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

Abstract

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. 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. 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 63.5mg/ml for those with complicated and uncomplicated disease, respectively (p<0.001), and 139 and 60mg/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>90mg/ml had 88% sensitivity and 75% specificity for complicated disease. 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.