Alloreactive Memory B Lymphocytes and Anti-HLA Sensitization

In transplantation, B lymphocytes are major cellular players in the alloreactive humoral response through the production of antibodies targeting allogeneic HLA molecules expressed by the transplant. In subjects sensitized to HLA antigens, the contribution of pre-existing alloreactive memory B lymphocytes (Bmem) to allograft rejection phenomena after transplantation is now recognized. It has been proposed that the identification of these Bmem during the pre-transplant period could contribute to a better assessment of post-transplant immunological risk, allowing optimization of strategies to prevent humoral rejection. However, knowledge regarding the phenotypic and functional heterogeneity of Bmem as well as their clonal diversity is still extremely limited, not allowing discrimination between pathogenic and non-pathogenic alloreactive humoral responses. Such discrimination requires a better understanding of the modalities of differentiation of alloreactive B lymphocyte responses. To this end, this study aims to characterize the clonal, phenotypic and functional properties of alloreactive Bmem in subjects awaiting renal transplantation and sensitized to HLA antigens.

NCT Number	NCT07011238
Lead Sponsor	University Hospital, Rouen
Conditions	Kidney Transplant
Enrollment	51 participants
Start Date	2023-04-17
Primary Completion	2028-06-17 (estimated)
Study Completion	2028-06-17 (estimated)
Updated on ClinicalTrials.gov	2026-06-22