Background Anti-TNF drugs are effective treatments for the management of Crohn's disease but treatment failure is common. We aimed to identify clinical and pharmacokinetic factors that predict primary non-response at week 14 after starting treatment, non-remission at week 54, and adverse events leading to drug withdrawal.Methods The personalised anti-TNF therapy in Crohn's disease study (PANTS) is a prospective observational UK-wide study. We enrolled anti-TNF-naive patients (aged ≥6 years) with active luminal Crohn's disease at the time of first exposure to infliximab or adalimumab between March 7, 2013, and July 15, 2016. Patients were evaluated for 12 months or until drug withdrawal. Demographic data, smoking status, age at diagnosis, disease duration, location, and behaviour, previous medical and drug history, and previous Crohn's disease-related surgeries were recorded at baseline. At every visit, disease activity score, weight, therapy, and adverse events were recorded; drug and total anti-drug antibody concentrations were also measured. Treatment failure endpoints were primary non-response at week 14 ,non-remission at week 54, and adverse events leading to drug withdrawal. We used regression analyses to identify which factors were associated with treatment failure. Findings We enrolled 955 patients treated with infliximab (753 with originator; 202 with biosimilar) and 655 treated with adalimumab. Primary non-response occurred in 295 (23•8%, 95% CI 21•4-26•2) of 1241 patients who were assessable at week 14. Non-remission at week 54 occurred in 764 (63•1%, 60•3-65•8) of 1211 patients who were assessable, and adverse events curtailed treatment in 126 (7•8%, 6•6-9•2) of 1610 patients. In multivariable analysis, the only factor independently associated with primary non-response was low drug concentration at week 14 (infliximab: odds ratio 0•35 [95% CI 0•20-0•62], p=0•00038; adalimumab: 0•13 [0•06-0•28], p<0•0001); the optimal week 14 drug concentrations associated with remission at both week 14 and week 54 were 7 mg/L for infliximab and 12 mg/L for adalimumab. Continuing standard dosing regimens after primary non-response was rarely helpful; only 14 (12•4% [95% CI 6•9-19•9]) of 113 patients entered remission by week 54. Similarly, week 14 drug concentration was also independently associated with non-remission at week 54 (0•29 [0•16-0•52] for infliximab; 0•03 [0•01-0•12] for adalimumab; p<0•0001 for both). The proportion of patients who developed anti-drug antibodies (immunogenicity) was 62•8% (95% CI 59•0-66•3) for infliximab and 28•5% (24•0-32•7) for adalimumab. For both drugs, suboptimal week 14 drug concentrations predicted immunogenicity, and the development of anti-drug antibodies predicted subsequent low drug concentrations. Combination immuno-modulator (thiopurine or methotrexate) therapy mitigated the risk of developing anti-drug antibodies (hazard ratio 0•39 [95% CI 0•32-0•46] for infliximab; 0•44 [0•31-0•64] for adalimumab; p<0•0001 for both). For infliximab, multivariable analysis of immunododulator ...

The colorectal adenoma-carcinoma sequence has provided a paradigmatic framework for understanding the successive somatic genetic changes and consequent clonal expansions leading to cancer. As for most cancer types, however, understanding of the earliest phases of colorectal neoplastic change, which may occur in morphologically normal tissue, is comparatively limited. Here, we whole genome sequenced hundreds of normal crypts from 42 individuals. Signatures of multiple mutational processes were revealed, some ubiquitous and continuous, others only found in some individuals, in some crypts or during certain periods of life. Likely driver mutations were present in ~1% of normal colorectal crypts in middle-aged individuals, indicating that adenomas and carcinomas are rare outcomes of a pervasive process of neoplastic change across morphologically normal colorectal epithelium. Colorectal cancers exhibit substantially elevated mutation burdens relative to normal cells. Sequencing normal colorectal cells provides quantitative insights into the genomic and clonal evolution of cancerdriver mutations, which conceivably are morphologically indistinguishable from normal cells, are similarly unclear. In large part, these deficiencies are due to the technical challenge of identifying somatic mutations in normal tissues, which are composed of myriad microscopic cell clones. Several different approaches have been adopted to address this 4-14 , revealing signatures of common somatic mutational processes in normal cells of the small and large intestine, liver, blood, skin, and nervous system. Thus far, however, studies have not been of sufficient scale to characterise variation in signature activity or detect less frequent processes 4-14. Remarkably high proportions of normal skin, oesophageal, and endometrial epithelial cells have been shown to be members of clones already carrying driver mutations 10,11,15,16 , and large mutant clones have been detected in blood 17-20. The extent of this phenomenon in the colon, an organ with a high cancer incidence, has not been investigated. Colonic epithelium is a contiguous cell sheet organised into ~15,000,000 crypts each composed of ~2,000 cells 21. Towards the base of each crypt resides a small number of stem cells ancestral to the maturing and differentiated cells in the crypt 22. These stem cells stochastically replace one another through a process of neutral drift 23,24 such that all stem cells, and thus all cells, in a crypt derive from a single ancestor stem cell that existed in recent years 25-27. The somatic mutations that were present in this ancestor are thus found in all ~2,000 descendant cells and can be revealed by DNA sequencing of an individual crypt. These stem cells are thought to be the cells of origin of colorectal cancers 28. To characterise the earliest stages of colorectal carcinogenesis, somatic mutation burdens, mutational signatures, clonal dynamics, and the frequency of driver mutations in normal colorectal epithelium were explored by sequencing individual colorect...

BACKGROUND & AIMS: Anti-tumor necrosis factor (anti-TNF) therapies are the most widely used biologic drugs for treating immune-mediated diseases, but repeated administration can induce the formation of anti-drug antibodies. The ability to identify patients at increased risk for development of anti-drug antibodies would facilitate selection of therapy and use of preventative strategies. METHODS: We performed a genomewide association study to identify variants associated with time to development of anti-drug antibodies in a discovery cohort of 1240 biologic-naïve patients with Crohn's disease starting infliximab or adalimumab therapy. Immunogenicity was defined as an anti-drug antibody titer !10 AU/mL using a drug-tolerant enzyme-linked immunosorbent assay. Significant association signals were confirmed in a replication cohort of 178 patients with inflammatory bowel disease. RESULTS: The HLA-DQA1*05 allele, carried by approximately 40% of Europeans, significantly increased the rate of immunogenicity (hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.60-2.25; P ¼ 5.88 Â 10-13). The highest rates of immunogenicity, 92% at 1 year, were observed in patients treated with infliximab monotherapy who carried HLA-DQA1*05; conversely the lowest rates of immunogenicity, 10% at 1 year, were observed in patients treated with adalimumab combination therapy who did not carry HLA-DQA1*05. We confirmed this finding in the replication cohort (HR, 2.00; 95% CI, 1.35-2.98; P ¼ 6.60 Â 10-4). This association was consistent for patients treated with adalimumab (HR, 1.89; 95% CI, 1.32-2.70) or infliximab (HR, 1.92; 95% CI, 1.57-2.33), and for patients treated with anti-TNF therapy alone

A lymphocytic enterocolitis has been reported in a cohort of children with autistic spectrum disorder (ASD) and gastrointestinal (GI) symptoms. This study tested the hypothesis that dysregulated intestinal mucosal immunity with enhanced pro-inflammatory cytokine production is present in these ASD children. Comparison was made with developmentally normal children with, and without, mucosal inflammation. Duodenal and colonic biopsies were obtained from 21 ASD children, and 65 developmentally normal paediatric controls, of which 38 had signs of histological inflammation. Detection of CD3+ lymphocyte staining for spontaneous intracellular TNFalpha, IL-2, IL-4, IFNgamma, and IL-10, was performed by multicolor flow cytometry. Duodenal and colonic mucosal CD3+ lymphocyte counts were elevated in ASD children compared with noninflamed controls (p<0.03). In the duodenum, the proportion of lamina propria (LP) and epithelial CD3(+)TNFalpha+ cells in ASD children was significantly greater compared with noninflamed controls (p<0.002) but not coeliac disease controls. In addition, LP and epithelial CD3(+)IL-2+ and CD3(+)IFNgamma+, and epithelial CD3(+)IL-4+ cells were more numerous in ASD children than in noninflamed controls (p<0.04). In contrast, CD3(+)IL-10+ cells were fewer in ASD children than in noninflamed controls (p<0.05). In the colon, LP CD3(+)TNFalpha+ and CD3(+)IFNgamma+ were more frequent in ASD children than in noninflamed controls (p<0.01). In contrast with Crohn's disease and non-Crohn's colitis, LP and epithelial CD3(+)IL-10+ cells were fewer in ASD children than in nondisease controls (p<0.01). There was a significantly greater proportion of CD3(+)TNFalpha+ cells in colonic mucosa in those ASD children who had no dietary exclusion compared with those on a gluten and/or casein free diet (p<0.05). There is a consistent profile of CD3+ lymphocyte cytokines in the small and large intestinal mucosa of these ASD children, involving increased pro-inflammatory and decreased regulatory activities. The data provide further evidence of a diffuse mucosal immunopathology in some ASD children and the potential for benefit of dietary and immunomodulatory therapies.

We have reported lymphocytic colitis in children with regressive autism, with epithelial damage prominent. We now compare duodenal biopsies in 25 children with regressive autism to 11 with coeliac disease, five with cerebral palsy and mental retardation and 18 histologically normal controls. Immunohistochemistry was performed for lymphocyte and epithelial lineage and functional markers. We determined the density of intraepithelial and lamina propria lymphocyte populations, and studied mucosal immunoglobulin and complement C1q localisation. Standard histopathology showed increased enterocyte and Paneth cell numbers in the autistic children. Immunohistochemistry demonstrated increased lymphocyte infiltration in both epithelium and lamina propria with upregulated crypt cell proliferation, compared to normal and cerebral palsy controls. Intraepithelial lymphocytes and lamina propria plasma cells were lower than in coeliac disease, but lamina propria T cell populations were higher and crypt proliferation similar. Most strikingly, IgG deposition was seen on the basolateral epithelial surface in 23/25 autistic children, co-localising with complement C1q. This was not seen in the other conditions. These findings demonstrate a novel form of enteropathy in autistic children, in which increases in mucosal lymphocyte density and crypt cell proliferation occur with epithelial IgG deposition. The features are suggestive of an autoimmune lesion.

Inflammatory intestinal pathology has been reported in children with regressive autism (affected children). Detailed analysis of intestinal biopsies in these children indicates a novel lymphocytic enterocolitis with autoimmune features; however, links with cognitive function remain unclear. To characterize further, the nature and extent of this disease we examined the mucosal infiltrate using flow cytometry. Duodenal, ileal, and colonic biopsies were obtained from 52 affected children, 25 histologically normal, and 54 histologically inflamed, developmentally normal controls. Epithelial and lamina propria lymphocyte populations were isolated and examined by multicolor flow cytometry. Adjacent biopsies were assessed by semiquantitative histopathology. At all sites, CD3(+) and CD3(+)CD8(+) IEL as well as CD3(+) LPL were significantly increased in affected children compared with developmentally normal noninflamed control groups (p<0.01) reaching levels similar to inflamed controls. In addition, two populations--CD3(+)CD4(+) IEL and LP CD19(+) B cells--were significantly increased in affected children compared with both noninflamed and inflamed control groups including IBD, at all sites examined (p<0.01). Histologically there was a prominent mucosal eosinophil infiltrate in affected children that was significantly lower in those on a gluten- and casein-free diet, although lymphocyte populations were not influenced by diet. The data provide further evidence of a pan-enteric mucosal immunopathology in children with regressive autism that is apparently distinct from other inflammatory bowel diseases.

Intestinal HSPG loss occurs in kwashiorkor, which may precipitate protein-losing enteropathy to cause edema. If occurring systemically, impaired HSPG expression could cause several previously unexplained features of kwashiorkor. We speculate that a genetic predisposition to reduced HSPG biosynthesis may offer a contrasting selective advantage, by both diminishing protein catabolism during transient undernutrition and protecting against specific infectious diseases.

SUMMARY BackgroundAdalimumab is efficacious therapy for adults with Crohn's disease (CD).