kristen, Cleveland Clinic Glickman Urological and Kidney Institute, Cleveland, Ohio, United States
- Mehdi, Ali, Cleveland Clinic Glickman Urological and Kidney Institute, Cleveland, Ohio, United States
Introduction
Infection-related glomerulonephritis (IRGN) is typically an immune-complex mediated disease characterized by a diffuse proliferative process with mesangial, subendothelial and subepithelial deposits comprised of various combinations of IgM, IgG, IgA and C3. However, other forms of IRGN have also been reported, including those with a pauci-immune crescentic pattern of injury. The overwhelming majority of pauci-immune GN cases are associated with the presence of anti-neutrophil cytoplasmic antibodies (ANCA). However, approximately 2-10% of these patients may be ANCA negative, and here, we present two cases of IRGN, which were ANCA-negative, and demonstrated a pauci-immune crescentic pattern of injury.
Case Description
Table 1 describes the clinical characteristics, histologic features and outcomes for two patients who initially presented with acute kidney injury, were subsequently diagnosed with ANCA-negative pauci-immune crescentic GN on kidney biopsy and after further evaluation for secondary causes of pauci-immune GN, were found to have bacterial aortic/mitral valve endocarditis.
Discussion
This case series depicts two patients who developed ANCA-negative pauci-immune GN in association with bacterial endocarditis. The largest case series of 74 patients with ANCA-negative pauci-immune GN included 9 cases that were infection-related. 54% of these patients had extra-renal involvement and 23% of them required dialysis at diagnosis. The diverse glomerular presentations in association with infections have significant clinical implications since the prompt recognition of an underlying systemic infection is crucial to avoid inadvertent immunosuppressive therapy. It is imperative for clinicians to screen for occult infections not only when an immune-complex GN is seen, but also when a pauci-immune process is identified on a kidney biopsy.
Table 1
| Clinical Characteristics | Case 1 | Case 2 |
| Age (Years) / Sex | 69 / Female | 59 / Female |
| Clinical Manifestations | Exertional Dyspnea and Lower Extremity Edema | Progressive Weight Gain, Exertional Dyspnea and Lower Extremity Non-Blanching Petechial Rash |
| Serum Creatinine on Initial Presentation (Baseline Creatinine) (mg/dL) | 4.1 (1.0) | 3.0 (0.6) |
| Urinalysis Urine Protein/Creatinine Ratio (mg/mg) | Microscopic Hematuria (>25 RBCs/HPF) (Dysmorphic RBCs) 0.45 | Microscopic Hematuria: (>25 RBCs/HPF) (Dysmorphic RBCs) 0.95 |
| Available Serologic Testing | ANA Negative ANCA Negative Low Serum C3 (71 mg/dL) Low Serum C4 (7 mg/dL) | Polyclonal IgG Type 3 Cryoglobulinemia IgM Lambda M-Protein ANA Negative ANCA Negative Low C3 (79 mg/dL) Normal C4 (24 mg/dL) |
| Blood Cultures Echocardiogram Findings | Streptococcus Mutans Mitral/Aortic Valve Vegetations | Streptococcus Mitis Mitral Valve Regurgitation Mitral/Aortic Valve Vegetations |
| Histologic Features on Kidney Biopsy | Pauci-Immune GN Endocapillary Hypercellularity Cellular/Fibrous Crescents with Necrosis Moderate IFTA | Pauci-Immune GN with Trace IgA, C3 and C1q Endocapillary Hypercellularity Cellular Crescents Severe IFTA |
| Clinical Outcomes | S/P Mitral and Aortic Valve Replacement Initiated KRT at the time of kidney biopsy Repeat kidney biopsy 1 month later showed focal global glomerulosclerosis without ongoing proliferative activity Last Follow-Up: remains KRT-dependent 4 months following valvular surgery | S/P Mitral Valve Replacement and Aortic Valve Repair Initiated KRT immediately after valvular surgery Subsequent kidney recovery with cessation of KRT one week after initiation Last Follow-Up: remains liberated from KRT with serum creatinine 1.23 mg/dL 3 months following valvular surgery |
Interstitial Fibrosis and Tubular Atrophy (IFTA); Kidney Replacement Therapy (KRT)