Current pathological perspectives on chronic rejection in renal allografts

Area of Science:

• Nephrology
• Transplantation Immunology
• Pathology

Background:

• Chronic rejection significantly contributes to late renal graft loss after transplantation.
• Antibody-mediated rejection (ABMR), driven by donor-specific antibodies, is a primary cause of chronic rejection.
• The Banff classification has evolved to include detailed pathological features of chronic ABMR, such as microcirculation damage.

Purpose of the Study:

• To review current pathological perspectives on chronic renal allograft rejection.
• To highlight diagnostic challenges and potential amendments to the Banff classification.
• To explore the role of molecular phenotyping in understanding renal allograft dysfunction.

Main Methods:

• Review of existing literature on renal allograft rejection.
• Analysis of pathological characteristics of chronic antibody-mediated rejection (ABMR) and chronic active T cell-mediated rejection (TCMR).
• Discussion of diagnostic criteria within the Banff classification framework.

Main Results:

• Chronic ABMR involves microcirculation damage and arterial fibrous intimal proliferation.
• Chronic active ABMR and chronic active TCMR share characteristics that can lead to diagnostic confusion.
• Molecular phenotyping offers insights into allograft dysfunction and disease-specific gene expression changes.

Conclusions:

• The current Banff classification may require amendments to improve the diagnosis of chronic renal rejection.
• Distinguishing between chronic ABMR and TCMR is crucial for effective management.
• Molecular diagnostics hold promise for enhancing the pathological assessment of renal allografts.