Association between CD28 expression and juvenile idiopathic arthritis

Abstract

Objective To investigate the clinical significance of CD28 expression on peripheral blood T lymphocytes in children with juvenile idiopathic arthritis (JIA).Methods Flow cytometry and tri-color direct immunofluorescence were used to examine CD3 + T lymphocyte subsets and CD28 expression in whole blood (using the no-wash method) from 36 children with JIA.Results During the active phase of disease,the frequency of CD28 + expression on both CD4 + and CD8 + T cells in the peripheral blood of children with JIA was significantly lower than in normal controls (P ＜ 0.01).The frequency of CD4 + CD28-T cells in the peripheral blood of children with JIA was significantly higher than in normal controls (P ＜ 0.01).CD4 + T cell counts in the peripheral blood of children with JIA,which were mostly of the CD4 + CD28-T cell subtype,were significantly higher than in normal controls (P ＜ 0.01),whereas the CD8 + T cell count was significantly reduced (P ＜0.01).During the resting phase,CD4 +/CD8 + T cell counts and CD28 expression in the peripheral blood of children with JIA were significantly different from normal controls (P ＞ 0.05).Conclusions The frequency of CD4 + CD28-T cells can be used as an indicator of the active phase of JIA.CD4 + T cell and CD4+ CD28-T cell apoptosis was inhibited in JIA patients.These immune-active T lymphocytes with continued survival can promote the occurrence and development of JIA. Key words: Juvenile idiopathic arthritis; CD28