Search

Background: Circulating CD8 + T-cells expressing the C-X-C chemokine receptor type 5 (CXCR5) (CD8 + CXCR5 + T), a recently identified follicular cytotoxic T cell subset, are involved in antiviral immunity and autoimmunity, but their abundance and role in the pathogenesis of primary Sjögren syndrome (pSS) are unknown., Methods: Circulating CD8 + CXCR5 + T cell and CD8 + regulatory T cells (CD8 + Treg) were evaluated in 49 pSS patients (19 patients with pulmonary involvement) and 24 age- and sex-matched healthy controls (HCs) by flow cytometry. Orthogonal partial least squares discriminant analysis (OPLS-DA) was performed, and receiver operating characteristic curves (ROC) were generated to identify characteristic cell subsets. Spearman's correlation analysis was conducted to examine the relationships between CD8 + T cell subsets and clinical features., Results: The proportions and numbers of CD8 + CXCR5 + , CD8 + CXCR5 + programmed death 1-positive (PD-1 + ), and CD8 + CXCR5 - PD-1 + T cells were significantly higher, whereas those of CD8 + Treg were markedly lower, in pSS patients than HCs. The CD8 + CXCR5 + PD-1 + T cell to CD8 + Treg ratio had the greatest discriminatory power for pSS and HCs according to OPLS-DA and ROC analyses. The increased numbers of CD8 + CXCR5 + T cells and CD8 + CXCR5 + PD-1 + T cells were strongly associated with those of CD4 + CXCR5 + T and B cells. The proportions and numbers of CD8 + CXCR5 + PD-1 + T cells were increased in pSS patients with lung involvement., Conclusions: We identified a new CD8 + CXCR5 + PD-1 + T subset, which was increased in abundance in pSS patients, particularly those with lung involvement, compared with HCs. Also, the CD8 + CXCR5 + PD-1 + T to CD8 + Treg ratio may be useful for identifying pSS. Our findings suggest that targeting follicular CD8 + T cell subsets has therapeutic potential for pSS. Key Points • CD8+CXCR5+ T cells were expanded in the circulation of patients with pSS. • Reduced numbers CD8+Treg cells in pSS patients. • Increased CD8+CXCR5+PD-1+T cells in pSS patients with pulmonary involvement., (© 2022. International League of Associations for Rheumatology (ILAR).)

Background: Circulating CD8+ T-cells expressing the C-X-C chemokine receptor type 5 (CXCR5) (CD8+CXCR5+T), a recently identified follicular cytotoxic T cell subset, are involved in antiviral immunity and autoimmunity, but their abundance and role in the pathogenesis of primary Sjögren syndrome (pSS) are unknown. Methods: Circulating CD8+CXCR5+T cell and CD8+ regulatory T cells (CD8+Treg) were evaluated in 49 pSS patients (19 patients with pulmonary involvement) and 24 age- and sex-matched healthy controls (HCs) by flow cytometry. Orthogonal partial least squares discriminant analysis (OPLS-DA) was performed, and receiver operating characteristic curves (ROC) were generated to identify characteristic cell subsets. Spearman's correlation analysis was conducted to examine the relationships between CD8+ T cell subsets and clinical features. Results: The proportions and numbers of CD8+CXCR5+, CD8 + CXCR5+ programmed death 1-positive (PD-1+), and CD8+CXCR5−PD-1+T cells were significantly higher, whereas those of CD8+Treg were markedly lower, in pSS patients than HCs. The CD8+CXCR5+PD-1+T cell to CD8+Treg ratio had the greatest discriminatory power for pSS and HCs according to OPLS-DA and ROC analyses. The increased numbers of CD8+CXCR5+T cells and CD8+CXCR5+PD-1+T cells were strongly associated with those of CD4+CXCR5+T and B cells. The proportions and numbers of CD8+CXCR5+PD-1+T cells were increased in pSS patients with lung involvement. Conclusions: We identified a new CD8+CXCR5+PD-1+T subset, which was increased in abundance in pSS patients, particularly those with lung involvement, compared with HCs. Also, the CD8+CXCR5+PD-1+T to CD8+Treg ratio may be useful for identifying pSS. Our findings suggest that targeting follicular CD8+T cell subsets has therapeutic potential for pSS. Key Points • CD8+CXCR5+ T cells were expanded in the circulation of patients with pSS. • Reduced numbers CD8+Treg cells in pSS patients. • Increased CD8+CXCR5+PD-1+T cells in pSS patients with pulmonary involvement. [ABSTRACT FROM AUTHOR]