Browsing by Subject "Calprotectin"

Inflammatory bowel disease (IBD) is a globally increasing chronic disease, for which the pathogenesis still is unclear. The most common subtypes of IBD are Crohn’s disease (CD) and ulcerative colitis (UC). It is widely known that, in addition to the genetics, an altered immune response against the gut microbiome plays an important role in the development of the disease. For the IBD patients, to whom conventional medication is not sufficient, the TNF-α blocker infliximab, is given. However, about one third of the patients receiving infliximab treatment, do not respond to the drug, or lose response over time. Since there to this day are no reliable diagnostic markers available, the finding of such is of great importance. The goal of this study was to investigate possible markers for drug response in the gut mycobiota composition of IBD patients. The gut mycobiota composition of 72 IBD patients receiving infliximab was studied by MiSeq sequencing of fungal DNA from fecal samples, collected during one year. The sequencing data was analyzed using the mare package in R. In addition, anti-Saccharomyces cerevisiae antibody (ASCA) concentrations were measured from baseline serum samples by ELISA. Finally, calprotectin concentrations were measured from baseline and twelve weeks post infliximab serum samples by ELISA to study whether serum samples could be used instead of fecal samples for measuring calprotectin values. Results show an increase of the Candida and Spiromyces genera in the gut mycobiota of non-responding patients at baseline. At all timepoints, the Spiromyces genus was observed at a higher abundance, compared to the group of patients responding well or partially to the medication. Interestingly, the increase of Candida was seen only in Crohn’s disease patients, when looking at the composition at all timepoints. ASCA values did not differ between the response groups. The serum calprotectin values did not correlate with fecal calprotectin, and serum calprotectin can thus not be used as a marker of gut inflammation. In conclusion, the gut mycobiota can offer predictive markers for drug response prediction to infliximab in IBD patients, which can with further studies offer a clinical diagnostic tool for prediction of drug response.