Targeting IL-17 in psoriasis: from cutaneous immunobiology to clinical application. Clin Immunol. 2013;146:131-139. [PMID: 23314273 DOI: 10.1016/j.clim.2012.12.004]

Comparative Analysis of the Therapeutic Effects of Fresh and Cryopreserved Human Umbilical Cord Derived Mesenchymal Stem Cells in the Treatment of Psoriasis

Psoriasis, an inflammatory autoimmune skin disease, is characterized by scaly white or erythematous plaques, which severely influence patients' quality of life and social activities. Mesenchymal stem cells derived from the human umbilical cord (UCMSCs) represent a promising therapeutic approach for psoriasis because of its unique superiority in ethical agreeableness, abundant source, high proliferation capacity, and immunosuppression. Although cryopreservation provided multiple benefits to the cell therapy, it also greatly compromised clinical benefits of MSCs due to impaired cell functions. The current study aims to evaluate the therapeutic efficacy of cryopreserved UCMSCs in a mouse model of psoriasis as well as in patients with psoriasis. Our results showed that cryopreserved and fresh UCMSCs have comparable effects on the suppression of psoriasis-like symptoms such as thickening, erythema, and scaling, and serum IL-17 A secretion in mice model of psoriasis. Moreover, psoriatic patients injected with cryopreserved UCMSCs had a significant improvement in the Psoriasis Area and Severity Index (PASI), Physician Global Assessment (PGA), and Patient Global Assessments (PtGAs) scores compared to baseline values. Mechanically, cryopreserved UCMSCs markedly inhibit the proliferation of PHA-activated PBMCs, type 1 T helper (Th1) and type 17 T helper (Th17) cell differentiation and secretion of inflammatory cytokines including IFN-γ, TNF-a and IL-17 A in PBMCs stimulated by anti-CD3/CD28 beads. Taken together, these data indicated that cryopreserved UCMSCs exhibited great beneficial effect on psoriasis. Thus, cryopreserved UCMSCs can be systemically administered as ''off-the-shelf'' cell product for psoriasis therapy. Trial Registration ChiCTR1800019509. Registered on November 15, 2018-Retrospectively registered, http://www.chictr.org.cn/ .

Mast Cells and Interleukins

Mast cells play a critical role in inflammatory diseases and tumor growth. The versatility of mast cells is reflected in their ability to secrete a wide range of biologically active cytokines, including interleukins, chemokines, lipid mediators, proteases, and biogenic amines. The aim of this review article is to analyze the complex involvement of mast cells in the secretion of interleukins and the role of interleukins in the regulation of biological activities of mast cells.

A case report of recalcitrant aphthous ulcers in two patients treated with interleukin-17 inhibitors

The interleukin-17 signaling pathway plays a critical role in the pathogenesis of psoriasis. By inhibiting this pathway, there is a reduction in the severity of psoriasis and many patients achieve clear skin. We present two individuals, a 34-year-old male and a 40-year-old female, who developed aphthous ulcers on the oral mucosa and oral and vulvar mucosa, respectively, while undergoing treatment with interleukin-17 inhibitors. The ulcers did not respond to conventional therapy, including topical corticosteroids and nystatin 100,000 unit/mL oral suspension. Both patients underwent biopsies which confirmed the diagnosis of ulcer. Once confirmed, the interleukin-17 inhibitor was discontinued and the ulcers resolved in both cases. As we see biologic treatment, specifically interleukin-17 inhibitor, becoming more popular for the treatment of psoriasis, it is important for physicians to be aware of this potential adverse event. Early detection and intervention are important to avoid complications that can develop from rare but often painful ulcers.

Current Developments in the Immunology of Psoriasis

Psoriasis is a frequent inflammatory skin disease. Fundamental research on the pathogenesis of psoriasis has substantially increased our understanding of skin immunology, which has helped to introduce innovative and highly effective therapies. Psoriasis is a largely T lymphocyte-mediated disease in which activation of innate immune cells and pathogenic T cells result in skin inflammation and hyperproliferation of keratinocytes. B cells have thus far largely been neglected regarding their role for the pathogenesis of psoriasis. However, recent data shed light on their role in inflammatory skin diseases. Interestingly, interleukin (IL)-10-producing regulatory B cells have been assumed to ameliorate psoriasis. In this review, we will discuss the development of disease, pathogenicity, and current developments in therapeutic options. We describe different roles of T cells, B cells, and cytokines for the immunopathology and disease course of psoriasis.

Characterization of novel anti-IL-26 neutralizing monoclonal antibodies for the treatment of inflammatory diseases including psoriasis

Interleukin (IL)-26, known as a Th17 cytokine, acts on various cell types and has multiple biological functions. Although its precise role still remains to be elucidated, IL-26 is suggested to be associated with the pathology of diverse chronic inflammatory diseases such as psoriasis, inflammatory bowel diseases and rheumatoid arthritis. To develop novel neutralizing anti-human IL-26 monoclonal antibodies (mAbs) for therapeutic use in the clinical setting, we immunized mice with human IL-26 protein. Hybridomas producing anti-IL-26 mAbs were screened for various in vitro functional assays, STAT3 phosphorylation and antibiotic assays. Although the IL-20RA/IL-10RB heterodimer is generally believed to be the IL-26 receptor, our data strongly suggest that both IL-20RA-dependent and -independent pathways are involved in IL-26-mediated stimulation. We also investigated the potential therapeutic effect of anti-IL-26 mAbs in the imiquimod-induced psoriasis-like murine model using human IL-26 transgenic mice. These screening methods enabled us to develop novel neutralizing anti-human IL-26 mAbs. Importantly, administration of IL-26-neutralizing mAb did not have an effect on the antimicrobial activity of IL-26. Taken together, our data strongly suggest that our newly developed anti-human IL-26 mAb is a potential therapeutic agent for the treatment of diverse chronic inflammatory diseases including psoriasis.

Real world data from the use of secukinumab in the treatment of moderate-to-severe psoriasis, including scalp and palmoplantar psoriasis: A 104-week clinical study

Several clinical studies demonstrated the safety and efficacy of the interleukin-17 inhibitor secukinumab in the systemic treatment of moderate-to-severe psoriasis, as well as psoriatic arthritis (PsA) in adults, whereas real-world data is limited. A single-center clinical study was performed to evaluate in real-world practice the efficacy of secukinumab up to Week 104 of treatment in moderate-to-severe chronic plaque psoriasis, including scalp and palmoplantar involvement, according to Physician Global Assessment (PGA), PASI75/90/100 and scalp, and palmoplantar PGA. Drug survival, the safety profile of secukinumab, and patient's quality of life were also assessed during a 2-year observation period. Out of 83 patients included, 56.3% were biologic-naïve, and 94% had scalp, 25.3% palmoplantar, and 43.9% joint involvement. At Week 16, PASI75/PASI90/PASI100 were observed in 83.8/70.0/46.3%, respectively. Scalp and palmoplantar PGA were rapidly improved, with 98.7 and 95.5%, respectively, reaching clear/almost clear skin at Week 16. After 104 weeks, drug survival was 74.5%. A significant improvement of the quality of life was observed. Biologic-naïve patients without coexisting PsA benefited the most. Real-world data demonstrated secukinumab efficacious in chronic plaque psoriasis, including specific locations such as scalp and palmoplantar psoriasis with a safety profile similar to that in clinical trials.

Therapeutic Effects of Synthetic Antimicrobial Peptides, TRAIL and NRP1 Blocking Peptides in Psoriatic Keratinocytes

Psoriasis is a chronic, recurrent, heterogeneous, cutaneous inflammatory skin disease for which there is no cure. It affects approximately 7.5 million people in the United States. Currently, several biologic agents that target different molecules implicated in the pathogenic processes of psoriasis are being assessed in diverse clinical studies. However, relapse usually occurs within weeks or months, meaning there is currently no cure for psoriasis. Therefore, recent studies have discovered diverse new potential treatments for psoriasis: inhibitors of bacteria such as Staphylococcus aureus, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and neuropilin 1 (NRP1). A promising approach that has recently been described involves modifying antimicrobial peptides to develop new cutaneous anti-bacterial agents that target inflammatory skin disease induced by Staphylococcus. Increased expression of TRAIL and its death receptors DR4 and DR5 has been implicated in the pathogenesis of plaque psoriasis. In addition, TRAIL has the ability to inhibit angiogenesis by inducing endothelial cell death and by negative regulation of VEGF-induced angiogenesis via caspase-8-mediated enzymatic and non-enzymatic functions. Since NRP1 regulates angiogenesis induced by multiple signals, including VEGF, ECM and semaphorins, and also initiates proliferation of keratinocytes through NF-κB signaling pathway in involved psoriatic skin, targeting NRP1 pathways may offer numerous windows for intervention in psoriasis. In this review, we will focus on the current knowledge about the emerging role of synthetic antimicrobial peptides, TRAIL and NRP1 blocking peptides in the pathogenesis and treatment of psoriasis.

Where Does Inflammation Fit?

PURPOSE OF REVIEW

This review focuses on the complex relationship between inflammation and the onset of acute coronary syndrome and heart failure.

RECENT FINDINGS

In the last few years, two important lines of research brought new and essential information to light in the pathogenesis of acute coronary syndrome: a) the understanding of the immune mediate mechanisms of inflammation in Ischemic Heart Disease (IHD) and b) evidence that the inflammatory mechanisms associated with atherosclerosis and its complications can be modulated by anti-inflammatory molecules. A large amount of data also suggests that inflammation is a major component in the development and exacerbation of heart failure (HF), in a symbiotic relationship. In particular, recent evidence underlies peculiar aspects of the phenomenon: oxidative stress and autophagy; DAMPS and TLR-4 signaling activation; different macrophages lineage and the contribution of NLRP-3 inflammasome; adaptive immune system. A possible explanation that could unify the pathogenic mechanism of these different conditions is the rising evidence that increased bowel permeability may allow translation of gut microbioma product into the circulation. These findings clearly establish the role of inflammation as the great trigger for two of the major cardiovascular causes of death and morbidity. Further studies are needed, to better clarify the issue and to define more targeted approaches to reduce pathological inflammation while preserving the physiological one.

Clinical utility of ixekizumab in the treatment of moderate-to-severe plaque psoriasis

Psoriasis vulgaris is a chronic, immune-mediated systemic disease that affectŝ7.5 million people in the US. It can be treated with many therapies, often in combination, which include topicals, phototherapy, oral systemics, and biologics. Biologic agents target specific components of the immune system involved in the pathogenesis of psoriasis including TNF-alpha, IL-12, IL-17, and IL-23. The biologic ixekizumab, approved for the treatment of moderate–severe plaque psoriasis in the US, targets IL-17. This review describes the role of IL-17 in psoriasis, the mechanism by which ixekizumab targets this cytokine, and the clinical utility of ixekizumab.

Emerging targeted therapies for plaque psoriasis - impact of ixekizumab

BACKGROUND

Recent studies into the pathogenesis of psoriasis have identified the importance of interleukin 17 (IL-17) in disease activity and have thus provided a new target for biologic therapy. Ixekizumab, the most recent US Food and Drug Administration (FDA)-approved anti-IL-17 biologic agent, appears to be a promising medication for patients suffering from moderate-to-severe plaque psoriasis.

METHODS

We reviewed the results of phase III trials for ixekizumab in order to assess the efficacy, safety, and impact on quality of life of this agent in the treatment of plaque psoriasis. Additionally, we compared these results to phase II and phase III trials for other biologic psoriasis medications including the anti-IL-23 agents tildrakizumab and guselkumab, the combined anti-IL-12 and anti-IL-23 agent ustekinumab, and the anti-IL-17 agents brodalumab and secukinumab.

RESULTS

Pooled results from individual studies demonstrate that among the most efficacious dosing regimens of these anti-interleukin therapies, ixekizumab achieves higher Psoriasis Area and Severity Index 75 rates and similar or higher static Physician Global Assessment 0-1 rates than the other anti-IL-17 and anti-IL-23 agents. The safety profile of ixekizumab is similar to these agents, with nasopharyngitis, upper respiratory infection, headache, arthralgia, and injection-site erythema as the most commonly reported adverse events.

CONCLUSION

Ixekizumab is a highly efficacious, newly FDA-approved treatment for moderate-to-severe plaque psoriasis that demonstrates a robust clinical response, significant improvement in patient quality of life, and a favorable safety profile.

Role of IL-17 in plaque psoriasis: therapeutic potential of ixekizumab

Developments in the understanding of the immunopathogenesis of psoriasis have identified interleukin (IL)-17 as the key proinflammatory cytokine in the pathogenesis of plaque psoriasis, with the consequent development of drugs that target this cytokine or associated receptors. Ixekizumab is a subcutaneously administered humanized monoclonal antibody, which acts to neutralize IL-17A. This article reviews the role of IL-17 in the pathogenesis of psoriasis, the biological and pharmacokinetics of ixekizumab and the safety profile and the clinical efficacy of ixekizumab in Phase III clinical trials. Phase III clinical trials of ixekizumab have so far demonstrated excellent early clinical efficacy, with a comparable safety profile to the existing biologic therapies for psoriasis. To further assess its position in the treatment algorithm for psoriasis, a further head to head RCT with secukinumab could be established, alongside comparative effectiveness studies from observational research. In addition, trials are needed to assess its role in those with tumor necrosis factor inhibitors/ustekinumab resistant disease. However, it is clear that the IL-17 antagonists have changed the benchmark for clinical efficacy, and it is likely that ixekizumab along with the other IL-17 antagonists are set to achieve a new standard of care in the treatment of moderate to severe plaque psoriasis.

Brodalumab for the Treatment of Psoriasis: A Review of Phase III Trials

INTRODUCTION

Interleukin (IL)-17 inhibitors are the most recent class of monoclonal antibodies approved by the FDA for psoriasis treatment. Preclinical and phase II studies of brodalumab, a high-affinity IL-17 receptor monoclonal antibody, have been encouraging.

METHODS

We conducted a literature search using the PubMed database in order to assess the efficacy and safety profile of brodalumab. The search included the following key words: "psoriasis" and "IL-17" or "brodalumab." We also reviewed citations within articles to identify relevant sources.

RESULTS

At week 12, the proportion of patients attaining a 75% improvement from the baseline Psoriasis Area and Severity Index (PASI 75) was similar among the three phase III trials (AMAGINE-1, 83%; AMAGINE-2, 86%; AMAGINE-3, 85%). Brodalumab remained efficacious through 52 weeks of treatment. It maintained a satisfactory safety profile; the most frequently reported adverse events consisted of nasopharyngitis, headache, upper respiratory tract infection, and arthralgia.

CONCLUSION

Use of brodalumab revealed prompt clinical improvement and a favorable short-term safety profile in phase III trials, although further extension studies are needed to assess long-term safety. Based on the results, brodalumab appears to be a potent therapeutic option for patients with moderate-to-severe plaque-type psoriasis.

Ixekizumab for the Treatment of Psoriasis: A Review of Phase III Trials

INTRODUCTION

Interleukin-17 inhibitors are the newest class of monoclonal antibodies approved by the US Food and Drug Administration for the treatment of psoriasis. Preclinical and Phase II studies of ixekizumab, a high-affinity anti-IL-17A monoclonal antibody, have proved promising.

METHODS

We conducted an extensive literature search using the PubMed database to assess the efficacy and safety profile of ixekizumab. The search included the following key words: "psoriasis" and "IL-17" or "ixekizumab." We also reviewed citations within articles to identify relevant sources.

RESULTS

By week 12, the percentage of patients achieving a 75% improvement from baseline Psoriasis Area and Severity Index (PASI 75) was comparable among the three Phase III trials (UNCOVER-1, 89%; UNCOVER-2, 90%; UNCOVER-3, 87%). Ixekizumab continued to be efficacious through 60 weeks of treatment. The safety profile of ixekizumab was favorable; the most frequently reported adverse events consisted of nasopharyngitis, upper respiratory tract infection, injection-site reaction, and headache.

CONCLUSION

Overall, ixekizumab demonstrated rapid clinical improvement and favorable short-term safety profile in Phase III trials. The results support ixekizumab as an effective therapeutic option for patients with moderate-to-severe plaque-type psoriasis.

Natural killer cells from psoriasis vulgaris patients have reduced levels of cytotoxicity associated degranulation and cytokine production

Psoriasis vulgaris is a chronic inflammatory disease of the skin with a strong genetic component and immune system involvement. Although some evidence suggests that Natural Killer (NK) cells may play a part in psoriasis, their role is relatively unstudied and results are controversial. In this current study, NK cells from psoriasis patients exhibited reduced degranulation and produced lower levels of the pro-inflammatory cytokines IFN-γ and TNF-α. Further investigation found that NK cells from psoriasis patients and healthy controls expressed similar levels of activation markers, NK cell receptors and apoptosis-inducing molecules. In addition, comparable levels of several cytokines important in NK cell biology were found in the serum of psoriasis patients and healthy controls. Genotyping analysis revealed that HLA-C2, which provides a ligand for killer-cell immunoglobulin-like receptors (KIR) expressed by NK cells, was strongly associated with psoriasis susceptibility. However, no link between the KIR genes themselves and disease was found.

The effect of dimethyl fumarate on gene expression and the level of cytokines related to different T helper cell subsets in peripheral blood mononuclear cells of patients with psoriasis

BACKGROUND

Fumaric acid esters such as dimethyl fumarate (DMF) have proven to be effective in the treatment of psoriasis.

OBJECTIVES

In view of the role of Th17 in the pathogenesis of psoriasis, the present study was conducted to investigate the effects of DMF on Th1, Th2, and Th17 responses in patients.

METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated from psoriasis patients and healthy individuals and were cultured in the presence or absence of phytohemagglutinin and DMF. The cell supernatants were removed to measure cytokine secretion, and the lymphocytes were used for real-time polymerase chain reaction to establish gene expression.

RESULTS

An increase in gene expression of interferon-γ (IFN-γ), as a marker for Th1 activity, and interleukin-17 (IL-17), granulocyte macrophage colony-stimulating factor (GM-CSF) and IL-22 representing the Th17 subset in the PBMCs of patients in comparison with those of control subjects was observed. Culture of PBMCs from psoriasis patients and controls in the presence of DMF decreased IFN-γ and increased IL-4 gene expression in both groups. Treatment with DMF could significantly decrease IL-17, GM-CSF, and IL-22 mRNA levels in the PBMCs of patients. Decreased release of IFN-γ and GM-CSF cytokine secretion after DMF treatment was also observed in PBMC cultures of patients and controls.

CONCLUSIONS

These data show the effectiveness of DMF in modulating Th17 cells in addition to Th1/Th2 cells and reflect one of the underlying mechanisms of action of DMF in psoriasis. These findings may also support the possible benefits of using fumarate in the treatment of other autoimmune diseases in the pathogeneses of which Th1 and Th17 cells play major roles.

Treatment of Bullous Systemic Lupus Erythematosus

Bullous systemic lupus erythematosus (BSLE) is an autoantibody-mediated vesiculobullous disease in patients with SLE. Autoimmunity in BSLE is characterized by the presence of circulating anti-type VII collagen antibodies. BSLE patients often present with multiple, tense, clear fluid-filled vesicles and bullae overlying erythematous edematous plaques. Skin biopsy from BSLE patients shows subepidermal bullae with numerous neutrophils and only occasional eosinophils. Furthermore, immunofluorescence examination showed linear deposition of lgG, lgA, C3, and C1q along the basement membrane zone. BSLE patients with corticosteroids treatment constantly do not receive a marked improvement, while dapsone generally dramatically improved the skin condition. Recently, it has been reported that quite a few cases of BSLE were successfully treated with other immune suppressive drugs. Therefore, a comprehensive review of the treatment of BSLE would be beneficial to cure the disease.

Effect of interleukin-17 on receptor-interacting protein 4 expression and keratinocyte proliferation

The aim of the present study was to investigate the effect of receptor-interacting protein 4 (RIP4) on keratinocyte proliferation and its role in the pathogenesis of psoriasis vulgaris. The expression of RIP4 and Ki-67 in fixed sections from 30 patients with psoriasis vulgaris and 30 gender- and age-matched healthy controls was detected by two-step immunohistochemistry, prior to the correlation being examined with Pearson's analysis. Reverse transcription-semi-quantitative polymerase chain reaction and western blot analyses were carried out to detect the mRNA and protein expression of RIP4 in an immortalized human keratinocyte line, HaCaT, stimulated by different concentrations of interleukin-17 (IL-17), in order to analyze the change in RIP4 expression following IL-17 stimulation. The cell proliferation rate was measured using the cell counting kit-8 assay simultaneously. RIP4 was mainly present in the cytoplasm of the keratinocytes. Compared with its expression in the healthy control skin, RIP4 exhibited a significant upregulation in the psoriatic lesions (P<0.05). Pearson's correlation analysis revealed a positive correlation between the expression level of RIP4 and the proliferation index. Both RIP4 mRNA and protein levels were significantly increased following IL-17 stimulation. Exposure to IL-17 additionally increased the proliferation rate of the HaCaT cells. In conclusion, RIP4 may play a role in the pathogenesis of psoriasis vulgaris as a potential target of IL-17.

Control of tissue-localized immune responses by human regulatory T cells

Treg cells control immune responses to self and nonharmful foreign antigens. Emerging data from animal models indicate that Treg cells function in both secondary lymphoid organs and tissues, and that these different microenvironments may contain specialized subsets of Treg cells with distinct mechanisms of action. The design of therapies for the restoration of tissue-localized immune homeostasis is dependent upon understanding how local immune responses are influenced by Treg cells in health versus disease. Here we review the current state of knowledge about human Treg cells in four locations: the skin, lung, intestine, and joint. Despite the distinct biology of these tissues, there are commonalities in the biology of their resident Treg cells, including phenotypic and functional differences from circulating Treg cells, and the presence of cytokine-producing (e.g. IL-17(+)) FOXP3(+) cells. We also highlight the challenges to studying tissue Treg cells in humans, and opportunities to use new technologies for the detailed analysis of Treg cells at the single-cell level. As emerging biological therapies are increasingly targeted toward tissue-specific effects, it is critical to understand their potential impact on local immune regulation.

Mannan induces ROS-regulated, IL-17A-dependent psoriasis arthritis-like disease in mice

Psoriasis (Ps) and psoriasis arthritis (PsA) are poorly understood common diseases, induced by unknown environmental factors, affecting skin and articular joints. A single i.p. exposure to mannan from Saccharomyces cerevisiae induced an acute inflammation in inbred mouse strains resembling human Ps and PsA-like disease, whereas multiple injections induced a relapsing disease. Exacerbation of disease severity was observed in mice deficient for generation of reactive oxygen species (ROS). Interestingly, restoration of ROS production, specifically in macrophages, ameliorated both skin and joint disease. Neutralization of IL-17A, mainly produced by γδ T cells, completely blocked disease symptoms. Furthermore, mice depleted of granulocytes were resistant to disease development. In contrast, certain acute inflammatory mediators (C5, Fcγ receptor III, mast cells, and histamine) and adaptive immune players (αβ T and B cells) were redundant in disease induction. Hence, we propose that mannan-induced activation of macrophages leads to TNF-α secretion and stimulation of local γδ T cells secreting IL-17A. The combined action of activated macrophages and IL-17A produced in situ drives neutrophil infiltration in the epidermis and dermis of the skin, leading to disease manifestations. Thus, our finding suggests a new mechanism triggered by exposure to exogenous microbial components, such as mannan, that can induce and exacerbate Ps and PsA.

Targeting the IL-17/IFN-γ axis as a potential new clinical therapy for type 1 diabetes

Type 1 diabetes (T1D) results from the autoimmune destruction of insulin-producing pancreatic beta cells. There is now mounting evidence that pro-inflammatory pathways, which are mediated by T cells that secrete IL-17 and IFN-γ, play a critical role in the loss of beta cells. These data suggest that blockade of T cells that secrete IL-17 and IFN-γ may halt or reverse disease in subjects with recent-onset T1D. Agents to facilitate this approach are currently in clinical use. Ustekinumab, a humanized monoclonal antibody that targets the shared p40 subunit of IL-12 and IL-23, has been used for the treatment of psoriasis, an indication for which it has proven to be safe and effective. In this review, we summarize the evidence that supports a combined pathogenic role of IL-17 and IFN-γ in the development of T1D, with the aim of providing a rationale for testing agents such as ustekinumab for the treatment of T1D.

Correlations between skin lesions induced by anti-tumor necrosis factor-α and selected cytokines in Crohn's disease patients

AIM: To investigate the correlation between the appearance of skin lesions and concentration of interleukin (IL)-17A, IL-23 and interferon-γ (IFN-γ) in Crohn’s disease (CD) patients during anti-tumor necrosis factor-α (TNF-α) therapy

METHODS: A prospective study included 30 adult patients with CD of Caucasian origin (19 men and 11 women; mean age ± SD 32.0 ± 8.6 years) during biological therapy with anti-TNF-α antibodies from January 2012 to March 2013. Eighteen patients were treated with infliximab, seven with adalimumab and five with certolizumab. Inclusion criteria were exacerbation of the underlying disease, Crohn’s Disease Activity Index over 300 and the ineffectiveness of previously used non-biological therapies. Patients with a history of psoriasis, atopic dermatitis and other autoimmune skin lesions were excluded from the study. The control group consisted of 12 healthy subjects. A diagnostic survey was carried out, blood tests and careful skin examination were performed, and the serum levels of IL-17, IL-23 and IFN-γ were measured using an enzyme-linked immunosorbent assays technique. Dermatoses that have developed in the course of biological therapy in patients who had no pre-existing skin lesions of similar character were qualified as skin lesions induced by anti-TNF-α therapy.

RESULTS: Skin manifestations occurred in 18 of CD patients during the anti-TNF-α therapy (60%), in the average time of 10.16 ± 3.42 mo following the beginning of the 52-wk treatment cycle. Skin lesions observed in CD patients during biological therapy included psoriasiform lesions (44.4%), and eczema forms lesions (22.2%). In CD patients with drug induced skin lesions significantly higher levels of hemoglobin (13.3 ± 1.5 g/dL vs 10.8 ± 1.9 g/dL, P = 0.018) and hematocrit (39.9% ± 4.5% vs 34.3% ± 5.4%, P = 0.01), as well as a significantly lower level of platelets (268 ± 62 × 10³/μL vs 408 ± 239 × 10³/μL, P = 0.046) was observed compared with CD patients without skin manifestations. The concentrations of IL-17A and IL-23 in CD patients with skin lesions developed under anti-TNF-α therapy were significantly higher compared to those in patients without lesions (IL-17A: 39.01 ± 7.03 pg/mL vs 25.71 ± 4.90 pg/mL, P = 0.00004; IL-23: 408.78 ± 94.13 pg/mL vs 312.15 ± 76.24 pg/mL, P = 0.00556).

CONCLUSION: Skin lesions in CD patients during biological therapy may result from significantly increased concentrations of IL-17A and IL-23, which are strongly associated with TNF-α/Th1 immune pathways.

Rationale and early clinical data on IL-17 blockade in psoriasis

Psoriasis vulgaris is a chronic, immune-mediated, inflammatory disease that affects between 2 and 3% of the US population. Often severely physically and emotionally debilitating, psoriasis has driven investigators to strive to better characterize its complex immune pathogenesis. Some of the most promising and exciting advances have occurred in the last decade with recognition of the IL-23/Th17 pathway in disease initiation, progression and maintenance. Biologic therapies targeting various points in the pathway have met with success, prompting the study of the safety and efficacy of IL-17 blockade for moderate-to-severe plaque psoriasis. This article will review the rationale and early clinical data on IL-17 blockade in psoriasis.

Current and potential immune therapies and vaccines in the management of psoriasis

Psoriasis is a chronic, immune skin disease associated with significant morbidity. Development of psoriasis is influenced by numerous genes, one allele is HLA-CW*0602. Other genes and single nucleotide polymorphisms affect immunologic pathways and antimicrobial peptide synthesis. Dendritic cells initiate psoriasis by activating T-cells toward a Th1 and Th17 response, with increased cytokines including TNF-α, IL-6, -12, -17, -22, and -23. IL-22 appears to promote keratinocyte dedifferentiation and increased antimicrobial peptide synthesis while TNF-α and IL-17 induce leukocyte localization within the psoriatic plaque. These recent insights identifying key cytokine pathways have led to the development of inhibitors with significant efficacy in the treatment of psoriasis. While a strategy for vaccine modulation of the immune response in psoriasis is in progress, with new technology they may provide a cost-effective long-term treatment that may induce tolerance or targeted self-inhibition for patients with autoimmune disorders, such as psoriasis.

Therapeutic potential of interleukin-17 in inflammation and autoimmune diseases

INTRODUCTION

Interleukin-17 (IL-17) is a proinflammatory cytokine that mainly produced by T helper 17 (Th17) cells. In this article, we discussed the role of IL-17 in inflammation and autoimmune diseases, and the therapeutic strategies targeting IL-17.

AREAS COVERED

In this article, we discussed the proinflammatory cytokine IL-17 and IL-17 receptors signals, and their regulation. IL-17 expression was abnormal in the bacterium, virus and fungus infection, and its higher level caused the tissue inflammation. IL-17 was involved in the pathological process of autoimmune diseases, such as systemic sclerosis, rheumatoid arthritis, ankylosing spondylitis and systemic lupus erythematosus, and IL-17 has been put as a therapeutic target in the clinic.

EXPERT OPINION

IL-17/IL-17R signals and their application in inflammation process still need to be explored. Therapeutic strategies targeting IL-17 in autoimmune diseases ameliorated the inadequate response to anti-TNF-α therapy.

Comparison of interleukin-17- producing cells in different clinical types of alopecia areata

T helper 17 cells, characterized by interleukin-17 (IL-17) production, play a critical role in the pathogenesis of autoimmune disease, including alopecia areata (AA). In this report, we employed immunohistochemical staining for IL-17-producing cells, as well as interferon-γ-producing cells, granulysin-bearing cells and Foxp3+ regulatory T cells, and performed a quantitative analysis of IL-17-producing cells in the lesional skin of several clinical forms of AA by TissueFAXS analysis. Among them, interestingly, the ratio of IL-17-producing cells in acute, diffuse and total alopecia was significantly lower than those of multiple types of AA. Our study sheds light on one of the possible immunological mechanisms of AA.

Interleukin-7: Fuel for the autoimmune attack

Interleukin-7 (IL-7) is a critical survival factor for lymphocytes and recent studies suggest targeting the IL-7/IL-7Rα pathway holds promise for the treatment of autoimmune diseases. Several lines of evidence, genetic as well as functional, indicate an important role for this cytokine in autoimmune inflammation: polymorphisms in the IL-7Rα have been associated with increased risk for autoimmune disease and blocking IL-7/IL-7Rα with antibodies showed therapeutic efficacy in several autoimmune mouse models. Insights are starting to emerge about the mechanisms underlying IL-7's role in autoimmunity and tolerance, revealing surprising novel functions beyond its traditional activity as a T cell survival factor. In the first part of this review, the functions of IL-7 in the immune system are concisely described, providing a basis for understanding their potential role in promoting autoimmune responses. In the second part, current knowledge about the role of IL-7 in various autoimmune conditions is reviewed.

Immunotargeting in the management of psoriasis

The treatment of psoriasis has been revolutionized since the introduction of biologic therapies. Prior to their introduction, it was unclear if psoriasis was primarily a keratinocyte signaling dysfunction or an autoimmune T-cell mediated pathway. Nonspecific T-cell targeting treatments had been used with some success, but they were limited by a narrow therapeutic index. The nonspecific nature of these agents was fraught with side effects, and the efficacy of these treatments pales in comparison to current treatments. The initial biologic molecules, alefacept and efalizumab, were not specific for any T-cell driven pathway, and neither are currently available in the USA. The successors to these early therapies have shown high efficacy and low side effects in psoriasis and other autoimmune diseases through the specific targeting of tumor necrosis factor-alpha (TNF-α). Since the initial use of antitumor necrosis factor agents, a renaissance in our understanding of psoriasis has been underway, leading to the elucidation of the T-helper 17 (Th17) from the Th1 pathway. With each new treatment, the pathogenesis for psoriasis continues to be more defined, allowing for improved targeted therapies and the ability to achieve new milestones in efficacy.