MEASUREMENT OF TOTAL, FREE, AND AUTOANTIBODY-BOUND BIOMARKERS

The presence or absence of specific biomarkers can be predictive in the diagnosis of various conditions. The majority of diagnostic tests for quantitative measurement of biomarkers use immune-based techniques, which utilize detection antibodies. In individuals with autoimmune disorders, however, patient autoantibodies affect the immunoassay and cause inaccurate results or misdiagnosis.

The proposed method binds antibodies to specific analytes, converting all target analytes in the sample to antibody-bound form. This creates enriched fractions that facilitate more accurate measurement of biomarker concentration. This method has been used for quantification of total thyroglobulin in serum and plasma samples to detect recurrence of thyroid carcinoma. This approach can also be applied to other biomarkers where autoantibodies can adversely affect the assay used to detect the biomarker.