Prediction of corticosteroid responsiveness based on fibroblast-specific protein 1 (FSP1) in patients with IgA nephropathy

Nephrol Dial Transplant. 2008 Oct;23(10):3152-9. doi: 10.1093/ndt/gfn240. Epub 2008 May 7.


Background: Corticosteroids are frequently used to treat patients with active IgA nephropathy (IgAN); however, there have been few reports describing factors that are predictive of the response to corticosteroid treatment. The purpose of this study is to determine the extent to which fibroblast-specific protein 1-positive (FSP1(+)) cells are predictive of corticosteroid responsiveness in patients with IgAN.

Methods: Fifty biopsy-proven IgAN patients who received corticosteroid therapy were enrolled and followed for 7.1 +/- 3.0 years. FSP1(+) cells were identified using an anti-FSP1 antibody.

Results: Twelve patients showed progression of renal impairment or no reduction of urinary protein (non-responders) after steroid therapy. In the remaining 38 patients, renal function was stable during follow-up, and their urinary protein declined to <1.0 g/day (responders). Serum creatinine, estimated GFR, severity of mesangial proliferation, percent glomerulosclerosis/total glomeruli, extent of interstitial damage and FSP1(+) cell number were all significantly higher in non-responders than in responders. Cox regression analysis using two covariates with every possible combination of factors indicated that FSP1(+) cell number was the strongest and most significant predictor of corticosteroid responsiveness. When IgAN patients had >32.6 FSP1(+) cells/HPF at diagnosis, they were the more likely to show steroid resistance.

Conclusion: FSP1(+) cell number can serve as an excellent predictor of corticosteroid responsiveness in patients with IgAN.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adrenal Cortex Hormones / therapeutic use*
  • Adult
  • Biomarkers / metabolism
  • Calcium-Binding Proteins / metabolism*
  • Cell Count
  • Female
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Follow-Up Studies
  • Glomerulonephritis, IGA / drug therapy*
  • Glomerulonephritis, IGA / metabolism*
  • Glomerulonephritis, IGA / pathology
  • Humans
  • Kidney / metabolism
  • Kidney / pathology
  • Male
  • Middle Aged
  • S100 Calcium-Binding Protein A4
  • Treatment Outcome
  • Young Adult


  • Adrenal Cortex Hormones
  • Biomarkers
  • Calcium-Binding Proteins
  • S100 Calcium-Binding Protein A4
  • S100A4 protein, human