Preliminary study on the effects of belimumab combined with classic therapy on peripheral blood NK cells in patients with systemic lupus erythematosus / 中华风湿病学杂志

ABSTRACT

Objective:To assess the changes of peripheral blood NK cells in patients with systemic lupus erythematosus (SLE) following belimumab and classic therapy.Methods:From January 2020 to March 2022, peripheral lymphocyte subsets were detected by flow cytometry in SLE patients treated with Belimumab and classic therapy. The duration of treatment was 24 weeks. A total of 40 treated SLE patients were enrolled. The lymphocyte subsets in healthy donors were used as normal control group. Paired sample t-test, rank-sum test, Spearman correlation and generalized linear mixed model were used for statistical analysis. Results:In contrast to healthy subjects, the numbers of NK cells in SLE patients before treatment were significantly decreased [276.0 (179.8, 384.0) cells/μl vs. 61.4 (43.0, 105.1) cells/μl; Z=-7.32, P<0.001], although that after treatment was higher than that before treatment [61.4 (43.0, 105.1) cells/μl vs. 107.7 (72.5, 186.5) cells/μl; Z= -3.22, P<0.001]. Generalized linear mixed model results showed that the increase in serum levels of C3 ( t= -2.94, P=0.006) and NK cells ( t=-2.25, P=0.031) were associated with a decrease of anti-dsDNA antibody titers. The cutoff value of elevated counts of NK cells after treatment was equal or more than 38.5 cells/μl with a sensitivity of 61.9% and a specificity of 81.2%. Compared with those with elevated counts of NK cells ≤38.5 cells/μl, patients with elevated counts of NK cells >38.5 cells/μl had a bigger difference anti-dsDNA antibody [49.2 (0.2, 207.2) vs. 156.2 (19.8, 260.7); Z=-1.55, P=0.120] and a bigger difference of SLEDAI-2000[4.5 (0.0, 10.0) vs. 13.0 (4.5, 18.0); Z=-2.52, P=0.012]. Conclusion:The change in the numbers of NK cells may serve as biomarkers for evaluating the therapeutic responses of SLE. Combinatory approaches employing belimumab and classic therapy may control SLE disease by increasing the number of NK cells