Patients Converted to Belatacept Show Different Immunophenotyping Compared with De Novo Belatacept-Treated Patients

AMBROSI, NELLA; UVA, P; CARO, F; LEON, L; CASADEI, D; RIAL, M; GUERRIERI, D; CHULUYAN, E

Seattle

Congreso; American Transplant Congress; 2018

The incidence of adverse clinical events mainly in early, but not late post-transplantation such as an increased rate of acute rejection precludes the use of belatacept in all transplant patients. The aim of this study was to compare the cell immunophenotyping in kidney transplant patients treated with belatacept from the begining (de novo) with those converted to belatacept from calcineurin inhibitors.For both groups of patients, the immunophenotyping were performed after at least 9 months of the introduction of belatacept to the immunosuppresive regimen. Peripheral blood mononuclear cells were isolated from 30 transplant patients (16 de novo). There was not statistically significant difference in patients age, BMI, transplantation time, leukocytes numbers between both groups. Several costimulatory molecules and their ligands were measured on monocytes and lymphocytes by flow cytometry. There was not statistically differences on monocytes expression of CD80, CD86, B7H2, CD40 and PD-L1 between both groups of patients. However, there was a slightly higher expression of SLAM on monocytes derived from converted patients. On T cells, de novo patients had higher levels of CD27+ and CD28+ but lower of ICOS compared with converted patients.Then, we assessed the lymphoproliferation capacity of PBMC from de novo and converted group of patients. Regardless of the group of patients, proliferation was the same in response to PHA but de novo showed higher allostimulatory capacity than converted patients (p=0.02). Overall these results shows that belatacept converted-patients has a different leukocytes immunophenotype than de novo and this could affect the allostimulatory capacity.