title: C3 Glomerulopathy and post-infectious glomerulonephritis define a disease spectrum.
abstract: Post-infectious glomerulonephritis (PIGN) usually follows a benign course, but few children have an atypical, severe presentation, and these exceptional cases have been linked to the dysregulation of the complement alternative pathway (CAP). There is a considerable overlap in the histopathological features of PIGN and C3 glomerulopathy (C3G), which is also associated with CAP dysregulation but has a poorer outcome. We hypothesized that PIGN and C3G define a disease spectrum, and that in the past there may be some children with C3G who were misclassified with PIGN before C3G was described as a separate disease entity.
  
  
  
  Children with PIGN (n = 33) diagnosed between 1985 and 2010 who underwent a renal biopsy due to their unusual course were reviewed and of them, 8 were reclassified into C3G based on the current classification criteria. Outcome was based on the degree of proteinuria, C3 level, and renal function at follow-up.
  
  
  
  Sixteen (72.7%) children with typical PIGN recovered completely as compared to only 2 (25%) with C3G. Of note, children with "typical" PIGN had a more severe disease course at onset; however, the outcome at last follow up was favorable.
  
  
  
  Our results support the hypothesis that PIGN and C3G form a disease spectrum and have different long-term clinical implications and management strategies.
authors.affiliation: Division of Nephrology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: Badria
authors.initials: B
authors.lastname: Al-Ghaithi
authors.affiliation: Division of Nephrology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.|Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada.|Division of Nephrology, Department of Pediatrics, McMaster Children's Hospital, Hamilton, ON, Canada.
authors.forename: Rahul
authors.initials: R
authors.lastname: Chanchlani
authors.affiliation: Cell Biology Program, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Riedl
authors.affiliation: Division of Pathology, The Hospital for Sick Children, Toronto, ON, Canada.|Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Thorner
authors.affiliation: Division of Nephrology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada. christoph.licht@sickkids.ca.|Cell Biology Program, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada. christoph.licht@sickkids.ca.|Department of Pediatrics, University of Toronto, Toronto, ON, Canada. christoph.licht@sickkids.ca.
authors.forename: Christoph
authors.initials: C
authors.lastname: Licht
mesh_terms: D000293:Adolescent; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D003141:Communicable Diseases / Q000150:complications*; D003176:Complement C3 / Q000032:analysis* / Q000378:metabolism; D003170:Complement Pathway, Alternative; D005260:Female; D005921:Glomerulonephritis / Q000097:blood / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D015432:Glomerulonephritis, Membranoproliferative / Q000097:blood / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007678:Kidney Glomerulus / Q000473:pathology; D008137:Longitudinal Studies; D008297:Male; D011507:Proteinuria / Q000652:urine
chemical_list: D003176:Complement C3
keywords: C3 glomerulonephritis; C3 glomerulopathy; Complement alternative pathway; Dense deposit disease; Eculizumab; Post-infectious glomerulonephritis