C-reactive protein as a marker of complicated diverticulitis in patients on anti-inflammatory medications

Background: Diverticulitis is a common indication for surgical emergency room admission, often leading to abdominal computed tomography (CT) scanning for both diagnosis and staging. C-reactive protein (CRP) has been identified as a useful biomarker of inflammation. Aspirin and corticosteroids are known to down-regulate CRP production. In this study, we evaluated the usefulness of CRP as a biomarker for complicated diverticulitis and specifically in patients on anti-inflammatory medications: aspirin and corticosteroids. Methods: We analyzed the medical records of patients diagnosed at one medical center during a two-year period, with left-sided diverticulitis, according to clinical data and CT scan. Disease severity was assessed by the Hinchey score using the radiological findings detected by CT. Results: A total of 295 patients were included in the study. Two hundred and forty-three (82 %) were classified with uncomplicated (Hinchey 1a) and 52 (18 %) with complicated disease (Hinchey > 1a). Mean CRP levels were 133.5 and 63.5 mg/ml for those with complicated and uncomplicated disease, respectively (p < 0.001), and 139 and 60 mg/ml, respectively (p < 0.001) in the subgroup of patients taking aspirin (n = 61). For 14 patients on corticosteroid treatment, the difference in mean CRP levels for complicated and uncomplicated disease was not statistically significant. CRP > 90 mg/ml had 88 % sensitivity and 75 % specificity for complicated disease. Conclusions: The CRP level distinguished between complicated and uncomplicated disease among left-sided diverticulitis patients including those taking aspirin, but not among those on corticosteroid treatment.