Objective: To investigate the expressions of Foxp3 and CD25 on CD4+T cells from patients with new-onset systemic lupus erythematosus (SLE) and assess their clinical significance.
Methods: Ten active (SLEDAI≥10) and eleven inactive (SLEDAI≤5) new-onset SLE patients as well as eleven healthy volunteers were enrolled. The expressions of CD25, Foxp3 and CD127 on CD4+ T cells were analyzed by flow cytometry. Proliferation assays were performed on isolated CD4+CD25+ and/or CD4+CD25- T cells.
Results: There was no significant difference in number of CD4+CD25+Foxp3+T cells in subjects with either active or inactive SLE compared to normal controls (P>0.05). Moreover, suppressive capacity of CD4+CD25+T cells in new-onset lupus patients was not impaired as measured by the capacity to inhibit proliferation of CD4+CD25- T cells. Interestingly, CD4+CD25-Foxp3+T cells in new-onset lupus (2.97-10.94%) were significantly more frequent than in normal controls (1.01-3.62%) (P<0.01), and positively correlated with the titers of anti-dsDNA antibodies (P=0.029). Few of these cells expressed CD127. Treatment with glucocorticoids and cyclophosphamide reduced CD4+CD25-Foxp3+ T cells in eight of ten active patients.
Conclusions: There was a significant increase in CD4+CD25-Foxp3+T cells in new-onset SLE patients that correlated with anti-dsDNA titers, whereas no alteration in either the percentage or function of CD4+CD25+Foxp3+T cells was observed.