Diagnostic utility of fecal calprotectin in patients presenting to the emergency department with suspected acute appendicitis.

Background: Acute appendicitis (AA) is one of the most common diseases faced by the surgeon in the emergency department. In clinical practice, how to diagnose patients with AA accurately is still challenging.

Methods: We conducted a prospective study of 84 patients who presented in the emergency department with suspected AA and measured fecal calprotectin (FC) value. The final diagnosis of AA was independently determined without reference to the test results of FC. Then, we retrospectively analyzed the FC value for identifying AA.

Results: FC value in patients with AA were significantly higher than that in patients without AA (240.5 vs. 68.5 ug/g, P < 0.001). Receiver-operating characteristic analyses demonstrated FC value to be highly sensitive and specific for the diagnosis of AA, as indicated by an overall area under the curve (AUC) of 0.928 (500 times of boot strap estimated 95% CI, 0.855-0.972), with an optimal cut off point of 106 ug/g. FC levels in 26 patients with simple AA were significantly lower than it in the 14 patients with suppurative AA (206 vs. 304ug/g, P = 0.001).

Conclusions: FC test provides a sensitive, convenient and economical method to help facilitate the diagnosis of AA in emergency department. Especially for hospitals without computed tomography equipment or patients who are not suitable to exposed to radiation, FC test is of great significance for improving the diagnostic accuracy of AA.