title: Chromogranin A - unspecific neuroendocrine marker. Clinical utility and potential diagnostic pitfalls.
abstract: Chromogranin A, despite a number of limitations, is still the most valuable marker of neuroendocrine tumors (NETs). Granins belong to the family of acidic proteins that constitute a major component of secretory granules of various endocrine and neuroendocrine cells, which are components of both the classical endocrine glands and the diffuse neuroendocrine system. These cells are a potential source of transformation into neuroendocrine tumors. The awareness of potential causes influencing the false results of its concentrations simplifies diagnosis and treatment. One of the disadvantages of this marker is its non-specificity and the existence of a number of pathological processes leading to an increase in its concentration, which often results in confusion and diagnostic difficulties. The molecular structure is characterized by a number of sites susceptible to the proteolytic activity of enzymes, resulting in the formation of a number of biologically active peptides. Presumably they act as precursors of active proteins. Chromogranin expression correlates with the amount of secretory vesicles in neuroendocrine cells. The peptide chain during biochemical changes becomes a precursor of biologically active proteins with a wide range of activities. There are a number of commercially available kits for the determination of chromogranin A, which differ in methodology. We present the evaluation of chromogranin A as a marker of neuroendocrine tumors in clinical practice and the possible factors that may affect the outcome of its concentration.
authors.affiliation: Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Gut
authors.affiliation: Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Czarnywojtek
authors.affiliation: Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Jakub
authors.initials: J
authors.lastname: Fischbach
authors.affiliation: Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Bączyk
authors.affiliation: Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Ziemnicka
authors.affiliation: Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Wrotkowska
authors.affiliation: Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Gryczyńska
authors.affiliation: Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Ruchała
keywords: chromogranin A; neuroendocrine tumors