Ghrelin in human medullary thyroid carcinomas

Objective: Ghrelin is a novel gastrointestinal hormone involved in several metabolic functions. It has been identified previously in several normal and tumoral neuroendocrine tissues, including human medullary thyroid carcinomas (MTCs). The aim of the study was to evaluate ghrelin levels in patients with MTC and nontoxic goitre (NTG) with elevated calcitonin (CT) levels, as an additional marker of the disease. Patients and design: The study included 22 patients with MTC (four before and 18 after thyroidectomy), 12 patients with NTG with basal CT levels exceeding 10 ng/1 and 15 healthy subjects matched for age, sex and body mass index (BMI). After thyroidectomy, MTC patients were considered cured when basal and pentagastrin-stimulated CT levels were 50 ng/l). Immunohistochemistry showed positivity for ghrelin in a small proportion of CT positive cells from the four MTCs removed. Conclusions: Patients with MTC, NTG and controls showed similar ghrelin levels, ruling out this parameter as a marker of MTC. The increase in ghrelin levels in patients with a positive CT response to pentagastrin, together with the immunopositivity for ghrelin in some MTC cells, suggests C cells as minor source of ghrelin production. (copyright) 2005 Blackwell Publishing Ltd