Advanced Tertiary Lymphoid Tissues in Protocol Biopsies are Associated with Progressive Graft Dysfunction in Kidney...

Area of Science:

• Nephrology
• Immunology
• Transplantation Biology

Background:

• Tertiary lymphoid tissues (TLTs) are ectopic lymphoid structures in inflamed organs.
• Their clinical significance in kidney transplants is debated.
• This study investigates TLT impact on graft function and development.

Purpose of the Study:

• To assess the clinical relevance of TLTs in kidney allografts.
• To correlate TLT maturity stages with graft function and pathology.
• To identify risk factors for TLT development.

Main Methods:

• Retrospective analysis of 214 living donor kidney transplant protocol biopsies (0, 1, 6, 12 months).
• TLTs classified into stage I (no follicular dendritic cells) and stage II (with follicular dendritic cells).
• Association with Banff scores and graft function evaluated.

Main Results:

• TLT prevalence rose from 4% at 0 months to nearly 50% at 1 month post-transplant.
• Stage II TLTs increased over time, reaching 19% at 12 months.
• Stage II TLTs predicted poorer graft function and more severe interstitial fibrosis/tubular atrophy, independent of inflammation.

Conclusions:

• TLTs are frequently observed in stable kidney transplants.
• Advanced stage II TLTs indicate a higher risk of progressive graft dysfunction.
• Pre-transplant rituximab reduced stage II TLT development.