Abstract: TH-PO0589
Distinguishing Severe Alport Syndrome from Primary FSGS Using Retinal Optical Coherence Tomography (OCT): Diagnostic Role for Temporal Thinning
Session Information
- Monogenic Kidney Diseases: Glomerular
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Genetic Diseases of the Kidneys
- 1201 Genetic Diseases of the Kidneys: Monogenic Kidney Diseases
Authors
- Ibrahim, Abdelrahman, University of Utah Health, Salt Lake City, Utah, United States
- Mekki, Ossama, University of Utah Health, Salt Lake City, Utah, United States
- Nwaduru, Chinedu Elvis, University of Utah Health, Salt Lake City, Utah, United States
- Revelo Penafiel, Monica Patricia, University of Utah Health, Salt Lake City, Utah, United States
- Al-Rabadi, Laith, University of Utah Health, Salt Lake City, Utah, United States
Background
Focal segmental glomerulosclerosis (FSGS) may arise from both primary immune-mediated processes and inherited disorders such as Alport syndrome (AS), complicating diagnosis and treatment. Distinguishing these entities is critical to avoid misdiagnosis and inappropriate immunosuppression. We investigated whether the Temporal Thinning Index (TTIMax), derived from retinal OCT, could differentiate primary FSGS from genetically confirmed severe AS (XLAS-M + Compound).
Methods
We compared TTIMax values in 15 patients with biopsy-confirmed primary FSGS (all receiving immunosuppressive therapy) and 43 patients with genetically confirmed male X linked AS and both male and female autosomal recessive AS.. TTIMax was calculated from OCT scans using standard ETDRS grid-based segmentation. A generalized linear model adjusted for age and sex. Renal biopsy electron microscopy was also evaluated to assess basement membrane morphology in both groups.
Results
Adjusted mean TTIMax was significantly higher in the severe AS group (11.78 ± 1.16%) than in the primary FSGS group (6.27 ± 1.06%, p < 0.001). OCT in primary FSGS showed minimal temporal thinning, while severe AS cases consistently demonstrated marked temporal macular thinning. Electron microscopy confirmed diffuse podocyte effacement in primary FSGS, compared to basement membrane lamellation, thinning, and thickening in AS-associated inherited FSGS.
Conclusion
TTIMax is a reliable noninvasive biomarker that distinguishes inherited AS-associated FSGS from primary FSGS. Integration of OCT into nephrology workups may help clarify ambiguous diagnoses, particularly when histologic and genetic findings overlap. This approach supports more accurate treatment decisions and avoidance of unnecessary immunosuppression in inherited cases.