Serum Bile Acids Profiling in Inflammatory Bowel Disease Patients Treated with Anti-TNFs

Background: Inflammatory bowel diseases (IBD), ulcerative colitis (UC), and Crohn's disease (CD), represent systematic chronic conditions with a deficient intestinal absorption. We first attempt to investigate the serum bile acids (sBAs) profile in a large cohort of IBD patients to evaluate changes under anti-TNF alpha treatment. Methods: Forty CD and 40 UC patients were enrolled and BAs were quantified by high-pressure liquid chromatography-electrospray-tandem mass spectrometry (HPLC-ES-MS/MS). Up to 15 different sBAs concentrations and clinical biomarkers where added to a Principal Component Analysis (PCA) to discriminate IBD from healthy conditions and treatment. Results: PCA allowed a separation into two clusters within CD (biologic-free patients and patients treated with anti-TNF alpha drugs and healthy subjects) but not UC. The first included CD. CD patients receiving anti-TNF alpha have an increase in total sBAs (4.11 +/- 1.23 mu M) compared to patients not exposed. Secondary BAs significantly increase after anti-TNF alpha treatment (1.54 +/- 0.83 mu M). Furthermore, multivariate analysis based on sBA concentration highlighted a different qualitative sBAs profile for UC and CD patients treated with conventional therapy. Conclusion: According to our results, anti-TNF alpha in CD restores the sBA profile by re-establishing the physiological levels. These findings indicate that, secondary BAs might serve as an indirect biomarker of the healing process.