Background and study aim: Serotonin is a one of the monoamine neurotransmitters secreted by serotonergic nerve endings in multiple sites in the brain and gastro-intestinal tract wall. The presence of serotonin receptors on hepatic stellate cells can cause contraction of these cells closing the sinusoidal fenestrae and raising the portal vein pressure. The aim of this work is to study the relation between free serotonin level and the presence of varices in patients with cirrhosis.
Patients and Methods: This prospective case control study was carried out on 70 patients with liver cirrhosis attended or admitted to Hepatology Department in Shebein El-Kom Teaching Hospital within the period between May and October 2015. They divided into two groups: Group 1:  40 patients with varices diagnosed by upper GIT endoscopy. Group 2:  30 patients without varices. In addition, 20 healthy persons served as control group (Group 3). All subjects were subjected to full history taking, clinical examination and laboratory investigation including plasma free serotonin by Enzyme Linked Immunosorbant Assay (ELISA).
Results: serum serotonin level in group I was significantly higher than group II and control group. Serum serotonin level was significantly correlated to esophageal varices grade, Child, MELD and updated MELD scores. It was also clear that serotonin level rises significantly with higher grades of esophageal varices.
Conclusion: Free serotonin had a good power of prediction for development of varices and correlated well with severity of liver disease in patients with cirrhosis assessed by Child, MELD and updated MELD scores as well as OV grade.