Case report: anti-glomerular basement membrane antibody disease with normal renal function

BACKGROUND Anti-glomerular basement membrane (GBM) antibody disease is a rare autoimmune disorder characterized by rapidly progressive glomerulonephritis caused by autoantibodies against the α3-chain of type IV collagen in the GBM. CASE PRESENTATION An 8-year-old girl with hematuria and proteinuria due to anti-GBM nephritis was diagnosed with hematuria and proteinuria during a school urine screening program. Her blood pressure and serum creatinine levels were normal. Her hematuria and proteinuria persisted for several months. Since a spot urine protein to creatinine ratio was around 7 g/g Cre, a percutaneous renal biopsy was performed. Immunofluorescent staining demonstrated a linear pattern for immunoglobulin G along the entire GBM. Chest computed tomography was normal. Anti-GBM antibody assays were reported as slightly raised; thus, the diagnosis was anti-GBM disease with normal renal function. Treatment included plasma exchange, intravenous high-dose methylprednisolone, and cyclophosphamide as a mainstay medication. The treatment was rapidly effective with an immediate decrease in anti-GBM titers and proteinuria. CONCLUSIONS Cases of anti-GBM disease with normal renal function in children are rare. Treatment in children has not been established; therefore, clinicians need to carefully select an effective treatment because the prognosis is poor.