Cellular metabolic state and individual metabolites have been reported to regulate the functional phenotype of immune cells. Cytokine production by regulatory and inflammatory macrophages is thought to mainly involve fatty acid oxidation and glycolysis, respectively, which fuel mitochondrial oxidative phosphorylation. However, the association between metabolic pathways and the acquisition of specific macrophage phenotypes remains unclear. This study assessed the relationship between glycolysis and the differentiation of regulatory macrophages. Human monocytes derived from peripheral blood were cultured in vitro in the presence of macrophage colony-stimulating factor to yield regulatory macrophages (M-Mϕs). M-Mϕs had a regulatory macrophage phenotype and produced substantial IL-10 following stimulation with lipopolysaccharide. To analyze the role of glycolysis, glycolysis inhibitors (2-deoxy-d-glucose or dichloroacetate) were added during M-Mϕ differentiation. These cells cultured with glycolysis inhibitors produced significantly lower amounts of IL-10, but produced significantly higher amounts of IL-6 compared to M-Mϕs differentiated without glycolysis inhibitors. Such phenotypic change of M-Mϕs differentiated with glycolysis inhibitors was associated with the alteration of the gene expression pattern related to macrophage differentiation, such as CSF1, MMP9 and VEGFA. M-Mϕs differentiated with glycolysis inhibitors seemed to retain plasticity to become IL-10 producing cells. Furthermore, increased level of pyruvate in culture medium was found to partially reverse the effects of glycolysis inhibitors on cytokine production of M-Mϕs. These results indicate the importance of glycolytic pathway in macrophage differentiation to a regulatory phenotype, and pyruvate may be one of the key metabolites in this process.

Behçet's disease (BD) is an intractable systemic inflammatory disease characterized by four main symptoms: oral and genital ulcers and ocular and cutaneous involvement. The Japanese diagnostic criteria of BD classify intestinal BD as a specific disease type. Volcano-shaped ulcers in the ileocecum are a typical finding of intestinal BD, and punched-out ulcers can be observed in the intestine or esophagus. Tumor necrosis factor inhibitors were first approved for the treatment of intestinal BD in Japan and have been used as standard therapy. In 2007 and 2014, the Japan consensus statement for the diagnosis and management of intestinal BD was established. Recently, evidence-based JSBD (Japanese Society for BD) Clinical Practice Guidelines for BD (Japanese edition) were published, and the section on intestinal BD was planned to be published in English. Twenty-eight important clinical questions (CQs) for diagnosis (CQs 1–6), prognosis (CQ 7), monitoring and treatment goals (CQs 8–11), medical management and general statement (CQs 12–13), medical treatment (CQs 14–22), and surgical treatment (CQs 23–25) of BD and some specific situations (CQs 26–28) were selected as unified consensus by the members of committee. The statements and comments were made following a search of published scientific evidence. Subsequently, the levels of recommendation were evaluated based on clinical practice guidelines in the Medical Information Network Distribution Service. The degree of agreement was calculated using anonymous voting. We also determined algorithms for diagnostic and therapeutic approaches for intestinal BD. The present guidelines will facilitate decision making in clinical practice.

Many clinical trials have been conducted for inflammatory bowel disease (IBD), so various clinical indices (CIs) and endoscopic indices (EIs) have also been evaluated. However, recently, with the progress of IBD management, review of established indices from previous studies, and establishment of new indices, the landscape of the use of indices in clinical trials have changed. We investigated the number and frequency of the indices adapted in recent clinical trials for ulcerative colitis (CI and EI) and Crohn’s disease (CI, EI, index related to magnetic resonance imaging, index for evaluating patient-reported outcomes, and health-related quality of life). Based on the results, we selected representative indices and further reviewed their content and characteristics. Moreover, various definitions, including clinical and endoscopic response or remission, have been described by means of representative indices in clinical trials.

Background: Mirikizumab, a p19-directed interleukin-23 monoclonal antibody, is efficacious in inducing clinical remission at week 12 (W12) and maintaining clinical remission at W52 in patients with moderately to severely active ulcerative colitis. Results are presented from the open-label extension study through W104. Methods: Clinical, symptomatic, quality-of-life, and adverse event outcomes are reported for mirikizumab induction responders and extended induction responders, including biologic-failed patients, who entered LUCENT-3, with data shown for W52 maintenance responders or remitters. Discontinuations or missing data were handled by nonresponder imputation (NRI), modified NRI (mNRI), and observed case (OC). Results: Among W52 mirikizumab responders, clinical response at W104 was 74.5%, 87.2%, and 96.7% and clinical remission was 54.0%, 62.8%, and 70.1% for NRI, mNRI, and OC, respectively. Among W52 mirikizumab remitters, clinical response at W104 was 76.6%, 89.0%, and 98.3% and clinical remission was 65.6%, 76.1%, and 84.2%. Using mNRI, remission rates at W104 for W52 clinical remitters were 74.7% corticosteroid-free, 79.5% endoscopic, 63.9% histologic-endoscopic mucosal remission, 85.9% symptomatic, 59.8% bowel urgency, 80.5% Inflammatory Bowel Disease Questionnaire (using NRI), 71.2% histologic-endoscopic mucosal improvement, and 77.5% bowel urgency improvement. Previous biologic-failed vs not-biologic-failed patient data were generally similar. Extended induction mNRI clinical response was 81.9%. Serious adverse events were reported in 5.2% of patients; 2.8% discontinued treatment due to adverse events. Conclusions: Endoscopic, histologic, symptomatic, and quality-of-life outcomes support the long-term benefit of mirikizumab treatment up to 104 weeks in patients with ulcerative colitis, including biologic-failed patients, with no new safety concerns.

Ulcerative colitis (UC) is characterized by chronic intestinal inflammation. Patients with UC have repeated remission and relapse. Clinical biomarkers that can predict relapse in UC patients in remission have not been identified. To facilitate the prediction of relapse of UC, we investigated the potential of novel multivariate indexes using statistical modeling of plasma free amino acid (PFAA) concentrations. We measured fasting PFAA concentrations in 369 UC patients in clinical remission, and 355 were observed prospectively for up to 1 year. Relapse rate within 1 year was 23% (82 of 355 patients). The age- and gender-adjusted hazard ratio for the lowest quartile compared with the highest quartile of plasma histidine concentration was 2.55 (95% confidence interval: 1.41–4.62; p = 0.0020 (log-rank), p for trend = 0.0005). We demonstrated that plasma amino acid profiles in UC patients in clinical remission can predict the risk of relapse within 1 year. Decreased histidine level in PFAAs was associated with increased risk of relapse. Metabolomics could be promising for the establishment of a non-invasive predictive marker in inflammatory bowel disease.