ABSTRACT
Background: Serotonin appears to be a central physiologic mediator of many gastrointestinal functions and a mediator of the brain-gut connection
Aim: The aim of this study was to determine concentrations of free serotonin in plasma in patients with and without esophageal and fundal varices
Participants and methods: Patients diagnosed with stigmata of chronic liver disease [history, clinical, laboratory, and radiological findings - e.g. jaundice, lower limb edema, hepatomegaly, and splenomegaly] and presenting with gastrointestinal symptoms were included in the study. After upper gastointestinal endoscopy, patients were divided into two groups: group I included 30 patients with liver cirrhosis complicated with varices and group II included 30 patients with liver cirrhosis who did not have varices. Thirty healthy participants served as the control group. All patients were subjected to history taking, clinical examination, laboratory tests, abdominal ultrasound, and upper gastrointestinal tract endoscopy [for group I and II]. Plasma free serotonin was measured by the ELISA test
Results: All groups were age-matched and sex-matched. Estimation of plasma free serotonin showed a highly statistically significant difference between groups [F=59.32, P<0.01]. A serotonin cutoff value of 24 ng/ml was chosen, with 100% sensitivity, 96.7% specificity, 98.3 to discriminate all chronic liver disease patients from healthy controls [area under the curve=0.981]. A cutoff value of 58.0 ng/ml to differentiate between patients with and without esophageal varices, with 80% sensitivity and 86.7% specificity [area under the curve=0.855]. A highly significant stepwise progressive increase in the marker level was recorded through grades of oesophageal varices 2-5 [stage 2, 20.7 +/- 7.7 ng/ml; stage 3, 44.3 +/- 8.9 ng/ml, P<0.01; stage 4, 100.1 +/- 12.4 ng/ml, P<0.01; stage 5, 114.6 +/- 14.7 ng/ml, P<0.05]. There was highly significant difference in plasma free serotonin levels in patients with esophageal and gastric varices compared with those with esophageal varices alone
Conclusion: Plasma free serotonin levels could possibly be used as a noninvasive predictive method for the presence of gastroesophageal varices