The hormone ghrelin is produced predominantly by gastric X/A-like neuroendocrine cells, and exists in acylated (AG) and unacylated (UAG) forms. Acylation is necessary to activate the ghrelin receptor GHSR1a in vivo, but UAG could also act as a hormone independently from AG. Ghrelin’s function in neuroendocrine tumours (NETs) is not well understood, although levels correlate positively with tumour burden, and hyperghrelinaemia has been described in patients with NETs.

Van Adrichem et al. investigated whether AG and UAG levels could be potential biomarkers in patients with NETs. Fasting serum AG and UAG levels were compared between 28 non-obese, non-diabetic NET patients and their matched controls, and these were analysed alongside additional biochemical and clinical parameters.

There were no significant differences in plasma AG and UAG levels between NET patients and their matched controls, indicating these have no utility as diagnostic biomarkers in these patients. The authors suggest that hyperghrelinaemia in NET patients is not the result of hypersecretion from the tumour itself, and that a ‘ghrelinoma syndrome’ does not exist.

Read the full article in Endocrine Connections 5 143–151 (OA)