ABSTRACT
BACKGROUND: Due to lack of reliable biochemical/radiological markers, the diagnosis of acute appendicitis is based only on clinical features. METHODS: We estimated plasma serotonin levels in 48 patients with acute appendicitis (histologically proven), 27 patients with abdominal pain of other etiologies, and 20 healthy controls. RESULTS: The plasma serotonin levels were (mean +/- SD) 36.6 +/- 12.5 nmol/L, 12.5 +/- 3.6 nmol/L and 10.4 +/- 3.5 nmol/L in the three groups, respectively. The levels in patients with acute appendicitis were significantly higher (p < 0.001) than in the other groups, giving 93.8% sensitivity and 95.7% specificity to the test. CONCLUSION: Plasma serotonin level is a reliable marker of acute appendicitis, especially in the first 48 hours.