title: IgA1 dominant subclass of latent IgA mesangial deposition in donated kidney.
abstract: BACKGROUND
  In the pathogenesis of immunoglobulin A nephropathy (IgAN), the IgA1 subclass is more important than the IgA2 subclass. In healthy men, the prevalence of mesangial IgA deposition has been previously investigated. However, it remains unknown whether the presence of urinary abnormalities depends on the subclass of IgA deposition.
  
  
  METHODS
  We researched the subclasses of IgA (IgA1 and IgA2) by the direct immunofluorescence (IF) staining method using specimens in which we identified the deposition of IgA through zero-hour renal transplant biopsies from donors without urinary abnormalities. The samples of the zero-hour biopsies were collected from 46 cases of living renal transplant patients at Nishinomiya Hospital, Hyogo Prefecture, from January 2011 to December 2013.
  
  
  RESULTS
  In seven of the 46 cases (15%), IgA deposition and C3 in mesangium were confirmed. All seven cases showed IgA1 predominant mesangial deposition on IF. The results of the histological evaluations for all seven cases were Oxford Classification M0.S0.E0.T0.
  
  
  CONCLUSIONS
  This study showed similar patterns of latent mesangial IgA deposition according to IgA subclass and frequency of C3 deposition as IgAN. Latent mesangial IgA deposition may require some, as yet undefined factors, to become clinically apparent as IgAN.
authors.affiliation: Department of Pathology, Hyogo Prefectural Nishinomiya Hospital, Hyogo, Japan.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Oka
authors.affiliation: Department of Urology, Hyogo Prefectural Nishinomiya Hospital, Hyogo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Nishimura
authors.affiliation: Department of Urology, Hyogo Prefectural Nishinomiya Hospital, Hyogo, Japan.
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Kishikawa
authors.affiliation: Department of Urology, Joyo Ejiri Hospital, Hyogo, Japan.
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Ichikawa
keywords: IgA nephropathy; IgA subclass; IgA1; latent; mesangium