T-Cell Epitopes Shared Between Immunizing HLA and Donor HLA Associate With Graft Failure After Kidney Transplantation

Area of Science:

• Immunology
• Transplantation Science
• Genetics

Background:

• CD4+ T-helper cells are crucial in transplant rejection by driving immune responses.
• Pre-existing CD4+ memory T-helper cells can be reactivated by HLA mismatches sharing T-cell epitopes.
• This reactivation poses a risk for graft failure after kidney transplantation.

Purpose of the Study:

• To evaluate the association between donor-reactive CD4+ memory T-helper cells and long-term kidney graft failure risk.
• To utilize shared T-cell epitopes as a surrogate marker for assessing this risk.

Main Methods:

• The PIRCHE-II algorithm was employed to estimate T-cell epitopes.
• Shared T-cell epitopes between immunizing and donor HLA were calculated for 190 donor/recipient pairs.
• The natural logarithm-transformed PIRCHE-II overlap score (STEP score) was analyzed.

Main Results:

• A significant association was found between the STEP score and the 10-year risk of death-censored kidney graft failure.
• Higher STEP scores indicated an increased risk of graft failure.

Conclusions:

• Pre-transplant donor-reactive CD4+ memory T-helper cells, indicated by the STEP score, are a significant predictor of kidney graft failure.
• This finding suggests a potential biomarker for stratifying transplant recipients by risk.