Leucocyte count and C-reactive protein in the diagnosis of acute appendicitis

Background: The aim of the present work was to study the preoperative leuco cyte counts and C-reactive protein (CRP) values in three groups of patients operated on for a clinical suspicion of acute appendicitis with different findings at appendicectomy: an uninflamed appendix, uncomplicated acute app endicitis or complicated acute appendicitis. In particular, patients with a cute appendicitis but a normal leucocyte count and CRP level were sought. Methods: In this retrospective study, the mean preoperative leucocyte count and CRP value in 100 consecutive patients with an uninflamed appendix (gro up A), in 100 consecutive patients with uncomplicated acute appendicitis (g roup B) and in 100 consecutive patients with complicated acute appendicitis (group C) were calculated. The numbers of patients with (1) both values no rmal, (2) only leucocyte count raised, (3) only CRP level raised and (4) bo th values raised were calculated in each of the three groups. Results: The increase in leucocyte count was an early marker of appendiceal inflammation, whereas the CRP value increased markedly only after appendic eal perforation or abscess formation. Group A (uninflamed appendix) contain ed 24 patients in whom both values were normal. Neither group B (uncomplica ted acute appendicitis) nor group C (complicated acute appendicitis) contai ned any patient with both values in the normal range. Conclusion: Acute appendicitis is very unlikely when both the leucocyte cou nt and CRP value are normal.