Screening for Multiple Autoantibodies in Plasma of Patients with Breast Cancer

Abstract

Background/aim: Autoantibodies have potential as circulating biomarkers for early cancer detection. This study aimed to screen for known autoantibodies in human plasma using an Autoantibody Profiling System (APS) and quantify the levels in plasma of donors with/without breast cancer.

Materials and methods: Plasma from nine female donors diagnosed with breast cancer (test group) and nine matched donors with no personal history of cancer (reference group) were screened with an APS containing probes for 30 autoantibodies. Autoantibody levels ≥1.5 times the mean concentration of the group were considered elevated, and test/reference ratios ≥1.3 were considered higher in the test group compared to the reference group.

Results: Twenty percent of the probes detected elevated levels of autoantibodies against proteins involved in different cancer mechanisms. Amongst these, the levels of autoantibodies against interleukin 29 (IL29), osteoprotegerin (OPG), survivin (SUR), growth hormone (GRH) and resistin (RES) were significantly higher in the cancer group compared to the reference group (p<0.05), whereas the level of autoantibody against cytotoxic T-lymphocyte associated antigen-4 (CTLA4) was not significantly different between the two groups (p=0.38).

Conclusion: Disease-relevant autoantibodies were detected in the plasma of patients with breast cancer and donors without breast cancer. This means that identifying the type and level of autoantibodies in samples will be important in determining their significance in the disease process. A microtiter plate-based array system could be a fast and inexpensive screening method for identifying and quantifying autoantibodies in human plasma.

Keywords: Antigen array; autoantibody detection; breast cancer; plasma screening.

Figure 1. Schematic illustration of the Autoantibody Profiling System workflow for screening of plasma. A: Plasma from nine donors diagnosed with breast cancer was used as the test group. Three samples were pooled to obtain three test samples (T1, T2, and T3). B: Plasma from nine donors with no history of breast cancer was used as the reference (R) group. Three samples were pooled to obtain three reference samples (R1, R2, and R3). Only the screening of sample T2 and R2 are illustrated. A total 50 μl of each pooled sample was used for the assay. A total of six mini-APS plates were used for the study. All incubations and washes were performed at ambient temperature and the assay lasted for about 4 h.