Clinical Research Directory

Safety and Efficacy of the Bispecific T-Cell Engager (BiTE) in Kidney Transplant Recipients With Chronic Active Antibody-Mediated Rejection

This clinical trial aims to determine whether a bispecific T-cell engager (BiTE) targeting BCMA×CD3 effectively treats chronic active antibody-mediated rejection (cAMR) in kidney transplant recipients. The study also investigates the safety of BiTE in this patient population. The main questions it aims to answer are: 1. Is BiTE safe and tolerable in kidney transplant recipients with cAMR? 2. Can BiTE improve cAMR? (i.e., can it reduce donor-specific antibody levels, ameliorate histological injury on transplant biopsy, and stabilize or improve kidney function by depleting pathogenic B cells and plasma cells?) Researchers will evaluate the effects of BiTE by comparing clinical outcomes before and after treatment in all participants, as this is a single-arm study (all participants receive the same treatment).

Peripheral and Intrarenal B Cell Study in Antibody Mediated Transplant Rejection : Phenotypic and Transcriptional Study, Study of Reactivity

Humoral rejection of kidney transplants is responsible for a large number of kidney graft losses in a context of increasing shortage. Although it has been established that it is largely mediated by the alloreactive B lymphocyte, anti-B therapies are only partially effective. The mechanisms behind the loss of tolerance are also poorly understood, and the triggers of rejection remain to be elucidated. During this study, patients admitted for kidney graft biopsy for suspicion of rejection will be included ; patients presenting non inflammatory biopsies will be studied as controls. B cells will be extracted and cultured. Their antibodies will be studied along with reactivity towards HLA, non HLA targets and the gut microbiome. The same study will be led for late rejections needing graft removal : B cells extraction, culture, antibodies reactivity testing. Controls will be graft removal for non inflammatory causes. In both cases hight throughput sequencing the immunoglobulin genes will be performed.