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

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.

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.