Child Kidney Dis.
2021 Jun;25(1):29-34. 10.3339/jkspn.2021.25.1.29.
C3 Glomerulonephritis associated with Anti-complement Factor H Autoantibodies in an Adolescent Male: A Case Report
- Affiliations
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- 1Department of Pediatrics, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
- 2Department of Pediatrics, Seoul National University Children’s Hospital, Seoul, Korea
- 3Department of Pathology, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
- 4Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea
- KMID: 2518366
- DOI: http://doi.org/10.3339/jkspn.2021.25.1.29
Abstract
- C3 glomerulonephritis (C3GN), a rare condition associated with dysregulation of the alternative pathway of the complement system, is histopathologically characterized by isolated or dominant C3 deposition in the renal glomeruli. We report a case of C3GN associated with anti-complement factor H (CFH) autoantibodies and CHF-related protein deficiency in an adolescent male. A 16-year-old adolescent male was admitted to a hospital with a 1-month history of generalized edema prior to presentation. Persistent microscopic hematuria and low serum C3 levels were incidentally detected at 7 and 10 years of age, respectively. Laboratory test results revealed hypoalbuminemia, nephrotic-range proteinuria, microscopic hematuria, and normal serum creatinine levels. The serum C3 and C4 levels were 17 mg/dL (normal 80–150 mg/dL) and 22 mg/mL (17–40 mg/mL), respectively. Renal biopsy showed typical features of C3GN. Further investigations revealed positive results on plasma anti-CFH autoantibody testing and a homozygous deletion of CFHR1 and CFHR3, which encode CFH-related proteins 1 and 3, respectively. Proteinuria persisted despite treatment with intravenous methylprednisolone, mycophenolate mofetil, and angiotensin-receptor blocker; however, his renal function remained stable. In conclusion, anti-CFH autoantibodies serve as important contributors to C3GN. This is the first case report that describes C3GN in an adolescent Korean male with anti-CFH autoantibodies and homozygous CFHR1 and CFHR3 deletion.
