Inflammatory bowel disease (IBD) is a complex multifactorial disorder in which external and environmental factors have a large influence on its onset and development, especially in genetically susceptible individuals. Crohn’s disease (CD), one of the two types of IBD, is characterized by transmural inflammation, which is most frequently located in the region of the terminal ileum. Oxidative stress, caused by an overabundance of reactive oxygen species, is present locally and systemically in patients with CD and appears to be associated with the well-described imbalanced immune response and dysbiosis in the disease. Oxidative stress could also underlie some of the environmental risk factors proposed for CD. Although the exact etiopathology of CD remains unknown, the key role of oxidative stress in the pathogenesis of CD is extensively recognized. Epigenetics can provide a link between environmental factors and genetics, and numerous epigenetic changes associated with certain environmental risk factors, microbiota, and inflammation are reported in CD. Further attention needs to be focused on whether these epigenetic changes also have a primary role in the pathogenesis of CD, along with oxidative stress.

Vitamin D has recently been discovered to be a potential immune modulator. Low serum vitamin D levels have been associated with risk of relapse and exacerbation of clinical outcomes in Crohn’s disease (CD) and ulcerative colitis (UC). A retrospective, longitudinal study was conducted to determine the association between vitamin D levels and inflammatory markers and clinical disease activity in inflammatory bowel disease (IBD). In addition, circulating 25(OH)D₃ progression was evaluated according to vitamin D supplementation. Participants were separated into three groups according to their vitamin D level: severe deficiency (SD), moderate deficiency (MD) and sufficiency (S). Serum 25(OH)D₃ was inversely correlated with faecal calprotectin (FC) for CD and UC but was only correlated with C-reactive protein (CRP) for UC patients. In the multivariate analysis of FC, CRP and fibrinogen (FBG), we predicted the presence of a patient in the SD group with 80% accuracy. A deficiency of 25(OH)D₃ was associated with increased hospitalisations, flare-ups, the use of steroids and escalating treatment. Supplemental doses of vitamin D were likely to be insufficient to reach adequate serum levels of 25(OH)D₃. Vitamin D intervention studies are warranted to determine whether giving higher doses of vitamin D in IBD might reduce intestinal inflammation or disease activity.

Introduction: The association between infliximab (IFX) and fecal calprotectin (FC) levels on one hand, and the clinical and endoscopic response of patients with inflammatory bowel disease on the other, is well established. Objective and Methods: To investigate the association between inflammatory biochemical parameters and serum concentrations of IFX during induction treatment with a primary nonresponse in a prospective cohort of Crohn’s disease (CD) patients. Results: Of the 35 patients included, 8 (22.8%) had primary nonresponse at the end of induction. Induction IFX levels were lower among primary nonresponders at weeks 6 and 14 (week 6: median IFX level 7.3 vs. 11.2 μg/mL, respectively, p = 0.090; week 14: median IFX level 1.5 vs. 4.7 μg/mL, respectively, p = 0.020). FC levels were higher in patients with primary nonresponse versus primary response at weeks 0, 6, and 14 (week 0: median FC level 1,830 vs. 410 μg/g, ­respectively, p = 0.030; week 6: median FC level 1,150 vs. 230 μg/g, respectively, p = 0.074; week 14: median FC level 1,210 vs. 208 μg/g, respectively, p = 0.060). For the multivariate analysis, the median IFX level at week 14 and median FC level at week 0 were independently associated with primary nonresponse. A significant inverse correlation was determined between FC level at week 0 and IFX level at week 14 (Spearman’s rho correlation, 0.440; p < 0.05). Conclusions: IFX levels (at week 14) and baseline FC levels could predict primary nonresponse after induction IFX therapy in patients with CD. A high baseline inflammatory load might modify the pharmacokinetic processes of anti-tumor necrosis factor drugs. Drug level monitoring and measurement of baseline inflammatory parameters could improve the efficacy of IFX in the induction therapy of patients with active CD.

Background: The aims of this study were to characterize the immune response profile in patients with Crohn’s disease (CD) and early postoperative recurrence (POR), to identify predictive biomarkers, and to develop a noninvasive predictive tool for individual estimation of POR risk. Methods: Sixty-one patients who had undergone ileocolonic resection for CD were prospectively included and followed up for 24 months. Fecal calprotectin (FC), analytical parameters, and plasma cytokines were obtained before surgery and at various time points during postoperative follow-up. Morphological recurrence was assessed by ileocolonoscopy or magnetic resonance enterography within 6–12 months after surgery. Clinical activity was scored using the Harvey-Bradshaw Index. Results: Twenty-seven patients (44.3%) had morphological recurrence during follow-up. Fecal calprotectin values were significantly associated with POR risk over time. The receiver operating characteristic curve for FC provided an area under the curve (AUC) of 0.88 (95% confidence interval, 0.75–0.96), and morphological recurrence was best predicted by FC ≥160 μg/g at 6 months after surgery (85% sensitivity, 70% specificity, 26% predictive positive value, 98% negative predictive value [NPV]). The plasma cytokine profile showed higher presurgery interleukin (IL)-13 plasma levels and higher IL-6 and interferon (IFN)-γ levels at 6 months after surgery in patients with POR compared with patients without recurrence. The combination of FC, IL-6, and IFN-γ values at 6 months gave an AUC of 0.90 for predicting an early recurrence. Conclusions: FC values <160 μg/g at 6 months have a high NPV to rule out early lesions. Combined values of FC, IL-6, and IFN-γ levels at 6 months postsurgery constitute a prognostic index with a high predictive capacity to assess the risk of early POR.

Esteban S?ez Gonz?lez, Vicente Ortiz Bellver, Francia Carolina D?az Jaime, Juan Antonio Ortu?o Cort?s, and Vicente Garrigues Gil. Journal of Neurogastroenterology and Motility 2015;21:618-20. http://dx.doi.org/10.5056/jnm15108

Little is known about the association between the pharmacokinetic features of adalimumab (ADL) and disease outcome in patients with inflammatory bowel disease (IBD). To assess the association between random serum ADL levels and clinical or biochemical remission with clinical decision making in daily practice according to these levels; and to determine the cutoff value for successful dose reduction in patients with IBD treated with ADL. We conducted a prospective observational study of patients with IBD who received long-term maintenance therapy with ADL. Data were available for 157 serum samples from 87 patients. Serum ADL levels were associated with clinical remission: median 9.2 versus 6.0 μg/mL for patients with Crohn's disease with active disease (P = 0.009) and 14.4 versus 5.2 μg/mL in patients with ulcerative colitis with active disease (P = 0.002). Serum ADL levels were 9.2 μg/mL for patients with a normal C-reactive protein value (<5 mg/L) and 5.2 μg/mL for patients with a high C-reactive protein value (P = 0.002). ADL levels were significantly associated with normal fecal calprotectin value (<80 ng/g) (10.8 versus 7.6 μg/mL, respectively, P = 0.038). Serum ADL levels were significantly associated with successful deintensification, over a 6-month period of clinical follow-up, compared with the group in which doses remained unchanged (area under the curve 0.88; 95% confidence interval, 0.81–0.95; P < 0.001), with a cutoff value for successful deintensification of 12.2 μg/mL. Higher ADA levels were significantly associated with clinical and biochemical remission. Our results, which were obtained under conditions of daily clinical practice, suggest that an ADL cutoff of 12.2 μg/mL could be appropriate for successful dose reduction in patients with IBD treated with ADL.