An integral part of precision medicine involves the pairing of a drug with diagnostic tests (companion diagnostics) that have the potential to assess a person’s specific genetic make-up, thereby predicting drug efficacy, drug resistance and therapeutic response.
Profiling Autoantibody Levels to Cancer-Associated Antigens
It is well-established that antibodies to cancer-associated antigens appear in biological fluids (particularly in blood sera) of cancer patients and the persistence and stability of autoantibodies in the serum of cancer patients is an advantage over other potential markers. Detection of these antibody biomarkers in patient sera by immunochemical methods represents a promising approach to minimally invasive cancer diagnostics capable of early detection. The use of antigen arrays which can screen for multiple antibody biomarkers simultaneously allows the identification of so-called “autoantibody signatures”.
Researchers have demonstrated through the use of arrays of short overlapping peptide sets that some antibodies are critically dependent on an individual amino acid within a short linear peptide. They found that a single amino acid shift could eliminate the recognition by the antibodies in the serum and that the antibody responses to each specific epitope differed significantly in melanoma patients. Others found autoantibody titres to vary considerably across individual patients, suggesting that different patients raised autoantibodies to different epitopes of the same antigen. This could potentially impact clinical outcome of specific patients.