Correlation of serum C-reactive protein, white blood count and neutrophil percentage with histopathology findings in acute appendicitis

Acute appendicitis is one of the most common surgical emergencies. Accurate diagnosis of acute appendicitis is based on careful history, physical examination, laboratory and imaging investigation. The aim of the study is to analyze the role of C-reactive protein (CRP), white blood count (WBC) and Neutrophil percentage (NP) in improving the accuracy of diagnosis of acute appendicitis and to compare it with the intraoperative assessment and histopathology findings.

This investigation was a prospective double blinded clinical study. The study was done on 173 patients surgically treated for acute appendicitis. The WBC, NP, and measurement of CRP were randomly collected pre-operatively from all involved patients. Macroscopic assessment was made from the operation. Appendectomy and a histopathology examination were performed on all patients. Gross description was compared with histopathology results and then correlated with CRP, WBC, and NP.

The observational accuracy was 87,3%, as compared to histopathological accuracy which was 85.5% with a total of 173 patients that were operated on. The histopathology showed 25 (14.5%) patients had normal appendices, and 148 (85.5%) patients had acutely inflamed, gangrenous, or perforated appendicitis. 52% were male and 48% were female, with the age ranging from 5 to 59 with a median of 19.7. The gangrenous type was the most frequent (52.6%). The WBC was altered in 77.5% of the cases, NP in 72.3%, and C-reactive protein in 76.9% cases. In those with positive appendicitis, the CRP and WBC values were elevated in 126 patients (72.8%), whereas NP was higher than 75% in 117 patients (67.6%). Out of 106 patients with triple positive tests, 101 (95.2%) had appendicitis. The sensitivity, specificity, and positive predictive values of the 3 tests in combination were 95.3%, 72.2%, and 95.3%, respectively.

The raised value of the CRP was directly related to the severity of inflammation (p-value <0.05). CRP monitoring enhances the diagnostic accuracy of acute appendicitis. The diagnostic accuracy of CRP is not significantly greater than WBC and NP. A combination of these three tests significantly increases the accuracy. We found that elevated serum CRP levels support the surgeon's clinical diagnosis.