Diagnostic accuracy of random 5-Hydroxyindole acetic acid (5-HIAA) in early diagnosis of appendicitis

Background: Early detection of appendicitis has always been a challenge and essential to minimize the risk of injury and rupture and more complications. Objective: The present study aimed to evaluate 5-hydroxyindole acetic acid's diagnostic accuracy in the early detection of appendicitis. Method: Spot urine specimens were collected from 114 patients with appendicitis and 34 healthy controls. According to the kit manufacturer's protocol, urinary biomarker level 5- HIAA was determined by the ELISA method. Descriptive statistical methods were used to describe the variables. A significant level was considered 0.05. Results: The sensitivity and specificity of the urine 5HIAA test for the diagnosis of acute appendicitis at the cut-off point of 8.15% were 31.2% and 85.25%, respectively. The positive and negative predictive values were 83.3% and 34.5%, respectively. Also, the overall accuracy of the test was 47.36%. (Kappa equal to 0.11, P = 0.066). Conclusion: The present study results showed that measurement of urinary 5HIAA level is not a suitable diagnostic tool to rule out or determine acute appendicitis.