title: Changes in nephritogenic serum galactose-deficient IgA1 in IgA nephropathy following tonsillectomy and steroid therapy.
abstract: BACKGROUND
  Recent studies have shown that galactose-deficient IgA1 (GdIgA1) has an important role in the pathogenesis of IgA nephropathy (IgAN). Although emerging data suggest that serum GdIgA1 can be a useful non-invasive IgAN biomarker, the localization of nephritogenic GdIgA1-producing B cells remains unclear. Recent clinical and experimental studies indicate that immune activation tonsillar toll-like receptor (TLR) 9 may be involved in the pathogenesis of IgAN. Here we assessed the possibility of GdIgA1 production in the palatine tonsils in IgAN patients.
  
  
  METHODS
  We assessed changes in serum GdIgA1 levels in IgAN patients with clinical remission of hematuria and proteinuria following combined tonsillectomy and steroid pulse therapy. Further, the association between clinical outcome and tonsillar TLR9 expression was evaluated.
  
  
  RESULTS
  Patients (n = 37) were divided into two groups according to therapy response. In one group, serum GdIgA1 levels decreased after tonsillectomy (59%) alone, whereas in the other group most levels only decreased after the addition of steroid pulse therapy to tonsillectomy (41%). The former group showed significantly higher tonsillar TLR9 expression and better improvement in hematuria immediately after tonsillectomy than the latter group.
  
  
  CONCLUSIONS
  The present study indicates that the palatine tonsils are probably a major sites of GdIgA1-producing cells. However, in some patients these cells may propagate to other lymphoid organs, which may partially explain the different responses observed to tonsillectomy alone. These findings help to clarify some of the clinical observations in the management of IgAN, and may highlight future directions for research.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Junichiro
authors.initials: J
authors.lastname: Nakata
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan ; Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sato
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kano
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yanagawa
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan ; Kyoto University Health Service, Kyoto, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Matsuzaki
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Horikoshi
authors.affiliation: Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
authors.forename: Jan
authors.initials: J
authors.lastname: Novak
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tomino
mesh_terms: D015331:Cohort Studies; D005260:Female; D005690:Galactose / Q000378:metabolism; D005922:Glomerulonephritis, IGA / Q000097:blood* / Q000188:drug therapy / Q000601:surgery; D005938:Glucocorticoids / Q000008:administration & dosage*; D006031:Glycosylation; D006417:Hematuria / Q000097:blood / Q000188:drug therapy / Q000601:surgery; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage*; D011499:Protein Processing, Post-Translational; D014068:Tonsillectomy; D016896:Treatment Outcome
chemical_list: D005938:Glucocorticoids; D007070:Immunoglobulin A; D005690:Galactose; D008775:Methylprednisolone