Pathogenesis Of Immune-mediated Inflammatory Diseases Research Articles

Absolute and Relative Bioavailability of Oral Solid Dosage Formulations of Deucravacitinib in Humans.

itinib is an oral, selective, allosteric inhibitor of tyrosine kinase 2, an intracellular signaling kinase involved in the pathogenesis of immune-mediated inflammatory diseases. The absolute and relative bioavailability (BA) were evaluated in phase 1, open-label studies in healthy adults to assess (1) the absolute BA of the deucravacitinib tablet formulation following single oral administration of a 12-mg tablet and an intravenous microdose infusion of 0.1-mg carbon-13 and nitrogen-15-labeled deucravacitinib ([13 C2 , 15 N3 ] deucravacitinib) solution in 8 subjects, and (2) the relative oral BA of deucravacitinib tablet and capsule formulations at the 3- and 12-mg dose levels in 20 subjects. The absolute oral availability of deucravacitinib in the tablet formulation was near complete at approximately 99%. The total clearance (254mL/min) was low relative to hepatic blood flow, and volume of distribution (∼140L) was greater than total body water, indicating extravascular distribution. Deucravacitinib systemic exposure (maximum plasma concentration, area under the plasma drug concentration curve from time zero to the time of the last quantifiable nonzero concentration, and area under the plasma drug concentration-time curve from time zero extrapolated to infinity) after administration of the tablet formulation were similar to the capsule at the tested 3- and 12-mg doses. In both studies, deucravacitinib was safe with no clinically relevant changes in laboratory values, electrocardiogram parameters, or vital signs.

The role of platelets in immune-mediated inflammatory diseases.

Immune-mediated inflammatory diseases (IMIDs) are characterized by excessive and uncontrolled inflammation and thrombosis, both of which are responsible for organ damage, morbidity and death. Platelets have long been known for their role in primary haemostasis, but they are now also considered to be components of the immune system and to have a central role in the pathogenesis of IMIDs. In patients with IMIDs, platelets are activated by disease-specific factors, and their activation often reflects disease activity. Here we summarize the evidence showing that activated platelets have an active role in the pathogenesis and the progression of IMIDs. Activated platelets produce soluble factors and directly interact with immune cells, thereby promoting an inflammatory phenotype. Furthermore, platelets participate in tissue injury and promote abnormal tissue healing, leading to fibrosis. Targeting platelet activation and targeting theinteraction of platelets with the immune system are novel and promising therapeutic strategies in IMIDs.

Current view on the pathogenesis of immune-mediated inflammatory diseases associated with ocular manifestations

This literature review discusses the new concept of pathogenesis of systemic immune-mediated inflammatory diseases (IMIDs), presents their classification and analyzes their association with ocular manifestations.

Association of class II HLA alleles with susceptibility to develop immune-mediated diseases in Paraguayan patients.

Genetic and nongenetic factors are involved in the pathogenesis of immune-mediated inflammatory diseases (IMIDs). The best-known genetic factor for susceptibility to IMIDs is the human leukocyte antigen (HLA). The aim of the present study was to evaluate the association of HLA class II genes with the risk of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and systemic sclerosis (SSc) in the Paraguayan population. We included 254 patients with IMIDs (101 SLE, 103 RA, and 50 SSc) and 50 healthy controls. The haplotypes of five genes corresponding to HLA class II genes and their relationship to the IMIDs studied were determined. Note that 84.6% were women, with a mean age of 43.4 ± 14 years. Among the associated HLA alleles, we found the previously identified risk factors in other populations like HLA-DRB1*03:01 and HLA-DRB1*14:02 for RA, as well as new ones not previously identified, such as DPA1*02:01 for SLE and, DB1*02:01 for RA and SSc. In the genetic association analysis, already known associations have been replicated, and unpublished associations have been identified in Paraguayan patients with IMIDs. This is the first genetic association study in Paraguayan patients with IMIDs.

TYK2 in Immune Responses and Treatment of Psoriasis.

Tyrosine kinase 2 (TYK2), a key part of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, plays an integral role in the differentiation and immune responses of intrinsic immune cells and regulates the mediation of cytokines. TYK2 leads to inflammatory cascade responses in the pathogenesis of immune-mediated inflammatory diseases (IMIDs), especially psoriasis. Small-molecule TYK2 inhibitors are considered to be an effective strategy for modulating psoriasis. Here, we attempt to review the pro-inflammatory mechanisms of the JAK-STAT signaling pathway, the regulatory roles of TYK2 in the pathogenesis of psoriasis, and provide updates on ongoing and recently completed trials of TYK2 inhibitors.

Gut immune cell trafficking: inter-organ communication and immune-mediated inflammation.

Immune cell trafficking is a complex and tightly regulated process that is indispensable for the body's fight against pathogens. However, it is also increasingly acknowledged that dysregulation of cell trafficking contributes to the pathogenesis of immune-mediated inflammatory diseases (IMIDs) in gastroenterology and hepatology, such as inflammatory bowel disease and primary sclerosing cholangitis. Moreover, altered cell trafficking has also been implicated as a crucial step in the immunopathogenesis of other IMIDs, such as rheumatoid arthritis and multiple sclerosis. Over the past few years, a central role of the gut in mediating these disorders has progressively emerged, and the partly microbiota-driven imprinting of particular cell trafficking phenotypes in the intestine seems to be crucially involved. Therefore, this Review highlights achievements in understanding immune cell trafficking to, within and from the intestine and delineates its consequences for immune-mediated pathology along the gut-liver, gut-joint and gut-brain axes. We also discuss implications for current and future therapeutic approaches that specifically interfere with homing, retention, egress and recirculation of immune cells.

Patterns of T and B cell responses to Mycobacterium tuberculosis membrane-associated antigens and their relationship with disease activity in rheumatoid arthritis patients with latent tuberculosis infection.

This study was aimed at exploring whether latent tuberculosis infection (LTBI) contributes to the pathogenesis of immune-mediated inflammatory diseases in a TB endemic setting. We screened 198 rheumatoid arthritis (RA) patients with tuberculin skin test (TST) and studied 61 (median DAS28-ESR = 6.3) who were positive. Whole blood T cell proliferative responses to Mycobacterium tuberculosis (Mtb) membrane (MtM) antigens, including the latency-induced protein alpha crystallin (Acr), were determined by flow cytometry using Ki67 expression as the marker for nuclear proliferation. Serum antibody levels were determined by ELISA. Follow-up investigations (at 3-6, 9-12 and 15-18 months after baseline) were performed in 41 patients who were classified empirically as 'high' (HR-T/HR-B) or 'low' (LR-T/LR-B) responders based on their dynamic T cell or antibody responses. Significant correlations were seen between baseline T cell responses to MtM and Acr, and between IgG, IgA and IgM antibody responses to MtM. However, no correlation was seen between T and B cell responses. At all time points during the follow-up, T cell responses to both antigens (except for MtM at one point) were significantly higher in HR-T (n = 25) than LR-T (n = 16) patients. Levels of IgA and IgM (but not IgG) antibodies to MtM were also significantly higher in HR-B (n = 13) than LR-B (n = 28) at all time points. Importantly, HR-T patients exhibited significantly higher baseline and follow-up DAS28 scores than LR-T. Ten (of 61) patients had a history of TB and developed RA 6 years (median) after contracting TB. Three new TB cases (1 from TST-positive and 2 from TST-negative groups) emerged during the follow-up. Our results suggest that persistently elevated T cell responses to Mtb antigens may contribute to disease activity in RA.

The role of microbiome in the pathogenesis of immune-mediated inflammatory diseases: controversial issues

Increasing attention in rheumatology is today paid to the detection of diseases at the earliest possible (preclinical) stages, which can contribute to a more favorable response to therapy. The preclinical period of a systemic autoimmune reaction is assumed to be related to dysregulation of immune interactions with the synanthropic microflora. A sequencing method was used to study deviations in the diversity of the gut microflora in patients with rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis. However, a number of unresolved issues remain, since the emphasis has been on the cataloguing of the microorganisms present and on the identification of correlations between microbial species and diseases. The main difference in future microbiome research in patients with immune-mediated inflammatory diseases should be a closer examination of the functions of microbiota components, and not just their description. Long-term studies with the collection of intestinal microbiome samples are required at several time intervals: before disease-modifying antirheumatic drug therapy and during ineffective therapy. Such studies will contribute to the development of new diagnostic and therapeutic interventions. Until they are completed, it is untimely to recommend microbiome analysis as a diagnostic or prognostic tool for the management of rheumatic diseases in clinical practice.

The Janus Kinase inhibitor tofacitinib impacts human dendritic cell differentiation and favours M1 macrophage development.

Several cytokines signalling via Janus Kinase (JAK) proteins have been implicated in the pathogenesis of immune-mediated inflammatory diseases, including psoriasis and rheumatoid arthritis (RA). Tofacitinib, a small JAK inhibitor, is approved for the treatment of RA and has demonstrated good efficacy in psoriasis phase III clinical trials. In this work, we analysed the in vitro effects of tofacitinib on the functions of human dendritic cells (DCs) and macrophages. When assessing the effects of tofacitinib on monocyte-derived DCs, we observed reduced differentiation of monocytes into immature DCs, as evidenced by a decreased transcription of CD209 and CD80. Phenotype assessment in the presence of tofacitinib suggested a switch towards a M1-like macrophage phenotype, as evidenced by the expression of M1 markers such as iNOS, as well as cytokines typically expressed by M1 cells, including IL-12 and IL-23. Of note, Arginase1 and CD200R, typically expressed by M2 cells, were absent on tofacitinib-treated DCs. Furthermore, tofacitinib affected the response of differentiated DCs to maturation stimuli such as LPS and IFNγ, resulting in a partial up-regulation of IL-23 and down-regulation of IL-12, as assessed by qPCR. When investigating macrophage development, we found that tofacitinib inhibited the ability of monocytes to differentiate and polarize into regulatory M2 macrophages, while rather enhancing the ability to develop into inflammatory M1-like macrophages, as evidenced by decreased expression of the M2 marker CD200R and enhanced production of IL-12 and IL-23. In conclusion, tofacitinib impacts the differentiation of human DCs and macrophages, it particularly favours generation of M1-like pro-inflammatory macrophages.

Role of Microparticles in the Pathogenesis of Inflammatory Joint Diseases.

Rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), ankylosing spondylitis (AS), and psoriatic arthritis (PsA) make up a group of chronic immune-mediated inflammatory diseases (IMIDs). The course of these diseases involves chronic inflammation of joints and enthesopathies, which can result in joint damage and disability. Microparticles (MPs) are a group of small spherical membranous vesicles. The structure and cellular origin of MPs, mechanisms that stimulate their secretion and the place of their production, determine their biological properties, which could become manifest in the pathogenesis of immune-mediated inflammatory diseases. Microparticles can stimulate synovitis with proinflammatory cytokines and chemokines. MPs may also contribute to the pathogenesis of rheumatic diseases by the formation of immune complexes and complement activation, pro-coagulation activity, activation of vascular endothelium cells, and stimulation of metalloproteinase production. It seems that in the future, microparticles can become a modern marker of disease activity, a response to treatment, and, possibly, they can be used in the prognosis of the course of arthritis. The knowledge of the complexity of MPs biology remains incomplete and it requires further comprehensive studies to explain how they affect the development of rheumatic diseases. This review focuses on the immunopathogenic and therapeutic role of MPs in chronic immune-mediated inflammatory joint diseases.

Th17 Cells and the IL-23/IL-17 Axis in the Pathogenesis of Periodontitis and Immune-Mediated Inflammatory Diseases.

Innate immunity represents the semi-specific first line of defense and provides the initial host response to tissue injury, trauma, and pathogens. Innate immunity activates the adaptive immunity, and both act highly regulated together to establish and maintain tissue homeostasis. Any dysregulation of this interaction can result in chronic inflammation and autoimmunity and is thought to be a major underlying cause in the initiation and progression of highly prevalent immune-mediated inflammatory diseases (IMIDs) such as psoriasis, rheumatoid arthritis, inflammatory bowel diseases among others, and periodontitis. Th1 and Th2 cells of the adaptive immune system are the major players in the pathogenesis of IMIDs. In addition, Th17 cells, their key cytokine IL-17, and IL-23 seem to play pivotal roles. This review aims to provide an overview of the current knowledge about the differentiation of Th17 cells and the role of the IL-17/IL-23 axis in the pathogenesis of IMIDs. Moreover, it aims to review the association of these IMIDs with periodontitis and briefly discusses the therapeutic potential of agents that modulate the IL-17/IL-23 axis.

CD4+ T-cell subsets in inflammatory diseases: beyond the Th1/Th2 paradigm.

CD4(+)T cells are crucial for directing appropriate immune responses during host defense and for the pathogenesis of inflammatory diseases. In addition to the classical biphasic model of differentiation of T-helper 1 (Th1) and Th2 cells, unexpected increases in the numbers of CD4(+)T-cell subsets, including Th17, Th9, T follicular-helper (Tfh) and T-regulatory (Treg) cells, have been recognized. In the present review, we focus on how these various T-helper cell subsets contribute to the pathogenesis of immune-mediated inflammatory diseases. In particular, we focus on multiple sclerosis, psoriasis and asthma as typical model diseases in which multiple T-helper cell subsets have recently been suggested to play a role. We will also discuss various unique sub-populations of T-helper cells that have been identified. First, we will introduce the heterogeneous T-helper cell subsets, which are classified by their simultaneous expression of multiple key transcription factors. We will also introduce different kinds of memory-type Th2 cells, which are involved in the pathogenesis of chronic type-2 immune-related diseases. Finally, we will discuss the molecular mechanisms underlying the generation of the plasticity and heterogeneity of T-helper cell subsets. The latest progress in the study of T-helper cell subsets has forced us to reconsider the etiology of immune-mediated inflammatory diseases beyond the model based on the Th1/Th2 balance. To this end, we propose another model--the pathogenic T-helper population disease-induction model--as a possible mechanism for the induction and/or persistence of immune-mediated inflammatory diseases.

Pathogenic Th cell subsets in chronic inflammatory diseases.

CD4(+) T cells play central roles to appropriate protection against pathogens. While, they can also be pathogenic driving inflammatory diseases. Besides the classical model of differentiation of T helper 1 (Th1) and Th2 cells, various CD4(+) T cell subsets, including Th17, Th9, T follicular helper (Tfh) and T regulatory (Treg) cells, have been recognized recently. In this review, we will focus on how these various CD4(+) T cell subsets contribute to the pathogenesis of immune-mediated inflammatory diseases. We will also discuss various unique subpopulations of T helper cells that have been identified. Recent advancement of the basic immunological research revealed that T helper cells are plastic than we imagined. So, we will focus on the molecular mechanisms underlying the generation of the plasticity and heterogeneity of T helper cell subsets. These latest finding regarding T helper cell subsets has pushed us to reconsider the etiology of immune-mediated inflammatory diseases beyond the model based on the conventional Th1/Th2 balance. Toward this end, we put forward another model, "the pathogenic Th population disease induction model", as a possible mechanism for the induction and/or persistence of immune-mediated inflammatory diseases.

Anti-TNF agents as therapeutic choice in immune-mediated inflammatory diseases: focus on adalimumab.

The complex pathogenesis of immune-mediated inflammatory diseases (IMIDs) has been extensively investigated and dysregulation of cytokines, such as tumour necrosis factor (TNF) has been shown to play a dominant role in the pathogenesis of various IMIDs, such as rheumatoid arthritis, ankylosing spondylitis, Crohn's disease, ulcerative colitis, psoriasis and psoriatic arthritis. The subsequent development of biological agents capable of blocking TNF has led to important advances in the pharmacotherapy of such diseases and confirmed the concept of a common pathophysiology among IMIDs with TNF having a predominant role. Five TNF inhibitors have currently been approved for treatment of one or more IMIDs; these include infliximab, etanercept, adalimumab, golimumab and certolizumab pegol. Given the similarities in the pathogenic background of IMIDs, one could expect that anti-TNF agents be similarly effective and with comparable tolerability profiles; however, this may not be the case. Structural and pharmacological differences among the anti-TNF drugs are likely to result in differences in efficacy and tolerability among the agents in the different IMIDs, together with differences in potency, therapeutic dose ranges, dosing regimens, administration routes, and propensity for immunogenicity. Among the five TNF inhibitors approved for treatment of IMIDs, adalimumab has the widest range of indications. Data from controlled clinical trials of adalimumab, showing its excellent efficacy and tolerability in a wide range of indications, are supported by real-world long-term data from observational studies, which confirm the value of adalimumab as a suitable choice in the management of IMIDs.

Adalimumab in the treatment of immune-mediated diseases.

Tumour necrosis factor (TNF) plays an important role in the pathogenesis of immune-mediated inflammatory diseases (IMIDs). TNF inhibition results in down-regulation of abnormal and progressive inflammatory processes, resulting in rapid and sustained clinical remission, improved quality of life and prevention of target organ damage. Adalimumab is the first fully human monoclonal antibody directed against TNF. In this article, we review the role and cost effectiveness of adalimumab in the treatment of IMIDs in adults and children. The efficacy and tolerability of adalimumab has been demonstrated in patients with a wide range of inflammatory conditions, leading to regulatory approval in rheumatoid arthritis (RA), psoriatic arthritis (PsA), plaque psoriasis, inflammatory bowel diseases (Crohn's disease, ulcerative colitis, paediatric Crohn's disease, and intestinal Behçet's disease), ankylosing spondylitis (AS), axial spondyloarthritis (SpA) and juvenile idiopathic arthritis. The major tolerability issues with adalimumab are class effects, such as injection site reactions and increased risk of infection and lymphoma. As with all anti-TNF agents, adalimumab is immunogenic, although less than infliximab, and some patients receiving long-term adalimumab will develop anti-drug antibodies, causing a loss of response. Comparisons of its clinical utility and cost effectiveness have shown it to be a valid treatment choice in a wide range of patients. Recent data from Italian economic studies show the cost effectiveness of adalimumab to be below the threshold value for health care interventions for most indications. In addition, analysis of indirect costs shows that adalimumab significantly reduces social costs associated with RA, PsA, AS, Crohn's disease and psoriasis. The fact that adalimumab has the widest range of approved indications, many often presenting together in the same patient due to the common pathogenesis, may further improve the utility of adalimumab. Current clinical evidence shows adalimumab to be a valuable resource in the management of IMIDs. Further research, designed to identify patients who may benefit most from this drug, will better highlight the role and cost-effectiveness of this versatile TNF inhibitor.

Angiogenin reduces immune inflammation via inhibition of TANK-binding kinase 1 expression in human corneal fibroblast cells.

Angiogenin (ANG) is reportedly multifunctional, with roles in angiogenesis and autoimmune diseases. This protein is involved in the innate immune system and has been implicated in several inflammatory diseases. Although ANG may be involved in the anti-inflammatory response, there is no evidence that it has direct anti-inflammatory effects. In this study we sought to determine whether ANG has an anti-inflammatory effect in human corneal fibroblasts (HCFs) exposed to media containing tumor necrosis factor-alpha (TNF-α). We found that ANG reduced the mRNA expression of interleukin-1 beta (IL-1β), -6, -8 and TNF-α receptors (TNFR) 1 and 2. In contrast, ANG increased the mRNA expression of IL-4 and -10. Protein levels of TANK-binding kinase 1 (TBK1) were reduced by ANG in HCFs treated with TNF-α. Moreover, ANG diminished the expression of IL-6 and -8 and monocyte chemotactic protein- (MCP-) 1. The protein expression of nuclear factor-κB (NF-κB) was downregulated by ANG treatment. These findings suggest that ANG suppressed the TNF-α-induced inflammatory response in HCFs through inhibition of TBK1-mediated NF-κB nuclear translocation. These novel results are likely to play a significant role in the selection of immune-mediated inflammatory therapeutic targets and may shed light on the pathogenesis of immune-mediated inflammatory diseases.

Heme Cytotoxicity and the Pathogenesis of Immune-Mediated Inflammatory Diseases

Heme, iron (Fe) protoporphyrin IX, functions as a prosthetic group in a range of hemoproteins essential to support life under aerobic conditions. The Fe contained within the prosthetic heme groups of these hemoproteins can catalyze the production of reactive oxygen species. Presumably for this reason, heme must be sequestered within those hemoproteins, thereby shielding the reactivity of its Fe-heme. However, under pathologic conditions associated with oxidative stress, some hemoproteins can release their prosthetic heme groups. While this heme is not necessarily damaging per se, it becomes highly cytotoxic in the presence of a range of inflammatory mediators such as tumor necrosis factor. This can lead to tissue damage and, as such, exacerbate the pathologic outcome of several immune-mediated inflammatory conditions. Presumably, targeting “free heme” may be used as a therapeutic intervention against these diseases.

Pathophysiology and Pathogenesis of Immune-Mediated Inflammatory Diseases: Commonalities and Differences

Immune-mediated inflammatory diseases (IMID) represent a diverse group of chronic conditions that share common pathways. Although the etiology of IMID has yet to be identified, it is well known that both genetic and environmental factors play an important role in the development of these disorders. Genome-wide association (GWA) studies and GW nonsynonymous single-nucleotide polymorphism (nsSNP) scans have recently led to identification of genes commonly found in several different IMID as well as those that are disease-specific. Current epidemiological, clinical, and experimental evidence has also confirmed an association between IMID and a large number of seemingly unrelated environmental factors, which include smoking, diet, drugs, geographical and social status, stress, and microbial agents. Data supporting the involvement of each of these factors in predisposing to, triggering, or modulating the course or outcome of IMID vary from strong to tenuous. The notion of shared genetic pathways creates new and powerful approaches for discovering the full spectrum and potential of susceptible genes in these potentially disabling chronic conditions. Insights relating to a specific immune pathway could provide targets for therapeutic interventions.

Tumor Necrosis Factor and Anti-Tumor Necrosis Factor Therapies

Tumor necrosis factor (TNF) plays a crucial role in the pathogenesis of immune-mediated inflammatory diseases (IMID). As a result, the inhibition of TNF is an important therapeutic avenue in the treatment of these pathophysiologically diverse disease states. This section discusses TNF, its receptors, and its role in immunoregulation and inflammation, as well as the currently available anti-TNF-based therapies.

Anti-Tumor Necrosis Factor Therapies in Immune-Mediated Rheumatic Diseases. Other Observations from the Clinic

To date, over 2 million patients worldwide have been treated with anti-tumor necrosis factor (TNF) therapies, dramatically improving the treatment outcomes of immune-mediated inflammatory diseases (IMID). Observations from clinicians have identified some curious disconnects between clinical and radiographic outcomes, and the paradoxical occurrence of anti-TNF therapy-induced IMID such as psoriasis or reactivation of uveitis and Crohn's disease. These observations point to the need for a better understanding of the mechanisms underlying the ability of anti-TNF therapies to reduce inflammation and how this is linked to the pathogenesis of IMID.