Increased serum levels of interleukin-23 circulating in patients with non-segmental generalized vitiligo

Vitiligo: advances in pathophysiology research and treatment development

The autoimmune condition vitiligo, characterized by skin depigmentation, presents challenges for effective treatment design, with Janus kinase (JAK) inhibitors and other repurposed drugs offering a promising strategy for symptom management. This review explores advantages and shortcomings of current therapies, while presenting the urgent need for further innovative approaches. We emphasize the growing understanding of autoimmune involvement in vitiligo, highlighting several novel treatment avenues including relieving melanocyte stress, preventing dendritic cell activation, halting T cell migration, and suppressing inflammation and autoimmunity. Integrating psychodrama therapy to remediate stress alongside medical interventions marks a holistic approach to enhance patient well-being. The molecular underpinnings of vitiligo care are covered, emphasizing exciting advances revolutionizing vitiligo treatment and improving the quality of life for affected individuals.

Serum Levels of IL-35, One of the Newest Members of Interleukin-12 Family of Cytokines, in Patients With Vitiligo

INTRODUCTION

Vitiligo is a chronic skin disorder in which immune dysregulation has been reported as one of the major etiopathological factors. Interleukin-12 (IL-12), IL-23 and IL-27 of IL-12 cytokine family were identified as critical cytokines in the pathogenesis of many autoimmune and inflammatory skin diseases including vitiligo. IL-35 is one of the newest member of IL-12 cytokine family.

OBJECTIVES

The purpose of our study was to examine serum IL-35 levels in addition to serum IL-12, IL-23, IL-27 levels in the vitiligo patients and control group, and to investigate the relationship of these cytokines with the characteristics of vitiligo.

METHODS

Serum IL-12, IL-23, IL-27 and IL-35 levels of 87 vitiligo patients and 70 healthy volunteers were analyzed using the enzyme-linked immunosorbent assay (ELISA). We compared the IL-12 cytokine family levels in the patient and control groups, and investigated the relationship of these levels with the characteristics of vitiligo.

RESULTS

Patients had higher levels of IL-12 (31.2 versus 20.1, P < 0.001) and IL-35 (9.6 versus 8.1, P = 0.031). Patient and control groups had similar levels of IL-23 (P = 0.78) but were correlated with the Vitiligo Area Scoring Index (VASI) (P = 0.022, r = 0.35). Patients had lower levels of IL-27 (207.6 versus 258.7, P < 0.001). In addition, the levels of serum IL-27 were correlated negatively with the Vitiligo Disease Activity (VIDA), and positively with disease duration (P = 0.007, r = 0.30).

CONCLUSIONS

Differences of serum levels between Vitiligo patients and healthy controls, significant relationships with the characteristics of vitiligo suggest that the IL-12 cytokine family may play a role in the pathogenesis of vitiligo.

Treatment update for vitiligo based on autoimmune inhibition and melanocyte protection

INTRODUCTION

The treatment of vitiligo remains challenging due to the complexity of its pathogenesis, influenced by genetic factors, oxidative stress and abnormal cell adhesion that collectively impact melanocyte survival and trigger immune system attacks, resulting in melanocyte death. Melanocytes in vitiligo are believed to exhibit genetic susceptibility and defects in cellular mechanisms, such as defects in autophagy, that reduce their ability to resist oxidative stress, leading to increased expression of the pro-inflammatory protein HSP70. The low expression of adhesion molecules, such as DDR1 and E-cadherin, accelerates melanocyte damage and antigen exposure. Consequently, autoimmune attacks centered on IFN-γ-CXCR9/10-CXCR3-CD8⁺ T cells are initiated, causing vitiligo.

AREAS COVERED

This review discusses the latest knowledge on the pathogenesis of vitiligo and potential therapeutic targets from the perspective of suppressing autoimmune attacks and activating melanocytes functions.

EXPERT OPINION

Vitiligo is one of the most challenging dermatological diseases due to its complex pathogenesis with diverse therapeutic targets. Immune suppression, such as corticosteroids and emerging JAK inhibitors, has proven effective in disease progression. However, during the early stages of the disease, it is also important to optimize therapeutic strategies to activate melanocytes for alleviating oxidative stress and improving treatment outcomes.

A review of JAK and IL-23 inhibitors to treat vitiligo

Vitiligo is an autoimmune skin disorder resulting in the depigmentation of skin characterised by patches of varying sizes and shapes. A common disorder of pigmentation that affects 0.5%-2% of the global population. Despite its well-understood autoimmune pathogenesis, the targets for effective cytokine intervention remain unclear. Current first-line treatments include oral or topical corticosteroids, calcineurin inhibitors and phototherapy. These treatments are limited, have varying efficacies, and are associated with significant adverse events or can be time-consuming. Therefore, biologics should be explored as a potential treatment for vitiligo. There are currently limited data for the use of JAK and IL-23 inhibitors for vitiligo. A total of 25 studies were identified in the review. There is promising evidence regarding the use of JAK and IL-23 inhibitors for the treatment of vitiligo.

Vitiligo and Mental Health: Natural Compounds' Usefulness

Vitiligo is an autoimmune dermatosis frequently associated with other comorbidities, such as mental health disorders. It is unclear if vitiligo triggers mental disorders or if mental disorders trigger vitiligo, but each one affects and worsen the other, if present at the same time. Both mental health disorders and vitiligo present a multifactorial pathogenesis and often require prolonged periods of therapy, sometimes with poor results. Given the possible link of common pathogenetic factors and the need of integrated therapies, the aim of this review is to look at natural compounds as possible supplements for both conditions. The results yielded show a possible role of these supplements in ameliorating both conditions, thus helping these patients to achieve a better quality of life and reduce the need for prolonged therapies. The limitations regarding the relative lack of in vivo studies, and the increasing need to lighten the burden of these chronic diseases, suggests that it is mandatory to proceed with further trials.

Biologic and targeted therapeutics in vitiligo

BACKGROUND

Vitiligo is a long-standing progressive autoimmune disease with depigmented macules/patches with significant psychological morbidity to the patients. From being one of the most poorly understood diseases in the past, there has been a rampant advance in determining the molecular and genetic factors influencing the disease process. More light has been shed on the complex intracellular environment and interplay between innate and adaptive immunity. Numerous cytokines and signaling pathways have been associated with disease pathogenesis in the recent past.

OBJECTIVE

The aim of this review the efficacy of biologic and targeted therapeutics in vitiligo.

METHODS

A detailed literature search was conducted on databases like PubMed, COCHRANE Central, EMBASE and Google Scholar using keywords-"biologics," "vitiligo," "treatment," "repigmentation," "JAK inhibitors,", "TNF-ꭤ inhibitors," and "IL17/23 inhibitors," Relevant studies and review articles in English were analyzed in detail and report was written. This article aimed at a comprehensive review of all the biologicals and newer targeted therapeutics tried in vitiligo and their efficacy with an insight into the potential complications arising as a result of the therapy.

RESULTS

Most conventional vitiligo treatment modalities are restricted to generalized nonspecific immunosuppressants like topical and oral corticosteroids, calcineurin inhibitors, phototherapy, and surgical modalities. There have been reports and studies on the usage of biologicals in treating vitiligo. JAK inhibitors have shown good efficacy in vitiligo; however, it lacks substantial evidence in the form of randomized control trials. Similarly, the use of targeted therapeutics in treating vitiligo is substantiated by limited evidence and requires more randomized trials for further evidence.

CONCLUSION

JAK inhibitors have shown promising results and good tolerability; Adjuvant phototherapy can achieve a superior response compared to monotherapy. Though TNF-ꭤ has been tried in a few cases, it is best used if vitiligo is present in association with other chronic autoimmune diseases for which it is indicated. More in vitro studies and clinical research are required to understand the pathogenesis clearly, and therapy has to be targeted at specific pathways for a better approach toward vitiligo. Treatment aimed at induction and differentiation of melanocytes may be added to achieve faster repigmentation.

The role of cytokines and vitamin D in vitiligo pathogenesis

Vitiligo is a pigment-related disease with a global prevalence of 0.2% to 1.8% associated with considerable burden on quality of life. The treatment is still a challenge because of relapses and/or incomplete re-pigmentation. Although the exact cause is still unclear, its pathogenesis seems to be justifiable with the autoimmune theory, supported by the results of clinical research. In this narrative review, we aimed to summarize the evidence related to cytokines and vitiligo development. This review is consisted of English articles published in PubMed and Google Scholar concerning levels of inflammatory mediators, especially interleukins, in vitiligo patients over the last 20 years. References of relevant articles were also considered for review. Crucial role of dysregulated levels of interleukins and their synergistic function to each other, in the onset or progression of the disease is evident. The theory of autoimmune vitiligo is reinforced by the results of the studies in the literature, due to the association of pathogenesis with increased secretion of pro-inflammatory mediators and reduction of anti-inflammatory mediators. Decreased vitamin D levels may have a considerable role in vitiligo development by affecting Th1- and Th17-related immune responses. Cytokines play an important role in the pathogenesis or progression of the disease. Moreover, we believe that decreased vitamin D level has a considerable role in vitiligo development by affecting Th1- and Th17-related immune responses.

Advances in vitiligo: Update on therapeutic targets

Vitiligo, whose treatment remains a serious concern and challenge, is an autoimmune skin disease characterized by patches of depigmentation. The increasing application of molecular-targeted therapy in skin diseases, such as psoriasis and systemic lupus erythematosus, has dramatically improved their condition. Besides, there is a favorable effect of repigmentation in the treatment of the above diseases combined with vitiligo, implying that molecular-targeted therapy may also have utility in vitiligo treatment. Recently, the role of cytokine and signaling pathways in vitiligo pathogenesis are increasingly recognized. Thus, investigations are underway targeting the molecules described above. In this paper, we present a synopsis of current practices in vitiligo treatment and introduce the improvement in identifying new molecular targets and applying molecular-targeted therapies, including those under development in vitiligo treatment, providing valuable insight into establishing further precision medicine for vitiligo patients.

Photodynamic therapy in pediatric age: Current applications and future trends

Photodynamic therapy (PDT) is a photochemotherapy based on local application of a photosensitive compound and subsequent exposure to a light source of adequate wavelength. It is a non-invasive therapeutic procedure widely used in oncodermatology for treatment of numerous skin cancers, but in the last years its use has been gradually extended to an increasing list of skin diseases of both infectious and inflammatory nature. Although PDT is proven as a safe and effective therapeutic option in adults, its use is not well standardized in the pediatric population. In this review, we will focus on clinical applications, mechanisms of action, protocols, and adverse events in children and adolescents. Most of pediatric experiences concerned treatment of skin cancers in Gorlin syndrome and xeroderma pigmentosum, acne vulgaris, and viral warts, but other applications emerged, such as cutaneous lymphoma and pseudo-lymphomas, necrobiosis lipoidica, hidradenitis suppurativa, dissecting cellulitis, leishmaniasis, angiofibromas, verrucous epidermal nevus, and linear porokeratosis. In these pediatric diseases, PDT appeared as an effective therapeutic alternative. The results on vitiligo were limited and not fully encouraging. Although highly versatile, PDT is not a therapy for all skin diseases, and a deeper knowledge of its mechanisms of action is required to better define its spectrum of action and safety in pediatric patients.

Role of Cytokines in Vitiligo: Pathogenesis and Possible Targets for Old and New Treatments

Vitiligo is a chronic autoimmune dermatosis of which the pathogenesis remains scarcely known. A wide variety of clinical studies have been proposed to investigate the immune mediators which have shown the most recurrency. However, such trials have produced controversial results. The aim of this review is to summarize the main factors involved in the pathogenesis of vitiligo, the latest findings regarding the cytokines involved and to evaluate the treatments based on the use of biological drugs in order to stop disease progression and achieve repigmentation. According to the results, the most recurrent studies dealt with inhibitors of IFN-gamma and TNF-alpha. It is possible that, given the great deal of cytokines involved in the lesion formation process of vitiligo, other biologics could be developed in the future to be used as adjuvants and/or to entirely replace the treatments that have proven to be unsatisfactory so far.

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.

Therapies with Antioxidant Potential in Psoriasis, Vitiligo, and Lichen Planus

Oxidative stress plays an important pathogenetic role in many chronic inflammatory diseases, including those of dermatological interest. In particular, regarding psoriasis, vitiligo, and lichen planus, excess reactive oxygen species and a decline in endogenous antioxidant systems are observed. In this regard, treatments with antioxidant properties could be appropriate therapeutic options. To date, clinical trials in dermatology on these treatments are limited. We reviewed the available studies on the efficacy of antioxidant therapies in psoriasis, vitiligo, and lichen planus. The role of herbal derivatives, vitamins, and trace elements was analyzed. The antioxidant properties of conventional therapies were also evaluated. Data from the literature suggest that antioxidants might be useful, but available studies on this topic are limited, heterogeneous, not completely standardized, and on small populations. Furthermore, in most cases, antioxidants alone are unable to induce significant clinical changes, except perhaps in mild forms, and must be used in conjunction with standard drug treatments to achieve measurable results. Further studies need to be conducted, considering larger populations and using internationally validated scales, in order to compare the results and clinical efficacy.

Omalizumab for treatment of refractory severe atopic dermatitis. A pediatric perspective

Omalizumab is a monoclonal antibody, targeting Fc receptor of IgE, approved for the treatment of allergic asthma and chronic spontaneous urticaria. Its utility in atopic dermatitis appears controversial from data in literature since the molecule is well tolerated but it seems less effective than other medications used in adult patients (eg, Dupilumab). At present, the use of Dupilumab is not approved in pediatric patients therefore there are no second level treatments available in this age group. Here we report two clinical cases of patients (15 and 16 years old) suffering from both atopic dermatitis and asthma, treated with Omalizumab. Our experience suggests that atopic eczema of young patients with allergic comorbidities can benefit from asthma treatment with Omalizumab observing improvement on both conditions.

Critical role of metabotropic glutamate receptor 4 in bone marrow-derived dendritic cells in the Th17 cell differentiation and the melanogenesis of B16 cells

Vitiligo is an acquired pigmentary disorder resulting from selective destruction of melanocytes. Emerging studies have suggested that T helper cell 17 (Th17) is potentially implicated in vitiligo development and progression. It was recently discovered that metabotropic glutamate receptor 4 (mGluR4) can modulate Th17-mediated adaptive immunity. However, the influence of mGluR4 on melanogenesis of melanocytes has yet to be elucidated. In the present study, we primarily cultured mouse bone marrow-derived dendritic cells (BMDC) and then knocked down and over-expressed mGluR4 using transfection. Transduced BMDC were co-cultured with CD4⁺ T cells and the expression of Th17-related cytokines were measured. The morphology and melanogenesis of B16 cells were observed after being treated with co-culture medium of CD4⁺ T cells and transduced BMDC. We found that mGluR4 knockdown did not affect the co-stimulatory CD80 and CD86 upregulation after lipopolysaccharide stimulation but did increase the expression of Th17-related cytokines, and further down-regulated the expression of microphthalmia-associated transcription factor (MITF) and the downstream genes, decreased melanin production, and destroyed the morphology of B16 cells. Conversely, over-expression of mGluR4 reduced the expression of CD80 and CD86, suppressed the production of Th17-related cytokines, increased the expression of MITF, and did not destroy the morphology of B16 cells. Our study confirmed that mGluR4 modulated the Th17 cell polarization and resulted in the alteration of melanogenesis and morphology of B16 cells. Collectively, these findings suggest mGluR4 might be a potent target involved in the immune pathogenesis of vitiligo.

Predominant role of innate pro-inflammatory cytokines in vitiligo disease

Vitiligo is a skin disorder with melanocyte destruction and an autoimmune basis. Given the importance of cytokines in autoimmunity, we aimed to find the cytokine profile of innate and adaptive immunity in vitiligo patients, and correlate them with clinical parameters. The serum levels of innate immunity [interleukin(IL)-1α, IL-1β, IL-6, IL-8, IL-12, IL-15 and tumor necrosis factor (TNF)-α] and T helper(Th)1 [IL-2, interferon (IFN)-γ, TNF-β], Th2 (IL-4, IL-5, IL-10, IL-13) and Th17 (IL-17, IL-23) cytokines in 44 vitiligo patients were measured by multiplex cytokine assay and compared with 44 healthy subjects. All innate immunity (p < 0.04), Th1 (p < 0.01), Th2 (p < 0.05) and Th17 (p < 0.001) cytokines were higher in patients than controls. Total summation levels of innate immunity and adaptive immunity cytokines showed a remarkable up-regulation in the patients (p < 0.0001). The ratio of innate immunity to Th1 (p = 0.03), Th2 (p = 0.01) and Th17 (p = 0.03) cytokines was significantly higher in patients vs. controls. We found significant higher ratio of Th1 to Th2 cytokines and TNF-β elevated levels in patients with a family history of autoimmunity (p < 0.05). IL-4 and IL-13 (p < 0.04) levels were lower in patients with amelanotic hair. Increased IL-10 level was observed in patients with stable disease (p = 0.02).In conclusion, the profile of cytokines in patients showed a dominant role of innate immunity pro-inflammatory cytokines in vitiligo, which suggests the potential of targeting these cytokines for vitiligo treatment. While a higher ratio of Th1/Th2 cytokines was observed in the patients, association of decreased Th2 cytokines with disease complications suggests a protective role for Th2 pathway.

Learning From Success and Failure: Biologics for Non-approved Skin Diseases

The impressive potential of biologics has been demonstrated in psoriasis, hidradenitis suppurativa, and urticaria. Numerous biologicals are entering the field for a restricted number of skin disorders. Off-label use of biologics in other recalcitrant skin diseases has increased. Mounting data point to the potential of already existing biologics acting on the IL-17/IL-23 pathway in skin disorders with epidermal hyperkeratosis (e.g., pityriasis rubra pilaris), acneiform inflammation (e.g., hidradenitis suppurativa), and loss of mucosal integrity (e.g., aphthosis). TNF-α blockers are also effective in the latter conditions but seem of particular value in granulomatous (e.g., granuloma annulare) and neutrophilic disorders (e.g., pyoderma gangrenosum). Failure of IL-17 blockade in skin diseases resulting from immune-mediated cell destruction (e.g., alopecia areata and vitiligo) illustrates its limited involvement in Th1-dependent skin immunology. Overall, disappointing results of TNF-α blockers in alopecia areata and vitiligo point to the same conclusion although promising results in toxic epidermal necrolysis suggest TNF-α exerts at least some in vivo Th1-related activities. Acting on both the Th1 and Th17 pathway, ustekinumab has a rather broad potential with interesting results in lupus and alopecia areata. The efficacy of omalizumab in bullous pemphigoid has revealed an IgE-mediated recruitment of eosinophils leading to bullae formation. Reconsidering reimbursement criteria for less common but severe diseases seems appropriate if substantial evidence is available (e.g., pityriasis rubra pilaris). For other disorders, investigator- and industry-initiated randomized clinical trials should be stimulated. They are likely to improve patient outcome and advance our understanding of challenging skin disorders.

Therapeutic effects of iNOS inhibition against vitiligo in an animal model

Nitric oxide (NO) is involved in several biological processes, but its role in human melanogenesis and vitiligo need further studies. Previous studies revealed that exposure to UVA and UVB were capable of the inducing nitric oxide production in keratinocytes and melanocytes through the activation of constitutive nitric oxide synthase, whereas inducible nitric oxide synthase overexpression has been reported to play an important role in hyperpigmentary disorders. The aim of this study was to evaluate iNOS inhibitor aminoguanidine (AG) as a therapeutic agent in our mouse model of vitiligo. In this study, male C57BL/6J Ler-vit/vit mice were purchased to evaluate the effect of iNOS inhibitor (aminoguanidine) (50 and 100 mg/kg) and L-arginine (100 mg/kg) in a mouse model of vitiligo induced by monobenzone 40%. Moreover, we used phototherapy device to treat the mice with NBUVB as a gold standard.The findings revealed that monobenzone was capable of inducing depigmentation after 6 weeks. However, aminoguanidine in combination with monobenzone was decrease the effect of monobenzone, while L-arginine play a key role in promoting the effect of monobenzone (P<0.001). Based on the phototherapy, the efficacy of phototherapy significantly increased by adding L-arginine (P<0.05). Taken together, we suggest that iNOS inhibitor can be a novel treatment for the prevention and treatment of vitiligo by combination of NBUVB therapy, furthermore; NO agents like L-arginine could also increase the effectiveness of phototherapy. Taken together, this pilot study showed significant repigmentation of vitiligous lesions treated with iNOS inhibitor plus NBUVB therapy, where other aspect including expression of an inducible iNOS, NO and TNF levels remained to be evaluated in mice model.

The role of interleukins in vitiligo: a systematic review

Vitiligo is a disorder of the skin that causes depigmentation and asymptomatic macules whose exact cause is still unclear. Although its aetiology is not fully elucidated, the main theory of its pathomechanism is that it is associated with the autoimmune process. There is few summarized information about the role of inflammatory mediators, as interleukins, in vitiligo, so our aim was to present a systematic review of the role of interleukins in vitiligo, focusing on interleukins. In this review, we included all studies assessing interleukin levels in vitiligo patients conducted up to June 2017. Quality assessment of these studies was performed using the Newcastle-Ottawa Scale (NOS). The interleukins mainly involved were IL-2, IL-4, IL-6, IL-10 and IL-17. The studies highlight the crucial role of IL-17 in the onset and progression of the disease, and its synergistic action with IL-2, IL-6 and IL-33. Dysregulated levels of the interleukins were also correlated with the stage of disease, the affected skin surface area, and indicated as the main factor for lymphocyte infiltration found in depigmented regions. These findings illustrate the growing need for new therapies targeting vitiligo and further research into the role of interleukins as an area of particular interest.

Autoimmunity and autoimmune co-morbidities in psoriasis

Psoriasis is characterized by widespread scaly erythematous plaques that cause significant physical and psychological burdens for the affected individuals. Accelerated inflammation driven by the tumour necrosis factor-α/interleukin-23/interleukin-17 axis is now known to be the major mechanism in the development of psoriasis. In addition, psoriasis has an autoimmune nature that manifests as autoreactive T cells and is co-morbid with other autoimmune diseases, such as autoimmune bullous diseases, vitiligo, alopecia and thyroiditis. In this article, we review the recent topics on autoimmunity and autoimmune co-morbidities in psoriasis.

Vitiligo: An Update on Pathophysiology and Treatment Options

The pathophysiology of vitiligo is becoming increasingly clarified. In non-segmental vitiligo, early factors include activation of innate immunity, inflammasome activation, oxidative stress, and loss of melanocyte adhesion. Nonetheless, the main mechanism leading to non-segmental vitiligo involves an immune-mediated destruction of melanocytes. Anti-melanocyte-specific cytotoxic T cells exert a central role in the final effector stage. Genetic research revealed a multi-genetic inheritance displaying an overlap with other autoimmune disorders. However, some melanocyte-specific genes were also affected. Segmental vitiligo carries a different pathogenesis with most evidence indicating a mosaic skin disorder. Current management includes topical corticosteroids and immunomodulators. Narrow-band ultraviolet B can be used in patients not responding to topical treatment or in patients with extensive disease. Pigment cell transplantation offers an alternative for the treatment of segmental vitiligo or stable non-segmental lesions. Recent findings have revealed new targets for treatment that could lead to more efficient therapies. Targeted immunotherapy may halt the active immune pathways, although combination therapy may still be required to induce satisfying repigmentation. A recently established core set of outcome measures, new measurement instruments, and biomarker research pave the way for future standardized clinical trials.

Screening and identification of differentially expressed serum proteins in patients with vitiligo using two‑dimensional gel electrophoresis coupled with mass spectrometry

In the clinic, vitiligo is characterized by two stages: Stable and progressive. The pathogenesis of vitiligo is still not clear. Here, we identified serum markers of vitiligo by screening for differentially expressed proteins in patients with vitiligo compared to healthy individuals. Serum samples were collected from patients with vitiligo (n=10 for both the stable and progressive stages) and healthy individuals (n=10). Two‑dimensional gel electrophoresis followed by matrix‑assisted laser desorption/ionization time‑of‑flight mass spectrometry and western blotting were used to validate the differential expression of the proteins in the serum (n=20 each, at both stages for patients and healthy individuals). A total of 48 differentially expressed proteins were identified by gel image analysis. There were 28 differentially expressed proteins in patients with progressive vitiligo (PV) and 13 differentially expressed proteins in patients with stable vitiligo (SV) compared with that in healthy individuals. Additionally, 7 differentially expressed proteins were identified in patients with PV compared with those in patients with SV. The western blotting results showed that Peroxiredoxin‑6, apolipoprotein L1, apolipoprotein E and mannose‑binding protein were differentially expressed in patients with different stages of vitiligo. Our results showed that change serum levels of several proteins might be useful as biomarkers or in understanding the pathogenesis of vitiligo.

Differential Expression of Nitric Oxide Synthase Isoforms nNOS and iNOS in Patients with Non-Segmental Generalized Vitiligo

Nitric oxide (NO) is involved in several biological processes, but its role in human melanogenesis is still not well understood. Exposure to UVA and UVB induces nitric oxide production in keratinocytes and melanocytes through the activation of constitutive nitric oxide synthase, increasing tyrosinase activity and melanin synthesis, whereas inducible nitric oxide synthase over expression might be involved in hypopigmentary disorders. The aim of this study was to evaluate whether inducible nitric oxide synthase and neuronal nitric oxide synthase expression were modified in vitiligo skin compared to healthy controls. Skin biopsies were obtained from inflammatory/lesional and white/lesional skin in 12 patients with active, non-segmental vitiligo; site-matched biopsies of normal skin from eight patients were used as controls. Nitric oxide synthase isoforms expression was evaluated by confocal laser scanning microscopy and Western Blot analysis. Inducible nitric oxide synthase expression was significantly increased in inflammatory/lesional skin compared to healthy skin; melanocytes showed a moderate neuronal nitric oxide synthase expression in white/lesional skin, demonstrating that metabolic function still goes on. The obtained data demonstrated that vitiligo lesions were characterized by modifications of nitric oxide synthase isoforms, thus confirming the hypothesis that nitric oxide imbalance is involved in vitiligo and supporting the idea that nitric oxide synthase inhibitors might be used as a possible therapeutic approach for the management of vitiligo.

The Changing Landscape of Alopecia Areata: The Therapeutic Paradigm

Alopecia areata (AA), a prevalent inflammatory cause of hair loss, lacks FDA-approved therapeutics for extensive cases, which are associated with very poor rates of spontaneous hair regrowth and major psychological distress. Current treatments for severe cases include broad immune-suppressants, which are associated with significant adverse effects, precluding long-term use, with rapid hair loss following treatment termination. As a result of the extent of the disease in severe cases, topical contact sensitizers and intralesional treatments are of limited use. The pathogenesis of AA is not yet fully understood, but recent investigations of the immune activation in AA skin reveal Th1/IFN-γ, as well as Th2, PDE4, IL-23, and IL-9 upregulations. Tissue analyses of both animal models and human lesions following broad-acting and cytokine-specific therapeutics (such as JAK inhibitors and ustekinumab, respectively) provide another opportunity for important insights into the pathogenesis of AA. As reviewed in this paper, numerous novel therapeutics are undergoing clinical trials for AA, emphasizing the potential transformation of the clinical practice of AA, which is currently lacking. Dermatologists are already familiar with the revolution in disease management of psoriasis, stemming from better understanding of immune dysregulations, and atopic dermatitis will soon follow a similar path. In light of these recent developments, the therapeutic arena of AA treatments is finally getting more exciting. AA will join the lengthening list of dermatologic diseases with mechanism-targeted drugs, thus changing the face of AA.

Oxidation products are increased in patients affected by non-segmental generalized vitiligo

Several lines of evidence support the relevance of reactive oxygen species (ROS) in vitiligo, but the exact role of glycation and oxidation of macromolecules needs to be better addressed. To investigate the involvement of advanced oxidation protein products (AOPPs) and advanced glycation end-products (AGEs), we performed a case-control association study by spectrofluorimetry and spectrophotometry, in 47 patients with non-segmental generalized vitiligo and 47 age- and sex-matched controls. Significantly higher levels of both AOPPs (p < 0.0001) and AGEs (p < 0.0001) were observed in vitiligo patients compared to healthy controls. In vitiligo patients, AGEs and AOPPs serum levels were directly associated with extension, duration of vitiligo, and disease activity. ROS, and in particular AGEs and AOPPs, could represent one of the main biomarkers to assess the onset and progression of vitiligo, due to the potential role as direct inducers of cell damage and also as autoimmunity triggers. Further longitudinal studies involving larger cohorts of patients are required to elucidate the role of oxidation products in the pathogenesis of vitiligo.

Enhanced Th1 and Th17 responses in peripheral blood in active non-segmental vitiligo

Accumulating studies have indicated that vitiligo, especially non-segmental vitiligo (NSV), is one kind of autoimmune diseases and CD4⁺ T cells play important roles in the pathogenesis. However, there have been very limited data on the detailed changes of each of the CD4⁺ T cell subsets in periphery in active NSV. To clarify this issue, we collected the peripheral blood mononuclear cells (PBMCs) from 30 patients with active NSV and 30 age- and sex-matched healthy controls. The percentages of circulating Th1, Th2, Th17 and Tregs were evaluated using flow cytometry and the expressions of their specific transcription factors T-bet, GATA3, RORγt and FOXP3 at mRNA level and protein levels were qualified by qPCR and flow cytometry, respectively. Meanwhile, the expression levels of IFN-γ, IL-4, TGF-β, and IL-17A in serum were measured. We found that in patients with NSV, the percentages and absolute numbers of circulating Th1 and Th17 were both significantly higher than those of healthy controls, while the percentages of Th2 and Tregs and absolute numbers showed no significant difference compared to healthy controls. Moreover, the ratios of Th1/Tregs and Th17/Tregs in circulation were both statistically elevated in active NSV. Similar results were got in qualification of their corresponding transcription factors at mRNA level and protein levels. Compared with healthy controls, the expression level of IL-17A was significantly increased in serum of patients with NSV, while the productions of IFN-γ, IL-4, TGF-β had no significant change. These data suggested that in circulating CD4⁺ T cell subsets, Th1 and Th17 played the major role in cellular immunity in the progression of vitiligo. The immune lever in circulation was inclined to effector CD4⁺ T cells not suppressor CD4⁺ T cells that may result in the loss of self-tolerance to melanocytes.

IL-33 circulating serum levels are increased in patients with non-segmental generalized vitiligo

IL-33 is a recently identified cytokine, encoded by the IL-33 gene, which is a member of the IL-1 family that drives the production of T-helper-2 (Th-2)-associated cytokines. Serum levels of IL-33 have been reported to be up-regulated in various T-helper (Th)-1/Th-17-mediated diseases, such as psoriasis, rheumatoid arthritis, and inflammatory bowel. To investigate whether cytokine imbalance plays a role in the pathogenesis of vitiligo, we performed a case-control association study by enzyme-linked immunosorbent assay of IL-33 in our patients. IL-33 serum levels were measured by a quantitative enzyme immunoassay technique in patients with non-segmental generalized vitiligo and compared with those of healthy controls. IL-33 serum levels in patients with vitiligo were significantly increased than those in healthy controls. There was a positive correlation of IL-33 serum levels with extension of vitiligo and disease activity. This study suggests a possible systemic role of IL-33 in the pathogenesis of vitiligo. Inhibiting IL-33 activity might be a novel therapeutic strategy in the treatment of autoimmune inflammatory disease, like vitiligo.