Diminished natural killer T-like cells correlates with aggravated primary Sjögren's syndrome.

Objective: To reveal the characteristics and potential role of natural killer T-like cells (NKT-like cells) in the pathogenesis of primary Sjögren's syndrome (pSS).

Methods: Forty-six patients with pSS and 30 healthy subjects were enrolled in the study. The frequencies and cell count of NKT-like cells as well as other lymphocyte subsets were analyzed by flow cytometry. The clinical and laboratory indicators of pSS patients were also collected. Then, the correlation between NKT-like cells and pSS patient manifestations was analyzed by Spearman's rank test. In addition, NKT-like cells before and after therapy were also compared.

Results: Both the number and the frequencies of NKT-like cells were significantly decreased in pSS patients. The counts of NKT-like cells were positively correlated with CD4 T cells (r = 0.464, P = 0.001), CD8 T cells (r = 0.363, P = 0.013), NK cells (r = 0.488, P = 0.001), and IgM levels (r = 0.443, P = 0.002), while negatively correlated with the disease duration (r =  - 0.33, P = 0.027). Moreover, after effective therapy, NKT-like cells were recovered both in the cell counts and frequencies.

Conclusion: In pSS, NKT-like cells were fundamentally decreased, potentially contributing to the disease pathogenesis. Modulating the status of NKT-like cells might provide a novel strategy for treating the disease.

Key Points: • NKT-like cells were significantly decreased in pSS patients. • NKT-like cells were correlated with pSS patient manifestations. • NKT-like cells might be serverd as a new marker for assessing the status of pSS.