Ahsan Rao1, Michael Wilson2, Gwen Kennedy3, Devender Mittapalli2, Iain Tait2, Afshin Alijani2. 1. Department of Surgery, Ninewells Hospital and Medical School, Dundee DD2 9SY, UK. Electronic address: a.rao@imperial.ac.uk. 2. Department of Surgery, Ninewells Hospital and Medical School, Dundee DD2 9SY, UK. 3. Immunoassay Biomarker Core Laboratory, School of Medicine, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK.
Abstract
BACKGROUND AND PURPOSE OF THE STUDY: There is growing evidence to suggest the use of urinary 5-hydroxyindoleacetic acid (5-HIAA) test to help with the diagnosis of appendicitis. The aim of our study was to establish whether urinary 5-HIAA could be used as an effective diagnostic test for acute appendicitis. DESIGN AND METHODS: A prospective double-blinded study was carried out from December 2014 to October 2015. Patients admitted to the emergency surgical ward of a teaching hospital with suspected appendicitis were included in the study. The diagnostic accuracy of the test was measured by receiver operating characteristic curve. RESULTS: Ninety-seven patients were divided into 2 groups: acute appendicitis (n=38) and other diagnosis (n=59). The median value of urinary 5-HIAA was 24.19μmol/L (range, 5.39-138.27) for acute appendicitis vs 18.87μmol/L (range, 2.27-120.59) for other diagnosis group (P=.038). The sensitivity and specificity of urinary 5-HIAA at a cutoff value of 19μmol/L were 71% and 50%, respectively. Receiver operating characteristic analysis showed that the area under curve was 0.64 (confidence interval [CI], 0.513-0.737) for urinary 5-HIAA, which was lower than white blood cell count (0.69; CI, 0.574-0.797), neutrophil count (0.68; CI, 0.565-0.792), and C-reactive protein (0.76; CI, 0.657-0.857). There was no significant difference in the median values of 5-HIAA between different grades of severity of appendicitis (P=.704). CONCLUSION: Urinary 5-HIAA is not an ideal test for the diagnosis of acute appendicitis.
BACKGROUND AND PURPOSE OF THE STUDY: There is growing evidence to suggest the use of urinary 5-hydroxyindoleacetic acid (5-HIAA) test to help with the diagnosis of appendicitis. The aim of our study was to establish whether urinary 5-HIAA could be used as an effective diagnostic test for acute appendicitis. DESIGN AND METHODS: A prospective double-blinded study was carried out from December 2014 to October 2015. Patients admitted to the emergency surgical ward of a teaching hospital with suspected appendicitis were included in the study. The diagnostic accuracy of the test was measured by receiver operating characteristic curve. RESULTS: Ninety-seven patients were divided into 2 groups: acute appendicitis (n=38) and other diagnosis (n=59). The median value of urinary 5-HIAA was 24.19μmol/L (range, 5.39-138.27) for acute appendicitis vs 18.87μmol/L (range, 2.27-120.59) for other diagnosis group (P=.038). The sensitivity and specificity of urinary 5-HIAA at a cutoff value of 19μmol/L were 71% and 50%, respectively. Receiver operating characteristic analysis showed that the area under curve was 0.64 (confidence interval [CI], 0.513-0.737) for urinary 5-HIAA, which was lower than white blood cell count (0.69; CI, 0.574-0.797), neutrophil count (0.68; CI, 0.565-0.792), and C-reactive protein (0.76; CI, 0.657-0.857). There was no significant difference in the median values of 5-HIAA between different grades of severity of appendicitis (P=.704). CONCLUSION: Urinary 5-HIAA is not an ideal test for the diagnosis of acute appendicitis.