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Abstract: FR-PO0901

Podocin Mutation in a Patient with Systemic Lupus Erythematosus and Proteinuria: A Case Report

Session Information

Category: Glomerular Diseases

  • 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

  • Zakrocka, Izabela Natalia, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
  • Gut, Anna Karolina, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
  • Gierska, Joanna, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
  • Nour Mohammadi, Amir, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
  • Korolczuk, Agnieszka, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
  • Zaluska, Wojciech T., Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
  • Kronbichler, Andreas, Medizinische Universitat Innsbruck, Innsbruck, Tyrol, Austria
Introduction

Systemic lupus erythematosus (SLE) is an autoimmune multiorgan disease frequently affecting the kidney, and lupus nephritis (LN) leads to the end-stage kidney disease in up to 20% of affected individuals. Early detection and treatment of LN are crucial to preserve kidney function. Kidney biopsy remains the gold standard for diagnosing LN, repeated based on clinical indications, especially when LN flare is suspected.
Pathogenic genetic variants are identified in 10-20% of patients with chronic kidney disease, predominantly related with glomerular disease. Focal segmental glomerulosclerosis (FSGS) is the most common histological pattern associated with gene-related glomerular damage.
In this case, we present a patient with SLE, with progressive proteinuria, atypical histological lesions in kidney biopsy and confirmed podocin mutation.

Case Description

A 37-year-old female with a long-standing history of SLE was admitted to the nephrology clinic due to increased proteinuria of close to 1.2 g/day and suspicion of LN flare. Family history was negative for kidney or autoimmune diseases. A kidney biopsy performed 15 years prior was nondiagnostic. The patient was under rheumatology care, receiving a triple immunosuppressive regimen consisting of mycophenolate mofetil, cyclosporine and prednisone. Laboratory results revealed lymphopenia, mildly impaired kidney function, urinalysis indicated proteinuria without hematuria. After excluding secondary causes of kidney impairment, a kidney biopsy was performed, which revealed FSGS without immunological deposits. Due to an atypical clinical presenting genetic testing was pursued, which confirmed a missense mutation in NPHS2 gene encoding podocin (NM_014625.4:c.686G>A, heterozygous variant).

Discussion

LN is a severe condition with a significant impact on patient health. However, other causes of kidney damage should be considered in patients with nonspecific clinical manifestations. Heterozygous NPHS2 variants are claimed to play a role in atypical cases, in patients with mild, late onset disease. Podocin mutations may predispose to glomerular damage under additional conditions. Kidney biopsy combined with genetic testing provide important information regarding patient management and prediction of kidney outcomes.

Digital Object Identifier (DOI)