title: Clinicopathological and immunohistological features in childhood IgA nephropathy: a single-centre experience.
abstract: BACKGROUND
  IgA nephropathy is a glomerular disease diagnosed by renal biopsy and is characterized by a highly variable course ranging from a completely benign condition to rapidly progressive renal failure. We aimed to evaluate the clinical, histopathological and inflammatory characteristics of children with IgA nephropathy.
  
  
  METHODS
  Data of 37 patients with IgA nephropathy diagnosed between the years 1980 and 2008 were retrospectively reviewed. Immunohistochemistry was performed in 24 patients. Expression of CD3, CD4, CD8, CD20, CD68, IL-1β, IL-10, IL-17, TGF-β, TNF-α and the newly proposed tubulointerstitial fibrosis marker nestin were evaluated.
  
  
  RESULTS
  The median age at diagnosis was 10 years. Recurrent macroscopic haematuria (66%) was the most common clinical manifestation, and 35% of the patients had synpharyngitic presentation. A significant correlation was found between proteinuria and increase in mesangial matrix (r= 0.406, P = 0.013). The presence of CD4+ T lymphocytes and CD68+ macrophages were also significantly associated with proteinuria >1 g/day. While cytokines IL-1β, IL-10 and TNF-α were mainly expressed in tubular epithelial cells, TGF-β was evident in glomeruli but they had no correlation to clinical features and severity of the disease. Nestin was detected at the tubules in almost half of the patients with no correlation to proteinuria and tubulointersititial fibrosis.
  
  
  CONCLUSIONS
  We found a correlation between proteinuria and mesangial matrix expansion. The presence of CD4+ T-lymphocytes and CD68+ macrophages were also significantly associated with proteinuria >1 g/day. Although there are many evidences, for immunological basis of IgA nephropathy, the immunological markers were not fully expressed in children to evaluate glomerular and tubulointerstitial inflammation, and progression of the disease. Further studies with the extended number of children are needed to shed light on the immunological basis of the disease.
authors.affiliation: Department of Pediatric Nephrology and Rheumatology , Faculty of Medicine, Hacettepe University , Ankara , Turkey.
authors.forename: Rezan
authors.initials: R
authors.lastname: Topaloglu
authors.forename: Dicle
authors.initials: D
authors.lastname: Orhan
authors.forename: Yelda
authors.initials: Y
authors.lastname: Bilginer
authors.forename: Erdem
authors.initials: E
authors.lastname: Karabulut
authors.forename: Fatih
authors.initials: F
authors.lastname: Ozaltin
authors.forename: Ali
authors.initials: A
authors.lastname: Duzova
authors.forename: Gulsev
authors.initials: G
authors.lastname: Kale
authors.forename: Nesrin
authors.initials: N
authors.lastname: Besbas
keywords: childhood IgA nephropathy; cytokines; histopathology; inflammatory cells; nestin