Analysis of CCR4high CD4+ in Kidney Graft Blood After Steroid Withdrawal

Abstract

Introduction Steroids represent a mainstay of immunosuppression after kidney transplant. The infiltration into the graft of active T cells following KT depends on the expression of chemokines and their interaction with their T-cell receptors. However, the natural history of the expression of these molecules in patients who undergo steroid withdrawal after transplant is unknown. Materials and Methods In a controlled clinical trial (NCT02284464), a total of 176 KT patients with low immunological risk were recruited to randomly receive either conventional triple immunosuppression: steroids, TAC and MMF (Group A) versus steroid withdrawal at the 3 post-KT month (Group B). We compared the evolution of CCR4highCD4+ and CXCR3highCD4+ lymphocyte subpopulations in graft blood (GB) extracted by fine needle aspiration puncture determined by flow cytometry in patients after steroid withdrawal at the 3 month post-KT versus patients who continue to receive conventional triple immunosuppression. Measurements were made at 3 (baseline) and 6 months post-KT in GB and in peripheral blood (PB). Results So far, 68 patients have been randomized (34 in each group). There were no significant differences in the clinical and demographic characteristics between the groups at baseline. The first analysis (at 3 months) in those patients who had completed 6 months of follow-up (Group A: n=13; Group B: n=15) showed a significant increase in the CCR4highCD4 subpopulations in GB versus PB in both groups. However, at six months a significant increase in GB versus PB was only seen in Group A. There were no significant differences in the CXCR3highCD4+ lymphocyte subpopulation at the third or sixth month between GB and PB in either group (Table).Conclusion These preliminary results could suggest a possible effect of prednisone that would favor the recruitment of CCR4highCD4+ cells into the renal graft. Spanish Ministry of Economy and Competitiveness (MINECO) (grant ICI14/00016) from the Instituto de Salud Carlos III co-funded by the Fondo Europeo de Desarrollo Regional–FEDER, RETICS (REDINREN RD12/0021/0015, RD16/0009/0006).