Subclinical Inflammation and Renal Allograft Dysfunction: Myth or Reality?

Area of Science:

• Nephrology
• Transplant Immunology
• Pathology

Background:

• The Banff classification standardized transplant rejection diagnosis but overlooked milder inflammation.
• Inflammatory infiltrates not meeting rejection criteria were inadequately addressed.

Purpose of the Study:

• To revise the natural history of kidney allograft inflammation.
• To explore origins of inflammation based on cellular and transcriptomic changes.
• To propose an updated definition and management approach for subclinical inflammation.

Main Methods:

• Review of existing literature on kidney allograft inflammation.
• Analysis of cellular composition in kidney biopsies.
• Evaluation of transcriptomic expression changes.

Main Results:

• Subclinical inflammation, defined by inflammation in protocol biopsies without renal function decline, has decreased with modern immunosuppression.
• Lower levels of inflammation negatively impact long-term transplant outcomes.
• Subclinical inflammation can be transient in some patients.

Conclusions:

• Managing subclinical inflammation is challenging due to incomplete definitions and biopsy interpretation limitations.
• An updated definition and management strategy are needed.
• Understanding inflammation's origins is key to improving long-term allograft survival.