IL-17 inhibition: is it the long-awaited savior for alopecia areata?

Deciphering the Complex Immunopathogenesis of Alopecia Areata

Alopecia areata (AA) is an autoimmune-mediated disorder in which the proximal hair follicle (HF) attack results in non-scarring partial to total scalp or body hair loss. Despite the growing knowledge about AA, its exact cause still needs to be understood. However, immunity and genetic factors are affirmed to be critical in AA development. While the genome-wide association studies proved the innate and acquired immunity involvement, AA mouse models implicated the IFN-γ- and cytotoxic CD8+ T-cell-mediated immune response as the main drivers of disease pathogenesis. The AA hair loss is caused by T-cell-mediated inflammation in the HF area, disturbing its function and disrupting the hair growth cycle without destroying the follicle. Thus, the loss of HF immune privilege, autoimmune HF destruction mediated by cytotoxic mechanisms, and the upregulation of inflammatory pathways play a crucial role. AA is associated with concurrent systemic and autoimmune disorders such as atopic dermatitis, vitiligo, psoriasis, and thyroiditis. Likewise, the patient's quality of life (QoL) is significantly impaired by morphologic disfigurement caused by the illness. The patients experience a negative impact on psychological well-being and self-esteem and may be more likely to suffer from psychiatric comorbidities. This manuscript aims to present the latest knowledge on the pathogenesis of AA, which involves genetic, epigenetic, immunological, and environmental factors, with a particular emphasis on immunopathogenesis.

Novel investigational drugs for alopecia areata and future perspectives

INTRODUCTION

Alopecia areata (AA) is an immune-mediated disease that causes non-scarring hair loss. While acute, solitary patches often spontaneously remit, developing secondary patches or failure of the disease to resolve within 6-12 months predicts a poor prognosis, with an increased risk of alopecia totalis or universalis. Chronic AA increases the risk of depression and suicidality and reduces quality of life. Treatment options for chronic or acute diffuse AA were previously limited to corticosteroids and traditional immunomodulators. Two Janus Kinase (JAK) inhibitors are now approved for the treatment of chronic AA.

AREAS COVERED

The results of landmark phase 3 trials for three JAK inhibitors, baricitinib, ritlecitinib, and deuruxolitinib are discussed. Evidence for other JAK inhibitors, biologics, and phosphodiesterase-4 inhibitors are also presented. Therapies currently undergoing clinical trials are listed.

EXPERT OPINION

JAK inhibitors are a safe and efficacious treatment of moderate-to-severe AA. Early intervention, regardless of severity, allows for improved treatment efficacy. It is uncertain how long patients should remain on JAK inhibitors; discontinuation often leads to relapse. A black-box warning for JAK inhibitors was extrapolated from safety data in a rheumatoid arthritis cohort; recent meta-analyses of JAK inhibitors used in dermatology cohorts do not demonstrate the same risk profile.

The clinical and immunological features of alopecia areata following SARS-CoV-2 infection or COVID-19 vaccines

INTRODUCTION

Alopecia areata (AA) is an autoimmune disease induced by viral infection or vaccination. With the increased incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the incidence of AA has also increased. Recently the incidence was found to be 7.8% from a previously reported rate of 2.1%. The physical and psychological damage caused by AA could seriously affect patients' lives, while AA is a challenging dermatological disease owing to its complex pathogenesis.

AREAS COVERED

This paper presents a comprehensive review of the prevalence, pathogenesis and potential therapeutic targets for AA after infection with SARS-CoV-2 or SARS-CoV-2 vaccine.

EXPERT OPINION

The treatment of AA remains challenging because of the complexity of its pathogenesis. For patients with AA after SARS-CoV-2 infection or vaccination, the use of sex hormones and alternative regenerative therapies may be actively considered in addition to conventional treatments. For preexisting disease, therapeutic agents should be adjusted to the patient's specific condition.

Ophiasis Alopecia Areata in a Patient With Spondyloarthritis on Secukinumab: A Case Report and Review of the Literature

Secukinumab (Cosentyx), an interleukin-17A-targeting biological agent, is commonly prescribed for psoriasis, psoriatic arthritis, and spondyloarthritis (SpA). Alopecia areata (AA), an IL-17-mediated autoimmune disorder characterized by nonscarring hair loss, particularly in an ophiasis pattern, represents a rare adverse effect associated with secukinumab therapy. We present a case of a 46-year-old female with SpA undergoing secukinumab treatment, who developed an ophiasis pattern of AA, subsequently experiencing regrowth upon medication discontinuation. The patient's clinical course and treatment response are detailed, alongside a discussion on the potential pathophysiological mechanisms underlying secukinumab-induced AA. Additionally, we provide a review of existing literature, discussing similar cases and proposing hypotheses on the immunological basis of this adverse event. This report underscores the importance of recognizing and managing secukinumab-induced AA, highlighting the need for further investigation and tailored therapeutic approaches in affected patients.

Secukinumab-Induced Alopecia Areata Successfully Treated with Tofacitinib in a Patient with Palmoplantar Pustulosis

Secukinumab, a monoclonal antibody targeting interleukin-17 (IL-17), has exhibited encouraging results in the therapeutic management of palmoplantar pustulosis (PPP). The development of alopecia areata (AA) is closely related to IL-17, and IL-17A inhibitors were considered as a potential treatment modality. Therefore, the development of AA during secukinumab treatment for PPP is a rare adverse event that has been rarely reported worldwide. Here we report a 35-year-old female patient with PPP who developed AA after completing the induction period of secukinumab treatment. Discontinuing secukinumab and initiating treatment with tofacitinib resulted in a significant improvement in both PPP and AA. The emergence of AA in this patient can be attributed to paradoxical skin reactions associated with IL-17 inhibitors. Tofacitinib appears to alleviate biologic-induced AA during PPP syndrome 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.

Alopecia Areata After Initiation of Secukinumab Therapy for Plaque Psoriasis

The development of psoriasis and alopecia areata (AA) is multifactorial. The interleukin-17 (IL-17) cytokine is believed to be associated with the pathophysiology of both diseases. This case report demonstrates a 64-year-old female patient who experienced a new onset of AA after the initiation of IL-17A inhibitor, secukinumab, for the treatment of her psoriasis. To our knowledge, there are only three case reports specifically discussing IL-17A inhibitors and AA. This case report highlights a potential rare but significant side effect of IL-17A inhibitors.

[Janus kinase inhibitors for the treatment of alopecia areata]

Alopecia areata is a common condition that leads to nonscarring hair loss. It can be severe and lead to complete hair loss of the scalp or the whole body. In more severe cases, the disease can be very recalcitrant to treatment and result in a significant impairment of the quality of life of the patients. In recent years, there is increasing evidence on the potential of janus kinase (JAK) inhibitors to treat alopecia areata. In the beginning, this was based on case reports, but later, this potential was further established by large case series and in vitro and in vivo data. It is on this basis that JAK inhibitors are being tested specifically for the treatment of alopecia areata in phase 3, randomized, placebo-controlled trials, raising hopes that there will soon be a JAK inhibitor approved by the US Food and Drug Administration (FDA) for the treatment of alopecia areata. Here we provide a review of the information available on the use of JAK inhibitors to treat alopecia areata, and the potential benefits and risks of this class of medications.

Evaluation of the level of serum Interleukins (IL-2, IL-4, IL-15 andIL-17) and its relationship with disease severity in patients with alopecia areata

Background

Alopecia areata (AA) is a hair disease that causes hair loss without scarring. The etiopathogenesis of AA has not been fully understood yet.

Objective

To determine serum interleukin levels (IL-2, IL-4, IL-15, and IL-17) in patients diagnosed with alopecia areata and to investigate the relationship of IL levels with the duration and severity of alopecia areata and the response to tofacitinib therapy.

Methods

Patients (≥16 years old) diagnosed with alopecia areata and healthy individuals as a control group was enrolled. Baseline serum interleukin levels of the patients and controls were measured. In the patient group receiving tofacitinib therapy, serum interleukin levels were measured again after 6 months. Disease severity for alopecia areata was assessed using the Severity of Alopecia Tool.

Results

Sixty-one AA patients and 30 healthy individuals were included; they were comparable regarding age and sex. The mean disease duration for AA was 7 ± 6 years and the baseline mean Severity of Alopecia Tool score was 71 ± 30 (range, 20–100). Baseline IL-2, IL-4 and IL-15 levels were significantly higher in the patient group than those in the control group (p < 0.001 for each). No significant correlation was found between the baseline interleukin levels and either disease duration or disease severity (baseline Severity of Alopecia Tool score). Among the patients receiving tofacitinib (n = 22), all interleukin levels significantly decreased after treatment. However, no significant relationship between the change in interleukin levels and the change in the Severity of Alopecia Tool scores was observed after tofacitinib treatment.

Study limitations

This is a monocentric study conducted in a single university hospital.

Conclusion

High interleukin levels in alopecia areata patients and the significant decrease with treatment support the idea that interleukins have a role in pathogenesis. Nevertheless, no relationship could be demonstrated between IL levels and disease duration or severity.

Serum IL-17 levels in patients with rosacea

BACKGROUND

Rosacea is a chronic inflammatory skin disease characterized with increased serum and tissue inflammatory mediators. IL-17 is a well-known inflammatory mediator that plays important roles in pathogenesis of inflammatory skin diseases. Previous studies reported that Th17 pathway is activated in rosacea and IL-17, one of Th17 signature cytokines, is elevated in tissue samples of rosacea patients.

OBJECTIVES

The aim of this study was to investigate serum IL-17 levels in rosacea patients and to study its relationship with disease characteristics.

METHODS

Sixty patients diagnosed with rosacea and 60 healthy controls were included in the study. Serum IL-17 concentrations were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

The mean serum IL-17 level was 8.03 pg/mL (SD = 1.47) in rosacea patients and 7.37 pg/mL (Sd = 1.19) in controls. Serum IL-17 levels were significantly higher in rosacea (p = 0.002). Serum IL-17 levels were similar among patients with erythematotelangiectatic (ET) and papulopustular (PP) rosacea (8.02 vs 8.06, p = 0.83). Serum IL-17 levels did not correlate with rosacea severity (p = 0.59, r = 0.07 in ET rosacea; p = 0.88, r = 0.02 in PP rosacea), age of onset (p = 0.58, r = -0.07), and disease duration (p = 0.37, r = -0.11). Primary features and global assessments did not correlate with serum IL-17 levels (all p > 0.05). Among secondary features, edema showed a significant negative correlation with serum IL-17 concentrations (p = 0.037, r = -0.26).

CONCLUSIONS

Our study showed increased serum IL-17 levels in rosacea patients and a significant correlation between IL-17 concentrations and secondary features of the disease suggesting IL-17 may contribute to pathogenesis of rosacea and may be a new target for rosacea treatment.

Two Cases of Cutaneous Adverse Effects Induced by Tumor Necrosis Factor-Alpha Inhibitors

Here, we report two cases of cutaneous adverse effects possibly induced by the use of tumor necrosis factor-alpha (TNF-α) inhibitors. The first case presented alopecia areata (AA) and atopic dermatitis (AD) that developed during the treatment of ulcerative colitis using infliximab; the other case presented urticaria and AD that developed during the treatment of rheumatoid arthritis using etanercept. AA, AD, and urticaria are relatively common skin diseases; however, they are not well known as adverse effects of TNF-α inhibitors. Although immunological studies were not performed, the clinical courses suggested that these skin disorders might have developed as a result of an immune four-way imbalance in T helper 1 (Th1), Th2, Th17, and regulatory T cells by the administration of TNF-α inhibitors.

Italian Survey for the Evaluation of the Effects of Coronavirus Disease 2019 (COVID-19) Pandemic on Alopecia Areata Recurrence

INTRODUCTION

The inflammation storm involved in coronavirus disease 2019 (COVID-19) infection and worsening and the psychological stress derived from current quarantine conditions can affect the course of many skin and scalp conditions. This study examined the possible effects of COVID-19 on alopecia areata (AA) relapse in patients suffering from these scalp conditions during the pandemic.

METHODS

The study was carried out in the form of an observational cross-sectional type using a questionnaire sent by mail to a cohort of patients affected by AA during the pandemic from March 2020 to October 2020.

RESULTS

During the pandemic, AA relapse was reported in 42.5% of the participants who also declared COVID-19 infection, confirmed by nasopharyngeal swab or hematological analysis. The relapse was reported about 2 months later COVID-19 infection (median of 2.14 months) and 74.0% of these participants continue to experience AA symptoms when the survey was proposed. Only 12.5% of participants reported AA relapse in the absence of COVID-19 infection.

CONCLUSIONS

The present study reported a significant relapse in patients suffering from AA and infected by COVID-19. This phenomenon could be attributed to the inflammation storm typical of COVID-19 infection and the psychological stress derived from quarantine conditions.

Udenafil Induces the Hair Growth Effect of Adipose-Derived Stem Cells

Udenafil, which is a PDE₅ inhibitor, is used to treat erectile dysfunction. However, it is unclear whether udenafil induces hair growth via the stimulation of adipose-derived stem cells (ASCs). In this study, we investigated whether udenafil stimulates ASCs and whether increased growth factor secretion from ASCs to facilitate hair growth. We found that subcutaneous injection of udenafil-treated ASCs accelerated telogen-to-anagen transition in vivo. We also observed that udenafil induced proliferation, migration and tube formation of ASCs. It also increased the secretion of growth factors from ASCs, such as interleukin-4 (IL-4) and IL12B, and the phosphorylation of ERK1/2 and NFκB. Furthermore, concomitant upregulation of IL-4 and IL12B mRNA levels was attenuated by ERK inhibitor or NFκB knockdown. Application of IL-4 or IL12B enhanced anagen induction in mice and increased hair follicle length in organ culture. The results indicated that udenafil stimulates ASC motility and increases paracrine growth factor, including cytokine signaling. Udenafil-stimulated secretion of cytokine from ASCs may promote hair growth via the ERK and NFκB pathways. Therefore, udenafil can be used as an ASC-preconditioning agent for hair growth.

Alopecia Diffusa while Using Interleukin-17 Inhibitors against Psoriasis Vulgaris

We report two cases of alopecia diffusa during the treatment of psoriasis vulgaris with interleukin (IL)-17 inhibitors. Psoriasis is one of the most common immune-mediated chronic skin diseases, strongly associated with IL-17A. Clinically, the monoclonal antibodies to IL-17A or its receptor, IL-17R, show a dramatic effect against psoriasis. Alopecia is also an IL-17-mediated autoimmune disease, and IL-17 inhibitors have been expected to be the gold standard for the treatment of alopecia; therefore, the complication of alopecia while using IL-17 may be regarded as an unexpected "paradoxical reaction." T helper (Th)17 cells are not cytotoxic enough by themselves to undermine the hair follicle under normal circumstances, they need the coexistence of CD8+ cytotoxic Th1 cells. Th17 cells may be the initiator of the damage of the hair follicle, but CD8 T cells or more powerful Th1 cells are required as followers. The Th17/Th1 axis might convert into a Th1-dominant immune status using IL-17 inhibitors, and the destruction of the hair follicle might result in alopecia. An accumulation of cases is to be expected.