FOXP3 autoantibody as a potential early prognostic serum biomarker in patients with cervical cancer

Overexpression of tumor-associated antigens has been reported in many types of cancer and may trigger secretion of their autoantibodies. The present work was designed to test whether circulating antibody to FOXP3 protein-derived antigens was altered in early cervical cancer and cervical benign tumors.

A total of 141 patients with cervical cancer, 133 patients with cervical benign tumors and 148 healthy age-matched volunteers were recruited. The level of circulating anti-FOXP3 IgG antibody was tested using an enzyme-linked immunosorbent assay developed in-house with linear peptide antigens derived from FOXP3 protein. The linear peptide antigens were designed according to the computational prediction of HLA-II epitopes.

Student's t test showed that anti-FOXP3 IgG in the malignant tumor group and the benign tumor group was significantly higher than in the control group (t = 6.127, p < 0.001; t = 2.704, p = 0.007). In addition, patients with stage I cervical cancer (t = 2.968, p = 0.003) had a significantly higher level of FOXP3 autoantibodies than patients with benign tumors. The sensitivity against >90 % specificity was 20.6 % with an interassay deviation of 11.7 % in the cervical cancer group. Based on a cut-off value determined by the 98th percentile of the control group IgG levels, the anti-FOXP3 IgG positivity was 2.1 % in patients with cervical cancer compared to 2.0 % in the health controls (chi-squared = 0.004, p = 0.952, OR = 1.051, 95 % CI 0.209-5.295).

The circulating autoantibody to FOXP3 reflecting the continuous development of the cervical lesion, may be a potential biomarker with early prognostic values for cervical cancer.