NK/T cell ratios associate with interleukin-2 receptor alpha chain expression and shedding in multiple sclerosis

NK/T-cell ratios predict disease activity in relapsing remitting multiple sclerosis (RRMS). We investigated in 50 RRMS patients whether interleukin-2 receptor alpha-chain (IL-2R alpha) expression and shedding associates with NK/T-cell balance, as suggested by daclizumab-trials in RRMS. A subsample (N = 31) was genotyped for IL2RA-associated MS risk SNPs. CD56(bright) NK-cell/IL-17A(+)CD4(+) T-cell ratios correlated negatively with plasma and PBMC-culture supernatant sIL-2R alpha-levels [R = -0.209; p = 0.038 and R = -0.254; p = 0.012, resp.], and with CD4(+) T-cell CD25 MFI [R = -0.341; p = 0.001]. Carriers of the rs3118470 risk-allele showed higher sIL-2R alpha-levels (P = 0.031) and a lower CD56(bright) NK-cell/IL-17A(+)CD4(+) T-cell ratio (P = 0.038). Therefore, IL-2R alpha may be involved in the interplay between NK-cells and T-cells.