Isolated endarteritis and kidney transplant survival: a multicenter collaborative study.

Area of Science:

• Nephrology
• Transplant Surgery
• Immunology

Background:

• Isolated endarteritis in kidney transplants is increasingly recognized.
• Microarray studies often show no immunologic rejection signatures in these cases.
• The clinical significance and response to treatment for isolated endarteritis remain unclear.

Purpose of the Study:

• To investigate the response of isolated endarteritis to rejection treatment.
• To determine the impact of isolated endarteritis on kidney transplant survival.
• To identify isolated endarteritis as a potential independent risk factor for transplant failure.

Main Methods:

• Retrospective cohort study of kidney transplant recipients from 1999-2011 across seven centers.
• Exclusion of blood group-incompatible, crossmatch-positive, or C4d-positive biopsies.
• Patients categorized into isolated endarteritis, positive controls (Type I acute T cell-mediated rejection with endarteritis), and negative controls (no rejection).

Main Results:

• Isolated endarteritis patients showed significant kidney function improvement post-treatment (mean creatinine decrease 132.6 µmol/L), comparable to positive controls.
• Functional improvement occurred in 80% of isolated endarteritis patients, similar to positive controls (81%).
• Kidney transplant survival rates were lower in isolated endarteritis (79%) and positive control groups (79%) compared to negative controls (91%) (P=0.01).

Conclusions:

• Isolated endarteritis responds clinically to rejection treatment, suggesting an underlying, albeit non-classical, immune component.
• Isolated endarteritis is an independent risk factor for kidney transplant failure, associated with a 3.51-fold increased risk.
• These findings highlight the importance of recognizing and managing isolated endarteritis to improve long-term kidney transplant outcomes.