Study of circulating antibodies against CD25 and FOXP3 in breast cancer.

Our recent work suggests that circulating levels of anti-CD25 and anti-FOXP3 antibodies were significantly increased in patients with either lung cancer or esophageal cancer. To confirm if these two autoantibodies are specific for certain types of malignant tumors, the present work was thus undertaken to examine an alteration of anti-CD25 and anti-FOXP3 IgG levels in breast cancer. A total of 152 patients with breast cancer and 112 control subjects were recruited in this study. The levels of circulating anti-CD25 and anti-FOXP3 IgG antibodies were tested using an in-house enzyme-linked immunosorbent assay (ELISA). Student's t test showed no significant differences in the levels of either anti-CD25 IgG or anti-FOXP3 IgG between patients with breast cancer and control subjects, although patients at stage I had increased levels of anti-CD25 IgG compared with control subjects (t = 2.11, P = 0.037); there was no significant association of the anti-FOXP3 IgG levels with stages of breast cancer. In conclusion, circulating IgG autoantibody to CD25 instead of FOXP3 may be a potential biomarker for early diagnosis of breast cancer but further investigation remains needed to replicate this initial finding.