Chromogranin-A (CgA)

Chromogranins are co-stored and co-released with neuropeptides and hormones in the neuroendocrine cells throughout the body. A role for chromogranins in the generation of hormonal granules and package of hormones has been suggested. Furthermore, chromogranins can be cleaved into smaller fragments, which can display biological activities such as inhibition of hormonal release, vasodilatation and anti-microbiological effects.Tumours of neuroendocrine origin usually present with increased serum/plasma levels of chromogranin A. The neuroendocrine tumours are derived from the neuroendocrine cells and typical neuroendocrine tumours are carcinoid tumours, pheochromocytomas, neuroblastomas, small
cell lung cancers, hyperparathyroid adenomas, pituitary tumours, prostate cancers and pancreatic islet tumours and including the MEN1 and MEN2 syndromes. This also includes the different neuroendocrine tumour syndromes, namely the gastrinomas, insulinomas, glucagonomas,
somatostatinomas. PPomas and the non-functioning neuroendocrine tumours (Eriksson, B. et al. 2000). For these tumours, chromogranin A has been shown to be the best circulating marker (Bajetta, E. et al. 1999).