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Background Prospectively and systematically collected real-world data on the effectiveness of ustekinumab (anti-interleukin-12/23) for treating Crohns disease (CD) are still limited. Aim To assess the short-term real-world effectiveness of ustekinumab in Swedish patients with active CD. Methods Prospective multicentre study of adult CD patients initiating ustekinumab according to recommended doses at 20 hospitals, between January 2017 and November 2018. Data were collected through an electronic case report form (eCRF) linked to the Swedish Inflammatory Bowel Disease Registry (SWIBREG). The primary outcomes were clinical response (>= 3-point-decrease of Harvey-Bradshaw index (HBI)) and remission (HBI = 1 and 58 (51%) >= 2 biological agents (anti-tumour necrosis factor [aTNF] agents or vedolizumab). The 16-week ustekinumab retention rate was 105 (92%). Data on HBI at baseline were available for 96 patients. At week 16, response or remission was achieved in 38/96 (40%) patients (25/96 (26%) achieving clinical remission and 23/96 (24%) showing a clinical response). The median CRP concentration (N = 65) decreased from 6 to 4 mg/l (p = .006). No significant changes in Hb were observed. No incident malignancies or infections, requiring antibiotic treatment, were reported. Conclusions In this nation-wide prospective real-world study of adult patients with CD, ustekinumab was associated with clinical effectiveness when administered according to clinical practice and seemed to represent a safe treatment option. Funding Agencies|Janssen Cilag AB, Sweden

Prospectively and systematically collected long-term real-world clinical data on ustekinumab (anti-interleukin-12/23) are still scarce.To assess the long-term effectiveness of ustekinumab in patients with active Crohn's disease (CD).This is a prospective multicenter study of adult patients with CD initiating ustekinumab according to recommended doses at 20 Swedish hospitals. The primary outcome was clinical remission (Harvey-Bradshaw Index (HBI) ≤ 4 points) at weeks 52 and 104. Secondary outcomes included clinical response (≥ 3-point-decrease in HBI among patients with initial HBI ≥ 5 points), treatment retention, and biomarkers (C-reactive protein (CRP), hemoglobin, fecal-calprotectin) at weeks 52 and 104 compared to baseline. We also reported Health-related Quality of Life (HRQoL) measures.Of 114 included patients, 107 (94%) had previously failed ≥ 1 and 58 (51%) ≥ 2 anti-tumor necrosis factor agents. Forty (35%) had failed anti-integrin agents. Ustekinumab retention rates at weeks 52 and 104 were 70% (n = 80/114) and 61% (n = 69/114), respectively. Clinical response was seen in 36% (n = 25/69) and 29% (n = 20/69) of the patients, and remission was achieved in 32% (n = 31/96) and 29% (n = 28/96) at weeks 52 and 104, respectively. Median HBI and CRP levels decreased significantly at both timepoints as compared to baseline. Significant improvements were also observed in HRQoL. Adverse events were reported in 11% (n = 13/114) of the patients, including five cases of severe adverse events. No malignancies were observed.In this nationwide prospective real-world 104-week-follow-up study of adult patients with active CD, ustekinumab was associated with long-term clinical effectiveness and improvement in HRQoL measures when used in routine clinical care.

In Aotearoa/New Zealand, the soilborne pathogen Phytophthora agathidicida threatens the survival of the iconic kauri, and the ecosystem it supports. In 2011, a surveillance project to identify areas of kauri dieback caused by Phytophthora agathidicida within the Waitākere Ranges Regional Park (WRRP) highlighted the potential impact of the pathogen. A repeat of the surveillance in 2015/16 identified that approximately a quarter of the kauri area within the Regional Park was infected or possibly infected, an increase from previous surveys. The surveillance program mapped 344 distinct kauri areas and showed that 33.4% of the total kauri areas were affected or potentially affected by kauri dieback and over half (58.3%) of the substantial kauri areas (above 5 ha in size) were showing symptoms of kauri dieback. Proximity analysis showed 71% of kauri dieback zones to be within 50 m of the track network. Spatial analysis showed significantly higher proportions of disease presence along the track network compared to randomly generated theoretical track networks. Results suggest that human interaction is assisting the transfer of Phytophthora agathidicida within the area. The surveillance helped trigger the declaration of a cultural ban (rāhui) on recreational access. Te Kawerau ā Maki, the iwi of the area, placed a rāhui over the kauri forest eco-system of the Waitākere Forest (Te Wao Nui o Tiriwa) in December 2017. The purpose of the rāhui was to help prevent the anthropogenic spread of kauri dieback, to provide time for investment to be made into a degraded forest infrastructure and for research to be undertaken, and to help protect and support forest health (a concept encapsulated by the term mauri). Managing the spread and impact of the pathogen remains an urgent priority for this foundation species in the face of increasing pressures for recreational access. Complimentary quantitative and qualitative research programs into track utilization and ecologically sensitive design, collection of whakapapa seed from healthy and dying trees, and remedial phosphite treatments are part of the cross-cultural and community-enabled biosecurity initiatives to Kia Toitu He Kauri “Keep Kauri Standing”.

Background Success in personalized medicine in complex disease is critically dependent on biomarker discovery. We profiled serum proteins using a novel proximity extension assay [PEA] to identify diagnostic and prognostic biomarkers in inflammatory bowel disease [IBD]. Methods We conducted a prospective case-control study in an inception cohort of 552 patients [328 IBD, 224 non-IBD], profiling proteins recruited across six centres. Treatment escalation was characterized by the need for biological agents or surgery after initial disease remission. Nested leave-one-out cross-validation was used to examine the performance of diagnostic and prognostic proteins. Results A total of 66 serum proteins differentiated IBD from symptomatic non-IBD controls, including matrix metallopeptidase-12 [MMP-12; Holm-adjusted p = 4.1 × 10–23] and oncostatin-M [OSM; p = 3.7 × 10–16]. Nine of these proteins are associated with cis-germline variation [59 independent single nucleotide polymorphisms]. Fifteen proteins, all members of tumour necrosis factor-independent pathways including interleukin-1 (IL-1) and OSM, predicted escalation, over a median follow-up of 518 [interquartile range 224–756] days. Nested cross-validation of the entire data set allowed characterization of five-protein models [96% comprising five core proteins ITGAV, EpCAM, IL18, SLAMF7 and IL8], which define a high-risk subgroup in IBD [hazard ratio 3.90, confidence interval: 2.43–6.26], or allowed distinct two- and three-protein models for ulcerative colitis and Crohn’s disease respectively. Conclusion We have characterized a simple oligo-protein panel that has the potential to identify IBD from symptomatic controls and to predict future disease course. Further prospective work is required to validate our findings.

Background: The in situ proximity ligation assay (PLA) allows a protein or protein complex to be represented as an amplifiable DNA molecule. Recognition is mediated by proximity probes consisting of antibodies coupled with oligonucleotides. Upon dual binding of the proximity probes, the oligonucleotides direct the formation of a circular DNA molecule, which is then amplified by rolling-circle replication. The localized concatemeric product is then detected with fluorescent probes. The in situ PLA enables localized detection of individual native proteins or interacting protein pairs in fixed cells or tissue sections, thus providing an important tool for basic and clinical research. Methods: We used horseradish peroxidase (HRP)-conjugated oligonucleotides to couple in situ PLA with enzymatic visualization of the localized detection event. Results: We demonstrate the detection of protein complexes, both in cells and in tissue sections, and show that we can quantify the complexes with image-analysis software specially developed for recognizing HRP signals in bright-field microscopy images. We show that fluorescence and HRP signals produce equivalent results, both in cultured cells and in tissue samples. Conclusions: The combination of in situ PLA with bright-field detection and automated image analysis allows the signals present to be counted in an automated fashion and thus provides a sensitive and specific method for quantification of proteins and protein complexes with bright-field microscopy. With this approach, in situ PLA can be used without the requirement for expensive fluorescence microscopes, thereby avoiding problems with nonspecific fluorescence while maintaining compatibility with conventional histologic staining.

Epigenetic alterations may provide important insights into gene-environment interaction in inflammatory bowel disease (IBD). Here we observe epigenome-wide DNA methylation differences in 240 newly-diagnosed IBD cases and 190 controls. These include 439 differentially methylated positions (DMPs) and 5 differentially methylated regions (DMRs), which we study in detail using whole genome bisulphite sequencing. We replicate the top DMP (RPS6KA2) and DMRs (VMP1, ITGB2 and TXK) in an independent cohort. Using paired genetic and epigenetic data, we delineate methylation quantitative trait loci; VMP1/microRNA-21 methylation associates with two polymorphisms in linkage disequilibrium with a known IBD susceptibility variant. Separated cell data shows that IBD-associated hypermethylation within the TXK promoter region negatively correlates with gene expression in whole-blood and CD8+ T cells, but not other cell types. Thus, site-specific DNA methylation changes in IBD relate to underlying genotype and associate with cell-specific alteration in gene expression., Epigenetic perturbations may be an important factor in diseases where both genes and environment play a role. Here, Ventham and colleagues show that DNA methylation changes in inflammatory bowel disease are related to the underlying genotype, and are associated with cell-specific changes to gene expression.

IgE administered with its specific antigen in vivo induces enhanced proliferation of specific T cells as well as enhanced production of specific antibodies. Both effects are dependent on the low-affinity receptor for IgE (CD23) and the underlying mechanism is thought to be increased antigen presentation following uptake of IgE/antigen complexes via CD23(+) B cells. By contrast, CD23 negatively regulates antibody responses to antigens administered with alum, i.e. without IgE. This effect has been observed as low IgG1 and IgE responses in transgenic mice overexpressing CD23 (CD23Tg). The present study was designed to test whether IgE could enhance antibody and T-cell responses in CD23Tg animals or whether CD23's downregulatory effect precludes IgE-mediated enhancement. IgE-anti-TNP administered with OVA-TNP enhances the OVA-specific antibody responses in wild-type (wt) and CD23Tg mice equally well. Interestingly, the total magnitude of antibody responses to IgE + OVA-TNP and to uncomplexed OVA-TNP, as well as to sheep erythrocytes and keyhole limpet haemocyanine, were lower in the CD23Tg mice. IgE induced proliferation of OVA-specific CD4(+) T cells to the same degree in wt and CD23Tg mice. The effect on T cells was dependent on CD23(+) B cells as demonstrated in in vitro proliferation assays. In conclusion, CD23 does indeed have dual immunoregulatory effects in the same animal. The receptor mediates enhancement of antibody and T-cell responses to IgE-complexed antigen, most likely via increased presentation of complexed antigen, while it negatively regulates the total antibody response to a variety of antigens.

Antibodies, administered together with their specific antigen, can feedback-regulate antibody responses to this antigen. IgG1, IgG2a and IgG2b enhance antibody responses to soluble protein antigens. This effect is primarily mediated by FcRs as enhancement is impaired in FcR gamma-/- mice, reported to lack Fc gammaRI and Fc gammaRIII because of deletion of the common FcR gamma chain. Also IgG3 can enhance antibody responses. However, this effect is unperturbed in FcR gamma-/- mice but severely impaired in complement-depleted animals and in animals lacking complement receptor 1 and 2. Although this argues against involvement of Fc gammaRs, FcR gamma-/- mice may express one-fifth of the normal levels of Fc gammaRI and, in addition, Fc gammaRI has been suggested to bind IgG3. We re-investigated the dependence of IgG3-mediated enhancement on Fc gammaRs using a mouse strain selectively lacking Fc gammaRI and found that IgG3-mediated enhancement is completely normal. Unlike IgE and IgG2a, which are both thought to enhance T-cell proliferation via FcR-mediated antigen presentation, IgG3 was a poor enhancer of T-cell proliferation both in vivo and in vitro. These findings argue against a significant involvement of Fc gammaRs in IgG3-mediated enhancement of antibody responses and support our previous conclusion that complement plays a major role.

IgE Abs, passively administered together with their specific Ag, can enhance the production of Abs recognizing this Ag by >100-fold. IgE-mediated feedback enhancement requires the low affinity receptor for IgE, CD23. One possible mechanism is that B cells take up IgE-Ag via CD23 and efficiently present Ag to Th cells, resulting in better Ab responses. To test whether IgE Abs have an effect on Th cells in vivo, mice were adoptively transferred with CD4+ T cells expressing a transgenic OVA-specific TCR, before immunization with IgE anti-TNP (2,4,6-trinitrophenyl) plus OVA-TNP or with OVA-TNP alone. IgE induced a 6- to 21-fold increase in the number of OVA-specific T cells. These cells acquired an activated phenotype and were visible in splenic T cell zones. The T cell response peaked 3 days after immunization and preceded the OVA-specific Ab response by a few days. Transfer of CD23+ B cells to CD23-deficient mice rescued their ability to respond to IgE-Ag. Interestingly, in this situation also CD23-negative B cells produce enhanced levels of OVA-specific Abs. The data are compatible with the Ag presentation model and suggest that B cells can take up Ag via “unspecific” receptors and activate naive T cells in vivo.

Proximity Extension Assay technology identifies novel serum biomarkers for predicting Inflammatory Bowel Disease : IBD Character Consortium

Ag administered i.v. to mice along with specific IgE or IgG2a induces higher Ab- and CD4+ T cell responses than Ag administered alone. The IgE effect is completely dependent on the low-affinity receptor for IgE, CD23, whereas the IgG2a effect depends on activating FcγRs. In vitro studies suggest that IgE/Ag is presented more efficiently than Ag alone to CD4+ T cells by CD23+ B cells and that IgG2a/Ag is presented by FcγR+ dendritic cells (DCs). In this study, we investigate in vivo the early events leading to IgE- and IgG2a-mediated enhancement of immune responses. OVA administered i.v. in PBS in combination with specific IgE binds circulating B cells after 5 min and is found in B cell follicles bound to follicular B cells (CD23high) after 30 min. This novel B cell-dependent route of entry is specific for IgE because IgG2a-Ag complexes were trapped in the marginal zone. OVA-specific CD4+ T cells were found at the T-B border in the T cell zones 12 h after immunization both with IgE/OVA or IgG2a/OVA and proliferated vigorously after 3 days. The findings suggest that IgE- and IgG2a-immune complexes are efficient stimulators of early CD4+ T cell responses and that Ag bound to IgE has a specific route for transportation into follicles.

Introduction Advances in protein profiling using proximity extension assays (PEA) have transformed our ability to compare concentrations of multiple proteins across biological samples. PEA utilises the specificity of antibody proximity and the sensitivity of polymerase chain reaction (qPCR) to detect proteins of interest. As part of the EC funded IBD Character initiative to discover biomarkers for clinical use using multiomic technologies, we performed high-throughput prospective case-control serum profiling to identify protein biomarkers that can predict Inflammatory Bowel Disease (IBD). Method Utilising Proseek Multiplex panels (Olink Bioscience, Sweden), serum profiling was performed in patients with a new diagnosis of IBD. Our control group consisted of symptomatic individuals. Phenotypic data was captured including age, sex, diagnosis and IBD medications. Statistical analysis was performed using R. Data were normalised and then batch corrected using ComBAT. Linear models were created for each protein including age and sex as covariates. After quality control, data from 186 proteins was available for analysis. Results A total of 245 patient serum samples (n = 153) newly diagnosed IBD, n = 92 symptomatic controls) from 4 IBD centres from Norway, United Kingdom and Sweden were included in the study from December 2012 to June 2014. 70 had Crohn’s disease (CD), 70 ulcerative colitis (UC) and 13 Inflammatory Bowel Disease Unclassified (IBDU). The mean age of the entire cohort was 33 years (range 0–79 years) and 54% were female. Multivariable analysis identified a set of 48 protein markers that were significantly associated with IBD. The 5 most significant protein markers were MMP-12 (Holm-adjusted p = 3.3 × 10 –13 ), OSM (p = 2.4 × 10 –12 ), CXCL9 (p = 1.7 × 10 –9 ), MMP10 (p = 1.7 × 10 –9 ) and EGFR (p = 1.8 × 10 –9 ). Of these five, all except EGFR were upregulated in IBD. The top 2 markers, MMP-12 and OSM were able to discriminate IBD from controls with an area under the receiver operator characteristics curve of 0.81 and 0.75 respectively. Using linear discriminant analysis, a combined biomarker consisting of MMP-12 and OSM was able to discriminate IBD from controls with a sensitivity and specificity of 80% and 72% respectively. Conclusion We have identified serum biomarkers that can predict IBD. These data demonstrate a potential for a PEA multiplex technology in IBD diagnostics and its ability to identify novel proteins that may be relevant in disease pathogenesis. Disclosure of interest R. Kalla Grant/Research Support from: IBD Character, N. Kennedy Grant/Research Support from: Wellcome Trust, Conflict with: Abbvie, MSD, Warner Chilcott, Ferring speaker fees, F. Hjelm: None Declared, E. Modig: None Declared, M. Sundell: None Declared, J. Soderholm: None Declared, B. Andreassen: None Declared, D. Bergemalm: None Declared, N. Ventham Grant/Research Support from: IBD BIOM, H. Hjortswang: None Declared, R. Petr: None Declared, M. Vatn: None Declared, J. Halfvarson: None Declared, M. Gullberg: None Declared, J. Satsangi Grant/Research Support from: EC Grants, Wellcome, CSO, MRC, Consultant for: Takeda, Conflict with: MSD speaker fees.

Antibodies administered in vivo together with the antigen they are specific for can regulate the immune response to that antigen. This phenomenon is called antibody-mediated feedback regulation and has been known for over 100 years. Both passively administered and actively produced antibodies exert immunoregulatory functions. Feedback regulation can be either positive or negative, resulting in >1000-fold enhancement or >99% suppression of the specific antibody response. Usually, the response to the entire antigen is up- or downregulated, regardless of which epitope the regulating antibody recognizes. IgG of all isotypes can suppress responses to large particulate antigens like erythrocytes, a phenomenon used clinically in Rhesus prophylaxis. IgG suppression works in mice lacking the known Fc-gamma receptors (FcgammaR) and a likely mechanism of action is epitope masking. IgG1, IgG2a and IgG2b administered together with soluble protein antigens will enhance antibody and CD4+ T-cell responses via activating FcgammaR, probably via increased antigen presentation by dendritic cells. IgG3 as well as IgM also enhance antibody responses but their effects are dependent on their ability to activate complement. A possible mechanism is increased B-cell activation caused by immune complexes co-crosslinking the B-cell receptor with the complement-receptor 2/CD19 receptor complex, known to lower the threshold for B-cell activation. IgE-antibodies enhance antibody and CD4+ T-cell responses to small soluble proteins. This effect is entirely dependent on the low-affinity receptor for IgE, CD23, the mechanism probably being increased antigen presentation by CD23+ B cells.

Olink Bioscience's Proseek protein assay enables sensitive detection and quantification of proteins in a 1-μl sample volume. With the Proseek Assay Development kit, a new assay can rapidly be developed for any target protein with appropriate antibodies available. Proseek's minimal sample consumption and excellent assay performance make it highly suitable for analyzing biomarkers and cytokines in precious biological samples.

Background Shb, a ubiquitously expressed Src homology 2 domain-containing adaptor protein has previously been implicated in the signaling of various tyrosine kinase receptors including the TCR. Shb associates with SLP76, LAT and Vav, all important components in the signaling cascade governing T cell function and development. A Shb knockout mouse was recently generated and the aim of the current study was to address the importance of Shb deficiency on T cell development and function. Results Shb knockout mice did not display any major changes in thymocyte development despite an aberrant TCR signaling pattern, including increased basal activation and reduced stimulation-induced phosphorylation. The loss of Shb expression did however affect peripheral CD4+ TH cells resulting in an increased proliferative response to TCR stimulation and an elevated IL-4 production of naïve TH cells. This suggests a TH2 skewing of the Shb knockout immune system, seemingly caused by an altered TCR signaling pattern. Conclusion Our results indicate that Shb appears to play an important modulating role on TCR signaling, thus regulating the peripheral CD4+ TH2 cell response.