Involvement of IL-23 in enteropathic arthritis patients with inflammatory bowel disease: preliminary results

A multicenter study of the real-world effectiveness and safety of risankizumab in Crohn's disease

BACKGROUND

We aimed to evaluate the effectiveness and safety of risankizumab (RZB) for Crohn's disease (CD) in routine clinical practice.

METHODS

We performed a retrospective review of a multicenter consortium of CD patients treated with RZB. Co-primary outcomes were week 12 clinical remission (Harvey Bradshaw Index [HBI] score of ≤4 or physician global assessment in those without HBI or with ileostomy) and 6-month endoscopic remission (Simplified Endoscopic Mucosal Assessment for Crohn's Disease of 0-1 or absence of ulcers). Secondary outcomes included steroid-free clinical remission, clinical response, radiographic response, cumulative clinical and endoscopic remission rates at 6 and 12 months, and adverse events.

RESULTS

A total of 309 patients were included (median disease duration 14 years [IQR, 6-24]; median follow-up 7.1 months [IQR, 4.1-10.3]). Most patients (85.8%) were advanced therapy (AT)-exposed, and 169 (54.7%) had prior ustekinumab (UST) exposure. Week 12 clinical remission rates were 49.7% (98/197) overall, and 44.2% (50/113) vs 57.1% (48/84) in UST-exposed vs naïve patients (P = .073). Among those with active disease on baseline endoscopy (n = 122) who had an available follow-up at 6 months, 52.4% (22/42) achieved endoscopic remission. Cumulative rates of clinical and endoscopic remission at 12 months were 65.0% and 49.5%, respectively. Cumulative 12-month endoscopic remission was 33.9% (19/56) in UST-exposed and 68.1% (32/47) in UST-naïve patients (P < .001). Risankizumab was well-tolerated with no new safety signals identified.

CONCLUSIONS

In this large multicenter cohort of patients with CD, RZB was well-tolerated and effective in achieving favorable clinical and endoscopic outcomes in both AT-exposed and naïve populations, including those with exposure to UST.

Interleukin-10 production by innate lymphoid cells restricts intestinal inflammation in mice

Interleukin-10 (IL-10) is an immunomodulatory cytokine critical for intestinal immune homeostasis. IL-10 is produced by various immune cells but IL-10 receptor signaling in intestinal CX3CR1+ mononuclear phagocytes is necessary to prevent spontaneous colitis in mice. Here, we utilized fluorescent protein reporters and cell-specific targeting and found that Rorc-expressing innate lymphoid cells (ILCs) produce IL-10 in response to anti-CD40-mediated intestinal inflammation. Deletion of Il10 specifically in Rorc-expressing ILCs led to phenotypic changes in intestinal macrophages and exacerbated both innate and adaptive immune-mediated models of experimental colitis. The population of IL-10+ producing ILCs shared markers with both ILC2 and ILC3 with nearly all ILC3s being of the NCR+ subtype. Interestingly, Ccl26 was enriched in IL-10+ ILCs and was markedly reduced in IL-10-deficient ILC3s. Since CCL26 is a ligand for CX3CR1, we employed RNA in situ hybridization and observed increased numbers of ILCs in close proximity to Cx3cr1-expressing cells under inflammatory conditions. Finally, we generated transgenic RorctdTomato reporter mice that faithfully marked RORγt+ cells that could rescue disease pathology and aberrant macrophage phenotype following adoptive transfer into mice with selective Il10 deficiency in ILC3s. These results demonstrate that IL-10 production by a population of ILCs functions to promote immune homeostasis in the intestine possibly via direct effects on intestinal macrophages.

High-Throughput Whole-Exome Sequencing and Large-Scale Computational Analysis to Identify the Genetic Biomarkers to Predict the Vedolizumab Response Status in Inflammatory Bowel Disease Patients from Saudi Arabia

Background/Objectives: Vedolizumab (VDZ) is the new monoclonal drug targeting α4β7 integrin for patients with moderate/severe IBD. Between 30 and 45% of patients fail to respond to VDZ after 14-16 weeks of treatment. The aim of the study was to explore the genetic profile of vedolizumab-treated Arab IBD patients in Saudi Arabia to identify the potential biomarkers to differentiate the responders from non-responders. Methods: A cohort of 16 patients with IBD, including 4 with Crohn's disease and 12 with ulcerative colitis, were recruited. Following 16 weeks of VDZ treatment, nine were found to be responders and seven non-responders. Blood samples were collected for the whole exome sequencing of DNA from all patients. The variants in the whole-exome sequencing data were analyzed with a variety of bioinformatics tools and databases, such as Polyphen2, Mutation Taster, CADD, FATHMM, Open Target Platform, TOPPFun, STRING, and GTEx. Results: More than 1.6 million variants from 16 samples were analyzed. The rare variant analysis prioritized NOD2, IL23, IL10, IL27, and TRAF1 genes in non-responders. NOD2, IL23, IL10, IL27, and TRAF1 were found to be the significant IBD risk factors in multiple genome-wide association studies, and their pro-inflammatory activity might contribute to the inherent resistance to VDZ. Rare variants of CARD9, TYK2, IL4, and NLRP1 genes present in VDZ responders enhance the anti-inflammatory/immune modulation effects. Conclusions: This investigation is the first to apply whole-exome sequencing to identify the potential drug response biomarkers for the IBD drug VDZ in Saudi Arabia.

Mirikizumab Sustained Impact on Fatigue in Patients with Moderately to Severely Active Crohn's Disease in the Phase 2 AMAG Study

BACKGROUND

Fatigue is a burdensome, under-recognized, multidimensional symptom experienced by patients with Crohn's disease (CD). We evaluated the impact of mirikizumab on fatigue and the association between changes in select patient-reported outcomes and clinical measures with changes in fatigue from baseline to week 104 (W104).

METHODS

Patients (N = 191) were randomized (2:1:1:2) to receive placebo (PBO), 200 mg, 600 mg, or 1000 mg of mirikizumab, administered intravenously (IV) every 4 weeks at W0, W4, and W8. Patients who achieved ≥1 point improvement in Simple Endoscopic Score for Crohn's Disease (SES-CD) and received mirikizumab at W12 (rerandomized maintenance cohort) were rerandomized to continue induction IV treatment assignment (IV-C) or received 300 mg of mirikizumab subcutaneously (SC) until W52. Nonrandomized maintenance cohort had endoscopic nonimprovers (1000 mg) and PBO patients (PBO/1000 mg) who received 1000 mg of mirikizumab until W52. Subjects from the maintenance period with clinical benefit received 300 mg SC Q4W from W52 to W104. The Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) questionnaire was used to assess fatigue, and the FACIT-F associations were assessed using Pearson correlation coefficient.

RESULTS

At W12, mirikizumab groups reported improved FACIT-F scores compared with PBO, and improvement was maintained through W52 and W104. Changes in FACIT-F at W52 and W104 had strong correlations with changes at the same time point in quality of life (QoL) scores but lacked correlations with changes in inflammatory biomarkers.

CONCLUSIONS

Mirikizumab treatment significantly improved fatigue in patients with moderately to severely active CD, which was sustained to W104. The improvement in fatigue was correlated with improvement in clinical measures and was strongly correlated with improvement in QoL.

Role of Mirikizumab in the Treatment of Inflammatory Bowel Disease-From Bench to Bedside

Mirikizumab is a monoclonal antibody directed against the p19 subunit of interleukin (IL)-23 to inhibit its interaction with the IL-23 receptor. IL-23 is a key cytokine involved in initiating and perpetuating the inflammatory cascade in inflammatory bowel disease (IBD). Mirikizumab is the first agent from the novel anti-IL-23p19 drug class to be licensed for ulcerative colitis and the first to present long-term endoscopic, histologic, symptomatic, and quality-of-life outcomes. More recently, the VIVID trial programme has led to the approval of mirikizumab in moderate to severe Crohn's disease. This review explores the history of its development, discusses key immunopharmacological properties unique to the drug, and details the available clinical trials and real-world evidence supporting its use in IBD.

Efficacy and safety of mirikizumab in patients with moderately-to-severely active Crohn's disease: a phase 3, multicentre, randomised, double-blind, placebo-controlled and active-controlled, treat-through study

BACKGROUND

Mirikizumab, a humanised monoclonal antibody that inhibits IL-23p19, is effective in moderate-to-severe ulcerative colitis. We aimed to evaluate the efficacy and safety of mirikizumab in patients with moderately-to-severely active Crohn's disease.

METHODS

VIVID-1 was a global phase 3, randomised, double-blind, double-dummy, placebo-controlled and active-controlled, treat-through study. The study enrolled adult patients at 324 sites (hospitals or medical centres, clinical practices, and clinical research sites) in 33 countries across Europe, Asia, North America, Central America, South America, and Australia. Adult patients with moderately-to-severely active Crohn's disease and previous inadequate response, loss of response, or intolerance to one or more approved biological therapies or conventional therapies were randomly assigned 6:3:2 to receive mirikizumab 900 mg intravenously at weeks 0, 4, and 8, then 300 mg subcutaneously every 4 weeks from weeks 12 to 52; ustekinumab about 6 mg/kg intravenously at week 0, then 90 mg subcutaneously every 8 weeks from weeks 8 to 52; or placebo. The coprimary endpoints assessing superiority of mirikizumab over placebo were composite endpoints: patient-reported outcome (PRO) clinical response at week 12 and endoscopic response at week 52 (endoscopic response-composite), and PRO clinical response at week 12 and Crohn's Disease Activity Index (CDAI) clinical remission at week 52 (CDAI clinical remission-composite). The adjusted risk differences were calculated, and the comparison was performed by the Cochran-Mantel-Haenszel test. Non-responder imputation was used. VIVID-1 was registered on ClinicalTrials.gov, NCT03926130, and is now complete.

FINDINGS

Between July 23, 2019, and Aug 23, 2023, 1150 patients were randomly assigned and received study treatment (safety population); 1065 patients were included in the efficacy population and received mirikizumab (n=579), ustekinumab (n=287), or placebo (n=199). Both coprimary endpoints were met: endoscopic response-composite was reached in 220 (38·0%) of 579 patients on mirikizumab versus 18 (9·0%) of 199 on placebo (99·5% CI 20·6-36·8; p<0·0001); CDAI clinical remission-composite was reached in 263 (45·4%) of 579 patients on mirikizumab versus 39 (19·6%) of 199 patients on placebo (99·5% CI 15·9-35·6; p<0·0001). The incidence rates of overall adverse events and discontinuations in patients treated with mirikizumab were lower compared with placebo. The most common adverse event across the three groups was COVID-19. Serious adverse events were reported in 65 (10·3%) of 630 patients on mirikizumab, 33 (10·7%) of 309 patients on ustekinumab, and 36 (17·1%) of 211 patients on placebo. There were three deaths during VIVID-1, one in the ustekinumab group, and two in the placebo group, including one in a placebo non-responder who switched to mirikizumab after week 12. None of the deaths were considered related to the study drug. The safety of mirikizumab in Crohn's disease was consistent with its known favourable profile.

INTERPRETATION

Mirikizumab was safe and effective as induction and maintenance treatment for patients with moderately-to-severely active Crohn's disease who had intolerance, inadequate response, or loss of response to standard therapy.

FUNDING

Eli Lilly and Company.

Gut instinct: harnessing the power of probiotics to tame pathogenic signaling pathways in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) marked by persistent inflammation of the mucosal lining of the large intestine, leading to debilitating symptoms and reduced quality of life. Emerging evidence suggests that an imbalance of the gut microbiota plays a crucial role in UC pathogenesis, and various signaling pathways are implicated in the dysregulated immune response. Probiotics are live microorganisms that confer health benefits to the host, have attracted significant attention for their potential to restore gut microbial balance and ameliorate inflammation in UC. Recent studies have elucidated the mechanisms by which probiotics modulate these signaling pathways, often by producing anti-inflammatory molecules and promoting regulatory immune cell function. For example, probiotics can inhibit the nuclear factor-κB (NF-κB) pathway by stabilizing Inhibitor of kappa B alpha (IκBα), dampening the production of proinflammatory cytokines. Similarly, probiotics can modulate the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway, suppressing the activation of STAT1 and STAT3 and thus reducing the inflammatory response. A better understanding of the underlying mechanisms of probiotics in modulating pathogenic signaling pathways in UC will pave the way for developing more effective probiotic-based therapies. In this review, we explore the mechanistic role of probiotics in the attenuation of pathogenic signaling pathways, including NF-κB, JAK/STAT, mitogen-activated protein kinases (MAPKs), Wnt/β-catenin, the nucleotide-binding domain (NOD)-, leucine-rich repeat (LRR)- and pyrin domain-containing protein 3 (NLRP3) inflammasome, Toll-like receptors (TLRs), interleukin-23 (IL-23)/IL-17 signaling pathway in UC.

Dysbiosis in Inflammatory Bowel Disease and Spondyloarthritis: Still a Long Way to Go?

The association between Inflammatory Bowel Disease (IBD) and Spondyloarthritis (SpA) has been known for years, as has the concept that IBD is associated with an altered intestinal bacterial composition, a condition known as "dysbiosis". Recently, a state of intestinal dysbiosis has also been found in SpA. Dysbiosis in the field of IBD has been well characterized so far, as well as in SpA. The aim of this review is to summarize what is known to date and to emphasize the similarities between the microbiota conditions in these two diseases: particularly, an altered distribution in the gut of Enterobacteriaceae, Streptococcus, Haemophilus, Clostridium, Akkermansia, Ruminococcus, Faecalibacterium Prausnitzii, Bacteroides Vulgatus, Dialister Invisus, and Bifidubacterium Adolescentis is common to both IBD and SpA. At the same time, little is known about intestinal dysbiosis in IBD-related SpA. Only a single recent study has found an increase in Escherichia and Shigella abundances and a decrease in Firmicutes, Ruminococcaceae, and Faecalibacterium abundances in an IBD-related SpA group. Based on what has been discovered so far about the altered distribution of bacteria that unite both pathologies, it is appropriate to carry out further studies aiming to improve the understanding of IBD-related SpA for the purpose of developing new therapeutic strategies.

Serum biomarkers and their relationship to axial spondyloarthritis associated with inflammatory bowel diseases

Spondyloarthritis (SpA) constitute a group of chronic inflammatory immune-mediated rheumatic diseases characterized by genetic, clinical, and radiological features. Recent efforts have concentrated on identifying biomarkers linked to axial SpA associated with inflammatory bowel disease (IBD), offering predictive insights into disease onset, activity, and progression. Genetically, the significance of the HLA-B27 antigen is notably diminished in ankylosing spondylitis (AS) associated with IBD, but is heightened in concurrent sacroiliitis. Similarly, certain polymorphisms of endoplasmic reticulum aminopeptidase (ERAP-1) appear to be involved. Carriage of variant NOD2/CARD15 polymorphisms has been demonstrated to correlate with the risk of subclinical intestinal inflammation in AS. Biomarkers indicative of pro-inflammatory activity, including C-reactive protein (CRP) along with erythrocyte sedimentation rate (ESR), are among the consistent predictive biomarkers of disease progression. Nevertheless, these markers are not without limitations and exhibit relatively low sensitivity. Other promising markers encompass IL-6, serum calprotectin (s-CLP), serum amyloid (SAA), as well as biomarkers regulating bone formation such as metalloproteinase-3 (MMP-3) and Dickkopf-related protein 1 (DKK-1). Additional candidate indicators of structural changes in SpA patients include matrix metalloproteinase-3 (MMP-3), vascular endothelial growth factor (VEGF), tenascin C (TNC), and CD74 IgG. Fecal caprotein (f-CLP) levels over long-term follow-up of AS patients have demonstrated predictive value in anticipating the development of IBD. Serologic antibodies characteristic of IBD (ASCA, ANCA) have also been compared; however, results exhibit variability. In this review, we will focus on biomarkers associated with both axial SpA and idiopathic intestinal inflammation, notably enteropathic spondyloarthritis.

Risankizumab to treat moderately to severely active Crohn's disease in adults: an evaluation of trials and data

INTRODUCTION

Risankizumab is a humanized monoclonal antibody that selectively inhibits interleukin (IL)-23. It is approved for the treatment of moderate-to-severe plaque psoriasis, psoriatic arthritis, and more recently moderate-to-severe Crohn's disease (CD).

AREAS COVERED

After examining the current landscape of CD management including therapies which are currently approved and those in late stages of development, we will review the interleukin pathway and discuss the specific mechanism of targeted IL-23 inhibition, summarize available clinical trial data on efficacy and safety of Risankizumab, consider future positioning of Risankizumab in the therapeutic armamentarium, and ultimately discuss future needs for the field.

EXPERT OPINION

Risankizumab represents the first and only targeted IL-23 inhibitor approved for the treatment of CD, providing a promising addition to the therapeutic armamentarium for CD, with a favorable safety profile and demonstrated efficacy in both biologic-naïve and exposed populations. It is possible that the targeted nature of Risankizumab may enhance efficacy and safety over combined IL-12/23 inhibition, with trials underway attempting to shed light on that hypothesis.

Generation and Characterization of Mirikizumab, a Humanized Monoclonal Antibody Targeting the p19 Subunit of IL-23

Interleukin (IL)-23 exists as a heterodimer consisting of p19 and p40 and is a key cytokine for promoting inflammatory responses in a variety of target organs. IL-23 plays a key role in the differentiation and maintenance of T helper 17 cells, and deregulation of IL-23 can result in autoimmune pathologies of the skin, lungs, and gut. This study describes the generation and characterization of mirikizumab (miri), a humanized IgG4 monoclonal antibody directed against the p19 subunit of IL-23. Miri binds human and cynomolgus monkey IL-23 with high affinity and binds rabbit IL-23 weakly but does not bind to rodent IL-23 or the other IL-23 family members IL-12, IL-27, or IL-35. Miri effectively inhibits the interaction of IL-23 with its receptor, and potently blocks IL-23-induced IL-17 production in cell-based assays while preserving the function of IL-12. In both local and systemic in vivo mouse models, miri blocked IL-23-induced keratin mRNA or IL-17 production, respectively. These data provide a comprehensive preclinical characterization of miri, for which efficacy and safety have been demonstrated in human clinical trials for psoriasis, ulcerative colitis, and Crohn's disease. SIGNIFICANCE STATEMENT: This article describes the generation and characterization of mirikizumab, a high affinity, neutralizing IgG4 variant monoclonal antibody that is under development for the treatment of ulcerative colitis and Crohn's disease. Neutralization of interleukin (IL)-23 is achieved by preventing the binding of IL-23 p19 subunit to the IL-23 receptor and does not affect the IL-12 pathway.

The Role of IL-23 in the Pathogenesis and Therapy of Inflammatory Bowel Disease

Interleukin-23 (IL-23) is a proinflammatory cytokine produced mainly by macrophages and antigen-presenting cells (APCs) after antigenic stimulation. IL-23 plays a significant role as a mediator of tissue damage. Indeed, the irregularities in IL-23 and its receptor signaling have been implicated in inflammatory bowel disease. IL-23 interacts with both the innate and adaptive immune systems, and IL-23/Th17 appears to be involved in the development of chronic intestinal inflammation. The IL-23/Th17 axis may be a critical driver of this chronic inflammation. This review summarizes the main aspects of IL-23's biological function, cytokines that control cytokine production, effectors of the IL-23 response, and the molecular mechanisms associated with IBD pathogenesis. Although IL-23 modulates and impacts the development, course, and recurrence of the inflammatory response, the etiology and pathophysiology of IBD are not completely understood, but mechanism research shows huge potential for clinical applications as therapeutic targets in IBD treatment.

Changes in health-related quality of life and associations with improvements in clinical efficacy: a Phase 2 study of mirikizumab in patients with ulcerative colitis

OBJECTIVE

Mirikizumab, a monoclonal antibody targeting the interleukin-23 p19 subunit, was effective in a Phase 2 study (NCT02589665) of moderately-to-severely active ulcerative colitis (UC). We studied mirikizumab's impact on health-related quality of life (HRQoL).

DESIGN

HRQoL was evaluated using the Inflammatory Bowel Disease Questionnaire (IBDQ) and 36-Item Short Form Health Survey (SF-36) Physical Component Score (PCS) and Mental Component Score (MCS). Mixed effects models for repeated measures compared score changes between mirikizumab and placebo groups. Additional analyses evaluated associations between HRQoL score changes and achievement of efficacy endpoints at weeks 12 and 52.

RESULTS

At week 12, IBDQ improved compared with placebo for all mirikizumab groups except mirikizumab 50 mg (50 mg, p=0.073; 200 mg, p<0.001; 600 mg, p<0.001). SF-36 PCS was significantly higher in all mirikizumab groups at week 12 (50 mg, p=0.011; 200 mg, p=0.022; 600 mg, p=0.002); MCS was significantly higher in mirikizumab 200 and 600 mg groups compared with placebo (50 mg, p=0.429; 200 mg, p=0.028; 600 mg, p<0.001). Achievement of clinical response and remission were associated with greater HRQoL improvements at week 12. Improvements in HRQoL scores were sustained through week 52. Of the clinical symptoms evaluated, reduction in rectal bleeding was associated with greater improvements in IBDQ and SF-36 scores.

CONCLUSION

Mirikizumab improved HRQoL in patients with moderately-to-severely active UC.

Inflammatory Bowel Disease: A Review of Pre-Clinical Murine Models of Human Disease

Crohn’s disease (CD) and ulcerative colitis (UC) are both highly inflammatory diseases of the gastrointestinal tract, collectively known as inflammatory bowel disease (IBD). Although the cause of IBD is still unclear, several experimental IBD murine models have enabled researchers to make great inroads into understanding human IBD pathology. Here, we discuss the current pre-clinical experimental murine models for human IBD, including the chemical-induced trinitrobenzene sulfonic acid (TNBS) model, oxazolone and dextran sulphate sodium (DSS) models, the gene-deficient I-kappa-B kinase gamma (Iκκ-γ) and interleukin(IL)-10 models, and the CD4⁺ T-cell transfer model. We offer a comprehensive review of how these models have been used to dissect the etiopathogenesis of disease, alongside their limitations. Furthermore, the way in which this knowledge has led to the translation of experimental findings into novel clinical therapeutics is also discussed.

The Treatment with Interleukin 17 Inhibitors and Immune-Mediated Inflammatory Diseases

IL-17 inhibitors (IL-17i) are medicines used to treat dermatological and rheumatic diseases They belong to a class of medicines called biological disease-modifying anti-rheumatic drugs (bDMARDs). This class of drugs has had a major impact on the therapy of autoimmune diseases, being much safer and more effective than treatment with small molecules. At the same time, they have highly beneficial effects on skin and joint changes, and their efficacy has been extensively monitored and demonstrated in numerous clinical trials. More and more such drugs are still being discovered today to ensure the best possible treatment of these patients, but more frequently and relatively constantly three agents are used. Two of them (Secukinumab and Ixekizumab) inhibit IL-17A directly, and the third, Brodamulab, inhibits the IL-17A receptor. Although they are extremely effective in the treatment of these diseases, sometimes their administration has been associated with paradoxical effects, i.e., there is an exacerbation of the inflammatory process. Tough, clinical trials of IL-17i have described cases of exacerbation or even onset of inflammatory bowel disease (IBD), such as Crohn's disease and ulcerative colitis, after administration of these drugs in patients previously diagnosed with psoriasis (PS), psoriatic arthritis (PsA), or ankylosing spondylitis (AS). The pathophysiological mechanism of action is not well understood at present. One explanation would be that this hyperreactive inflammatory process would be triggered by Interferon 1 derived from dendritic plasma cells. Even though there are many reports in the recent literature about the role of IL17i in the onset of IBD, conclusions of studies do not converge. Some of them show an increased incidence of IBD in patients treated with IL17i, while some others affirm their safety of them. In the near future we will surely have more data emerging from ongoing meta-analyses regarding safety of use IL17i in patients who are at risk of developing IBD. Clinical and paraclinical evaluation (inflammatory intestinal markers) are carefully advised before recommending treatment with IL-17i and after initiation of treatment, and prospective surveillance by clinical and biomarkers of patients treated with IL-17i is absolutely essential to capture the onset of IBD.

Serum Interleukin (IL)-23 and IL-17 Profile in Inflammatory Bowel Disease (IBD) Patients Could Differentiate between Severe and Non-Severe Disease

Interleukin (IL)-17 and IL-23 are crucial for mediating gut mucosal inflammation in inflammatory bowel disease (IBD), which has led to new therapeutic strategies. We assessed the relevancy of IL-17 and IL-23 serum levels as potential biomarkers towards severe IBD discrimination and disease-related complications. Sixty-two patients diagnosed with Crohn's disease (CD) and ulcerative colitis (UC) were included. Serum IL-17 and IL-23 were measured by sandwich enzyme-linked immunosorbent assays (ELISA). IL-23 and fecal calprotectin (FCal) were significantly higher in severe CD (p < 0.001) and UC (p < 0.001 and p = 0.001, respectively), compared to mild or moderate. Elevated C-reactive protein (CRP) was correlated with severe disease only in CD (p = 0.008), whereas for UC, disease severity was associated with increased IL-17 values (p < 0.001). Diagnostic role of IL-23 was superior to FCal in discriminating between severe and mild to moderate CD (p < 0.001). IL-23 levels were also significantly higher in CD patients with intestinal complications (p = 0.04). Both IL-17 and IL-23 correlate with IBD severity, and IL-23 might be a promising novel biomarker for severe CD. Identifying the dominant IL pathway involved in IBD severity could serve as guidance for clinical decision-making on biologic therapy.

The IL23-IL17 Immune Axis in the Treatment of Ulcerative Colitis: Successes, Defeats, and Ongoing Challenges

Ulcerative colitis (UC) is a chronic relapsing disorder of the colonic tract, characterized by a dysregulated innate and adaptive immune response to gut microbiota that contributes to the perpetuation of intestinal inflammatory processes. The Interleukin (IL) 23/IL17 axis has been reported to play a key role in UC pathogenesis promoting Th17 cells and cytokines-related immune response. Recently, the blockade of IL23/IL17 pathways has been raised enormous interest in the treatment o several chronic inflammatory disorders. In this review, we summarize the emerging results from clinical trials that evoked both promise and discouragement in IL23/IL17 axis in the treatment of UC. Targeting IL23 p40 through Ustekinumab results safe and effective to induce and maintain clinical remission, low inflammatory indexes, mucosal healing, and a better quality of life. Studies targeting IL23 p19 through Mirikizumab, Risankizumab, Brazikumab and Guselkumab are still ongoing. To date, no clinical studies targeting IL17 pathway are ongoing in UC. IL-17 targeting is thought to have a context-dependent biological effect, based on whether cytokine is selectively targeted or if its function is dampened by the upstream block of IL23.

Haptoglobin and Its Related Protein, Zonulin-What Is Their Role in Spondyloarthropathy?

Haptoglobin (Hp) is an acute phase protein which supports the immune response and protects tissues from free radicals. Its concentration correlates with disease activity in spondyloarthropathies (SpAs). The Hp polymorphism determines the functional differences between Hp1 and Hp2 protein products. The role of the Hp polymorphism has been demonstrated in many diseases. In particular, the Hp 2-2 phenotype has been associated with the unfavorable course of some inflammatory and autoimmune disorders. Its potential role in modulating the immune system in SpA is still unknown. This article contains pathophysiological considerations on the potential relationship between Hp, its polymorphism and SpA.

All are Equal, Some are More Equal: Targeting IL 12 and 23 in IBD - A Clinical Perspective

Chronic inflammatory diseases like inflammatory bowel diseases (IBD) or psoriasis represents a worldwide health burden. Researchers provided great achievements in understanding the origin of these diseases leading to improved therapeutic options. The discovery of cytokines like tumor necrosis factor-α or transforming growth factor-β are examples for these efforts. Interleukin 12 (IL 12) and interleukin 23 (IL 23) represent different important cytokines in this regard. They both belong to the interleukin 12 family and are related by sharing the subunit p40. Ustekinumab is an antibody that blocks p40 and thereby interleukins 12 and 23. Trials showed promising results in treating IBD patients with this drug. Consequently, new questions arose about the distinct features of IL 12 and 23. This review focuses on these interleukins regarding their functions in the healthy and inflamed gut and provides an overview about the results from in vitro and in vivo studies as well as clinical trials.

Biomarkers in Inflammatory Bowel Disease-Associated Spondyloarthritis: State of the Art and Unmet Needs

Inflammatory bowel disease-associated spondyloarthritis is a systemic disease characterized by the chronic inflammation of both the gastrointestinal tract and the musculoskeletal system. Since inflammatory bowel disease-associated spondyloarthritis has been associated with a significant diagnostic delay, which may lead to poor quality of life and progression of joint damage, efforts to discover new reliable and noninvasive diagnostic biomarkers have been made. We reviewed the state of the art of biomarker research in inflammatory bowel disease-associated spondyloarthritis, showing that to date it has been largely unsatisfactory. Only a few of the biomarkers that have been investigated are likely to enter the clinical practice upon further validation in independent cohorts. The research of new and innovative biomarkers for inflammatory bowel disease-associated spondyloarthritis is warranted.

Cytokines and integrins related to inflammation of joint and gut in patients with spondyloarthritis and inflammatory bowel disease

Objectives

Inflammatory bowel disease (IBD) and spondyloarthritis (SpA) have some overlapping clinical features, i.e. gut and joint inflammation. Cytokines of interleukin 17(IL-17)/IL-23 axis play a pathogenic role in both diseases. Integrins (ITGs) regulate migration of immune cells to inflamed tissues (ITGβ7 into gut, ITGβ2 into gut and also to other tissues). In this study, we search for differences in the serum concentrations of these cytokines and integrins between patients suffering from SpA or IBD with and without overlapping symptoms.

Material and methods

Patients with SpA (n = 30), IBD (n = 68), and healthy volunteers (n = 28) were included in the study. Fourteen SpA patients reported symptoms characteristic for IBD. Spondyloarthritis symptoms were diagnosed in 50% of IBD patients, while other patients of this group reported arthralgia only. Serum concentrations of IL-17, IL-22, IL-23, ITGβ2, and ITGβ7 were measured by specific enzyme-linked immunosorbent assay using commercially available sets. The Mann-Whitney and Spearman’s rank tests were used for intergroup comparison and correlation assessment, respectively.

Results

Comparison of patient groups showed significantly higher serum concentrations of IL-17, IL-22, and ITGβ7 in SpA, and up-regulated levels of IL-23 in IBD patients. Similar differences were observed between patient subgroups, both with and without overlapping symptoms. In SpA but not in IBD patients, serum concentrations of ITGβ7 inversely correlated (r = –0.552) with C-reactive protein.

Conclusions

Patients with SpA and IBD differ in the circulating concentrations of IL-17/IL-23 axis cytokines and ITGβ7, irrespectively of the presence or absence of overlapping symptoms. Therefore, we conclude that observed differences are attributed rather to underlying than concurrent disease.

Ustekinumab in treatment of Crohn's disease: design, development, and potential place in therapy

Crohn’s disease is characterized by a dysregulation of both innate and adaptive immunity responses. Interleukin-12/23 (IL-12/23) pathway has been found to be a major driver of inflammation in adaptive immune responses. Ustekinumab is a fully human immunoglobulin G1 kappa monoclonal antibody that blocks the p40 subunit of IL-12 and IL-23 and prevents their interaction with their cell surface receptor and further cytokine activation. It is currently approved in the management of plaque psoriasis and psoriatic arthritis. Very promising data have emerged through phase II and phase III trials (UNITI-1, UNITI-2, and IM-UNITI) for both induction and maintenance of clinical response and remission in moderate-to-severe Crohn’s disease, resulting in approval by the Food and Drug Administration for this condition. This article reviews the immunology of the IL-12/23 pathway, available data regarding the initial designing of ustekinumab, drug development through clinical trials including pharmacokinetics, efficacy, and safety, and its potential place in the treatment of Crohn’s disease.

Subclinical sacroiliitis in brucellosis. Clinical presentation and MRI findings

PURPOSE

The aim of this work was to detect subclinical sacroiliac joint involvement in patients with brucellosis and study their clinical and laboratory features.

PATIENTS AND METHODS

The study included 100 brucellosis patients being followed-up in the Gastroenterology and Hepatology Unit, Theodor Bilharz Research Institute and Cairo University outpatient clinics. A thorough history, physical examination, routine laboratory tests, and abdominal ultrasound were obtained for all patients. Extended rheumatological examination was performed including clinical testing for sacroiliitis and enthesitis. None of the patients reported a history of back pain or any symptoms suggestive of sacroiliitis during the course of the infection. Plain x-ray and MRI scan of the sacroiliac joints were performed for all patients.

RESULTS

Asymptomatic sacroiliitis was present in 24 % of the brucellosis patients; none of the patients had tenderness over their spine with preserved lumbar spine mobility. Sacroiliitis was mainly unilateral being bilateral in 20.83 %. There was an obvious relationship with animal contact and occupation of the patients. Osteoarticular involvement was common (67 %) including arthralgias, arthritis, myalgias, spondylitis, enthesitis and bursitis, being clearly higher in those with sacroiliitis. The MRI scan showed blurring of the margins in 66.67 %, widening in 25 %, narrowing in 54.17 %, erosions in 20.83 %, and sclerosis in 12.5 %.

CONCLUSION

Osteoarticular manifestations of brucellosis are prevalent and subclinical sacroiliitis is evident, a finding that may classify these patients as having brucellar spondyloarthropathy (BSA). Referring brucellosis patients for rheumatological assessment has the advantage of early assessment of asymptomatic cases with sacroiliitis which is commonly overlooked.

Gut inflammation and microbiome in spondyloarthritis

Spondyloarthritis (SpA) is chronic inflammatory disease involving joints and the spine. Bowel inflammation is common in SpA, which may be classified as acute or chronic. Chronic gut inflammation is most common in SpA patients with axial involvement as compared to those presenting with peripheral involvement alone. The pathogenesis of gut inflammation in SpA could be explained by two factors-over-activation of immunological cells and altered gut microbiome. This is exemplified by SpA animal models, namely HLA-B27-expressing transgenic animals and SKG mice models. Immunological mechanisms include homing of activated T cells from gut into synovium, excess pro-inflammatory cytokines secretion by immune cells such as IL-23 and genetic variations in immunological genes. The evidence for role of gut microbiome in SpA is gradually emerging. Recently, metagenomic study of gut microbiome by sequencing of microbial nucleic acids has enabled identification of new microbial taxa and their functions in gut of patients with SpA. In SpA, the gut microbiome could emerge as diagnostic and prognostic marker of disease. Modulation of gut microbiome is slated to have therapeutic potential as well.

Mesenchymal stem cells ameliorate experimental autoimmune hepatitis by activation of the programmed death 1 pathway

Previous studies have shown beneficial effects of mesenchymal stem cells (MSCs) transplantation in many autoimmune diseases. However, few studies have focused on the effects of MSCs on autoimmune hepatitis. In our study, we investigated the therapeutic effects of BMSCs (bone mesenchymal stem cells) transplantation in mouse experimental autoimmune hepatitis (EAH) and explored the potential mechanism. BMSCs were injected intravenously into EAH mice. Then, serum levels of ALT and AST, and pathologic alteration of liver tissue were measured to evaluate the liver function and inflammation degree. The expressions of programmed death ligand 1, IL-17 and IL-23 were detected by enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR), and western blotting. Upon serum biochemical levels and pathological examination, the BMSCs-treated mice especially with multiple dosing administration showed significantly reduction of liver damage. Moreover, the expression of IL-17 was down-regulated by BMSCs intervention as compared to the model group, whereas the PD-L1 and IL-23 were up-regulated following the administration of MSCs. In conclusion, the results of this study suggest that BMSCs transplantation, especially on multiple dosing, may exert immunosuppression effect to ameliorate EAH through the inhibition of IL-17 and up-regulation of PD-L1.