The Diagnostic Value of Serum Fibrinogen Level in the Diagnosis of Acute Appendicitis

Background and purpose: Appendicitis is the most common cause of acute abdominal pain requiring surgical intervention. Diagnostic tests with high accuracy could lead to immediate diagnosis and timely surgery could prevent further complications. This study was performed to assess the diagnostic value of serum fibrinogen level in diagnosis of acute appendicitis. Materials and methods: This cross-sectional diagnostic study was performed in patients (n=165) attending the emergency department in Sari Imam Khomeini Hospital with an initial diagnosis of appendicitis and available histopathologic examination results in 2016-2017. Fibrinogen levels were measured before surgery. Student's t test, Mann-Whitney test, and Chi-square were used to examine the relationship between fibrinogen level, demographic and clinical variables, acute appendicitis, and complicated/uncomplicated appendicitis. ROC Curve test was also performed and indicators associated with diagnostic accuracy were calculated. Results: The mean fibrinogen level in patients with normal appendices was 278.0±50.5, while it was 349.4 ± 68.7 in those with appendicitis (P<0.0001). The area under the curve was 0.794 (CI = 0.724-0.853). Moreover, at the optimal cut-point of fibrinogen level of 344 mg/dl, the sensitivity, specificity, negative predictive value, and positive predictive value were 51.7%, 90.4%, 94.4%, and 37.6%, respectively. Positive and negative likelihood ratios were 5.43 and 0.53, respectively. Conclusion: This study showed that measuring serum fibrinogen levels, as an acute phase reactant, is useful for diagnostic screening of acute appendicitis and for predicting complicated appendicitis.