Fibrosis with inflammation at one year predicts transplant functional decline

J Am Soc Nephrol. 2010 Nov;21(11):1987-97. doi: 10.1681/ASN.2010010049. Epub 2010 Sep 2.

Abstract

Lack of knowledge regarding specific causes for late loss of kidney transplants hampers improvements in long-term allograft survival. Kidney transplants with both interstitial fibrosis and subclinical inflammation but not fibrosis alone after 1 year have reduced survival. This study tested whether fibrosis with inflammation at 1 year associates with decline of renal function in a low-risk cohort and characterized the nature of the inflammation. We studied 151 living-donor, tacrolimus/mycophenolate-treated recipients without overt risk factors for reduced graft survival. Transplants with normal histology (n = 86) or fibrosis alone (n = 45) on 1-year protocol biopsy had stable renal function between 1 and 5 years, whereas those with both fibrosis and inflammation (n = 20) exhibited a decline in GFR and reduced graft survival. Immunohistochemistry confirmed increased interstitial T cells and macrophages/dendritic cells in the group with both fibrosis and inflammation, and there was increased expression of transcripts related to innate and cognate immunity. Pathway- and pathologic process-specific analyses of microarray profiles revealed that potentially damaging immunologic activities were enriched among the overexpressed transcripts (e.g., Toll-like receptor signaling, antigen presentation/dendritic cell maturation, IFN-γ-inducible response, cytotoxic T lymphocyte-associated and acute rejection-associated genes). Therefore, the combination of fibrosis and inflammation in 1-year protocol biopsies associates with reduced graft function and survival as well as a rejection-like gene expression signature, even among recipients with no clinical risk factors for poor outcomes. Early interventions aimed at altering rejection-like inflammation may improve long-term survival of kidney allografts.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Biopsy
  • Cohort Studies
  • Female
  • Fibrosis
  • Follow-Up Studies
  • Glomerular Filtration Rate / physiology
  • Graft Rejection / diagnosis
  • Graft Rejection / etiology*
  • Graft Rejection / physiopathology*
  • Humans
  • Kaplan-Meier Estimate
  • Kidney / pathology*
  • Kidney / physiopathology
  • Kidney Transplantation / pathology
  • Kidney Transplantation / physiology*
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Nephritis / complications*
  • Nephritis / pathology*
  • Nephritis / physiopathology
  • Predictive Value of Tests
  • Prognosis