page_title: Chromogranin A
section_title: Clinical significance
hierarchical_section_title: Chromogranin A / Clinical significance
caption_attribution_description: English: Intermediate magnification micrograph of a paraganglioma of the duodenum, also duodenal paraganglioma. Chromogranin A immunostain. Paragangliomas may be seen a number of syndromes - including: von Hippel-Lindau disease. Neurofibromatosis type I. Multiple endocrine neoplasia type 2a. Multiple endocrine neoplasia type 2b. Hereditary paragangliomatosis. The histomorphologic differential diagnosis of paraganglioma is: Metastatic renal cell carcinoma. Adrenal cortical rest. Related images Low mag. Intermed. mag. High mag. Very high mag. Intermed. mag. High mag. High mag. Very high mag.
context_page_description: Chromogranin A or parathyroid secretory protein 1 is a member of the granin family of neuroendocrine secretory proteins. As such, it is located in secretory vesicles of neurons and endocrine cells such as islet beta cell secretory granules in the pancreas. In humans, chromogranin A protein is encoded by the CHGA gene.
context_section_description: Chromogranin A is elevated in pheochromocytomas. It has been identified as autoantigen in type 1 diabetes. A peptide fragment of ChgA located in the Vasostatin-1, namely ChgA29-42 has been identified as the antigenic epitope recognized by diabetogenic BDC2.5 T cells from type 1 diabetes prone NOD mice.
  It is used as an indicator for pancreas and prostate cancer and in carcinoid syndrome. It might play a role in early neoplasic progression.  Chromogranin A is cleaved by an endogenous prohormone convertase to produce several peptide fragments. See chromogranin A GeneRIFs for references. In immunohistochemistry it can be used to identify a range of neuroendocrine tumours and is highly specific for both benign and malignant cells of this type.
  Mass spec data shows that several peptides originating from CHGA (163-194; 194-214; 272-295;) are significantly lower in samples from ulcerative colitis patients compared to control biopsies.
  There are considerable differences in the amino acid composition between different species' chromogranin A . Commercial assays for measuring human CGA can usually not be used for measuring CGA in samples from other animals. Some specific parts of the molecule have a higher degree of amino acid homology and methods where the antibodies are directed against specific epitopes can be used to measure samples from different animals. Region-specific assays measuring defined parts of CGA, CGB and SG2 can be used for measurements in samples from cats and dogs. In dogs, the catestatin concentration showed weak negative associations with left atrial and ventricular sizes and the catestatin concentration showed weak positive associations with blood pressure.
caption: Micrograph of a paraganglioma stained with chromogranin A immunostain.
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