Crohn's-like disease in a patient exposed to anti-Interleukin-17 blockade (Ixekizumab) for the treatment of chronic plaque psoriasis: a case report

Bimekizumab safety in patients with moderate-to-severe plaque psoriasis: pooled data from up to 3 years of treatment in randomized phase III trials

BACKGROUND

Patients with psoriasis require long-term management; therefore, understanding the long-term safety of new treatments, such as bimekizumab (BKZ), is crucial.

OBJECTIVES

To evaluate BKZ's 3-year safety profile in patients with moderate-to-severe plaque psoriasis.

METHODS

Three years of safety data were pooled from three phase III trials (BE VIVID, BE READY and BE SURE) and their ongoing open-label extension (BE BRIGHT). Treatment-emergent adverse events (TEAEs) are reported using exposure-adjusted incidence rates (EAIRs) per 100 patient-years (PY).

RESULTS

In total, 1495 patients received at least one BKZ dose; total BKZ exposure was 3876.4 PY. The overall EAIR of TEAEs was 175.5/100 PY and decreased with longer exposure to BKZ. The most commonly reported TEAEs were nasopharyngitis, oral candidiasis and upper respiratory tract infection (EAIRs of 15.0/100 PY, 10.1/100 PY and 6.5/100 PY, respectively); 99.3% of oral candidiasis events were mild or moderate in severity, none were serious and few led to discontinuation. EAIRs of other TEAEs of interest were low, including serious infections (1.2/100 PY), adjudicated inflammatory bowel disease (0.2/100 PY) and laboratory elevations in aspartate aminotransferase or alanine aminotransferase (> 5 × upper limit of normal: 0.6/100 PY).

CONCLUSIONS

In these analyses pooled across 3 years, no new safety signals were observed with longer exposure to BKZ. The vast majority of oral candidiasis events were mild or moderate in severity, as reported previously.

TH17 cell: a double-edged sword in the development of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic nonspecific inflammatory disease of the gastrointestinal tract, and its pathogenesis has not been fully understood. Extensive dysregulation of the intestinal mucosal immune system is critical in the development and progression of IBD. T helper (Th) 17 cells have the characteristics of plasticity. They can transdifferentiate into subpopulations with different functions in response to different factors in the surrounding environment, thus taking on different roles in regulating the intestinal immune responses. In this review, we will focus on the plasticity of Th17 cells as well as the function of Th17 cells and their related cytokines in IBD. We will summarize their pathogenic and protective roles in IBD under different conditions, respectively, hoping to further deepen the understanding of the pathological mechanisms underlying IBD and provide insights for future treatment.

Ustekinumab as a Treatment for Ixekizumab-Associated New-Onset Crohn's Disease in a Patient with Psoriasis

Interleukin-17 inhibitors are effective treatments for plaque psoriasis. However, these medications have been linked to the development of new-onset inflammatory bowel disease (IBD) and the worsening of existing IBD in some patients. This case report describes a patient with plaque psoriasis who developed new-onset Crohn's disease after treatment with ixekizumab, an interleukin-17A inhibitor. He was then transitioned to ustekinumab, which resulted in successful remission of both psoriasis and Crohn's disease. This case highlights the potential for ustekinumab to be an effective rescue treatment for psoriasis patients with new-onset IBD triggered by medications.

Ixekizumab for the treatment of moderate-to-severe plaque psoriasis: the first septennium

Ixekizumab is a humanized monoclonal antibody that specifically inhibits IL-17A. It has been approved for the treatment of adult and pediatric psoriasis, psoriatic arthritis and axial spondyloarthropathies by the US FDA and the EMA. Phase III trials, post hoc analyses and real-life data have reported its efficacy, effectiveness and safety. This review summarizes the latest evidence on the clinical efficacy, pharmacology and safety profile of ixekizumab for the treatment of moderate-to-severe psoriasis. A literature search was performed for articles published through December 2022. Ixekizumab is one of the most efficacious biologics for psoriasis, with a rapid onset of response, favorable long-term outcomes and an adequate safety profile.

Drug-induced entero-colitis due to interleukin-17 inhibitor use; capsule endoscopic findings and pathological characteristics: A case report

BACKGROUND

Interleukin-17 (IL-17) inhibitors are known to cause exacerbation or new onset of inflammatory bowel disease upon administration. However, few reports have described characteristic endoscopic and histopathologic findings, and no small intestinal lesions have been reported so far.

CASE SUMMARY

A woman in her 60s with psoriasis was administered ixekizumab (IXE), an anti-IL-17A antibody, for the treatment of psoriasis. Twenty months after commencing treatment, the patient visited our hospital because of persistent diarrhea. Blood tests performed at the time of the visit revealed severe inflammation, and colonoscopy revealed multiple round ulcers throughout the colon. A tissue biopsy of the ulcer revealed infiltration of inflammatory cells and granuloma-like findings in the submucosal layer. Capsule endoscopy revealed multiple jejunal erosions. After the withdrawal of IXE, the symptoms gradually improved, and ulcer reduction and scarring of the colon were endoscopically confirmed.

CONCLUSION

To the best of our knowledge, 17 reports have documented IL-17 inhibitor-induced entero-colitis with endoscopic images, endoscopic findings, and pathological characteristics, including the present case. Nine of these cases showed diffuse loss of vascular pattern, coarse mucosa/ulcer formation in the left colon, and endoscopic findings similar to those of ulcerative colitis. In the remaining eight cases, discontinuous erosions and ulcerations from the terminal ileum to the rectum were seen, with endoscopic findings similar to those of Crohn's disease. In this case, the findings were confirmed by capsule endoscopy, which has not been previously reported.

An Insight on the Possible Association between Inflammatory Bowel Disease and Biologic Therapy with IL-17 Inhibitors in Psoriasis Patients

Psoriasis is a chronic, inflammatory, multisystemic disease which affects approximately 2-3% of the population globally, whose onset is triggered by genetic and environmental factors which activate both dendritic cells and keratinocytes, resulting in the production of proinflammatory cytokines such as tumor necrosis factor alpha, interleukin 17, interleukin 23, interleukin 22, and interleukin 1β. An in-depth understanding of the pathophysiology of psoriasis led to significant advances in the development of safe and efficient novel therapeutic options, with four classes of biologic therapy being approved for the management of moderate to severe psoriasis: tumor necrosis factor alpha inhibitors, interleukin 23 inhibitors, anti-interleukin 12/23 agents, anti-interleukin 17 agents, as well as small-molecule inhibitors, such as apremilast. Psoriasis is associated with comorbid conditions, namely psoriatic arthritis, cardiovascular disease, metabolic syndrome, psychiatric disorders, malignancy, as well as inflammatory bowel disease. For patients affected by both psoriasis and inflammatory bowel disease, there is a strong recommendation to avoid IL-17 inhibitors since they may play a part in the exacerbation of the gastrointestinal disease. Our aim was to perform a thorough literature review regarding the development of inflammatory bowel disease lesions in psoriasis patients treated with IL-17 inhibitors, along with a case presentation to emphasize the need for close follow-up of these patients.

IL-17-driven induction of Paneth cell antimicrobial functions protects the host from microbiota dysbiosis and inflammation in the ileum

Interleukin (IL)-17 protects epithelial barriers by inducing the secretion of antimicrobial peptides. However, the effect of IL-17 on Paneth cells (PCs), the major producers of antimicrobial peptides in the small intestine, is unclear. Here, we show that the targeted ablation of the IL-17 receptor (IL-17R) in PCs disrupts their antimicrobial functions and decreases the frequency of ileal PCs. These changes become more pronounced after colonization with IL-17 inducing segmented filamentous bacteria. Mice with PCs that lack IL-17R show an increased inflammatory transcriptional profile in the ileum along with the severity of experimentally induced ileitis. These changes are associated with a decrease in the diversity of gut microbiota that induces a severe ileum pathology upon transfer to genetically susceptible mice, which can be prevented by the systemic administration of IL-17a/f in microbiota recipients. In an exploratory analysis of a small cohort of pediatric patients with Crohn's disease, we have found that a portion of these patients exhibits a low number of lysozyme-expressing ileal PCs and a high ileitis severity score, resembling the phenotype of mice with IL-17R-deficient PCs. Our study identifies IL-17R-dependent signaling in PCs as an important mechanism that maintains ileal homeostasis through the prevention of dysbiosis.

Paradoxical Reactions to Anti-TNFα and Anti-IL-17 Treatment in Psoriasis Patients: Are Skin and/or Gut Microbiota Involved?

Psoriasis is a chronic, immune-mediated, inflammatory disease primarily affecting the skin. It is currently coming to light that patients with psoriasis have disrupted intestinal barrier and often suffer from comorbidities associated with the gastrointestinal tract. Moreover, there is growing evidence of both cutaneous and intestinal paradoxical reactions during biologic treatment in patients with psoriasis. This review focuses on barrier defects and changes in immune responses in patients with psoriasis, which play an important role in the development of the disease but are also influenced by modern biological treatments targeting IL-17 and TNFα cytokines. Here, we highlight the relationship between the gut-skin axis, microbiota, psoriasis treatment, and the incidence of paradoxical reactions, such as inflammatory bowel disease in patients with psoriasis. A better understanding of the interconnection of these mechanisms could lead to a more personalized therapy and lower the incidence of treatment side effects, thereby improving the quality of life of the affected patients.

Biologic and Small-Molecule Therapies for Moderate-to-Severe Psoriasis: Focus on Psoriasis Comorbidities

Psoriasis is a systemic immune-mediated disease associated with an increased risk of comorbidities, such as psoriatic arthritis, cardiovascular disease, metabolic syndrome, inflammatory bowel disease, psychiatric disorders, and malignancy. In recent years, with the advent of biological agents, the efficacy and safety of psoriasis treatments have dramatically improved. Presently, tumor necrosis factor-α inhibitors, interleukin-17 inhibitors, interleukin-12/23 inhibitors, and interleukin-23 inhibitors are approved to treat moderate-to-severe psoriasis. Small-molecule inhibitors, such as apremilast and deucravacitinib, are also approved for the treatment of psoriasis. Although it is still unclear, systemic agents used to treat psoriasis also have a significant impact on its comorbidities by altering the systemic inflammatory state. Data from clinical trials and studies on the safety and efficacy of biologics and small-molecule inhibitors provide important information for the personalized care and treatment for patients with psoriasis. Notably, treatment with interleukin-17 inhibitors is associated with new-onset or exacerbations of inflammatory bowel disease. In addition, great caution needs to be taken when using tumor necrosis factor-α inhibitors in patients with psoriasis with concomitant congestive heart failure, multiple sclerosis, and malignancy. Apremilast may induce weight loss as an adverse effect, presenting also with some beneficial metabolic actions. A better understanding of the characteristics of biologics and small-molecule inhibitors in the treatment of psoriasis comorbidities can provide more definitive guidance for patients with distinct comorbidities.

IL-17 inhibitor-associated inflammatory bowel disease: A study based on literature and database analysis

Objective: Few real-world studies have shown clear association between interleukin (IL)-17 inhibitors and inflammatory bowel disease (IBD) onset. This study investigated the reporting prevalence and evaluated the clinical features and management of IL-17 inhibitor-related IBD events. Methods: We used the US FDA Adverse Event Reporting System database and retrieved data, from 2015 to 2022, on IL-17 inhibitors to identify gastrointestinal inflammatory events and conduct disproportionality analyses by estimating the reporting odds ratios (RORs) and corresponding 95% confidence intervals (CIs). Furthermore, case reports and case series, from 2015 to 30 November 2022, on IBD induced by IL-17 inhibitors were collected for retrospective analysis. Results: A total of 388 cases of primary suspected IL-17 inhibitor-associated gastrointestinal events were reported (268 IBD and 120 colitis), including 348 cases involving secukinumab (SEC), 36 cases involving ixekizumab (IXE), and 4 cases involving brodalumab (BRO). Statistically significant reporting rates of total IBD events were observed for SEC and IXE (ROR = 2.13, 95% CI [1.96-2.30] and ROR = 2.79, 95% CI [2.39-3.27], respectively), whereas BRO did not trigger a safety signal. Twenty-nine studies, which included 34 cases, showed evidence of IBD, following SEC (79.4%) and IXE (20.6%) treatment. The median age was 42 years; typical initial symptoms included diarrhea (90.9%), abdominal pain (57.6%), bloody diarrhea (51.5%), and fever (36.4%). The median time to onset of IBD symptoms was 2.9 months. Some cases were accompanied by elevated white blood cell (WBC) count (87.5%), erythrocyte sedimentation rate (ESR; 85.7%), C-reactive protein (CRP; 100%), and fecal calprotectin (FC; 100%). Cessation of IL-17 inhibitors plus treatment with corticosteroids and TNF antagonists, as either monotherapy or in combination, could lead to complete clinical remission. The median time to remission after IL-17 inhibitor discontinuation was 4 weeks. Conclusion: IL-17 inhibitor treatment is associated with exacerbation and new onset of IBD and colitis. Obtaining a detailed patient history before initiation of treatment and monitoring gastrointestinal symptoms and intestinal inflammatory biomarkers during IL-17 inhibitor treatment is important for safe use of these drugs.

Intestinal Epithelial Responses to IL-17 in Adult Stem Cell-derived Human Intestinal Organoids

BACKGROUND

Th17 cells and their signature cytokine, interleukin-17A [IL-17], are considered as the main pathogenic factors in inflammatory bowel diseases [IBDs]. However, IL-17 neutralising antibodies, a theoretically curative medication for IBDs, paradoxically aggravated intestinal inflammation. The mechanisms by which IL-17 mediates the protective and pathological effects of IL-17 remain unclear in the intestinal epithelium.

METHODS

The intestinal epithelial responses induced by IL-17 were evaluated using the human small intestinal organoid [enteroid] model.

RESULTS

Organoid-forming efficiency, cell viability, and proliferation of enteroids were decreased in proportion to IL-17 concentration. The IL-17 induced cytotoxicity was predominantly mediated by pyroptosis with activation of CASP1 and cleavage of GSDMD. Bulk RNA-sequencing revealed the enrichment of secretion signalling in IL-17 treated enteroids, leading to mucin exocytosis. Among its components, PIGR was up-regulated significantly as the concentration of IL-17 increased, resulting in IgA transcytosis. Mucin exocytosis and IgA transcytosis have a protective role against enteric pathogens. Single-cell RNA sequencing identified that CASP1-mediated pyroptosis occurred actively in intestinal stem cells [ISCs] and enterocytes. IL-17 neutralising antibody completely restored IL-17 induced cytotoxicity, but suppressed mucin secretion and IgA transcytosis. Pyroptosis inhibition using CASP1 inhibitors significantly improved IL-17 induced cytotoxicity without diminishing its beneficial effects.

CONCLUSIONS

IL-17 induces the pyroptosis of ISCs and enterocytes, as well as mucin secretion of goblet cells and IgA transcytosis of epithelial cells. Paradoxical gastrointestinal effects of IL-17 neutralising antibodies may be associated with inhibition of mucin secretion and IgA transcytosis. The inhibition of pyroptosis using CASP1 inhibitors prevents IL-17 induced cytotoxicity without compromising its beneficial effects.

Arid5a Mediates an IL-17-Dependent Pathway That Drives Autoimmunity but Not Antifungal Host Defense

IL-17 contributes to the pathogenesis of certain autoimmune diseases, but conversely is essential for host defense against fungi. Ab-based biologic drugs that neutralize IL-17 are effective in autoimmunity but can be accompanied by adverse side effects. Candida albicans is a commensal fungus that is the primary causative agent of oropharyngeal and disseminated candidiasis. Defects in IL-17 signaling cause susceptibility to candidiasis in mice and humans. A key facet of IL-17 receptor signaling involves RNA-binding proteins, which orchestrate the fate of target mRNA transcripts. In tissue culture models we showed that the RNA-binding protein AT-rich interaction domain 5A (Arid5a) promotes the stability and/or translation of multiple IL-17-dependent mRNAs. Moreover, during oropharyngeal candidiasis, Arid5a is elevated within the oral mucosa in an IL-17-dependent manner. However, the contribution of Arid5a to IL-17-driven events in vivo is poorly defined. In this study, we used CRISPR-Cas9 to generate mice lacking Arid5a. Arid5a -/- mice were fully resistant to experimental autoimmune encephalomyelitis, an autoimmune setting in which IL-17 signaling drives pathology. Surprisingly, Arid5a -/- mice were resistant to oropharyngeal candidiasis and systemic candidiasis, similar to immunocompetent wild-type mice and contrasting with mice defective in IL-17 signaling. Therefore, Arid5a-dependent signals mediate pathology in autoimmunity and yet are not required for immunity to candidiasis, indicating that selective targeting of IL-17 signaling pathway components may be a viable strategy for development of therapeutics that spare IL-17-driven host defense.

Review of secukinumab-induced adverse events of special interest and its potential pathogenesis

Although secukinumab has demonstrated high efficacy and favorable safety in moderate-to-severe psoriasis and psoriatic arthritis, patients developing adverse events of special interest (AESI) were reported increasingly in real-world practice. A systematic literature search of the PubMed database was conducted to identify clinical studies or case reports on secukinumab-induced AESI. More than 1077 patients (aged 18-74 years) from 55 studies were reported to have 24 AESI 3 days to 96 weeks after secukinumab treatment. The four most common AESI was inflammatory bowel disease (n > 1000), eczematous drug eruption (n > 30), drug-associated vasculitis (n = 8), and drug-induced lupus erythematosus (n = 4). Most of these AESI were only mild to moderately severe and resolved after secukinumab discontinuation without or with symptomatic treatment. Secukinumab has the potential to develop a number of AESI by probably dysregulating the different expression of polar T-cell axes (Th1, Th2, Th17, Th22, and/or Treg) and driving various cytokines in some patients. Physicians should be aware of these AESI for timely diagnosis and proper treatment. This article is protected by copyright. All rights reserved.

Bimekizumab Safety in Patients With Moderate to Severe Plaque Psoriasis: Pooled Results From Phase 2 and Phase 3 Randomized Clinical Trials

Importance

Psoriasis is a chronic disease requiring long-term management; understanding the long-term safety profiles of psoriasis treatments, such as bimekizumab, is important.

Objective

To evaluate the 2-year safety profile of bimekizumab in patients with moderate to severe plaque psoriasis.

Design, Setting, and Participants

Safety data were pooled from a cohort of patients from 4 phase 2 randomized clinical trials (BE ABLE 1, BE ABLE 2, PS0016, and PS0018) and 4 phase 3 randomized clinical trials (BE VIVID, BE READY, BE SURE, and BE BRIGHT) to include 2 years of study treatment. Data were obtained on adults with moderate to severe plaque psoriasis (Psoriasis Area and Severity Index level ≥12, ≥10% body surface area affected by psoriasis, and an Investigator's Global Assessment score ≥3 on a 5-point scale) who were eligible for systemic psoriasis therapy and/or phototherapy.

Interventions

Included patients received 1 or more doses of bimekizumab during the phase 2 or phase 3 trials.

Main Outcomes and Measures

Treatment-emergent adverse events (TEAEs), serious TEAEs, and TEAEs leading to treatment discontinuation are reported using exposure-adjusted incidence rates (EAIRs) per 100 person-years.

Results

A total of 1789 patients (1252 [70.0%] men; mean [SD] age, 45.2 [13.5] years) were treated with 1 or more doses of bimekizumab across the phase 2/3 trials and were included in these analyses; total bimekizumab exposure was 3109.7 person-years. TEAEs occurred at an EAIR of 202.4 per 100 person-years and did not increase with longer duration of bimekizumab exposure. The 3 most frequently reported TEAEs were nasopharyngitis (19.1 per 100 person-years; 95% CI, 17.4-20.9 per 100 person-years), oral candidiasis (12.6 per 100 person-years; 95% CI, 11.3-14.0 per 100 person-years), and upper respiratory tract infection (8.9 per 100 person-years; 95% CI, 7.8-10.1 per 100 person-years). Most oral candidiasis events were mild or moderate; 3 events led to discontinuation. The EAIRs of inflammatory bowel disease (0.1 per 100 person-years; 95% CI, 0.0-0.3 per 100 person-years), adjudicated suicidal ideation and behavior (0.0 per 100 person-years; 95% CI, 0.0-0.2 per 100 person-years), and adjudicated major adverse cardiac events (0.5 per 100 person-years; 95% CI, 0.3-0.8 per 100 person-years) were low.

Conclusions and Relevance

In these pooled analyses of data from a cohort of patients from 8 randomized clinical trials, bimekizumab was well tolerated aside from an increased incidence of mild to moderate oral candidiasis. No safety signals were observed compared with previous reports, and there was no increased risk of AEs with longer duration of bimekizumab exposure.

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.

Therapeutic agents affecting the immune system and drug-induced inflammatory bowel disease (IBD): A review on etiological and pathogenetic aspects

In recent years, therapeutic agents affecting the immune system have been largely implemented in the treatment of various hematological, rheumatological and dermatological disorders. Their clinical use has offered important benefits for affected patients and has also ameliorated clinical outcome and prognosis in many cases. Nonetheless, as any treatment, the use of these drugs may be associated with side effects. One of the target organs in such cases is the gastrointestinal tract. In particular, the exacerbation or the onset of inflammatory bowel disease (IBD) in treated patients is not infrequent, although the mechanism of action of these agents may be different. In this review we will focus on the use of therapeutic agents affecting the immune system and the development or exacerbation of IBD, with a mention on the possible underlying pathogenetic mechanisms.

Severe drug-associated colitis with Crohn's features in setting of ixekizumab therapy for chronic plaque psoriasis

Background

Ixekizumab is monoclonal antibody targeted against interleukin-17 (IL-17) and has been approved for use in chronic plaque psoriasis. Despite its efficacy in treating psoriasis, concerns have been raised regarding Ixekizumab’s potential to induce and exacerbate inflammatory bowel disease (IBD).

Case presentation

Here we report the new onset of severe drug-associated colitis with surgical complications in a 45-year-old male patient who was receiving Ixekizumab therapy for chronic plaque psoriasis. Review of the patient’s colonic pathology demonstrated acute inflammatory changes with features of Crohn’s disease. The patient remained disease-free 9-months following his hospitalization and cessation of Ixekizumab.

Conclusions

This case raises suspicion for an association between Ixekizumab and IBD and calls on clinicians to have heightened awareness of potential risks before prescribing anti-IL-17 agents.

Gastroenterological safety of IL-17 inhibitors: a systematic literature review

INTRODUCTION

Interleukin 17 is a proinflammatory cytokine considered to play a significant role in the immunopathogenesis of many chronic immune-mediated disorders. Interleukin 17 inhibitors provide an excellent treatment option for patients with psoriasis, psoriatic arthritis, or ankylosing spondylitis. However, Interleukin 17 inhibitors have been suspected of worsening or triggering new-onset inflammatory bowel disease.

AREAS COVERED

A literature search was conducted until March 2021 to investigate reporting prevalence, and characteristics of all gastroenterological adverse events in patients treated with Interleukin 17 inhibitors. One hundred and six clinical randomized trials were included, involving 40,053 patients. Inflammatory bowel disease cases were reported in 0.4% of patients exposed to Interleukin 17 inhibitors. The most frequent other gastrointestinal adverse events were diarrhea (2.5%), nausea or vomiting (0.7%), and gastroenteritis (0.2%). Sixty-one uncontrolled or retrospective studies were included, involving 16,791 patients. Sixty (0.36%) inflammatory bowel disease cases were reported, 0.6% of patients reported other gastrointestinal adverse events.

EXPERT OPINION

Interleukin 17 inhibitors are safe and effective in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis. Low incidence rate of developing new-onset inflammatory bowel disease or exacerbating preexisting inflammatory bowel disease with anti-IL-17 agents has been reported. Clinicians should be aware of the possibility of these concerns when considering this therapy.

An immuno-blocking agent targeting IL-1β and IL-17A reduces the lesion of DSS-induced ulcerative colitis in mice

In recent decades when biological agents have flourished, a part of patients suffering from inflammatory bowel disease (IBD) have received the treatment of tumor necrosis factor inhibitors or IL-1 antibodies. This study aims to investigate the anti-colitis effects of bispecific antibody (FL-BsAb1/17) targeting IL-1β and IL-17A comparing with TNF-α soluble receptor medicine etanercept. IBD model in mice was established by drinking 3% DSS (dextran sulfate sodium salt). On the first day of drinking DSS, treatments with etanercept (5 mg/kg) or different doses of FL-BsAb1/17 (1 mg/kg, 5 mg/kg, and 10 mg/kg) were started by intraperitoneal injection every other day. The results demonstrated that FL-BsAb1/17 treatment was more effective than etanercept at the same dose (5 mg/kg) in relieving the typical symptom of ulcerative colitis induced by DSS (such as the severity score and intestinal shortening), and down-regulating the expression of inflammatory factors (IL-17A, IL-6, IL-12, IL-22, IL-1β, IL-23, TNF-α) in the serum and colon. FL-BsAb1/17 could also reduce the degree of intestinal fibrosis. The same dose of FL-BsAb1/17 (5 mg/kg) performed better than etanercept in down-regulating MDA and up-regulating SOD (superoxide dismutase), CAT (catalase), and T-AOC (total antioxidant capacity) in serum. Both FL-BsAb1/17 and etanercept could reduce the transcription of Bax and increase the transcription of Bcl-2 and slow down apoptosis in colitis colon tissue. We conclude that the blocking of IL-1β and IL-17A can inhibit DSS-induced ulcerative colitis and FL-BsAb1/17 may have potential to become a new dual-target candidate for colitis treatment.

Interleukin-17 and Interleukin-23: A Narrative Review of Mechanisms of Action in Psoriasis and Associated Comorbidities

Psoriasis is an immune-mediated inflammatory skin disease associated with numerous inflammatory comorbidities, including increased cardiovascular risk. The interleukin (IL)-23/IL-17 axis plays a central role in the immunopathogenesis of psoriasis and related comorbidities by acting to stimulate keratinocyte hyperproliferation and feed-forwarding circuits of perpetual T cell-mediated inflammation. IL-17 plays an important role in the downstream portion of the psoriatic inflammatory cascade. This review discusses the distinct mechanisms of action of IL-17 and IL-23 in the immunopathogenesis of psoriasis and related comorbidities plus the significant therapeutic benefits of selectively inhibiting these cytokines in patients with moderate to severe plaque psoriasis.

IL-17 Inhibitors and Inflammatory Bowel Diseases: A Postmarketing Study in Vigibase

Several gastrointestinal symptoms and chronic inflammatory bowel diseases (IBDs) have been reported after therapy with IL-17 inhibitors. To date, however, no study has shown a clear association between these drugs and IBD onset. We searched on Vigibase, the worldwide pharmacovigilance database, to investigate reporting prevalence, characteristics, and prognosis of all gastroenterological adverse events in patients treated with IL-17 inhibitors. In total, 1,129 gastrointestinal Individual Case Safety Reports (ICSRs) were identified, including 850 IBD (42.5% Crohn's disease, 31.9% ulcerative colitis, and 25.6% undifferentiated IBD) and 279 colitis (mainly undifferentiated colitis (79.2%), and microscopic colitis (10.4%)). ICSRs were associated with secukinumab (SEC, 83.6%) or ixekizumab (IXE, 16.3%), whereas only one colitis occurred with brodalumab (0.1%). Most IBD and colitis cases were detected within 6 months from therapy start in both the SEC (68.8% and 73.5%) and IXE groups (100% and 66.7%). Patients' outcomes were reported in 428 ICSRs (37.9%). Complete or ongoing recovery from symptoms was detected in about two-thirds of patients experiencing IBD (59.5%) or colitis (64.2%), whereas in the other cases, there was no recovery (33.9% and 29.5%) or there were sequelae (5.4% and 4.2%). Fatal events occurred in four patients (1.2%) in the IBD group (3 after SEC and on1e with IXE) and two SEC-treated subjects in the colitis group (2.1%). Treatment with IL-17 inhibitors is associated with a relevant number of exacerbations and new onset of IBD and colitis. Careful evaluation of gastrointestinal symptoms and the monitoring of intestinal inflammatory biomarkers should be recommended before prescribing these drugs.

A Perspective Of Intestinal Immune-Microbiome Interactions In Alcohol-Associated Liver Disease

Uncovering the intricacies of the gut microbiome and how it interacts with the host immune system has opened up pathways in the search for the treatment of disease conditions. Alcohol-associated liver disease is a major cause of death worldwide. Research has shed light on the breakdown of the protective gut barriers, translocation of gut microbes to the liver and inflammatory immune response to microbes all contributing to alcohol-associated liver disease. This knowledge has opened up avenues for alternative therapies to alleviate alcohol-associated liver disease based on the interaction of the commensal gut microbiome as a key player in the regulation of the immune response. This review describes the relevance of the intestinal immune system, the gut microbiota, and specialized and non-specialized intestinal cells in the regulation of intestinal homeostasis. It also reflects how these components are altered during alcohol-associated liver disease and discusses new approaches for potential future therapies in alcohol-associated liver disease.

Candida albicans and candidalysin in inflammatory disorders and cancer

As our understanding of mycology progresses, the impact of fungal microbes on human health has become increasingly evident. Candida albicans is a common commensal fungus that gives rise to local and systemic infections, particularly in immunocompromised patients where it can result in mortality. However, C. albicans has also been quietly linked with a variety of inflammatory disorders, to which it has traditionally been considered incidental; recent studies may now provide new aspects of these relationships for further consideration. This review provides a novel perspective on the impact of C. albicans and its peptide toxin, candidalysin, on human health, exploring their contributions to pathology within a variety of diseases.

Molecular Genetic Architecture of Monogenic Pediatric IBD Differs from Complex Pediatric and Adult IBD

Inflammatory bowel disease (IBD) manifests as a complex disease resulting from gene-environment interactions or as a monogenic disease resulting from deleterious mutations. While monogenic IBD is predominantly pediatric, only one-quarter of complex IBD is pediatric. In this study, we were the first to systematically compare genetic architecture between monogenic and complex pediatric and adult IBD on genetic and molecular pathway levels. Genes reported as causal for monogenic pediatric IBD and related syndromes and as risk factors for pediatric and adult complex IBD were analyzed using CytoScape and ClueGO software tools to elucidate significantly enriched Gene Ontology (GO) terms. Despite the small overlap (seven genes) between monogenic IBD genes (85) and complex IBD loci (240), GO analysis revealed several enriched GO terms shared between subgroups (13.9%). Terms Th17 cell differentiation and Jak/STAT signaling were enriched in both monogenic and complex IBD subgroups. However, primary immunodeficiency and B-cell receptor signaling pathway were specifically enriched only for pediatric subgroups, confirming existing clinical observations and experimental evidence of primary immunodeficiency in pediatric IBD patients. In addition, comparative analysis identified patients below 6 years of age to significantly differ from complex pediatric and adult IBD and could be considered a separate entity.

Crohn's disease exacerbated by IL-17 inhibitors in patients with psoriasis: a case report

BACKGROUND

Previous studied revealed that psoriasis and Inflammatory bowel disease (IBD) have highly overlapping epidemiological characteristics, genetic susceptibility loci, disease risk factors, immune mechanisms, and comorbidities. More and more biologics have been used to treat psoriasis and IBD. Interleukin (IL)-17 inhibitors played an important role in the treatment of psoriasis, but induced and aggravated inflammatory bowel disease in some patients. IL-23 inhibitors have shown to be effective to both psoriasis and CD.

CASE PRESENTATION

Forty-one year old Chinese male patient who came to the hospital for psoriasis, developed severe gastrointestinal symptoms after using an IL-17 inhibitor, and was diagnosed with Crohn's disease (CD). The patient eventually used an IL-23 inhibitor to relieve both psoriasis and CD.

CONCLUSION

IBD patients and psoriasis patients have increased probability of suffering from the other disease. The case that patients had suffered from psoriasis and CD before the use of IL-17 inhibitor is quite rare. This case suggests that physicians need to be careful when treating patients with psoriasis and CD with biologics, and it is necessary to evaluate the gastrointestinal tract.

Somatic Evolution in Non-neoplastic IBD-Affected Colon

Inflammatory bowel disease (IBD) is a chronic inflammatory disease associated with increased risk of gastrointestinal cancers. We whole-genome sequenced 446 colonic crypts from 46 IBD patients and compared these to 412 crypts from 41 non-IBD controls from our previous publication on the mutation landscape of the normal colon. The average mutation rate of affected colonic epithelial cells is 2.4-fold that of healthy colon, and this increase is mostly driven by acceleration of mutational processes ubiquitously observed in normal colon. In contrast to the normal colon, where clonal expansions outside the confines of the crypt are rare, we observed widespread millimeter-scale clonal expansions. We discovered non-synonymous mutations in ARID1A, FBXW7, PIGR, ZC3H12A, and genes in the interleukin 17 and Toll-like receptor pathways, under positive selection in IBD. These results suggest distinct selection mechanisms in the colitis-affected colon and that somatic mutations potentially play a causal role in IBD pathogenesis.

Paradoxical gastrointestinal effects of interleukin-17 blockers

Secukinumab, ixekizumab and brodalumab are monoclonal antibody therapies that inhibit interleukin (IL)-17 activity and are widely used for the treatment of psoriasis, psoriatic arthritis and ankylosing spondylitis. The promising efficacy results in dermatology and rheumatology prompted the evaluation of these drugs in Crohn's disease and ulcerative colitis, but the onset of paradoxical events (disease exacerbation after treatment with a theoretically curative drug) prevented their approval in patients with inflammatory bowel diseases (IBDs). To date, the pathophysiological mechanisms underlying these paradoxical effects are not well defined, and there are no clear guidelines for the management of patients with disease flare or new IBD onset after anti-IL-17 drug therapy. In this review, we summarise the literature on putative mechanisms, the clinical digestive effects after therapy with IL-17 inhibitors and provide guidance for the management of these paradoxical effects in clinical practice.

"Small" Intestinal Immunopathology Plays a "Big" Role in Lethal Cytokine Release Syndrome, and Its Modulation by Interferon-γ, IL-17A, and a Janus Kinase Inhibitor

Chimeric antigen receptor T cell (CART) therapy, administration of certain T cell-agonistic antibodies, immune check point inhibitors, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2) and Toxic shock syndrome (TSS) caused by streptococcal as well as staphylococcal superantigens share one common complication, that is T cell-driven cytokine release syndrome (CRS) accompanied by multiple organ dysfunction (MOD). It is not understood whether the failure of a particular organ contributes more significantly to the severity of CRS. Also not known is whether a specific cytokine or signaling pathway plays a more pathogenic role in precipitating MOD compared to others. As a result, there is no specific treatment available to date for CRS, and it is managed only symptomatically to support the deteriorating organ functions and maintain the blood pressure. Therefore, we used the superantigen-induced CRS model in HLA-DR3 transgenic mice, that closely mimics human CRS, to delineate the immunopathogenesis of CRS as well as to validate a novel treatment for CRS. Using this model, we demonstrate that (i) CRS is characterized by a rapid rise in systemic levels of several Th1/Th2/Th17/Th22 type cytokines within a few hours, followed by a quick decline. (ii) Even though multiple organs are affected, small intestinal immunopathology is the major contributor to mortality in CRS. (iii) IFN-γ deficiency significantly protected from lethal CRS by attenuating small bowel pathology, whereas IL-17A deficiency significantly increased mortality by augmenting small bowel pathology. (iv) RNA sequencing of small intestinal tissues indicated that IFN-γ-STAT1-driven inflammatory pathways combined with enhanced expression of pro-apoptotic molecules as well as extracellular matrix degradation contributed to small bowel pathology in CRS. These pathways were further enhanced by IL-17A deficiency and significantly down-regulated in mice lacking IFN-γ. (v) Ruxolitinib, a selective JAK-1/2 inhibitor, attenuated SAg-induced T cell activation, cytokine production, and small bowel pathology, thereby completely protecting from lethal CRS in both WT and IL-17A deficient HLA-DR3 mice. Overall, IFN-γ-JAK-STAT-driven pathways contribute to lethal small intestinal immunopathology in T cell-driven CRS.

Is Psoriasis Treatment a Risk Factor for Inflammatory Bowel Disease?

Inflammatory bowel diseases—ulcerative colitis and Crohn’s disease—are linked with several environmental and genetic risk factors. There are also known drugs able to induce de novo disease or to exacerbate its course. Several autoimmune disorders are more frequent in patients with inflammatory bowel diseases, including psoriasis. The aim of the presented review was to summarise current knowledge on the links between psoriasis therapy and inflammatory bowel diseases. The interleukin-17 inhibitors (secukinumab, brodalumab and ixekizumab) and tumour necrosis factor inhibitor (etanercept), have the potential to induce ulcerative colitis and Crohn’s disease de novo or exacerbate existing but silent diseases. There is no evidence that other biologic agents used in psoriasis are lined with such risk. The biologic drugs for psoriasis differ in their potential to induce or worsen inflammatory bowel diseases. Currently, there are no recommendations in European guidelines to screen patients with psoriasis for inflammatory bowel diseases. However, based on available evidence, inflammatory bowel diseases should not be forgotten on in-depth diagnostics in patients with psoriasis.

Inflammatory bowel disease in patients with psoriasis treated with interleukin-17 inhibitors

BACKGROUND

Interleukin 17 (IL-17) inhibitors provide an excellent treatment option for patients with psoriasis and psoriatic arthritis, resulting in high levels of efficacy for skin clearance and joint improvement. Safety has also been established in clinical trials for this group of biologic agents; however, rare case reports of exacerbation or induction of inflammatory bowel disease (IBD) have been reported in the literature. No causal relationship has been established. When IL-17 inhibitors were investigated for the management of IBD, no benefit was found and worsening of disease was noted for some patients. IBD is more common in patients with psoriasis and, therefore, it remains unknown if these drugs cause de novo IBD or if the reported cases of IBD in patients on IL-17 therapy is due to the background risk in this predisposed population who may have already had an underlying or subclinical disease.

METHODS/RESULTS

A literature search was conducted for the terms 'IL-17 inhibitor,' 'ixekizumab,' 'secukinumab,' 'brodalumab' and 'inflammatory bowel disease,' 'ulcerative colitis,' and 'Crohn's disease' in PubMed and Google Scholar. Cases of new-onset or exacerbation of IBD were identified in the literature along with postmarketing pharmacovigilance data. These cases will be reviewed in this paper.

CONCLUSIONS

IL-17 inhibitors have proven efficacy for the treatment of psoriasis and psoriatic arthritis with a strong safety profile. However, rare cases of IBD onset and exacerbation in patients on IL-17 inhibitors have been reported in the literature, highlighting the need to select patients and therapeutic choices appropriately when treating this population.