Silent acute rejection during prolonged delayed graft function reduces kidney allograft survival

Area of Science:

• Nephrology
• Transplantation immunology
• Clinical research

Background:

• The impact of early, silent acute rejection (AR) and delayed graft function (DGF) on kidney allograft survival is debated.
• The utility of protocol biopsies in managing DGF remains unclear.

Purpose of the Study:

• To investigate the hypothesis that protocol biopsies during DGF reveal a high incidence of silent AR.
• To determine if silent AR adversely affects long-term kidney allograft survival.

Main Methods:

• Retrospective analysis of 410 kidney transplants.
• Routine protocol biopsies performed 7-10 days post-transplant for patients requiring dialysis.
• Cox proportional hazards analysis to assess the impact of silent AR during DGF on graft survival.

Main Results:

• The cumulative incidence of AR was 57.2% in patients with DGF undergoing protocol biopsy versus 15.1% without.
• Prolonged DGF significantly increased graft failure risk (HR 3.08).
• Silent AR detected by protocol biopsy carried a similar risk of graft failure as early AR in non-DGF patients (HR 2.91 vs. 2.95).
• After accounting for AR, the risk of graft failure from prolonged DGF was reduced (HR 1.76), indicating AR mediates much of the DGF risk.

Conclusions:

• Silent AR is a common finding during DGF in kidney transplant recipients.
• Prolonged DGF is linked to reduced graft survival, largely explained by the presence of silent AR.
• Protocol biopsies and treatment of silent AR during DGF are recommended in the absence of randomized trial data.