Monotypic IgG1-kappa Atypical Anti-Glomerular Basement Membrane Nephritis: A Case Report

Abstract

Anti-glomerular basement membrane (anti-GBM) glomerulonephritis is a rare disease caused by autoantibodies against the glomerular basement membrane. Atypical anti-GBM nephritis is clinically less aggressive and characterized by the absence of circulating autoantibodies to the basement membrane. A previously healthy 53-year-old white woman presented with a rising creatinine over a short observation period. Renal biopsy, urinary sediment, and laboratory testing confirmed the diagnosis of atypical anti-GBM disease. She received plasmapheresis, steroids, and cyclophosphamide. She developed hemorrhagic cystitis early in the treatment from oral cyclophosphamide and mycophenolate mofetil was substituted as a first-line drug. She responded favorably and continued on mycophenolate mofetil without evidence of relapse. Despite the absence of circulating autoantibodies, a diagnosis of atypical anti-GBM nephritis should not be excluded if a high index of clinical suspicion exists. Early renal biopsy should be considered. Mycophenolate mofetil may be a reasonable replacement for oral cyclophosphamide in the treatment of atypical anti-GBM disease when cyclophosphamide is contraindicated.

A Case of Glomerulopathy Associated With Monoclonal Glomerular Basement Membrane Antibody

“…The patient's renal function improved and remained stable at 3 months follow up. [5] Coley et al, reported the case of a 53-year-old man with decreased kidney function following an upper respiratory tract infection. He was also found with microscopic hematuria and nonnephrotic range proteinuria.…”

“…Olivier et al. 5 has described a 53-year-old woman who presented with rapidly worsening serum creatinine and whose biopsy examination revealed linear staining along GBMs by monotypic IgG1-kappa. Serum anti-GBM antibodies were negative by ELISA.…”

“…The patient’s renal function improved and remained stable at 3 months follow-up. 5 …”

KDIGO 2021 Clinical Practice Guideline for the Management of Glomerular Diseases

“…958 There are several case reports of patients with anti-GBM disease who were successfully treated with mycophenolate or MPA instead of cyclophosphamide. [959][960][961][962] Mycophenolate could be used instead of cyclophosphamide in patients who refuse cyclophosphamide or are intolerant of cyclophosphamide because of its toxicity.…”

Nephrotic syndrome in adults: symptoms and management

“…890 There are several case reports of patients with anti-GBM disease successfully treated with mycophenolate or MPA instead of cyclophosphamide. [891][892][893][894] Mycophenolate could be used instead of cyclophosphamide in patients refusing cyclophosphamide, or intolerant of cyclophosphamide because of its toxicity.…”