Abstract: FR-OR081

A Substantial Fraction of Standard-of-Care Transplant Biopsies Have Clinically Actionable Findings

Session Information

Category: Transplantation

  • 1702 Transplantation: Clinical and Translational

Authors

  • Farkash, Evan A., University of Michigan, Ann Arbor, Michigan, United States
  • Shammout, Ali K, University of Michigan, Ann Arbor, Michigan, United States
Background

Standard-of-care (SOC) or “protocol” biopsies may detect subclinical disease impacting renal allograft longevity. Transplant recipients at our center have SOC biopsies at 3, 6, and 12 months after implantation. Indication biopsies are also performed in the setting of graft dysfunction or de novo DSA. We hypothesize that a substantial percentage of SOC biopsies identify pathologic processes that trigger patient management changes.

Methods

An Access database was populated with pathology reports on all renal biopsies over a 40 month period, obtained from a pathology laboratory information system (Soft) and a transplantation clinical database (Otis). Biopsies were categorized by type (native vs. allograft, indication vs. SOC) and time after transplantation. Natural language diagnoses were standardized. Rejection (antibody and cellular), infection (bacterial and viral), recurrent disease, calcineurin inhibitor toxicity, and obstruction were identified as clinically actionable diagnoses.

Results

2410 of the 3724 biopsies over this time period were allograft biopsies. At 3, 6, and 12 months after transplant, 15.1%, 17.8%, and 17.8% of SOC biopsies had clinically actionable diagnoses, respectively. 47.9% of indication biopsies had clinically actionable diagnoses (p<0.0001 compared to SOC, chi-squared). Cellular rejection tended to be diagnosed earlier than antibody mediated rejection diagnoses in this population (Figure 1). About 1 in 20 biopsies at or before 6 months had evidence of viral or bacterial infection, many of which were SOC biopsies.

Conclusion

The SOC biopsy program frequently identified findings affecting patient management and is a valuable addition to post-transplant patient care. The temporal spectrum of rejection related diagnoses in all biopsies over this time period is consistent with the literature. Infectious diagnoses, particularly subclinical infections, are frequent and can occur early after transplantation.

The primary diagnosis for 2410 consecutive indication and SOC renal transplant biopsies are plotted together on a logarithmic timescale after transplantation.

Funding

  • Other NIH Support