Loss of Response to Anti-Tumor Necrosis Factor Alpha Therapy in Crohn's Disease Is Not Associated with Emergence of Novel Inflammatory Pathways.

BACKGROUND: While monoclonal antibodies against tumor necrosis factor-α (TNFα) are effective in treating Crohn's disease (CD), approximately one-third of patients lose response. The mechanisms underlying this loss of response remain elusive. AIM: We sought to determine if novel biological pathways, including TNFα-independent inflammatory pathways, emerge in those with loss of response to anti-TNFα. METHODS: Using RNA microarray technology in 28 patients with CD, we examined the colonic gene expression differences between those with active inflammation in the setting of loss of response to TNFα-antagonist therapy ("loss of responders") compared to anti-TNFα naïve patients with active inflammation and those on anti-TNF therapy in disease remission. Pathway enrichment analyses were performed. RESULTS: We found that colonic expression of chemokines known to drive inflammation (CXCL20, CXCL9, and CXCL10) was elevated in those with loss of response compared to those in remission. Expression of genes critical to modulating oxidative stress burden (DUOX2, DUOXA2, and NOS2) was also elevated. Additionally, MMP3, MMP1, and MMP12 were elevated in those with continued inflammation. Gene enrichment analysis revealed that loss of responders exhibited dysregulation in the cysteine and methionine metabolism pathway, suggesting alteration in oxidative stress burden. There were no differences in genes or pathways between loss of responders and those who were TNFα-naïve. However, loss of response occurred despite the ability of anti-TNFα therapy to normalize APO gene expression. CONCLUSION: Our analyses suggest that loss of response to anti-TNFα is not driven by the emergence of pathways that bypass the action or induce resistance to anti-TNFα therapy.

Vedolizumab Therapy Is Associated with an Improvement in Sleep Quality and Mood in Inflammatory Bowel Diseases.

INTRODUCTION: Poor sleep, depression, and anxiety are common in patients with inflammatory bowel diseases (IBD) and associated with increased risk of relapse and poor outcomes. The effectiveness of therapies in improving such psychosocial outcomes is unclear but is an important question to examine with increasing selectivity of therapeutic agents. METHODS: This prospective cohort enrolled patients with moderate-to-severe CD or UC starting biologic therapy with vedolizumab or anti-tumor necrosis factor α agents (anti-TNF). Sleep quality, depression, and anxiety were measured using validated short-form NIH PROMIS questionnaires assessing sleep and mood quality over the past 7 days. Disease activity was assessed using validated indices. Improvement in sleep and mood scores from baseline was assessed, and regression models were used to identify determinants of sleep quality. RESULTS: Our study included 160 patients with IBD (49 anti-TNF, 111 Vedolizumab) among whom half were women and the mean age was 40.2 years. In the combined cohort, we observed a statistically significant and meaningful decrease in mean scores from baseline (52.8) by week 6 (49.8, p = 0.002). Among vedolizumab users, sleep T-score improved from baseline (53.6) by week 6 (50.7) and persisted through week 54 (46.5, p = 0.009). Parallel reductions in depression and anxiety were also noted (p < 0.05 by week 6). We observed no difference in improvement in sleep, depression, and anxiety between vedolizumab and anti-TNF use at week 6. CONCLUSIONS: Both vedolizumab and anti-TNF biologic therapies were associated with improvement in sleep and mood quality in IBD.

Multi-omics reveal microbial determinants impacting responses to biologic therapies in inflammatory bowel disease.

The intestinal microbiome is a key determinant of responses to biologic therapy in inflammatory bowel disease (IBD). However, diverse therapeutics and variable responses among IBD patients have posed challenges in predicting clinical therapeutic success. In this prospective study, we profiled baseline stool and blood in patients with moderate-to-severe Crohn's disease or ulcerative colitis initiating anti-cytokine therapy (anti-TNF or -IL12/23) or anti-integrin therapy. Patients were assessed at 14 weeks for clinical remission and 52 weeks for clinical and endoscopic remission. Baseline microbial richness indicated preferential responses to anti-cytokine therapy and correlated with the abundance of microbial species capable of 7α/ß-dehydroxylation of primary to secondary bile acids. Serum signatures of immune proteins reflecting microbial diversity identified patients more likely to achieve remission with anti-cytokine therapy. Remission-associated multi-omic profiles were unique to each therapeutic class. These profiles may facilitate a priori determination of optimal therapeutics for patients and serve as targets for newer therapies.

Hepatic connexin 32 associates with nonalcoholic fatty liver disease severity.

Emerging data highlight the critical role for the innate immune system in the progression of nonalcoholic fatty liver disease (NAFLD). Connexin 32 (Cx32), the primary liver gap junction protein, is capable of modulating hepatic innate immune responses and has been studied in dietary animal models of steatohepatitis. In this work, we sought to determine the association of hepatic Cx32 with the stages of human NAFLD in a histologically characterized cohort of 362 patients with NAFLD. We also studied the hepatic expression of the genes and proteins known to interact with Cx32 (known as the connexome) in patients with NAFLD. Last, we used three independent dietary mouse models of nonalcoholic steatohepatitis to investigate the role of Cx32 in the development of steatohepatitis and fibrosis. In a univariate analysis, we found that Cx32 hepatic expression associates with each component of the NAFLD activity score and fibrosis severity. Multivariate analysis revealed that Cx32 expression most closely associated with the NAFLD activity score and fibrosis compared to known risk factors for the disease. Furthermore, by analyzing the connexome, we identified novel genes related to Cx32 that associate with NAFLD progression. Finally, we demonstrated that Cx32 deficiency protects against liver injury, inflammation, and fibrosis in three murine models of nonalcoholic steatohepatitis by limiting initial diet-induced hepatoxicity and subsequent increases in intestinal permeability. Conclusion: Hepatic expression of Cx32 strongly associates with steatohepatitis and fibrosis in patients with NAFLD. We also identify novel genes associated with NAFLD and suggest that Cx32 plays a role in promoting NAFLD development. (Hepatology Communications 2018;2:786-797).