Evaluation of molecular profiles in calcineurin inhibitor toxicity post-kidney transplant: input to chronic allograft...

Area of Science:

• Nephrology
• Transplant Immunology
• Molecular Biology

Background:

• Calcineurin inhibitor toxicity (CNIT) is a significant concern in kidney transplantation (KT), potentially contributing to chronic allograft dysfunction (CAD).
• Understanding the molecular basis of CNIT is crucial for differentiating its role from other causes of graft injury, such as acute rejection.
• Interstitial fibrosis (IF) and tubular atrophy (TA) are key histological features of CAD.

Purpose of the Study:

• To identify specific molecular pathways associated with CNIT in kidney allografts.
• To assess the contribution of the identified CNIT molecular signature to the progression of CAD with IF/TA.
• To determine if CNIT acts as a non-immunological factor in CAD development.

Main Methods:

• Cross-sectional analysis of kidney biopsies from patients with CNIT, acute rejection, CAD with IF/TA, and normal allografts.
• Longitudinal study of 122 biopsies from 61 KT patients at 3 and ~12 months post-transplant.
• Molecular signature identification and comparison between patient groups (progressors vs. non-progressors to CAD).

Main Results:

• Specific molecular signatures characterizing CNIT were identified.
• Progressors to CAD showed a significant overlap with the CNIT molecular signature at both 3 months (7%) and ~12 months (22%) post-KT.
• Non-progressors to CAD exhibited minimal overlap (<1% and 1%) with the CNIT signature.

Conclusions:

• CNIT is characterized by a distinct molecular signature in kidney allografts.
• The identified CNIT molecular signature is associated with the progression to chronic allograft dysfunction with interstitial fibrosis/tubular atrophy.
• CNIT functions as a non-immunological factor contributing to CAD progression in kidney transplant recipients.