[Role of circulating T follicular helper subsets and T follicular helper effector memory cells in systemic lupus erythematosus].

To investigate the role of T follicular helper (Tfh) subsets and T follicular helper effector memory (Tfhem) cells in circulation of patients with systemic lupus erythematosus (SLE), and explore their roles in SLE disease activity index as biomarkers. This study enrolled 64 patients with SLE and 15 healthy controls. In peripheral blood from patients with SLE and health controls, the percentage of Tfhem (CD3(+)CD4(+)CD45RA(-)CXCR5(+)CCR7(low)PD-1(high)) cells, Tfh (CD3(+)CD4(+)CD127(high)CD25(l)ow CD45RA(-)CXCR5(+)) subset: Tfh1 (CXCR3(+)CCR6(-)Tfh), Tfh2 (CXCR3(-)CCR6(+) Tfh), Tfh17 (CXCR3(-)CCR6(+) Tfh), were detected by flow cytometry. The correlations of Tfhem/Tfh subsets with clinical indicators which we collected were analyzed. The percentage of Tfhem was significantly increased in SLE patients compare to health controls (1.40±1.12 vs 0.51±0.24, 0.000 1), and it was also correlated with systemic lupus erythematosus disease activity index (SLEDAI) (0.015 3) and anti-dsDNA antibody (0.003 1), but not with complement C3 (C3), complement C4 (C4), erythrocyte sedimentation rate (ESR), and C reaction protein (CRP). In addition, the percentage of Tfh2, but not Tfh1 or Tfh17, was significantly increased in SLE patients compare to health controls (3.83±2.74 vs 2.18±1.07, 0.000 4). As compared to anti-dsDNA antibody<25 group, the percentage of Tfh2 in anti-dsDNA antibody>25 group was increased with no significant statistical difference (4.33±3.20 vs 3.70±1.070, 0.069 6). Our investigation show that Tfhem is associated with SLEDAI and it is a valuable evaluation biomarker for disease process and treatment. Meanwhile Tfhem is also associated with anti-dsDNA antibody, and it plays an important role in autoantibody production in SLE pathogenesis. Tfhem may be a good therapeutic target in SLE. For the meantime, the percentage of Tfh2 is significantly increased in SLE patients, and it had certain correlation with anti-dsDNA antibody, it might be involved in the development of SLE.