Decreased natural killer T-like cells correlated to disease activity in systemic lupus erythematosus

Abstract

Objectives: To evaluate the absolute numbers and frequencies of natural killer T-like (NKT-like) cells in systemic lupus erythematosus (SLE) and to characterize the possible role of the cells.

Methods: Seventy-nine patients with SLE together with 30 age- and sex-matched healthy controls were enrolled. Flow cytometric determination of peripheral NKT-like cells was carried out for all participants by detecting the absolute counts (Abs) and percentage (%) of CD3 + CD16 + CD56 + cells. Disease activity index, laboratory parameters, and clinical manifestations were collected. The correlation between the cells and these parameters was analyzed.

Results: SLE patients had, with respect to controls, considerably decreased values of NKT-like cells (P < 0.001 in both absolute number and percentage). The absolute number of NKT-like cells was found to have positive correlations with WBC, RBC, PLT, C3, C4, IgM and negative correlations with the disease duration, SLEDAI-2 K, anti-dsDNA, anti-nucleosome, anti-ribosomal protein, CRP, ESR. Meanwhile, it was found that the percentage values of NKT-like cells decreased in SLE patients with nephritis which was correlated with anti-ribosomal protein and CRP in comparison to SLE patients without nephritis. Moreover, an increase in the NKT-like cell counts was also observed in the patients with a clinical response to the treatment.

Conclusions: The absolute counts and frequencies of NKT-like cells decreased in SLE patients significantly, which correlated to disease activities and could recover to normal after the treatment. The NKT-like cells may play an important role in the pathogenesis of SLE and could be a useful marker in the disease assessment. Key Points • The absolute counts and frequencies of NKT-like cells decreased in SLE patients significantly. • NKT-like cells were related to the disease activities and could restore after the treatment. • NKT-like cells may be a useful marker in the disease assessment.

Keywords: Disease activity; NKT-like cells; Systemic lupus erythematosus; T-lymphocytes.