title: Atypical postinfectious glomerulonephritis is associated with abnormalities in the alternative pathway of complement.
abstract: Postinfectious glomerulonephritis is a common disorder that develops following an infection. In the majority of cases, there is complete recovery of renal function within a few days to weeks following resolution of the infection. In a small percentage of patients, however, the glomerulonephritis takes longer to resolve, resulting in persistent hematuria and proteinuria, or even progression to end-stage kidney disease. In some cases of persistent hematuria and proteinuria, kidney biopsies show findings of a postinfectious glomerulonephritis even in the absence of any evidence of a preceding infection. The cause of such 'atypical' postinfectious glomerulonephritis, with or without evidence of preceding infection, is unknown. Here we show that most patients diagnosed with this 'atypical' postinfectious glomerulonephritis have an underlying defect in the regulation of the alternative pathway of complement. These defects include mutations in complement-regulating proteins and antibodies to the C3 convertase known as C3 nephritic factors. As a result, the activated alternative pathway is not brought under control even after resolution of the infection. Hence, the sequela is continual glomerular deposition of complement factors with resultant inflammation and development of an 'atypical' postinfectious glomerulonephritis.
authors.affiliation: Division of Anatomic Pathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota 55905, USA. Sethi.sanjeev@mayo.edu
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Sethi
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Fervenza
authors.forename: Yuzhou
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ladan
authors.initials: L
authors.lastname: Zand
authors.forename: Nicole C
authors.initials: NC
authors.lastname: Meyer
authors.forename: Nicolò
authors.initials: N
authors.lastname: Borsa
authors.forename: Samih H
authors.initials: SH
authors.lastname: Nasr
authors.forename: Richard J H
authors.initials: RJ
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D050577:Complement C3-C5 Convertases / Q000502:physiology; D003170:Complement Pathway, Alternative; D005260:Female; D005921:Glomerulonephritis / Q000188:drug therapy / Q000209:etiology / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007239:Infections / Q000150:complications*; D007668:Kidney / Q000473:pathology; D008297:Male; D008875:Middle Aged
chemical_list: D050577:Complement C3-C5 Convertases