Increased Proportion of CD226+ B Cells Is Associated With the Disease Activity and Prognosis of Systemic Lupus Erythematosus

• Main Authors: Miki Nakano, Masahiro Ayano, Kazuo Kushimoto, Shotaro Kawano, Kazuhiko Higashioka, Shoichiro Inokuchi, Hiroki Mitoma, Yasutaka Kimoto, Mitsuteru Akahoshi, Nobuyuki Ono, Yojiro Arinobu, Koichi Akashi, Takahiko Horiuchi, Hiroaki Niiro
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2021-07-01
• Series: Frontiers in Immunology
• Subjects: systemic lupus erythematosus; CD226; B cells; lupus low disease activity; lupus nephritis
• Online Access: https://www.frontiersin.org/articles/10.3389/fimmu.2021.713225/full

BackgroundCD226, an activating receptor expressed on the surface of natural killer (NK) cells and T cells, is also seen on B cells and CD226 polymorphism is associated with systemic lupus erythematosus (SLE). Because the specific roles of CD226+ B cells in SLE are still unknown, we investigated the association of CD226+ B cells with SLE.MethodsWe measured CD226 expression on B cells and its subsets using flow cytometry in 48 SLE patients and 24 healthy controls (HCs). We assessed the relationships between CD226+ B cells and SLE Disease Activity Index 2000 (SLEDAI-2K), clinical manifestations, laboratory data, and prognosis after 12 months.ResultsThe proportions of CD226+ cells in whole B cells and all its subsets were significantly higher in SLE patients than HCs. In SLE patients, the proportions of CD226+ B cells and CD226+ switched-memory (SM) B cells were significantly correlated with SLEDAI-2K scores and anti-dsDNA antibody titers, and negatively correlated with serum complement levels. Moreover, basal percentages of CD226+ B cells and CD226+ SM B cells were low in patients who were in Lupus Low Disease Activity State after 12 months. In patients with renal involvement, the proportion of CD226+ B cells increased. Additionally, the proportion of CD226+ B cells was higher in patients who were not in complete renal remission after 12 months.ConclusionsIncreased proportion of CD226+ B cells was associated with disease activity and prognosis of SLE. CD226+ B cells may be a useful biomarker for the management of SLE.