Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells that expand after inflammation and are able to suppress innate and adaptive immune responses in different settings. Based on their phenotype could be divided in early (eMDSC), Monocytic (M-MDSC), poli-morpho nuclear (PMN-MDSC) with different functions. The MDSCs can expand regulatory T cells after kidney transplantation (KT) and potentially could be involved in allograft tolerance. The aim of the work was to analyze MDSC subsets in end-stage renal disease and correlate with further clinical events after KT.Materials and Methods
31 patients on waiting list were recruited in our hospital. MDSC subsets were measured in peripheral blood by flow cytometry prior KT and prospectively clinical events were recorded. MDSC were studied as detailed previously (1).Results
A total of 12 (38.7%) developed acute rejection post-KT. No differences in sensitization status or previous transplant between AR and No rejection groups. The frequency of M-MDSC: MDSC4 (CD33+CD11b+CD14+HLADR-/low) within peripheral blood mononuclear cells was statistically higher in AR group vs No rejection 1.76 (1.1-2.5) vs 0.18 (0.09-0.74), p=0.0014. The other M-MDSC subsets, MDSC1 (CD14+CD124+), MDSC7 (CD15-CD14+CD33highDRlow) were increased in AR group, p=0.01 and p=0.06 respectively. No differences between PMN-MDSC and eMDSC between the groups were found.Discussion
The inflammation prior kidney transplantation can induce the expansion of M-MDSCs, and the patients with increased number of MDSC-4 are at risk of suffering an acute rejection episode after KTConclusion
The measurement of MDSC could identify KT patients at risk of acute rejection, although these findings should be confirmed in large and multicenter studiesReference
(1) Mandruzzato et al. Cancer Immunol Immunother (2016); 65: 161Reference
ISCiii (FIS16/00386). REDinREN RD16/0009/0027. IDIVAL (NEXTVAL 16/022).