Quantitation of HER2 and telomerase biomarkers in solid tumors with IgY antibodies and nanocrystal detection.

In an effort to improve affinity biomarker validation in fixed patient tissue specimens, we have developed a novel quantum dot-based bioimaging system that utilizes chicken IgY antibody for high sensitivity and specificity relative quantitation of cancer proteins. Monospecific, polyclonal IgYs were generated against human HER2 and telomerase, and analytically validated for specificity by western blot and immunohistochemistry on tumor and normal cells and for relative affinity by layered peptide array (LPA). IgYs bound desired targets in cell lines and fixed tissues and showed greater affinity than commercial mammalian antibodies for both HER2 and telomerase proteins. In tissue microarray experiments, HER2 quantitation with IgY antibody and quantum dot imaging correlated well with chromogenic in situ hybridization (CISH), whereas telomerase quantitation suggested a trend toward correlation with prostate cancer Gleason Grade and differentiation. Although patient numbers were small, these findings demonstrate the feasibility of relative quantitation of cancer biomarkers with IgY and quantum dot fluorophores, and show promise for rigorous clinical validation in large patient cohorts.

Standards for autoantibody testing; addressing future needs for autoimmune disease and cancer diagnosis.

It is widely held that determination of increased levels of serum autoantibodies can play an important role in the diagnosis and, in some cases, management of many autoimmune diseases. It is also widely held that such testing is fraught with problems relating to accuracy and detection of clinically relevant autoantibodies. Attempts to standardize autoantibody testing by making available standard reference sera, have helped to some degree to improve the testing. Nevertheless, problems still exist and may be causing the delayed diagnosis of severely debilitating and sometimes fatal autoimmune diseases. This paper discusses current practice, as well as, possible new approaches intended to make more robust, autoantibody determinations in all fields of medicine.