Expression and clinical significance of inducible co-stimulator on peripheral blood T lymphocyte subsets in patients with systemic lupus erythematosus

Abstract

To investigate the expression of inducible co-stimulator (ICOS) and other immunological molecules on peripheral blood T lymphocyte subsets in patients with systemic lupus erythematosus (SLE) and to find out the relationship with disease-activity, disease-stage and the contents of anti-dsDNA antibody and immunoglobulin in serum so as to pave the way for further studying the possibly immunologically pathological role of ICOS in SLE. Peripheral blood samples were collected from 51 patients with SLE, 3 males and 22 females. Three-color flow cytometry was used to detect the levels of ICOS, CD45RO, CD45RA, and HLA-DR expression on the peripheral blood T lymphocytes subsets. The results were analyzed along with the disease-activity, disease-stage, contents of anti-dsDNA antibody and immunoglobulin in serum. Thirty healthy subjects were used as controls. Compared with the healthy subjects the level of ICOS expression on the peripheral blood CD4+ and CD8+ T cells in the patients with SLE during active- and stable-stages were significantly increased (all P < 0.05), but there was no significant difference between the last two group patients (P > or = 0.05); In the same patients, the level of ICOS expression on the peripheral blood CD4+, CD8+, CD45RO+, CD4+CD45RO+ and CD8+CD45RO+ cells in active-stage were significantly increased compared with those in stable-stage (P <0.05); The level of ICOS expression on the peripheral blood CD45RO+ cells in the untreated primary patients was higher than those with disease-relapse (P <0.05); The levels of ICOS expression on the peripheral blood CD45RO+ and CD4+CD45RO+ cells were significantly increased in the patients with serum anti-dsDNA antibody(+) and the patients with aberrantly high content of immunoglobulin compared with those of the patients with serum anti-dsDNA antibody(-) and the patients with normal content of immunoglobulin, respectively (all P < 0.05). ICOS is aberrantly highly expressed on certain peripheral blood T lymphocyte subsets in patients with SLE, which is related to disease-activity, disease-stage and the contents of serum anti-dsDNA antibody and immunoglobulin, thus ICOS may play a role in SLE pathogenesis.