Assessment of high-sensitivity CRP as a marker of micro-inflammation in irritable bowel syndrome K. HOD,* R. DICKMAN,  A. SPERBER, à S. MELAMED,§ R. DEKEL, à Y. RON, à Z. HALPERN, à S. BERLINER– & N. MAHARSHAKà *Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel  Department of Gastroenterology, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel àDepartment of Gastroenterology and Liver Diseases, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel §The Academic College of Tel-Aviv-Yaffo, Israel –Department of Medicine ‘D’, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel Abstract Background The diagnosis of irritable bowel syn- drome (IBS) is symptom-based. Although considered a functional disease, accumulating evidence supports a low-grade gut inflammation as an element of its pathophysiology. Thus, high-sensitivity C-reactive protein (hs-CRP), a marker of micro inflammation, may be elevated in IBS. Our aim was to assess whe- ther hs-CRP is higher in IBS patients compared to healthy controls (HC) and does it differ among the IBS clinical subgroups and correlate with disease severity. Methods A diagnostic case control study was con- ducted in two gastroenterology departments. Eighty- eight IBS patients who were recruited prospectively answered the Rome III diagnostic questionnaire. They all completed the Functional Bowel Disorder Severity Index (FBDSI), dietary, and general health question- naires. All patients underwent blood sampling for hs-CRP levels. Each IBS patient was matched to four HC by age, gender, and BMI. Blood samples were obtained from the HC at a periodic health survey. Key Results The mean hs-CRP level in the IBS group was significantly higher than in HC (1.17 ± 1.26 mg L )1 vs 0.72 ± 0.91 mg L )1 respectively, P = 0.001). Hs-CRP levels were highest in patients with diarrhea-predom- inant IBS and in patients with greater disease severity. A cut-off value of 1.08 mg L )1 had a sensitivity of 60.2% and a specificity of 68% for differentiating IBS from HC. Conclusions & Inferences Hs-CRP levels are higher in IBS patients than HC, but still in the normal laboratory range. This may reflect the low-grade gut inflammation believed to occur in IBS and support its existence. Keywords high-sensitivity C-reactive protein, irritable bowel syndrome, low grade inflammation. Abbreviations: ESR, erythrocyte sedimentation rate; FBDSI, functional bowel disorder severity index; GI, gastrointestinal; HC, healthy controls; Hs-CRP, high- sensitivity C-reactive protein; IBS, irritable bowel syn- drome; IBS-C, constipation predominant IBS; IBS-D, diarrhea predominant IBS; IBS-M, mixed type IBS; TAM- CIS, Tel Aviv Medical Center Inflammation Survey; WBC, white blood cells; Wr-CRP, wide range C-reactive protein. INTRODUCTION Irritable bowel syndrome (IBS) is one of the most common gastrointestinal (GI) disorders. Its diagnosis is based on the Rome III criteria that include chronic complaints of abdominal pain or discomfort associated with a change in bowel habits. Patients are categorized by their predominant symptom into diarrhea predom- inant (IBS-D), constipation predominant (IBS-C) or mixed type IBS (IBS-M). Severity of symptoms may be assessed by validated questionnaires such as the Func- tional Bowel Disorder Severity Index (FBDSI) that are used mainly for research purposes. 1,2 Address for Correspondence Nitsan Maharshak, Department of Gastroenterology and Liver Diseases, 6 Weizmann St. Tel Aviv Sourasky Medical Center, Tel Aviv, Israel 64239. Tel: 972 3 6974282; fax: 972 3 6974622; e-mail: nitsan_maharshak@walla.com All affiliated with the Sackler Faculty of Medicine except Dr. Sperber who is affiliated with the Faculty of Health Sciences, Ben-Gurion University of the Negev. Received: 16 February 2011 Accepted for publication: 27 August 2011 Neurogastroenterol Motil (2011) 23, 1105–e541 doi: 10.1111/j.1365-2982.2011.01788.x Ó 2011 Blackwell Publishing Ltd 1105