Abstract: FR-PO1052

Circulating Fibrocytes Predict eGFR Slope Post Transplant and Are Associated with Chronic Tubular Changes

Session Information

Category: Transplantation

  • 1702 Transplantation: Clinical and Translational

Authors

  • Lee, Michael Ho-Yan, McMaster University, Hamilton, Ontario, Canada
  • Ribic, Christine M., McMaster University, Hamilton, Ontario, Canada
  • Gangji, Azim S., McMaster University, Hamilton, Ontario, Canada
  • Margetts, Peter, McMaster University, Hamilton, Ontario, Canada
Background

Interstitial fibrosis and tubular atrophy predicts renal transplant outcomes. Circulating fibrocytes are associated with fibrogenic disease in other organs. We aim to evaluate the role of fibrocytes in predicting long-term renal function and the extent of graft fibrosis.

Methods

A single center observational study was conducted in patients undergoing a first kidney transplant. Blood was drawn pre-transplant, 1, 3, 6, and 12-months post-transplant. Circulating fibrocyte levels were identified by flow cytometry using cell surface CD45 and intracellular collagen I. Biopsy samples were stained for a-smooth muscle actin (SMA) and tissue fibrocytes were identified using dual labeling of CXCR4 and Prolyl-4-hydroxylase. The Banff classification was used to evaluate chronic biopsy changes.

Results

Eighty enrolled patients were followed to 12-months post-transplant. One-month circulating fibrocyte levels correlated inversely with the slope of the eGFR from 3 to 12 months (R=-0.257, p=0.03). Thirteen patients had a clinically indicated biopsy. The number of tissue fibrocytes correlated with a-SMA staining (R=0.637, p=0.026). Increased chronic tubular changes were associated with elevated 1-month circulating fibrocyte levels (p<0.001). Increased chronic interstitial changes were associated with increased numbers of tissue fibrocytes (p=0.028).

Conclusion

Elevated circulating fibrocytes at 1-month post-transplant may be prognostic of transplant outcome. Also, increased circulating fibrocytes at 1-month is predictive of chronic tubular changes on biopsy. The number of tissue fibrocytes correlates with interstitial fibrosis and a-SMA staining. Circulating fibrocytes at 1-month can be a biomarker for graft dysfunction and may predict the severity of graft fibrosis.

Funding

  • Commercial Support