Introduction: T regulatory cells (Treg) play an important role in the maintenance of immune cell homeostasis, as it has been reported that CD4+CD25+ T cells suppress the auto-reactive responses in autoimmune diseases such as systemic lupus erythematosus (SLE). The clinical significance of the recently identified population of CD4+CD25-Foxp3+ T cells and whether they are associated with particular organ involvement is still not clear. So, the aim of our study was to evaluate the presence of CD4+CD25-Foxp3+ cells in SLE patients in comparison to healthy controls and to determine whether their frequency is associated with disease activity and particular clinical manifestations in these SLE patients.
Material and methods: The frequency of CD4+CD25-Foxp3+ T cells was analyzed in 56 female SLE patients and 30 healthy female control subjects, using flow cytometry (FACS). CD4+CD25-Foxp3+ T cells were correlated with clinical and laboratory data and the SLE Disease Activity Index (SLEDAI).
Results: The level of CD4+CD25-Foxp3+ T cells was significantly increased in SLE patients (15.57 ±4.32%) as compared with the control group (2.46 ±0.65%). A significant correlation was observed for the percentage of CD4+CD25-Foxp3+ T cells with clinical disease activity scores and disease duration (r = 0.6, p < 0.001; r = 0.3, p = 0.02 respectively). It was also positively correlated with renal impairment and hematological involvement.
Conclusions: Systemic lupus erythematosus patients exhibited an altered level of their CD4+Foxp3+ T cells with increased levels of CD4+CD25-Foxp3+ cells.