Validation of a new assay that uses 2 monoclonal antibodies to measure intact and fragmented plasma CgA levels Abstract #152

Introduction: Plasma chromogranin A (CgA) levels are elevated in a variety of neuroendocrine tumors (NETs) and are used to aid in diagnosis, prognosis, and monitoring of treatment effects in NETs patients. We evaluated a newer sandwich ELISA assay (Cisbio US, Bedford, MA, USA) that utilizes two monoclonal antibodies that bind to the mid-region of the CgA protein and allow measurement of intact and fragmented circulating CgA. The results from the assay validation indicative of its overall robustness in terms of sensitivity, specificity, reproducibility, and stability are presented here.
Aim(s): To validate the CgA ELISA (Cisbio) assay according to the American Association of Pharmaceutical Sciences Ligand Binding Assay Bioanalytical Focus group guidelines and investigate its utility as a tool for use in the clinic.
Materials and methods: Commercial CgA ELISA kit (CisBio, MA) was used according to the manufacturer’s instructions. The sensitivity and dynamic range of the assay were established by measuring the recovery of recombinant CgA spiked into human plasma. Healthy donor and pancreatic NET patient plasma were used to assess the specificity, stability, intraday, and interday variability of the assay.
Conference: 7th Annual ENETS Conference (2010)
Category: Clinical
Presenting Author: Monica Motwani

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