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Interferon regulating factor 5 (IRF5) is a multifunctional regulator of immune responses, and has a key pathogenic function in gut inflammation, but how IRF5 is modulated is still unclear. Having performed a kinase inhibitor library screening in macrophages, here we identify protein-tyrosine kinase 2-beta (PTK2B/PYK2) as a putative IRF5 kinase. PYK2-deficient macrophages display impaired endogenous IRF5 activation, leading to reduction of inflammatory gene expression. Meanwhile, a PYK2 inhibitor, defactinib, has a similar effect on IRF5 activation in vitro, and induces a transcriptomic signature in macrophages similar to that caused by IRF5 deficiency. Finally, defactinib reduces pro-inflammatory cytokines in human colon biopsies from patients with ulcerative colitis, as well as in a mouse colitis model. Our results thus implicate a function of PYK2 in regulating the inflammatory response in the gut via the IRF5 innate sensing pathway, thereby opening opportunities for related therapeutic interventions for inflammatory bowel diseases and other inflammatory conditions. The transcription factor, IRF5, has been implicated in the regulation of inflammation, but how IRF5 protein is activated is still unclear. Here the authors use inhibitor library screening, biochemical analyses and in vivo/ex vivo data to show that a protein tyrosine kinase, Pyk2, may be key for the activation of IRF5 in macrophages and inflammatory responses in the gut. [ABSTRACT FROM AUTHOR]

Background: Acute severe colitis (ASC) is conventionally diagnosed by Truelove and Witts' criteria which are non-specific and can be affected by other pathologic conditions. Fecal calprotectin (FCP) is a gut-specific marker of inflammation which can predict short-term outcomes in patients with ASC. We aimed to define the role of FCP in the diagnosis of ASC.Methods: This prospective observational cohort study included adult patients (> 18 years) with ulcerative colitis (UC) for whom FCP was measured and was under follow-up from April 2015 to December 2016. Patients were divided into two cohorts: (1) all consecutive hospitalized patients with ASC as defined by Truelove and Witts' criteria; (2) outpatients with active UC (defined by Mayo score) who did not fulfill Truelove and Witts' criteria. FCP levels were compared between the two cohorts, and a cutoff for FCP to diagnose ASC was determined.Results: Of 97 patients, 49 were diagnosed with ASC (mean age: 36.1 ± 11.9 years, 36 males) and 48 with active UC (mean age: 37.9 ± 12.4 years, 25 males). Median FCP levels were significantly higher in patients with ASC [1776(952-3123) vs 282(43-568) µg/g, p < 0.001] than mild to moderately active UC (n = 48) or moderately active UC [n = 35, 1776(952-3123) vs 332(106-700) µg/g, p < 0.001]. A FCP cutoff of 782 μg/g of stool had excellent diagnostic accuracy, with an area under the curve of 0.92(95% CI 0.87-0.97), sensitivity of 84% and specificity of 88% to differentiate ASC from active UC.Conclusion: FCP could differentiate ASC from mild to moderate patients with UC, but requires validation before clinical use. [ABSTRACT FROM AUTHOR]

This paper in the series from the World Congress of Gastroenterology addresses the safety and immunogenicity of biological therapy. The safety profile in randomized controlled studies of all biological agents in Crohn's disease (CD) and ulcerative colitis has been generally favorable, but a small percentage of patients experience severe side effects on biological therapy, including pneumonia, tuberculosis, lymphoma, demyelination, drug-induced lupus, or hepatotoxicity. Although there is unequivocal evidence of an increased risk of serious infection among patients with rheumatoid arthritis treated with anti-tumor necrosis factor therapy, the evidence is less clear in CD. The risk of infection may be increased by combination therapy with steroids and/or immunomodulators. There is a specific risk of the rare γ δ hepatosplenic lymphoma that appears to have a predeliction for young males on combination therapy. The α4 integrin antagonist natalizumab also carries a specific risk of progressive multifocal leucoencephalopathy and reactivation of JC virus infection. The immunogenicity of biological therapy is complex: all agents are potentially immunogenic and this can be reduced by combination with immunomodulators. This may enhance both therapeutic efficacy and the risk of infection or malignancy, so the balance of risk and benefit must be judged for individual patients. [ABSTRACT FROM AUTHOR]

OBJECTIVES:Acute severe ulcerative colitis (ASC) is a potentially life-threatening disease. We aimed to formulate guidelines for managing ASC in children based on systematic review of the literature and robust consensus process. This manuscript is a product of a joint effort of the ECCO (European Crohn's and Colitis Organization), the Pediatric Porto Inflammatory Bowel Disease (IBD) Working group of ESPGHAN (European Society of Pediatric Gastroenterology, Hepatology, and Nutrition) and ESPGHAN.METHODS:A group of 19 experts in pediatric IBD participated in an iterative consensus process including two face-to-face meetings. A total of 17 predefined questions were addressed by working subgroups based on a systematic review of the literature.RESULTS:The recommendations and practice points were eventually endorsed with a consensus rate of at least 95% regarding: definitions, initial evaluation, standard therapy, timing of second-line therapy, the role of endoscopic evaluation and heparin prophylaxis, how to administer second-line medical therapy, how to assess response, surgical considerations, and discharge recommendations. A management flowchart is presented based on daily scoring of the Pediatric Ulcerative Colitis Activity Index (PUCAI), along with 28 formal recommendations and 34 practice points.CONCLUSIONS:These guidelines provide clinically useful points to guide the management of ASC in children. Taken together, the recommendations offer a standardized protocol that allows effective monitoring of disease progress and timely treatment escalation when needed. [ABSTRACT FROM AUTHOR]

Women with inflammatory bowel disease (IBD) have similar rates of fertility to the general population, but have an increased rate of adverse pregnancy outcomes compared with the general population, which may be worsened by disease activity. Infertility is increased in those undergoing ileal pouch-anal anastomosis. Anti-tumor necrosis factor therapy in pregnancy is considered to be low risk and compatible with use during conception in men and women and during pregnancy in at least the first two trimesters. Infliximab (IFX) and certolizumab pegol are also compatible with breastfeeding, but safety data for adalimumab (ADA) are awaited. The safety of natalizumab during pregnancy is unknown. For children with Crohn's disease (CD), IFX is effective at inducing and maintaining remission. Episodic therapy is not as effective as scheduled infusions. Disease duration in children does not appear to affect the efficacy of IFX. IFX promotes growth in prepubertal and early pubertal Crohn's patients. It is also effective for the treatment of extraintestinal manifestations. ADA is effective for children with active CD and for maintaining remission, even if they have lost response to IFX, although there are fewer data. Vaccination of infants exposed to biological therapy in utero should be given at standard schedules during the first 6 months of life, except for live-virus vaccines such as rotavirus. Inactivated vaccines may be safely administered to children with IBD, even when immunocompromised. [ABSTRACT FROM AUTHOR]

Coeliac disease is a common enteropathy with a strong inherited risk characterised by dietary wheat, rye and barley induced T-cell activation. Although there is replicated linkage to 2q33, results are inconsistent from association studies of the most promising candidate genes: the CD28/CTLA4/ICOS cluster. CTLA4 plays a key role in regulating T lymphocyte mediated inflammatory responses, and variants in the 3'region influence development of diabetes and thyroid disease. We genotyped CTLA4 variants (-1722 C/T,-658 T/C,-318 C/T,+49 A/G,+1822 C/T, CT60 A/G) to tag all common haplotypes (>5%frequency) and an ICOS variant (IVS+173 C/T) in 340 white UK Caucasian coeliac disease cases. Strict ascertainment criteria for coeliac cases required both villous atrophy at diagnosis and positive serology. In total, 973 healthy controls were available for SNP, and 705 for CTLA4 haplotype, based association analyses. Coeliac disease showed weak association with the CTLA4+1822T (P=0.019) and CT60 G (P=0.047) alleles. Strong association was seen with a common CTLA4 haplotype (P=0.00067, odds ratio 1.41) of frequency 32.7%in coeliac disease and 25.5%in healthy controls. A common CTLA4 haplotype shows strong association with coeliac disease, and contains multiple alleles reported to affect immunological function. Loss of tolerance to dietary antigens in coeliac disease may be mediated in part by heritable variants in co-signalling genes regulating T-cell responses.European Journal of Human Genetics (2005) 13, 440-444. doi:10.1038/sj.ejhg.5201357 Published online 12 January 2005 [ABSTRACT FROM AUTHOR]

An abstract of the article concerning RDP-58 as effective and novel therapy for ulcerative colitis is presented.