Quantification of Interstitial Fibrosis in Renal Allografts and Clinical Correlates of Long-Term Graft Function

Am J Nephrol. 2017;46(3):187-194. doi: 10.1159/000479983. Epub 2017 Aug 22.

Abstract

Background: The present study investigated interstitial fibrosis (IF) in 144 kidney recipients 0 h and 1 year post transplantation and assessed relationships with Banff code scores, clinical parameters, and long-term graft function.

Methods: A quantitative analysis of IF was performed using the computer-assisted imaging of Sirius red-stained biopsy samples. Percent IF (%IF) in the cortical region was assessed at 0 h and 1 year, and an increase in the ratio of %IF from 0 h to 1 year was calculated. The relationship between %IF and Banff code scores was analyzed. Demographics and trough concentrations of tacrolimus were tested as risk factors in the top 20 patients with increases in %IF. The influence of increases in the ratio of %IF at 1 year on long-term graft function and survival was also assessed in these 20 patients.

Results: Median %IF at 0 h and 1 year were 1.55 and 2.80%, respectively. No correlation was found between %IF and Banff code scores. The mean increase in the ratio of %IF from 0 h to 1 year was 4.31-fold. The increase in %IF in the top 20 patients correlated with diabetes mellitus. Graft function, but not graft survival, was lower in the top 20 patients for 10 years post transplantation.

Conclusions: A correlation was not found between %IF and Banff code scores. Greater increases in %IF within 1 year post transplantation may influence long-term graft survival. Computer-analyzed increases in %IF at 1 year may be a surrogate marker for long-term graft function.

Keywords: Banff scores; Graft function; Interstitial fibrosis; Renal transplantation; Sirius red.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Allografts / pathology*
  • Atrophy
  • Azo Compounds / chemistry
  • Biopsy
  • Coloring Agents / chemistry
  • Female
  • Fibrosis
  • Fluorescent Antibody Technique / methods
  • Glomerular Filtration Rate
  • Graft Survival*
  • Humans
  • Image Processing, Computer-Assisted
  • Kidney / pathology*
  • Kidney / surgery
  • Kidney Failure, Chronic / surgery*
  • Kidney Transplantation / adverse effects*
  • Male
  • Middle Aged
  • Staining and Labeling / methods
  • Time Factors
  • Transplantation, Homologous / adverse effects
  • Young Adult

Substances

  • Azo Compounds
  • Coloring Agents
  • C.I. direct red 80