Therapeutic outcome of diphencyprone and its correlation with serum cytokine profile in alopecia areata

Elucidating the role of T-Reg related cytokines: serum transforming growth factor beta and interleukin-35 in alopecia areata

Previous studies demonstrated that Th1 cytokines like IL-2, IL-12 and IFN-γ have initiatory role in alopecia areata (AA) and positive correlation with disease severity. They informed that serum levels of Th17 cytokines, IL-17, IL-22, IL-23 increased in active AA patients and corelated, particularly IL-17, with disease severity. In recent reports it was showed the balance between Th17 and Treg cells is crucial for maintaining tolerance to self-antigens, and an imbalance towards Th17 may contribute to the development of autoimmune diseases like AA. But research on serum Treg markers in AA is limited. It was aimed to investigate whether the Treg cells have a role in the pathogenesis of AA analyzing the serum levels of Treg cytokines IL-35 and TGF-β in the patients with AA. 42 AA patients and 38 healthy controls were enrolled. Patient demographics, clinical data, disease severity assessed by Severity of Alopecia Tool (SALT) scores were recorded. Serum samples were collected and analyzed for TGF-β and IL-35 levels using ELISA kits. The cytokine levels in both groups were statistically compared. Their relation with parameters of demographic and severity of disease was evaluated. The patient and control groups had no statistically significant difference, there was 71.4% males and 28.6% females in patient group, while the control group had 63.2% males and 36.8% females, Severity analysis classified 18 patients with mild AA, 19 with moderate AA, and 5 with alopecia totalis/areata universalis. While TGF-β levels exhibited no significant difference between groups, IL-35 levels were significantly elevated in AA patients (p = 0.002). Logistic regression identified IL-35 as a significant parameter influencing disease status (OR = 1.055). Correlation analysis revealed a weak positive correlation between patient age and IL-35 levels (r = 0.436; p = 0.004). Notably, IL-35 levels displayed a significant decrease in individuals with antinuclear antibody (ANA) positivity. No correlations were identified between cytokine levels and disease severity, prognosis, or disease activity. Elevated IL-35 levels suggest that IL-35 and specific Treg cell subsets can play a role in AA pathogenesis. The nuanced roles of TGF-β and IL-35 highlight the need for comprehensive studies to interpret their implications in the complex immunopathogenesis of AA. These findings open avenues for further research, positioning IL-35 as a prospective target for investigating and potentially intervening in AA pathogenesis.

Gut microbiome, metabolome and alopecia areata

Alopecia areata (AA) is a type of dermatological disease characterized by rapid and non-scarring hair loss of the scalp or body skin that may be related to genetic, immunological and physiological factors. It is now believed that AA is associated with oxidative stress, autoimmune disease, neuropsychological factors, pathogens, immune checkpoint inhibitors and microecological imbalance under the premise of host genetic susceptibility. In recent years, studies have revealed the significant role of the gut microbiome or metabolome in many aspects of human health. Diverse studies have revealed that the gut microbiome and metabolome have an important influence on skin conditions. This review highlights the relationship between AA and the gut microbiome or metabolome to provide novel directions for the prevention, clinical diagnosis and treatment of AA.

Alopecia Areata: Current Treatments and New Directions

Alopecia areata is an autoimmune hair loss disease that is non-scarring and is characterized by chronic inflammation at the hair follicle level. Clinically, patients' presentation varies from patchy, circumscribed scalp involvement to total body and scalp hair loss. Current management is guided by the degree of scalp and body involvement, with topical and intralesional steroid injections as primarily first-line for mild cases and broad immunosuppressants as the mainstay for more severe cases. Until recently, the limited number of blinded, randomized, placebo-controlled clinical trials for this disease had made establishing an evidence-based treatment paradigm challenging. However, growing insights into the pathogenesis of alopecia areata through blood and tissue analysis of human lesions have identified several promising targets for therapy. T-helper (Th) 1/interferon skewing has traditionally been described as the driver of disease; however, recent investigations suggest activation of additional immune mediators, including the Th2 pathway, interleukin (IL)-9, IL-23, and IL-32, as contributors to alopecia areata pathogenesis. The landscape of alopecia areata treatment has the potential to be transformed, as several novel targeted drugs are currently undergoing clinical trials. Given the recent US FDA approval of baricitinib and ritlecitinib, Janus kinase (JAK) inhibitors are a promising drug class for treating severe alopecia areata cases. This article will review the efficacy, safety, and tolerability of current treatments for alopecia areata, and will provide an overview of the emerging therapies that are leading the revolution in the management of this challenging disease.

Genetically predicted levels of circulating cytokines and the risk of six immune skin diseases: a two-sample Mendelian randomization study

Background

Circulating cytokines play a crucial role in the onset and progression of immune skin diseases. However, the causal relationships and the direction of causal effects require further investigation.

Methods

Two-sample Mendelian randomization (MR) analyses were conducted to assess the causal relationships between 41 circulating cytokines and six immune skin diseases including alopecia areata, chloasma, hidradenitis suppurativa (HS), lichen planus (LP), seborrheic dermatitis, and urticaria, using summary statistics from genome-wide association studies. Reverse MR analyses was performed to test for the reverse causation. Pleiotropy and heterogeneity tests were conducted to assess the robustness of the findings.

Results

Twelve unique cytokines showed a suggestive causal relationship with the risk of six immune skin diseases. Among them, the causal effects between 9 unique cytokines and immune skin diseases have strong statistical power. Additionally, the concentrations of six cytokines might be influenced by LP and urticaria. After Bonferroni correction, the following associations remained significant: the causal effect of beta-nerve growth factor on HS (odds ratio [OR] = 1.634, 95% confidence interval [CI] = 1.226-2.177, p = 7.97e-04), interleukin (IL)-6 on LP (OR = 0.615, 95% CI = 0.481-0.786, p = 1.04e-04), IL-4 on LP (OR = 1.099. 95% CI = 1.020-1.184, p = 1.26e-02), and IL-2 on urticaria (OR = 0.712, 95% CI = 0.531-0.955, p = 2.33e-02).

Conclusion

This study provides novel perspectives on the relationship between circulating cytokines and immune skin diseases, potentially providing valuable insights into their etiology, diagnostic approaches, and treatment.

Inheritance-Specific Dysregulation of Th1- and Th17-Associated Cytokines in Alopecia Areata

Autoimmune diseases tend to cluster in families, suggesting genetic predisposition to autoimmunity associated with familial background. We have previously reported similarities in gene expression patterns and PTPN22 polymorphisms between alopecia areata (AA) patients and their healthy relatives, but not unrelated healthy controls. However, the spectrum of disease promoting (or preventing) pathways that may be activated in blood relatives of AA patients remains to be defined. Here, we investigated the extent to which cytokines associated with the Th1 and Th17 pathway are differentially expressed in the blood of patients with AA and its clinical subtypes in comparison to both healthy relatives as well as unrelated healthy controls. A comprehensive set of Th1- and Th17-related cytokines were evaluated by ELISA. We found a significant elevation of the Th17 inducer IL-23, the Th17 product IL-17A, the Th1 hallmark cytokine IFNγ, and TNFα, a Th1 cytokine with relevance to the Th17 pathway in AA patients, regardless of disease subtype, compared to healthy individuals. On further examination, we found that healthy family members grouped together with patients in terms of elevated Th1- and Th17-pathway cytokines in an inheritance-specific manner, distinct from unrelated controls. The elevation of Th17-associated cytokines in healthy controls related to AA patients indicates that Th1 and Th17 dysregulation in AA may be genetically based. Of note, one unrelated control displayed elevated levels of IL-17A and IL-23 similar to those detected in patients. One year after initial blood draw, areas of beard hair loss consistent with the diagnosis of AA were reported by this individual, indicating that the elevation in Th17-related cytokines may have predictive value.

The Role of Serum Th1, Th2, and Th17 Cytokines in Patients with Alopecia Areata: Clinical Implications

Alopecia areata is a type of non-scarring hair loss. The dysregulation of numerous systemic Th1 (IL-2, IFN-γ, TNF, IL-12, and IL-18), Th2 (IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, IL-17E, IL-31 and IL-33) and Th17 (IL-17, IL-17F, IL-21, IL-22, IL-23 and TGF-β) cytokines was observed in patients with alopecia areata. Positive correlations between the severity of alopecia areata and an increased serum level of various cytokines including IL-2, TNF, IL-12, IL-17, and IL-17E were reported in the literature. An increased serum level of numerous cytokines, such as IL-2, IL-6, TNF, IL-12, IL-17E, and IL-22, was described as positively correlated with the duration of the disease. Moreover, it was shown that increased pre-treatment serum level of IL-12 was a positive, while increased serum levels of IL-4 and IL-13 were negative prognostic markers for the efficacy of diphenylcyclopropenone. In conclusion, alopecia areata is associated with the dysregulation of systemic Th1, Th2 and Th17 cytokines with their role in the pathogenesis, clinical manifestations and prognosis of the disease. Available data indicate the most significant role of serum IL-2, TNF, IL-12, IL-17, and IL-17E as markers of disease activity. The serum levels IL-4, IL-12 and IL-13 may be useful as potential predictors of diphenylcyclopropenone efficacy.

Altered T cell subpopulations and serum anti-TYRP2 and tyrosinase antibodies in the acute and chronic phase of alopecia areata in the C3H/HeJ mouse model

BACKGROUND

C3H/HeJ mouse models progress gradually in hair loss from acute to chronic phase and reflect the symptoms of patients with alopecia areata (AA). However, the underlying pathological characteristics alteration associated with disease progression and autoantigens remain unclear.

OBJECTIVE

We aimed at elucidating the pathological differences between acute and chronic-AA in the C3H/HeJ mouse model.

METHODS

We analyzed populations of PBMCs, skin-draining lymph node (SDLN) cells, and cutaneous cells of AA mice using flow cytometry. The cytokine and chemokine expressions in the serum and skin were determined using multiplex assay and qPCR. The antibody serum levels were determined using ELISA and the antigen-specific T cells were detected using the MHC class I tetramer.

RESULTS

The CD8⁺NKG2D⁺ T and CD8⁺ T_EM cell percentage in the chronic-AA SDLNs or among the unaffected and acute-AA mice PBMCs increased. The Th1 and CD4⁺ T_EM cell percentage in the SDLNs and among PBMCs increased in the unaffected and AA mice. The percentage of CD8⁺ T_EM/T_RM cells and MHC class I expression increased in the lesions of acute-AA or the non-lesions and lesions of chronic-AA. The Th1 cells, dendritic cell-related cytokines, CD11c⁺ cells and MHC class II expression increased in the skin of AA mice. The antibody levels and TYRP2 and tyrosinase-specific CD8⁺ T cell percentages were upregulated in AA mice.

CONCLUSION

These results suggest that the CD8⁺ and CD4⁺ T cell subpopulations, cytokine and chemokine expressions differ between the disease phases. Moreover, TYRP2 and tyrosinase are potential autoreactive targets in the AA mouse model.

Alopecia Areata: An Autoimmune Disease of Multiple Players

Alopecia areata (AA) is an autoimmune disease of the hair follicles. It is characterized by a well-defined non-scarring alopecic patch or patches that may extend to the entire scalp or lead to total body hair loss. Due to its unpredictable clinical course, AA causes substantial psychological harm. Despite the high prevalence of this disease and extensive research, its exact pathomechanism is unclear, and current treatments have a high relapse rate that has deemed AA incurable. Over the past few decades, researchers have investigated multiple potential factors that may help alleviate its pathogenesis and provide effective treatment. Given its complex immunopathogenesis, AA is considered an autoimmune disease with multiple factors. This review gathers current evidence that emphasizes molecular mechanisms, possible causative etiologies, and targeted immunotherapies for AA. Understanding its underlying mechanisms may shed light on new strategies to effectively manage AA in the future.

Application of Topical Immunotherapy in the Treatment of Alopecia Areata: A Review and Update

Treatment of extensive or recalcitrant alopecia areata (AA) is a major clinical challenge. Even after thorough investigation of several medications, its treatment outcomes have remained unsatisfactory. While there is no US Food and Drug Administration-approved medication for AA yet, topical immunotherapy has been a well-documented treatment option. Dinitrochlorobenzene, squaric acid dibutylester, and diphenylcyclopropenone are three substances that have demonstrated efficacy in the treatment of extensive or recalcitrant AA. Despite being commonly used, the mechanism underlying topical immunotherapy is not well-elucidated and a wide range of clinical efficacies have been reported in the literature. The aim of this review was to summarize and update the pharmacology, mechanism of action, therapeutic efficacy, and tolerability of topical immunotherapy in the treatment of AA.