B Cell Profile In Operationally Tolerant Kidney Recipients

Sophie Brouard, Centre Hospitalier Universitaire Hotel Dieu, Nantes, France

Although the achievement of immunological tolerance has been possible in animal models, the translation into the clinic is not feasible yet and remains highly experimental in human. Nevertheless, evidence have been accumulated that some transplant recipients permanently accept their grafts in the absence of immunosuppression. Up to 20% of liver recipients can withdraw immunosuppression and some cases in kidney transplantation have been observed. Since several years, efforts have been made in the scientific community to enroll large cohort of such rare patients. We and others have reported that operationally tolerant recipients were characterized by a high number of peripheral B cells with a specific B cell profile associated with an increase in B cell populations expressing CD5 and CD1d protein and transitional B cell markers. Transcripts for BANK1, a negative modulator of CD40-mediated AKT activation and a hypo responsive cytokine profile were also increased, suggesting an inhibitory blood B cell profile in patients with operational tolerance. Altogether these data show that blood B cell phenotype and key molecules of B cell regulation are regulated in operationally tolerant recipients. We will make the point on the different studies published recently.