Gut Microbial Diversity is Reduced in Smokers with Crohn’s Disease. JL Opstelten et al. Inflamm Bowel Dis 2016; 22: 2070-77. This study compared stools from 21 nonsmoking patients with Crohn’s disease (CD) with 21 smokers with CD. Smoking was accompanied by a reduced relative abundance of multiple genera. My take: It is unclear whether smoking’s effect on the microbiome directly contributes to worsened outcomes or whether the changes in the microbiome are only an epiphenomenon. Regardless, smoking increases the likelihood of worse outcomes in CD.
A Systematic Review on Infliximab and Adalimumab Drug Monitoring Levels, Clinical Outcomes and Assay. F Silva-Ferreira et al. Inflamm Bowel Dis 2016; 22: 2289-2301. This review selected 20 studies from an initial query of 1654 articles. Key points:
- Different studies are difficult to compare due to distinct assays with different limitations. Thus, specific cutoffs are based on the specific assay used.
- The authors state that proactive monitoring may be helpful at week 6, 14, 30 and 54 for infliximab. They recommend checking infliximab level and antidrug antibodies in those with loss of response, mucosal ulceration or elevated biomarkers (eg. CRP, Fecal calprotectin).