Increased proportion of CD226 + CD14 + monocytes correlates with clinical features and laboratory parameters in patients with primary Sjögren's syndrome

CD226 is widely expressed on the surface of immune cells as a co-stimulatory receptor, which is involved in the development of many autoimmune diseases. The purpose of this study was to investigate the proportion of CD226 on CD14 + monocytes in the peripheral circulation of patients with primary Sjögren's syndrome (pSS) and the clinical significance of pSS.

The proportion of CD226 on the surface of CD14 + monocytes was measured by flow cytometry in 45 pSS patients and 25 healthy controls (HC). The correlations between the proportion of CD226 + CD14 + monocytes and the clinical features and laboratory parameters of pSS were analyzed. Meanwhile, we analyzed the change in proportion of CD226 + CD14 + monocytes before and after treatment, and the clinical significance of pSS was evaluated.

The proportion of CD226 on CD14 + monocytes markedly increased in pSS patients compared to HC (p < .01). We found the proportion of CD226 + CD14 + monocytes was positively correlated with the disease activity and severity of pSS patients. The proportion of CD226 + CD14 + monocytes in pSS patients with decayed tooth, fatigue, interstitial lung disease (ILD), low WBC, high IgG, anti-Ro60, and anti-SSB positive increased compared to that in negative patients (p < .05). Furthermore, the proportion of CD226 + CD14 + monocytes was significantly higher in active patients than in nonactive patients (p < .01). Additionally, the proportion of CD226 + CD14 + monocytes decreased in seven pSS patients after treatment (p < .01).

Our study suggested that an increased CD226 proportion on CD14 + monocytes was associated with the clinical manifestations, disease activity, and prognosis of pSS patients. CD226+ CD14 + monocytes may present a potential target and a biomarker for the prognosis and therapy of pSS patients.