B Cell Lymphocyte in Humoral Rejection and Alloimmunisation

The principal objective is to better understand the B cell dependant mechanisms of the chronic antibody mediated rejection (cAMR). A particular focus will be done on the mechanisms that could explain the natural history of chronic humoral mediated rejection and of pathways from DSA negative status toward DSA positive status and from DSA positive status to histological lesions. The following will be undergone for three categories of patients (stable patients, DSA positive patients without cAMR and DSA positive patients with cAMR) : * A phenotypic analysis of B cells of patients suffering from chronic humoral rejection or who are simply DSA positive. * A functional analysis in autologous cultures in order to confirm our preliminary results. * A functional analysis in a heterologous proliferation test aiming at a better understanding of the absence of B cell regulation of T cell proliferation in patients suffering from cAMR. * A cytokine analysis (IL10, alpha-tumor necrosis factor, gamma-interferon dosing), for a better understanding of the mechanisms that are involved in the regulation of the T cell response that is induced by the B cells.