Hepcidin and Iron Status in Patients With Inflammatory Bowel Disease Undergoing Induction Therapy With Vedolizumab or Infliximab.

BACKGROUND: Hepcidin, the systemic iron regulator, could be critical in differentiating iron deficiency (ID) from functional iron restriction in inflammatory bowel disease (IBD). We assessed hepcidin as a diagnostic ID marker and explored the relationship between hepcidin and its regulators in patients with IBD undergoing induction therapy with infliximab (IFX) or vedolizumab (VEDO). METHODS: Patients with active IBD receiving induction therapy with IFX or VEDO were included. Serum samples at baseline and after 6 weeks of induction therapy were analyzed for hepcidin, inflammation- and hypoxia-associated cytokines, and oxidative stress. Data were analyzed by stratifying based on the response at week 14. Results were compared with samples from age- and sex-matched healthy control subjects. RESULTS: Patients receiving induction therapy with IFX (n = 71) or VEDO (n = 51) and healthy control subjects (n = 50) were included. At baseline, hepcidin correlated positively with ferritin and negatively with soluble transferrin receptor/log ferritin index (P < .001). ID was prevalent in 96.7% of patients who had hepcidin levels below the median. Hepcidin accurately identified ID: the area under the curve (hepcidin) was 0.89 (95% confidence interval, 0.82-0.95; P < .001). In total, 75.4% of patients responded to induction therapy; inflammation, hepcidin, and ferritin decreased significantly, while transferrin increased during induction therapy. These changes were observed only in patients who responded to the therapy. CONCLUSIONS: Hepcidin levels in IBD are primarily determined by ID, even in an inflammatory state. In addition, induction therapy can decrease hepcidin levels, which might lead to better bioavailability of iron supplements. Therefore, hepcidin is a potential diagnostic ID biomarker that could assist therapeutic decision making.

Absolute iron deficiency is the primary determinant of hepcidin levels, even in an inflammatory state. Induction therapy can decrease hepcidin levels, which might improve iron bioavailability. Hence, hepcidin is a potential diagnostic iron deficiency biomarker that could assist therapeutic decision making.

Isotype-specific Antibody Responses to Mycobacterium avium paratuberculosis Antigens Are Associated With the Use of Biologic Therapy in Inflammatory Bowel Disease.

BACKGROUND: The role of Mycobacterium avium paratuberculosis [MAP] in inflammatory bowel disease [IBD], especially Crohn's disease [CD] is controversial due conflicting results and lack of reproducibility and standardised tests. The current study focuses on the role of MAP in disease progression and genetic susceptibility, as MAP is likely one of many factors involved in the complex pathogenesis of IBD, potentially affecting a subgroup depending on genetic susceptibility. METHODS: Serum from 812 patients was evaluated with seven immunoglobulin [Ig] isotype-specific serology tests assessing humoral response to three different MAP antigens. For each of these in total 21 tests, the intra-assay and inter-assay coefficients were used to evaluate test accuracy. Reliable assays were subsequently analysed in relation to disease characteristics and need for biologic therapy/surgery. Genome-wide genotyping was available for all participants. Genetic determinants of humoral response to MAP antigens were evaluated using genome-wide association analysis and polygenic risk scores [PRS]. RESULTS: High IgA or IgM response to MAP2609 was associated with increased use of biologic therapy in CD and ulcerative colitis [UC] [odds ratios 2.69; 95% confidence interval 1.44-5.01; and 2.60, 1.46-4.64, respectively]. No associations were seen for risk of surgery [p-values > 0.29]. We could not identify genetic determinants nor polygenic risk scores for MAP response with genome-wide significance. CONCLUSIONS: Extensive assays for serological response to MAP were evaluated using stringent criteria for reliability. Increased IgA and IgM response to MAP antigens was seen in patients exposed to biologic therapy, but no genetic determinants underlying this humoral response were found.

Environmental factors associated with biological use and surgery in inflammatory bowel disease.

BACKGROUND AND AIM: While major efforts were made studying the complex etiology of inflammatory bowel disease (IBD) including environmental factors, less is known about underlying causes leading to the heterogeneous and highly variable course of disease. As cigarette smoking cessation is the best-known environmental factor with beneficial effect in Crohn's disease (CD), more exposome factors are likely involved. Further insights into the role of the exposome in heterogeneity of disease might not only further knowledge of underlying pathways, but also allow for better risk stratification. METHODS: Seven hundred twenty-eight IBD patients completed the validated Groningen IBD Environmental Questionnaire, collecting exposome data for 93 exposome factors. Associations with disease course, that is, for need for surgery or biological therapy, were evaluated using univariate and multivariate-adjusted logistic regression modeling. RESULTS: No significant associations were seen after Bonferroni correction. However, 11 novel exposome factors were identified with P < 0.05. Two factors were associated with course of CD and ulcerative colitis (UC): beer (CD OR0.3/UC OR0.3) and cannabis (0.5/2.2). While in CD, carpet flooring (0.5) was associated with biological use, and four factors were associated with surgery: working shifts (1.8), appendectomy (2.4), frequent tooth brushing (2.8), and large household size (0.1). For UC, migrants more often required biologicals (10.2). Childhood underweight (3.4), amphetamine use (6.2), and cocaine use (4.8) were associated with surgery. Five factors were replicated. CONCLUSIONS: We identified 16 environmental factors nominally associated with biological use and surgery in established IBD. These new insights form an important stepping stone to guide research on biological pathways involved, risk stratification, tailor-made interventions, and preventive strategies in IBD.

Riboflavin Supplementation in Patients with Crohn's Disease [the RISE-UP study].

BACKGROUND AND AIMS: Crohn's disease [CD] is characterised by chronic intestinal inflammation and dysbiosis in the gut. Riboflavin [vitamin B2] has anti-inflammatory, antioxidant and microbiome-modulatory properties. Here, we analysed the effect of riboflavin on oxidative stress, markers of inflammation, clinical symptoms, and faecal microbiome in patients with CD. METHODS: In this prospective clinical intervention study, patients received 100 mg riboflavin [DSM, Nutritional Products Ltd] daily for 3 weeks. Clinical disease activity [Harvey-Bradshaw Index: HBI], serum biomarkers of inflammation and redox status [plasma free thiols], and faecal microbiome taxonomical composition and functionality [fluorescent in situ hybridisation: FISH; and metagenomic shotgun sequencing: MGS], were analysed before and after riboflavin intervention. RESULTS: In total, 70 patients with CD with varying disease activity were included. Riboflavin supplementation significantly decreased serum levels of inflammatory markers. In patients with low faecal calprotectin [FC] levels, IL-2 decreased, and in patients with high FC levels, C-reactive protein [CRP] was reduced and free thiols significantly increased after supplementation. Moreover, HBI was significantly decreased by riboflavin supplementation. Riboflavin supplementation led to decreased Enterobacteriaceae in patients with low FC levels as determined by FISH; however, MGS analysis showed no effects on diversity, taxonomy, or metabolic pathways of the faecal microbiome. CONCLUSIONS: Three weeks of riboflavin supplementation resulted in a reduction in systemic oxidative stress, mixed anti-inflammatory effects, and a reduction in clinical symptoms [HBI]. FISH analysis showed decreased Enterobacteriaceae in patients with CD with low FC levels, though this was not observed in MGS analysis. Our data demonstrate that riboflavin supplementation has a number of anti-inflammatory and anti-oxidant effects in CD.