title: Epidermal growth factor receptor expression in human renal allograft biopsies: an immunohistochemical study.
abstract: OBJECTIVE
  Epidermal growth factor receptor (EGFR) expression has been implicated in the progression of many tumors related to cell proliferation, differentiation, invasion and inhibition of apoptosis, and EGFR-targeted therapy options are under development. EGFR expression has been identified in normal and diseased native kidneys. However, its expression in renal allografts and its relation to rejection remains unclear. We aimed to investigate EGFR expression in renal allograft biopsies.
  
  
  METHODS
  Sections from 52 renal allograft and 11 implantation biopsies were stained by EGFR antibody with streptavidin-biotin-immunoperoxidase method. Immunostaining of EGFR in renal tubules was scored semiquantitatively and the percentage of glomeruli expressing EGFR was determined. The results were correlated with Banff scores and serum creatinine values.
  
  
  RESULTS
  Tubular EGFR expression was observed in 81.8% of implantation and 92.3% of allograft biopsies. Glomerular EGFR expression was identified in 18.2% of implantation and in 26.9% of allograft biopsies. The mean percentage (%) of glomeruli-expressing EGFR was 3.73+/-0.84 for implantation biopsies and 7.9+/-0.17 for allograft biopsies (p = 0.53, Mann Whitney U test). For implantation biopsies, tubular EGFR expression scores were 1.90+/-2.11 and for allograft biopsies, 2.89+/-2.01 (p = 0.08, Mann Whitney U test). Tubular EGFR expression was moderately correlated with interstitial fibrosis and tubular atrophy for allograft biopsies (p = 0.04, r = 0.3 and p = 0.04, r = 0.3, respectively, Spearman's rank correlation).
  
  
  CONCLUSIONS
  These findings suggest a possible role of EGFR expression in renal scarring in the course of chronic allograft nephropathy, probably involved in a complex pathway.
authors.affiliation: Department of Pathology, Dokuz Eylül University School of Medicine, Inciralti, Izmir 35340, Turkey.
authors.forename: Banu
authors.initials: B
authors.lastname: Sis
authors.forename: Sulen
authors.initials: S
authors.lastname: Sarioglu
authors.forename: Ali
authors.initials: A
authors.lastname: Celik
authors.forename: Mujdat
authors.initials: M
authors.lastname: Zeybel
authors.forename: Alper
authors.initials: A
authors.lastname: Soylu
authors.forename: Seymen
authors.initials: S
authors.lastname: Bora
mesh_terms: D000293:Adolescent; D000328:Adult; D001706:Biopsy; D002648:Child; D066246:ErbB Receptors / Q000032:analysis / Q000096:biosynthesis*; D005260:Female; D006084:Graft Rejection; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism* / Q000473:pathology; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D014184:Transplantation, Homologous
chemical_list: D066246:ErbB Receptors