Increased Serum Level and High Tissue Immunoexpression of Interleukin 17 in Cutaneous Lichen Planus: A Novel Therapeutic Target for Recalcitrant Cases?

Secukinumab in adult patients with lichen planus: efficacy and safety results from the randomized placebo-controlled proof-of-concept PRELUDE study

BACKGROUND

Patients with lichen planus (LP) refractory to available therapies often experience a high disease burden, representing a population with a clear unmet need for new treatments.

OBJECTIVES

To evaluate the efficacy and safety of secukinumab 300 mg over 32 weeks in adult patients with biopsy-proven cutaneous LP (CLP), mucosal LP (MLP) or lichen planopilaris (LPP) that is inadequately controlled by topical corticosteroids.

METHODS

PRELUDE was a randomized double-blind placebo-controlled phase II proof-of-concept study that enrolled patients with CLP, MLP or LPP. Eligible patients were randomized to either secukinumab 300 mg every 4 weeks for 32 weeks (SECQ4W) or placebo for 16 weeks followed by secukinumab 300 mg every 2 weeks (SECQ2W) for 16 weeks. The primary endpoint was achievement of the newly designed Investigator's Global Assessment (IGA) score ≤ 2 at week 16.

RESULTS

Overall, 111 patients were randomized (n = 37 each) to CLP, MLP and LPP cohorts. As the proof-of-concept criteria were not met for any of the three cohorts, the primary objective was not met. A numerically higher proportion of patients achieved IGA ≤ 2 response at week 16 with SECQ4W vs. placebo in the MLP {37.5% [95% credibility interval (Crl) 20.3-57.2] vs. 23.1% (95% Crl 6.5-49.2)} and LPP cohorts [37.5% (95% Crl 20.2-57.3) vs. 30.8% (95% Crl 10.8-57.6)]. In the LPP cohort, a sustained response for IGA ≤ 2 from week 16 to week 32 was achieved with SECQ4W (week 16, 37.5%; week 32, 45.8%), and a substantial improvement was observed in IGA ≤ 2 response in patients from this cohort who switched from placebo (week 16, 30.8%) to SECQ2W after week 16 (week 32, 63.6%). The safety profile was consistent with the known profile of secukinumab and showed no new or unexpected signals.

CONCLUSIONS

PRELUDE is the first randomized controlled basket trial evaluating interleukin (IL)-17A inhibition with secukinumab across three subtypes of LP. Secukinumab was well tolerated and safe, showing different response rates across the three subtypes, with numerical IGA improvements in MLP and LPP, and no response in CLP. The study raises the question of a differential role of IL-17A across LP subtypes. The novel IGA score showed significant correlation with both patient- and physician-reported outcome measurements.

Immunohistochemical examination of immunoreactivity of transient receptor potential melastatin 2, glutathione peroxidase 4 and spexin in lichen planus

BACKROUND

In this study, we aimed to investigate the potential contributions to the disease by examining the immunoreactivities of SPX in LP-affected skin tissue using immunohistochemical methods, in light of its recent prominence as a molecule related to diabetes mellitus, along with apoptosis and ferroptosis mediated by GPX4 and TRPM2 channels facilitating oxidative stress-induced cell death.

OBJECTIVE

This research explored the immunohistochemical expressions of TRPM2, GPX4, and SPX in Lichen Planus (LP) patients compared to healthy individuals.

MATERIALS AND METHODS

Forty skin samples were collected, split equally between LP patients and healthy controls, excluding those with other conditions. Samples underwent immunohistochemical staining for TRPM2, SPX, and GPX4, using secondary antibodies and chromogens AEC or DAB. Histoscores were calculated based on staining diffusiveness and severity. Statistical analyses were performed with SPSS 22.0, using t-tests and ANOVA, with significance set at p < 0.05.

RESULTS

There were no demographic differences between groups (p > 0.05). LP patients showed significantly lower TRPM2 and GPX4 histoscores and higher SPX histoscores compared to controls (TRPM2 and GPX4: p < 0.001, SPX: p < 0.001). Gender and age did not affect histoscores significantly.

CONCLUSIONS

Findings suggest TRPM2, GPX4, and SPX play roles in LP pathogenesis, indicating a need for further molecular studies to clarify their involvement. This contributes to understanding LP beyond the traditional apoptosis perspective.

IL-17 family cytokines in inflammatory or autoimmune skin diseases

As potent pro-inflammatory mediators, IL-17 family cytokines play crucial roles in the pathogenesis of various inflammatory and autoimmune skin disorders. Although substantial progress has been achieved in understanding the pivotal role of IL-17A signaling in psoriasis, leading to the development of highly effective biologics, the functions of other IL-17 family members in inflammatory or autoimmune skin diseases remain less explored. In this review, we provide a comprehensive overview of IL-17 family cytokines and their receptors, with a particular focus on the recent advancements in identifying cellular sources, receptors and signaling pathways regulated by these cytokines. At the end, we discuss how the aberrant functions of IL-17 family cytokines contribute to the pathogenesis of diverse inflammatory or autoimmune skin diseases.

Increased expression of psoriasin (S100A7) and interleukin 17 (IL-17) in lesional skin in lichen planopilaris

Introduction

Lichen planopilaris (LPP) is an inflammatory, primary scarring alopecia, however its pathogenesis is not completely elucidated. S100A7 is a multifunctional, antimicrobial protein with proinflammatory properties. Interleukin-17 (IL-17) is implicated in the development of various autoimmune skin diseases.

Aim

To determine the tissue expression of S100A7, S100A4 and IL-17 in LPP.

Material and methods

The immunohistochemical analysis was performed on biopsy specimens obtained from individuals with histologically confirmed lichen planopilaris (n = 23), alopecia areata (AA) (n = 11), and healthy controls (n = 14). The expression was evaluated using Zeiss Axio Imager A2 light microscope.

Results

The number of cells showing S100A7 expression was significantly higher in LPP lesional skin compared to AA lesional skin (p = 0.0002) and normal skin of healthy controls (p < 0.0001). The number of cells showing IL-17 expression was significantly higher in LPP lesional skin compared to normal skin of healthy controls (p < 0.0001) and the number of cells showing IL-17 expression was significantly higher in AA lesional skin compared to normal skin of healthy controls (p < 0.0001). The number of cells showing IL-17 expression was not significantly different in LPP lesional skin and in AA lesional skin (p > 0.05). The number of cells showing S100A4 expression was not significantly different in LPP lesional skin, AA lesional skin and in normal skin of healthy controls.

Conclusions

The results of our study suggest the possible role of S100A7 and IL-17 in the pathogenesis of LPP.

IL-17: a novel player in the pathogenesis of vulvar lichen sclerosus

Introduction

Vulvar lichen sclerosus (VLS) is a chronic progressive, lymphocyte-mediated inflammatory disease whose pathogenesis is complex and not fully elucidated.

Aim

In the current study we have investigated for the first time the expression of interleukin-17 (IL-17) and S100A7 in lesional skin obtained from female individuals with histologically confirmed VLS.

Material and methods

In our study we used skin biopsies obtained from female patients with histologically confirmed VLS (n = 20) and skin samples from healthy age- and gender-matched individuals (plastic surgery procedures) (n = 10) serving as controls. The tissue expressions of IL-17 and S100A7 were assessed with an immunohistochemical method.

Results

The number of cells showing IL-17 expression was significantly higher in VLS lesional skin as compared to normal skin of healthy controls (p < 0.0001). In VLS lesional skin, IL-17 was expressed in the epidermis and by cells within the inflammatory infiltrate in the upper dermis. The number of cells showing S100A7 expression was significantly higher in VLS lesional skin as compared to normal skin of healthy controls (p < 0.0001). In VLS lesional skin, S100A7 was expressed by suprabasal keratinocytes in epidermis. S100A7 was also expressed by cells within the inflammatory infiltrate in the dermis.

Conclusions

The results of our study may suggest the involvement of IL-17 and S100A7 in the pathogenesis of VLS. The better understanding of this disease may lead to the development of novel, effective therapeutic strategies e.g. using well-known biologics IL-17 inhibitors class.

A Systematic Review of Interleukin-17 in Oral Lichen Planus: From Etiopathogenesis to Treatment

Lichen planus (LP) is a chronic autoimmune disease of skin and mucous membranes. World Health Organization has announced oral lichen planus (OLP) as a premalignant lesion. The exact etiology of OLP remains unknown; however, different mechanisms may be involved in its immunopathogenesis. The upregulation of cytokines, chemokines, and adhesion molecules is consistent with a persistent and erratic immunological response to OLP-mediated antigens generated by oral keratinocytes and innate immune cells. These molecules attract T cells, and mast cells to the disease site and regulate complex interactions among cells that lead to death of keratinocytes, degradation of basement membrane, and chronicity of the disease. It is believed that CD8+ and CD4+ T helper 1 (Th1) cells are the main lymphocytes involved in this process, although recent evidence suggests implication of other T helper subgroups, such as Th23, Th17, and regulatory T cells (Tregs), proposing a more complex cellular immunity process to be involved in its pathogenesis. The emphasis of this research review is on the function of IL-17 in the pathophysiology of OLP and how current discoveries may point to future treatment strategies. This research protocol will follow Preferred Reporting Items for Systematic Reviews (PRISMA 2020) checklist. An electronic search was conducted in PubMed, Scopus, Google Scholar, Embase, and Cochrane databases for articles published from 1960 to June 2022. Based on the eligibility criteria, 21 articles were enrolled. In comparison to healthy controls, the findings of this review demonstrated greater expression of IL-17 and Th-17 in the blood, saliva, and tissues of OLP and LP patients. Additionally, there was a strong link between the relative levels of IL-17 and IL-23 expression. Treatment with monoclonal antibodies against Th-17/Tc-17, IL-12/IL-23, and IL-23 would result in significant long-term improvement of LP symptoms.

Skin-infiltrating T cells display distinct inflammatory signatures in lichen planus, bullous pemphigoid and pemphigus vulgaris

Introduction

We here thought to dissect the inflammatory signature in lesions of three skin disorders, which show a common adaptive immune response against autoantigens of the skin but are characterized by diverging clinical phenotypes. Pemphigus vulgaris (PV) and bullous pemphigoid (BP) are type-2-dependent, IgG autoantibody-driven blistering disorders of mucous membranes and skin, which target desmoglein (Dsg)3 and bullous pemphigoid (BP)180, respectively. In contrast, lichen planus (LP) is a common chronic inflammatory disease of the skin and mucous membranes with a pronounced dermal T cell infiltrate. We previously identified peripheral type 1 and 17 T cell responses against Dsg3 and BP180 in a cohort of LP patients strongly suggesting that the underlying inflammatory T cell signature may drive the evolving phenotype.

Methods

Paraffin-embedded skin biopsies from well-characterized patients with LP (n=31), BP (n=19), PV (n=9), and pemphigus foliaceus (PF) (n=2) were analysed. Areas with the most prominent inflammatory infiltrate were excised with punch biopsies and tissue microarrays (TMA) containing multiple biopsies were created. Using multicolor immunofluorescence, the inflammatory infiltrate was stained with antibodies against multiple cellular markers, i. e. CD3ϵ, CD4, CD15, TCR-δ, the cytokine IL-17A, and the transcription factors, T-bet and GATA-3.

Results

In LP, there was a higher number of CD4+ T cells expressing T-bet compared to GATA-3. In contrast, CD4+ T cells in PV and BP skin lesions more frequently expressed GATA-3 than T-bet. IL-17A+ cells and IL-17A+ T cells were found to a similar extent in all the three disorders. IL-17A+ granulocytes were more predominant in BP than in LP or PV. Of note, the majority of IL-17A+ cells in LP were neither T cells nor granulocytes.

Discussion

Our findings in inflammatory skin infiltrates clearly show a predominant type 1 signature in LP in contrast to a preponderance of type 2 T cells in PV and BP. In contrast to LP, granulocytes and to a much lesser extent CD3+ T cells were a cellular source of IL-17A in BP and PV. These data strongly suggest that different inflammatory cell signatures drive evolving clinically diverse phenotypes of LP, PV and BP despite common target antigens of the skin.

Comprehensive Insight into Lichen Planus Immunopathogenesis

Lichen planus is a chronic disease affecting the skin, appendages, and mucous membranes. A cutaneous lichen planus is a rare disease occurring in less than 1% of the general population, while oral illness is up to five times more prevalent; still, both forms equally impair the patient's quality of life. The etiology of lichen planus is not entirely understood. Yet, immune-mediated mechanisms have been recognized since environmental factors such as hepatitis virus infection, mechanical trauma, psychological stress, or microbiome changes can trigger the disease in genetically susceptible individuals. According to current understanding, lichen planus immunopathogenesis is caused by cell-mediated cytotoxicity, particularly cytotoxic T lymphocytes, whose activity is further influenced by Th1 and IL-23/Th-17 axis. However, other immunocytes and inflammatory pathways complement these mechanisms. This paper presents a comprehensive insight into the actual knowledge about lichen planus, with the causal genetic and environmental factors being discussed, the immunopathogenesis described, and the principal effectors of its inflammatory circuits identified.

Increased Level of Serum Wingless-Type Mouse Mammary Tumor Virus Integration Site Family Member 5a in Patients with Cutaneous Lichen Planus

Purpose

Methods

Results

Conclusion

Lichen Planus

Lichen planus (LP) is a T cell-mediated disease affecting the stratified squamous epithelia of the skin and/or mucus membrane. Histologically, the disease is characterized by a lichenoid inflammatory infiltrate and vacuolar degeneration of the basal layer of the epidermis. LP has three major subtypes: Cutaneous, mucosal and appendageal LP. Rarely, it may affect the nails in the absence of skin and/or mucosal changes. LP may also be induced by several drugs, typically anti-hypertensive medication or be associated with infections, particularly viral hepatitis. The diagnosis is based on the clinical presentation and characteristic histological findings. Although the disease is often self-limiting, the intractable pruritus and painful mucosal erosions result in significant morbidity. The current first-line treatment are topical and/or systemic corticosteroids. In addition, immunosuppressants may be used as corticosteroid-sparing agents. These, however are often not sufficient to control disease. Janus kinase inhibitors and biologics (anti-IL-12/23, anti-IL17) have emerged as novel future treatment options. Thus, one may expect a dramatic change of the treatment landscape of LP in the near future.

Elevated Serum Interleukin-23 Levels in Patients with Oral and Cutaneous Lichen Planus

Lichen planus is considered a chronic inflammatory disease which affects different sites, such as the skin, mucous membranes, hair, and nails. Based on the evidence, a complex cytokine network plays a crucial role in lichen planus pathogenesis. The study was aimed at assessing the serum IL-23 levels in the patients with cutaneous and oral lichen planus compared to healthy controls. Method. The study included 30 cutaneous lichen planus patients, 20 oral lichen planus patients, and 33 control subjects. Five milliliters of peripheral blood was obtained from each patient, and the serum was separated. IL-23 levels were determined using the ELISA kit, and the data were analyzed using the Mann–Whitney test. Results. IL-23 levels in the patient serum with oral lichen planus (P value ≤ 0.001) were significantly higher than in controls. Furthermore, there were significant differences in IL-23 serum levels in the patients with cutaneous lichen planus compared to the healthy controls (P value ≤ 0.001). Moreover, IL-23 serum levels were statistically different between patients with cutaneous lichen planus and patients with oral lichen planus (P value ≤ 0.001). Based on the mean concentration of interleukin-23, IL-23 levels were higher in the patients with oral lichen planus than in the patients with cutaneous lichen planus. Conclusions. Elevated serum IL-23 levels in the patients with oral lichen planus may indicate that IL-23 plays a crucial role in the pathogenesis of oral lichen planus. However, more research is needed with a larger sample size.

Estimation of neutrophil activation marker in lichen planus patients

BACKGROUND

Lichen planus disease is a chronic inflammatory disorder of mucosal and cutaneous tissues, and its etiology and pathogenesis are unclear. Cytokines have a significant role in the beginning, the maintenance of inflammatory and intercellular crosstalk.

AIM

We assessed serum levels of neutrophil activation marker (calprotectin) in patients with cutaneous lichen planus with different subtypes and made a comparison with healthy individuals.

MATERIALS AND METHOD

Peripheral blood samples of 30 cases with lichen planus were compared with 30 healthy individuals. Serum samples were prepared from LP patients, using a commercial ELISA kit, and calprotectin level was measured in each serum sample.

RESULTS

The serum level of calprotectin was significantly raised in LP cases compared with control (141.34 ± 17.47 ng/ml versus 40.03 ± 1.54 ng/ml respectively; p < 0.001). No correlation was recorded among of serum of calprotectin and patients' ages, sex, disease period, and the existence or strength of pruritus. But a strong positive correlation was present between the coexistence of oral lesions and the number of locations.

CONCLUSION

Calprotectin can be used as a marker of Lichen planus severity and progression. Calprotectin may play a role in the pathogenesis of LP.