Abstract
Objective: Pancreastatin is a fragment of the chromogranin A (CgA) molecule. Existing pancreastatin assays, which depend on antibodies that cross-react in varying percents with the larger prohormone, may lack sensitivity and specificity to detect small changes in neuroendocrine tumor volume. Methods: We developed a highly specific, sensitive pancreastatin assay. The antibody used recognizes the carboxyl terminal of the peptide hormone and was raised against a 17-amino acid porcine pancreastatin fragment with high homology with the carboxy-terminal amino acids 286-301 of the human CgA. Results: Our assay measures more than 95% of circulating pancreastatin levels; has little or no cross-reactivity with CgA, even at plasma concentrations of 1000 ng/mL; and can detect pancreastatin levels of 17 pg/mL. Interassay reproducibility for the pancreastatin radioimmunoassay was determined from results of 3 quality control pools in 15 consecutive assays. Coefficients of variation for low, medium, and high pancreastatin levels were less than 20%. The sensitivity of serial pancreastatin assays to detect early liver tumor activity was demonstrated in 2 patients with slowly progressive neuroendocrine tumors and in patients undergoing surgical cytoreduction. Conclusions: This highly specific, sensitive pancreastatin assay can detect small changes in liver tumor progression and is up to 100-fold more sensitive and specific than CgA assays in the United States.
Original language | English (US) |
---|---|
Pages (from-to) | 611-616 |
Number of pages | 6 |
Journal | Pancreas |
Volume | 39 |
Issue number | 5 |
DOIs | |
State | Published - Jul 2010 |
Keywords
- biomarkers
- carcinoid
- chemoembolization
- chromogranins
- cytoreduction
- embolization
- islet cell tumors
- neuroendocrine tumors
- pancreastatin assay
ASJC Scopus subject areas
- Internal Medicine
- Endocrinology, Diabetes and Metabolism
- Hepatology
- Endocrinology