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Kidney Week

Abstract: PUB252

Tip-Variant FSGS with Alport Syndrome

Session Information

Category: Glomerular Diseases

  • 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

  • Elkhidir, Sabri Elamin abbas, Baylor College of Medicine, Houston, Texas, United States
  • Shah, Maulin, Baylor College of Medicine, Houston, Texas, United States
  • Worah, Parth, Baylor College of Medicine, Houston, Texas, United States
Introduction

While genetic testing in nephrotic syndrome can be a helpful diagnostic tool, there are details that kidney biopsies can provide that can significantly impact patient management. We report an interesting case in which genetic testing and kidney biopsy revealed conflicting results.

Case Description

A healthy 33-year-old gentleman was referred for nephrotic syndrome w/ 8.7g/day proteinuria (24-hr urine). Kidney biopsy revealed tip variant focal segmental glomerulosclerosis (FSGS) with diffuse podocyte effacement. He was treated with statin, ace-inhibitor, statin, and prednisone 1mg/kg with partial remission (1g/day proteinuria by 24-hr urine). A genetic workup was sent at the start of treatment and revealed heterozygous variant defect of COL4A4, consistent with Alport’s syndrome.
Attempts to taper off prednisone worsened his proteinuria (2g/day by 24-hr urine) and edema despite addition of tacrolimus. Since he had a partial response to high dose steroid therapy, we opted a trial of two doses of 1 g of rituximab, 2 weeks apart with significantly better response (UACR 188mg/g) and resolution of clinical signs of nephrotic syndrome (no edema, serum albumin 3.6mg/dL).

Discussion

It is well known that tip-variant FSGS typically has a more favorable response to steroid therapy while genetic causes of FSGS typically do not. Genetic causes of tip-variant FSGS are rare. It is unclear if this patient has a genetic tip-variant FSGS or rather a tip-variant FSGS in addition to Alport’s syndrome. Alport’s syndrome typically involves the kidneys but may present without kidney involvement.
Alport’s syndrome is not typically treated with immunosuppression while tip-variant FSGS is. This case highlights the importance of kidney biopsy in patients with nephrotic syndrome as it may drastically impact treatment plans.

Digital Object Identifier (DOI)