9; Figure 1). Receiver GS-4997 operating characteristic curve A-1210477 analysis suggested the best cutoff point for CRP level in the diagnosis of AA was 27.1 mg/dL, which had a sensitivity of 97% and a specificity of 41% (area under curve [AUC]: 0.77; Figure 1). RDW was not correlated with CRP and leukocyte levels. However, we found a correlation between CRP and leukocyte levels (Table 2). Table 1 Comparison of the demographic features and leukocyte count, CRP, and RDW levels of

the subjects in the acute appendicitis and the control groups   Acute appendicitis (n = 590) Control group (n = 121) p Male/female 332/258 69/52 .82 Age (y)* 36.7 ± 12.2 35.2 ± 8.1 .67 Leukocyte (× 10 3 /mm3)* 13.5 ± 4.5 7.5 ± 2 <0.01 CRP (mg/L)* 48.8 ± 73.6 4.6 ± 4.7 <0.01 RDW (%)* 15.4 ± 1.5 15.9 ± 1.4 0.01 *Values see more are means±standard deviation. Abbreviations: CRP C-reactive protein, RDW red cell distribution width. Figure 1 Receiver operating characteristic (ROC) curve of red cell distribution width (RDW), leukocyte,

and C-reactive protein (CRP). Table 2 Correlation analysis of leukocyte, CRP, and RDW levels in patients with acute appendicitis Parameters Correlation coefficient (r) P value Leukocyte – RDW -0.031 .44 Leukocyte – CRP 0.21 <0.01 CRP – RDW -0.065 .11 Abbreviations: CRP C-reactive protein, RDW red cell distribution width. Discussion A parameter with ability to establish the diagnosis of acute appendicitis has always been a center of attention for physicians. Many different parameters have been examined or are under active investigation for that purpose. The pathophysiology of acute appendicitis

is characterized by the mucosal ischemia of the appendix that results from ongoing mucus secretion from the appendiceal mucosa distal to an obstruction of the lumen, elevating intraluminal and, in turn, venous pressures. Once luminal pressure exceeds 85 mmHg, venules that drain the appendix become thrombosed and, in Branched chain aminotransferase the setting of continued arteriolar in flow, vascular congestion and engorgement of the appendix become manifest [5]. Infection is added to the inflammation of appendicitis. WBC count is most frequently used to diagnose AA. Several reports have suggested that an elevated WBC count is usually the earliest laboratory measure to indicate inflammation of the appendix, and most patients with AA present with leukocytosis [14, 15]. We found that WBC count was significantly higher in AA. In various studies, the range of sensitivity and specificity of WBC in the diagnosis of AA have been reported 67%- 97.8% and 31.9%-80%, respectively [16]. Similar to the literature, the present study found that the sensitivity and specificity of leukocyte level were 91% and 74%, respectively. CRP is a sensitive acute phase protein that lacks specificity due to increased levels in all acute inflammatory processes. Its concentration increases with the duration and extent of the inflammation.