Evaluation of plasma level of fibrinogen as a diagnostic criterion in acute appendicitis; cohort study

Background: Acute appendicitis (AA) is the most common etiology of abdominal operation worldwide. Despite advances in diagnostic guidelines there are still missed patients. This study evaluates assumption of plasma fibrinogen as a diagnostic criterion in AA.

Method: All patients over 12 years who were referred to emergency department and underwent index open appendectomy were enrolled in this cohort study. Histopathologically confirmed positive reports for presence of AA were allocated in a group. Controls experienced open appendectomy although pathological study was negative for AA. In addition to registering demographic data, plasma sample was examined for fibrinogen, quantitative C-reactive protein (CRP), and complete blood count preoperatively. Variables were compared. The ROC curve was customized and correlation coefficient for study markers was measured.

Results: Total 168 patients were enrolled. From all, 96 (57.1%) had confirmed AA, histopathologically. Gender, age, race, and body mass index had no difference between study groups (p > 0.05). In almost all patients increasing in white cell counts and left cellular shift was observed (p > 0.05). However, plasma level of fibrinogen and CRP reached to 389.2 ± 229.99 mg/dL (p = 0.001) and 33.06 ± 16.29 mg/L (p = 0.03) respectively, which both were significantly elevated in positive AA. Analysis showed area under the curve of serum fibrinogen was 0.892 (p < 0.001) with a cut-off point of 272 mg/dL had about 66.7% (95% CI:58.2-73.3) sensitivity, 92.8% (95% CI: 89.5-96.1) specificity, and 0.698 (p = 0.04) correlation coefficient for diagnosis of AA.

Conclusion: Amounts of elevated serum fibrinogen could imply on the diagnosis of AA specifically when concordance of clinical findings except for increasing CRP is unremarkable.