Increased Circulatory Interleukin-17A Levels in Patients with Progressive and Leukotrichial Vitiligo

Role of kinin receptors in skin pigmentation

Previous studies have shown that all kinin system is constitutively expressed in the normal and inflamed skin, with a potential role in both physiological and pathological processes. However, the understanding regarding the involvement of the kinin system in skin pigmentation and pigmentation disorders remains incomplete. In this context, the present study was designed to determine the role of kinins in the Monobenzone (MBZ)-induced vitiligo-like model. Our findings showed that MBZ induces higher local skin depigmentation in kinin receptors knockout mice (KOB1R, KOB2R and KOB1B2R) than in wild type (WT). Remarkably, lower levels of melanin content and reduced ROS generation were detected in KOB1R and KOB2R mice treated with MBZ. In addition, both KOB1R and KOB2R show increased dermal cell infiltrate in vitiligo-like skin, when compared to WT-MBZ. Additionally, lack of B1R was associated with greater skin accumulation of IL-4, IL-6, and IL-17 by MBZ, while KOB1B2R presented lower levels of TNF and IL-1. Of note, the absence of both kinin B1 and B2 receptors demonstrates a protective effect by preventing the increase in polymorphonuclear and mononuclear cell infiltrations, as well as inflammatory cytokine levels induced by MBZ. In addition, in vitro assays confirm that B1R and B2R agonists increase intracellular melanin synthesis, while bradykinin significantly enhanced extracellular melanin levels and proliferation of B16F10 cells. Our findings highlight that the lack of kinin receptors caused more severe depigmentation in the skin, as well as genetic deletion of both B1/B2 receptors seems to be linked with changes in levels of constitutive melanin levels, suggesting the involvement of kinin system in crucial skin pigmentation pathways.

The role of aryl hydrocarbon receptor in vitiligo: a review

Vitiligo is an acquired autoimmune dermatosis characterized by patchy skin depigmentation, causing significant psychological distress to the patients. Genetic susceptibility, environmental triggers, oxidative stress, and autoimmunity contribute to melanocyte destruction in vitiligo. Due to the diversity and complexity of pathogenesis, the combination of inhibiting melanocyte destruction and stimulating melanogenesis gives the best results in treating vitiligo. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that can regulate the expression of various downstream genes and play roles in cell differentiation, immune response, and physiological homeostasis maintenance. Recent studies suggested that AhR signaling pathway was downregulated in vitiligo. Activation of AhR pathway helps to activate antioxidant pathways, inhibit abnormal immunity response, and upregulate the melanogenesis gene, thereby protecting melanocytes from oxidative stress damage, controlling disease progression, and promoting lesion repigmentation. Here, we review the relevant literature and summarize the possible roles of the AhR signaling pathway in vitiligo pathogenesis and treatment, to further understand the links between the AhR and vitiligo, and provide new potential therapeutic strategies.

Vitamin D and Interleukin-17: Are These Serum Biomarkers Useful in Non-Segmental Vitiligo? A Case Control Study from Central India

Non-segmental vitiligo (NSV) is an autoimmune disorder due to the destruction of melanocytes, where cytokines like interleukin 17 (IL-17) and biomolecules like vitamin D play a theoretical role in pathogenesis. Previous studies in this regard yielded inconsistent results. This study aimed to compare the serum levels of IL-17 and vitamin D between NSV patients and healthy controls and to know the association of these biomarkers with disease activity and extent. This was a case-control study including adult patients with NSV and age and gender-matched healthy controls. Cases and controls with conditions likely to alter the serum levels of IL-17 and vitamin D were excluded. Serum levels of IL-17 were estimated by ELISA and vitamin D levels by chemiluminescence assay. 42 adult patients of NSV and 42 age and sex-matched healthy controls were recruited over a period of eighteen months. The mean value of serum vitamin D levels in the control group was 19.053 ± 5.340 ng/ml, whereas in the case group, it was 17.336 ± 6.931 ng/ml (P > 0.05). The mean value of serum IL-17 levels in the control group was 199.824 ± 51.244 pg/ml and 213.566 ± 69.018 pg/ml in the case group (P > 0.05). These molecules did not show any association with the disease activity and extent. In contrast to the previous studies, we could not establish the role of IL-17 in the pathogenesis of vitiligo. Furthermore, we could not find any association between vitamin D and vitiligo in our study, even though there is an inconsistent association between the two in the available literature.

Demographic and clinical feature disparity between progress and non-progress patients with vitiligo after COVID-19 vaccination: A cross-sectional study

There have been several case reports regarding newly developed vitiligo following the coronavirus disease 19 (COVID-19) vaccination. However, the relationship between COVID-19 vaccine and vitiligo progression remains unclear. To explore the relationship between COVID-19 vaccine and vitiligo progression and its potential influencing factors, A cross-sectional study was conducted on 90 patients with vitiligo who received inactivated COVID-19 vaccination. Detailed information covering demographic characteristics (age and sex), vitiligo clinical features (disease subtypes, duration, stage and comorbidities) and disease activity was collected through an electronic questionnaire. Ninety patients with vitiligo included 44.4% males, with an average age of 38.1 years (standard deviation, SD = 15.0). Patients were divided into progress group (29, 32.2%) and normal group (61, 67.8%) based on whether they experienced vitiligo progression after inactivated COVID-19 vaccination. 41.3% of patients in the progress group experienced vitiligo progression within 1 week after vaccination, and disease progression mainly occurred after the first dose inoculation (20, 69.0%). Logistic regression revealed that patients aged <45 years (odds ratio (OR) was 0.87, 95% confidence interval (CI): 0.34-2.22) and male patients (OR = 0.84, 95% CI: 0.34-2.05) had lower risk for vitiligo progression, while patients with segmental vitiligo (SV) subtype (OR = 1.68, 95% CI: 0.53-5.33), with <5 years disease duration (OR = 1.32, 95% CI: 0.51-3.47) had higher risk for vitiligo progression after COVID-19 vaccination, but without statistical significance. Over 30% patients experienced vitiligo progression after inactivated COVID-19 vaccination, and female patients, elder age, shorter disease duration and SV subtype are potential risk factors for vitiligo progression.

Vitiligo, from Pathogenesis to Therapeutic Advances: State of the Art

Vitiligo is an acquired hypopigmentation of the skin due to a progressive selective loss of melanocytes; it has a prevalence of 1-2% and appears as rounded, well-demarcated white macules. The etiopathology of the disease has not been well defined, but multiple factors contribute to melanocyte loss: metabolic abnormalities, oxidative stress, inflammation, and autoimmunity. Therefore, a convergence theory was proposed that combines all existing theories into a comprehensive one in which several mechanisms contribute to the reduction of melanocyte viability. In addition, increasingly in-depth knowledge about the disease's pathogenetic processes has enabled the development of increasingly targeted therapeutic strategies with high efficacy and fewer side effects. The aim of this paper is, by conducting a narrative review of the literature, to analyze the pathogenesis of vitiligo and the most recent treatments available for this condition.

Interleukin 38 serum level is increased in patients with vitiligo, correlated with disease severity, and associated with signs of disease activity

BACKGROUND

Vitiligo is an acquired cutaneous depigmenting disease caused by a T helper (Th) 1-cytotoxic T cells driven autoimmune attack against melanocytes, in which Th17 is also involved. Interleukin (IL)-38 belongs to the IL-1 family of cytokines and suppresses Th1 and Th17 activation. IL-38 protein and mRNA levels have been found to be elevated in various autoimmune disorders and correlated with disease severity and activity, including psoriasis, systemic sclerosis, rheumatoid arthritis, and atopic dermatitis. No previous studies have been performed to investigate the expression of IL-38 in patients with vitiligo.

AIM

To evaluate IL-38 serum level in patients with vitiligo compared to healthy controls (Hcs) and examine the association between IL-38 level and severity and activity of vitiligo.

PATIENTS AND METHODS

The study comprised 21 patients with vitiligo and 21 Hcs. Vitiligo severity and activity were evaluated via Vitiligo Extent Score (VES) and Vitiligo Disease Activity (VIDA) Score, respectively. IL-38 serum level was evaluated by enzyme-linked immunosorbent assay.

RESULTS

Vitiligo patients had significantly higher serum level of IL-38 than Hcs (p < 0.001). This level was significantly higher among patients with signs of vitiligo activity (p = 0.048), correlated positively with VES (p < 0.001), and correlated negatively with the age of patients (p = 0.001) and the age of disease onset (p = 0.022).

CONCLUSION

IL-38 serum level was higher in patients with vitiligo than in Hcs and was related to vitiligo severity and signs of activity.