title: Nephritis-associated plasmin receptor and acute poststreptococcal glomerulonephritis: characterization of the antigen and associated immune response.
abstract: The role of nephritis-associated antigen as a virulence factor for acute poststreptococcal glomerulonephritis (APSGN) remains to be fully clarified. Nephritis-associated plasmin receptor (NAPlr) was previously isolated from group A streptococcus (GAS) and shown to bind plasmin(ogen). The nucleotide sequence of the naplr gene from GAS isolates obtained from patients with APSGN was determined. The sequence of the putative open reading frame (1011 bp) showed 99.8% identity among isolated strains. Homology screen revealed an exact match with streptococcal glyceraldehyde-3-phosphate dehydrogenase (GAPDH). NAPlr exhibited GAPDH activity in zymography, and it activated the complement pathway in vitro. In APSGN kidney biopsy specimens, NAPlr was observed mainly in the early stage of the disease (1 to 14 d after onset) but was not colocalized with either C3 or IgG as assessed by double immunofluorescence staining. Sera of patients with APSGN, patients with GAS infection without renal involvement, nonrenal pediatric patients, and healthy adults as controls were assayed for anti-NAPlr antibody titers. Anti-NAPlr antibodies were present most frequently in APSGN sera, and antibody titers were also significantly higher than in patients with GAS infection alone or in other control patients. Moreover, antibody titers remained elevated during the entire 10-yr follow-up period.
authors.affiliation: Department of Public Health, National Defense Medical College, Saitama, Japan. yoshizawa-npr@umin.ac.jp
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Yoshizawa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yamakami
authors.forename: Masayuki
authors.initials: M
authors.lastname: Fujino
authors.forename: Takashi
authors.initials: T
authors.lastname: Oda
authors.forename: Kikuko
authors.initials: K
authors.lastname: Tamura
authors.forename: Koichi
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Tetsuzo
authors.initials: T
authors.lastname: Sugisaki
authors.forename: Michael D P
authors.initials: MD
authors.lastname: Boyle
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000595:Amino Acid Sequence; D001483:Base Sequence; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D003167:Complement Activation; D003176:Complement C3 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D005921:Glomerulonephritis / Q000209:etiology* / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D008297:Male; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D008969:Molecular Sequence Data; D009393:Nephritis / Q000473:pathology*; D016366:Open Reading Frames; D018000:Receptors, Peptide / Q000096:biosynthesis*; D017422:Sequence Analysis, DNA; D013290:Streptococcal Infections / Q000276:immunology*; D013997:Time Factors
chemical_list: D003176:Complement C3; D007074:Immunoglobulin G; D018000:Receptors, Peptide; C065181:plasmin receptor