The genetics of alopecia areata: New approaches, new findings, new treatments

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.

Treatment of in vitro generated Langerhans cells with JAK-STAT inhibitor reduces their inflammatory potential

Alopecia areata (AA) is a condition in which hair is lost in small regions or over the entire body. It has a prevalence of 1 in 1000 and has a great impact on psychological wellbeing. AA is generally considered an autoimmune disease in which a collapse of the immune privilege system of the hair follicle has shown to play an important role, potentially driven by interferon gamma (IFN-γ). The most prominent cells located in or around the hair follicle in AA are Langerhans cells, CD4+ or CD8+ T cells, macrophages and mast cells. Langerhans cells, specialized dendritic cells, are resident in the epidermis and are known to associate with hair follicles. Therefore, we aimed to develop in vitro generated Langerhans cells contributing as an in vitro model of disease. In vitro models provide insight into the behaviour of cells and are a valuable tool before being in need of an animal model or patient samples. For this, Langerhans-like cells were generated from CD14+ monocytes in the presence of GM-CSF and TGF-β. After 10 days of cell culture, Langerhans-like cells express CD207 and CD1a but lack CD209 expression as well as Birbeck granules. Next, Langerhans-like cells were exposed to inflammatory conditions and the effect of different AA treatments was investigated. All treatments-diphencyprone contact immunotherapy, UV-B light therapy and JAK-STAT inhibition-affect the expression of costimulatory and skin-homing markers on Langerhans-like cells. Importantly, also the T cell stimulatory capacity of Langerhans-like cells was significantly reduced following treatment under inflammatory conditions. Noteworthy, JAK-STAT inhibition outperformed conventional AA treatments. In conclusion, our findings demonstrate that in vitro generated Langerhans-like cells can be used as a model of disease. Moreover, JAK-STAT inhibition may become a valuable new approach for the treatment of AA.

Epidemiologic Study of Gene Distribution in Romanian and Brazilian Patients with Non-Cicatricial Alopecia

Background: Androgenetic alopecia (AGA) and alopecia areata (AA) are the most common types of non-cicatricial alopecia. Both diseases have limited effective therapeutic options and affect patient quality of life. Pharmacogenetic tests can help predict the most appropriate treatment option by evaluating the single nucleotide polymorphisms (SNPs) corresponding to genes related to alopecia. The objective of the study was to evaluate and compare selected SNPs and genes in AA and AGA patients from Romania and Brazil. Materials and Methods: We performed a retrospective study regarding the associations between AA and AGA and 45 tag SNPs of 15 genes in 287 Romanian and 882 Brazilian patients. The DNA samples were collected from oral mucosa using a swab. The SNPs were determined by the qPCR technique. Each genetic test displays the subject's genotype of the selected gene and the prediction of a successful treatment (e.g., genotype AA of the GR-alpha gene is related to a predisposition to normal sensibility to topical glucocorticoid, and, therefore, glucocorticoids should be effective). Results: The GR-alpha, GPR44-2, SULT1A1, and CRABP2 genes were statistically significantly different in Brazil compared to Romania. The SULT1A1 activity that predicts the response to minoxidil treatment showed in our analysis that minoxidil is recommended in half of the cases of AGA and AA. Patients with AGA and a high expression of SRD5A1 or PTGFR-2 may benefit from Dutasteride or Latanoprost treatment, respectively. Most of the studied genes showed no differences between the two populations. Conclusions: The DNA analysis of the patients with alopecia may contribute to a successful 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.

Clinical and Genetic Aspects of Alopecia Areata: A Cutting Edge Review

Alopecia areata (AA) is a chronic, non-scarring, immune-mediated skin disease that affects approximately 0.5-2% of the global population. The etiology of AA is complex and involves genetic and environmental factors, with significant advancements in genetic research occurring in recent years. In addition to well-known genes such as PTPN22, CTLA4, and IL2, which have been widely supported as being associated with AA, an increasing number of specific gene-related loci have been discovered through advances in genetic research. For instance, gene analysis of microRNAs can reveal the critical role of miRNAs in regulating gene expression, aiding in the understanding of cellular and organismal functional regulatory mechanisms. Furthermore, numerous studies have confirmed the existence of correlations between AA and other immune-related diseases. Examples include hyperthyroidism and rheumatoid arthritis. By understanding the interrelationships between AA and other immune diseases, we can further comprehend potential shared genetic foundations or pathogenic mechanisms among different diseases. Genetic research plays a crucial role in unraveling the pathogenesis of AA, as the identification of genetic variations associated with AA can assist in formulating more effective and targeted treatment strategies.

Genetic association of IL2RA, IL17RA, IL23R, and IL31RA single nucleotide polymorphisms with alopecia areata

The signalling of cytokine receptors plays a crucial role in regulating tolerance and immunity. Impaired immunological processes result in autoimmune inflammation that target the hair follicles, causing many hair disorders, mainly alopecia areata (AA). Therefore, polymorphisms in cytokine receptor genes are suggested to have a significant impact on the pathogenesis of AA, a disease with a multifactorial basis and uncertain etiology. In the present study, 152 AA patients of the Jordanian population were investigated for their genetic susceptibility to develop AA compared to 150 control subjects. Genomic DNA extraction and genotyping had conducted for IL17RA (rs879575, rs2229151, and rs4819554), IL2RA (rs3118470), IL23R (rs10889677), and IL31RA (rs161704) using the Sequenom MassARRAY® system. The allele frequency of IL17RA rs879575 is significantly higher in patients, while no statistical differences were found for IL2RA, IL23R, and IL31RA SNPs. Also, the recessive model of IL31RA rs161704 showing that AA genotype is significantly associated with AA development. To date, there is no published data regarding the association between AA and the selected genetic variants in our population. However, this study's findings assert that SNPs of IL17RA and IL31RA are linked to AA susceptibility in Jordanian patients.

[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.

Patient characteristics and disease burden of alopecia areata in the Danish Skin Cohort

PURPOSE

Alopecia areata (AA) is a common disorder of patchy hair loss which carries a substantial psychological burden for patients. The current understanding of AA prevalence, disease course and burden is limited, and further research is needed to improve patient care. This prospective cohort of AA patients within the Danish Skin Cohort was established to provide data that can serve as a tool in future studies of for example, AA epidemiology and disease burden.

PARTICIPANTS

A total of 1494 patients with dermatologist-verified AA were included in the cohort. Patients were invited and included through electronic or phone-based questionnaires. Information regarding demographics, biometrics, lifestyle factors, skin type, AA onset and development, health-related quality of life and self-reported severity assessment was collected.

FINDINGS TO DATE

The mean (SD) age of AA onset was 32.7 (17.6) years. The mean body mass index and history of cigarette smoking was comparable with the general population. The majority (92.5%) of participants were Caucasian. In total, 72.4% of patients received their diagnosis by a physician within a year after onset of symptoms, and 66.9% reported to still have symptoms of AA within the past year. A total of 12% reported to have a first-degree family member with AA. In total, 31.4% of patients were missing all or nearly all hairs on their scalp, 32.2% had no or barely no eyelashes and 36.2% had no or barely no eyebrow hairs. Overall, most patients (55.7%) did not experience irritated eyes, but 30% reported slight eye irritation and 47.2% reported no damage to finger nails or toenails.

FUTURE PLANS

Observational studies regarding comorbidities, psychosocial burden of AA and efficacy of pharmacological interventions will be carried out and additional data will be linked from nationwide registries of routinely collected data. Furthermore, follow-up survey data will be added for longitudinal analyses.

An integrated scalp and blood biomarker approach suggests the systemic nature of alopecia areata

BACKGROUND

Alopecia areata (AA) is characterized by immune dysregulation in both scalp and blood, but a large-scale approach establishing biomarkers of AA incorporating both scalp tissue and serum compartments is lacking. We aimed to characterize the transcriptomic signature of AA lesional and nonlesional scalp compared to healthy scalp and determine its relationship with the blood proteome in the same individuals, with comparative correlations to clinical AA disease severity.

METHODS

We evaluated lesional and nonlesional scalp tissues and serum from patients with moderate-to-severe AA (n = 18) and healthy individuals (n = 8). We assessed 33,118 genes in AA scalp tissue using RNAseq transcriptomic evaluation and 340 inflammatory proteins in serum using OLINK high-throughput proteomics. Univariate and multivariate approaches were used to correlate disease biomarkers with Severity of Alopecia Tool (SALT).

RESULTS

A total of 608 inflammatory genes were differentially expressed in lesional AA scalp (fold change/FCH>1.5, false discovery rate/FDR<0.05) including Th1 (IFNG/IL12B/CXCL11), Th2 (IL13/CCL18), and T-cell activation-related (ICOS) products. Th1/Th2-related markers were significantly correlated with AA clinical severity in lesional/nonlesional tissue, while keratins (KRT35/KRT83/KRT81) were significantly downregulated in lesional compared to healthy scalp (p < .05). Expression of cardiovascular/atherosclerosis-related markers (MMP9/CCL2/IL1RL1/IL33R/ST2/AGER) in lesional scalp correlated with their corresponding serum expression (p < .05). AA scalp demonstrated significantly greater biomarker dysregulation compared to blood. An integrated multivariate approach combining scalp and serum biomarkers improved correlations with disease severity/SALT.

CONCLUSION

This study contributes a unique understanding of the phenotype of moderate-to-severe AA with an integrated scalp and serum biomarker model suggesting the systemic nature of the disease, advocating for the need for immune-based systemic treatment.

[Alopecia areata with good response to tofacitinib]

We present a case of a 46-year-old woman suffering from active inflammatory alopecia areata universalis. After frustrating use of topical and systemic glucocorticoids, cream PUVA (psoralen and ultraviolet A) therapy and dithranol in increasing dosage, the patient was treated with 2 × 5 mg per day tofacitinib per os. After about 4-6 months, hair growth commenced, which led to full regrowth of scalp hair over the 18 months of therapy, which was well tolerated. The case shows impressively that the off-label application of tofacitinib is a therapeutic option for alopecia areata.

Single-nucleotide polymorphisms in 3'-untranslated region inducible costimulator gene and the important roles of miRNA in alopecia areata

Background

Alopecia areata (AA) spares the stem cell compartment and attacks only the base of the hair follicle, which is surrounded by infiltrating lymphocytes. AA is associated with polymorphisms in immune-related genes and with decreased function of CD4+CD25+ T regulatory (Treg) cells. Treg function is modulated by the costimulatory molecules, like inducible costimulator (ICOS) that are crucial in orienting T cell differentiation and function so that they strongly impact on the immunologic decision between tolerance or autoimmunity development.

Objective

The aim of our study was to investigate the possible association of AA with single-nucleotide polymorphisms (SNP) present in the ICOS 3'-untranslated region (3'UTR) region and to elucidate how SNPs modulate ICOS gene expression by affecting miRNA binding sites.

Methods

This is a case-control study performed in 184 patients with AA and 200 controls. ICOS gene and miRNA expression were analyzed by real-time polymerase chain reaction.

Results

The genotype carrying the rs4404254(C) [p = 0.012, OR (95% CI): 0.5 (0.3-0.8)] and rs4675379(C) [p = 0.015, OR (95% CI): 0.3 (0.1-0.8)] 3' UTR alleles was more frequently observed in AA patients than in controls and correlated with a reduced ICOS expression. miR-1276 significantly suppressed ICOS expression by binding to the 3'UTR of ICOS mRNA. Also, we observed that, miR-101 and miR-27b are upregulated, while miR-103 and miR-2355-3p are downregulated in peripheral blood mononuclear cells of AA patients compared to controls.

Conclusion

Our data show that rs4404254 and rs4675379 SNPs of ICOS gene are associated with AA and also reveal that the presence of rs4404254 polymorphism correlates with ICOS post-transcriptional repression by microRNA binding.

Prediction of the Risk of Alopecia Areata Progressing to Alopecia Totalis and Alopecia Universalis: Biomarker Development with Bioinformatics Analysis and Machine Learning

BACKGROUND

Alopecia areata (AA) is an autoimmune disease typified by nonscarring hair loss with a variable clinical course. Although there is an increased understanding of AA pathogenesis and progress in its treatments, the outcome of AA patients remains unfavorable, especially when they are progressing to the subtypes of alopecia totalis (AT) or alopecia universalis (AU). Thus, identifying biomarkers that reflect the risk of AA progressing to AT or AU could lead to better interventions for AA patients.

METHODS

In this study, we conducted bioinformatics analyses to select key genes that correlated to AU or AT based on the whole-genome gene expression of 122 human scalp skin biopsy specimens obtained from NCBI-GEO GSE68801. Then, we built a biomarker using 8 different machine learning (ML) algorithms based on the key genes selected by bioinformatics analyses.

RESULTS

We identified 4 key genes that significantly increased (CD28) or decreased (HOXC13, KRTAP1-3, and GPRC5D) in AA tissues, especially in the subtypes of AT and AU. Besides, the predictive accuracy (area under the curve [AUC] value) of the prediction models for forecasting AA patients progressing to AT/AU models reached 90.7% (87.9%) by logistic regression, 93.8% (79.9%) by classification trees, 100.0% (76.3%) by random forest, 96.9% (76.3%) by support vector machine, 83.5% (79.9%) by K-nearest neighbors, 97.1% (87.3%) by XGBoost, and 93.3% (80.6%) by neural network algorithms for the training (internal validation) cohort. Besides, 2 molecule drugs, azacitidine and anisomycin, were identified by Cmap database. They might have the potential therapeutic effects on AA patients with high risk of progressing to AT/AU.

CONCLUSIONS

In the present study, we conducted high accuracy models for predicting the risk of AA patients progressing to AT or AU, which may be important in facilitating personalized therapeutic strategies and clinical management for different AA patients.

IL12B and IL23R polymorphisms are associated with alopecia areata

Alopecia areata is an autoimmune disease in which activation of autoreactive T cells and inflammatory immune signals target the hair follicles autoantigens. Although cytokines are involved in regulating autoimmune inflammation, the specific involvement of these molecules in the pathogenesis of alopecia areata has been remained unsettled. Here, a possible influence of IL12B, IL17A, and IL23R variations on susceptibility to alopecia areata in Iranian patients was investigated. Genotyping of IL12B (rs3212227), IL17A (rs2275913), and IL23R (rs10889677) variants were performed by extracting genomic DNA from patients and controls. Gene expression was analyzed by real-time RT-PCR. The frequency of IL12B and IL23R gene polymorphisms is significantly higher in the patients than controls, while no significant difference was found for IL17A. Stratification of the patients with respect to age at disease onset indicated that CC genotype of IL12B (rs3212227) and AA genotype of IL23R (rs10889677) gene polymorphisms are significantly associated with late-onset alopecia areata disease. In contrast to IL17A and IL23R, IL12B gene expression levels elevated in patients to that of controls, but genotypes had no effect on levels of gene expression. Overall, our data confirmed that the IL12B and IL23R polymorphisms are associated with the risk to develop alopecia areata in our population.

Association of Autoimmune Regulator Gene Rs2075876 Variant, but Not Gene Expression with Alopecia Areata in Males: A Case-control Study

Alopecia areata (AA) is a non-scarring hair loss of autoimmune etiology. The autoimmune regulator (AIRE) gene is believed to be an important driver in AA pathogenesis. Genetic variants can alter mRNA expression levels which may provoke an autoimmune response. A total of 337 males (97 AA patients and 240 controls) were enrolled in the current case-control study. On screening of the most frequent variants in the gene, rs2075876 (A/G) polymorphism in intron 5 was selected and genotyped using Real-Time PCR (polymerase chain reaction) technology. Additionally, circulatory AIRE expression levels were quantified by quantitative reverse-transcription PCR (qRT-PCR). Allelic discrimination analysis revealed GG genotype to be more frequent in patients (90.7% in AA compared to 32.5% in controls, p < .001). G variant conferred increased risk to alopecia under homozygote comparison (GG versus AA: OR = 16.1, 95%CI = 5.57-46.3), dominant model (GG+AG versus AA: OR = 7.24, 95%CI = 2.5-20.5), recessive model (GG versus AG+AA: OR = 20.3, 95%CI = 9.7-42.4), and allelic model (G versus A: OR = 11.6, 95%CI = 6.47-21.1). The expression levels of AIRE gene did not differ significantly between patients and controls and were not related to rs2075876 variant. In conclusion, the intronic variant (rs2075876) is suggested to be a potent susceptibility variant for AA development in the studied population.Abbreviations: AA: Alopecia areata; AIRE: Autoimmune Regulator; APECED: Autoimmune, Polyendocrinopathy Candidiasis Ectodermal Dystrophy; DLQI: Dermatology life quality index questionnaire; MIQE: Minimum information for publication of quantitative real-time PCR experiments; mTEC: Medullary thymic epithelial cells; PHD: Plant homeodomain; qRT-PCR: Quantitative reversetranscription-polymerase chain reaction; RA: Rheumatoid arthritis.

Childhood Alopecia Areata: An Overview of Treatment and Recent Patents

BACKGROUND

Alopecia Areata (AA) is a systemic autoimmune condition that usually starts in childhood.

OBJECTIVE

This article aims to review genetics, therapy, prognosis, and recent patents for AA.

METHODS

We used clinical queries and keywords "alopecia areata" AND "childhood" as a search engine. Patents were searched using the key term "alopecia areata" in Patents.google.com and freepatentsonline. com.

RESULTS

Due to an immune-mediated damage to the hair follicles, hair is lost from the scalp and other areas of the body temporarily or even permanently. Children with AA are generally healthy. Evidence of genetic association and increased predisposition for AA was found by studying families with affected members. Pathophysiologically, T- lymphocytes attack hair follicles and cause inflammation and destruction of the hair follicles and hair loss. In mild cases, there would be well-demarcated round patchy scalp hair loss. The pathognomonic "exclamation mark hairs" may be seen at the lesion periphery. In more severe cases, the hair loss may affect the whole scalp and even the whole body. The clinical course is also variable, which may range from transient episodes of recurrent patchy hair loss to an indolent gradually deteriorating severe hair loss. The treatment of AA depends on factors including patients' age, the extent of the hair loss, duration of disease, psychological impact, availability and side effect profile of the treatments. For localized patchy alopecia, topical application of corticosteroids and/or intralesional corticosteroids are the treatment of choice. Other topical treatments include minoxidil, anthralin, coal tar and immunotherapy. In severe resistant cases, systemic immunosuppressants may be considered. Although herbal medicine, acupuncture, complementary and alternative medicine may be tried on children in some Asian communities, the evidence to support these practices is lacking. To date, only a few recent patents exist in topical treatments, including Il-31, laser and herbal medications. Clinical efficacy is pending for these treatment modalities.

CONCLUSION

None of the established therapeutic options are curative. However, newer treatment modalities, including excimer laser, interleukin-31 antibodies and biologics, are evolving so that there may be significant advances in treatment in the near future. AA can be psychosocially devastating. It is important to assess the quality of life, degree of anxiety, social phobia and mood of the patients and their families. Psychological support is imperative for those who are adversely affected psychosocially.

The prevalence of systemic sclerosis is increased among patients with alopecia areata: a population-based study

Although the coexistence of alopecia areata (AA) and systemic sclerosis (SSc) has been anecdotally reported, the association between these conditions has been poorly investigated. We aimed to assess the association between AA and SSc using a large-scale real-life computerized database. A cross-sectional study was conducted comparing the prevalence of SSc among patients with AA and among age-, sex-, and ethnicity-matched control subjects. Chi-square and t tests were used for univariate analysis, and logistic regression model was used for multivariate analysis. The study was performed utilizing the computerized database of Clalit Health Services ensuring 4.4 million subjects. A total of 51,561 patients with AA and 51,410 controls were included in the study. The prevalence of SSc was increased in patients with AA as compared with the control group (0.1% vs. 0.0%, respectively; OR, 2.30; 95% CI, 1.2-4.4; P = 0.010). The association was stronger among older and Jewish patients. In a multivariate analysis adjusting for sex, age, ethnicity, and other comorbidities, AA was still independently associated with SSc (OR, 2.3; 95% CI, 1.2-4.4; P = 0.012). In conclusion, a significant positive association was revealed between AA and SSc. Further studies are necessary to establish these findings in other study populations and to elucidate the mechanism underlying this association. Awareness of SSc may be of importance for physicians treating patients with AA, and screening for SSc in patients with relevant symptoms may be considered.

Monotherapy for Alopecia Areata: A Systematic Review and Network Meta-Analysis

BACKGROUND

There are many treatments available for alopecia areata; however, none are approved by the US Food and Drug Administration. Thus, there is clinician benefit in efficacy comparison.

METHODS

A network meta-analysis was used to create direct and indirect comparisons of alopecia areata studies in addition to an inconsistency analysis, risk of bias, and quality of evidence assessment.

RESULTS

For mild disease, intralesional corticosteroids were ranked the most likely to produce a response at 78.9% according to SUCRA (surface under the cumulative ranking curve) followed by topical corticosteroids (67.9%), prostaglandin analogs (67.1%), diphenylcyclopropenone (DPCP, 63.4%), topical minoxidil (61.2%), and squaric acid dibutylester (SADBE, 35.0%). In contrast, for moderate to severe disease (>50% scalp hair loss), DPCP was the top-ranked treatment (87.9%), followed by laser (77.9%), topical minoxidil (55.5%), topical corticosteroids (50.1%), SADBE (49.7%), and topical tofacitinib (47.6%). There were insufficient eligible trials to include oral tofacitinib in the network.

CONCLUSION

Statistically significant evidence is presented for the use of intralesional and topical corticosteroids for treatment of mild disease and DPCP, laser, SADBE, topical minoxidil and topical corticosteroids for moderate to severe disease. Further controlled trials are required to analyze the relative efficacy of oral tofacitinib.

Alopecia areata patients show deficiency of FOXP3+CD39+ T regulatory cells and clonotypic restriction of Treg TCRβ-chain, which highlights the immunopathological aspect of the disease

Alopecia areata (AA) is a hair loss disorder resulting from an autoimmune reaction against hair follicles. T-helper 1 cells are a major contributor to this disorder, but little is known about the role of T-regulatory cells (Tregs) in AA. Here, we analysed the distribution of circulating Treg subsets in twenty AA patients with active hair loss and fifteen healthy subjects by flow cytometry. The Treg suppressor HLA-DR+ subpopulation was significantly reduced in the patients (P<0.001) and there were significantly fewer cells expressing CD39 among the CD4+CD25+Foxp3+ Treg subpopulation in patients (P = 0.001). FOXP3 CD39 Treg cells were also reduced in hair follicles; by 75% in non-lesional skin and 90% in lesional skin, when compared to control healthy skin. To further characterise Treg cells in AA; Tregs (CD4+CD25+FOXP3+) were investigated for their TCRβ sequence. PCR products analysed by Next Generation Sequencing techniques, showed that all frequent public clonotypes in AA Tregs were also present in controls at relatively similar frequencies, excepting two public clonotypes: CATSRDEGGLDEKLFF (V15 D1 J1-4) and CASRDGTGPSNYGYTF (V2 D1 J1-2), which were exclusively present in controls. This suggests that these Treg clonotypes may have a protective effect and that they may be an exciting subject for future therapeutic applications.

Family recurrence risk of alopecia areata in the Faroe Islands

BACKGROUND

Reports of a positive family history of alopecia areata (AA) have led to the assumption of a genetic component. The Faroe Islands population is small, has been isolated until the 20th century, and is served by only one dermatology clinic, making it highly suitable for genealogical studies.

AIM

To determine the incidence of AA and to estimate the recurrence risk ratio (RRR) in five generations and in a nationwide dermatologist-based AA cohort using the Faroese genealogy database.

METHODS

All registered cases of AA during the period 1973-2011 were identified from the Faroese national dermatology clinics. The AA cases were linked with the genealogy database covering the entire Faroese population, and the probability of AA among first-, second- and third-degree relatives was calculated.

RESULTS

In total, 178 cases of AA were identified, giving a crude incidence of 10.1 per 100 000 person-years (10.9 for women and 9.4 for men). The cumulative incidence proportion over life was 0.8%. There was no apparent trend in the probabilities for AA in first-degree family members compared with second- and third-degree relatives. RRR was > 1 in second-degree family members only.

CONCLUSION

A lower prevalence rate of AA was found than previously published. The genealogical study failed to identify any apparent trend in the RRR estimates, questioning the role of genetic factors in AA in the Faroe Islands. However, it is possible that the trend is masked by bias and low power; larger studies are therefore warranted to estimate the heritability of AA.

Alopecia areata: a review of disease pathogenesis

BACKGROUND

Alopecia areata is a disorder that results in nonscarring hair loss. The psychological impact can be significant, leading to feelings of depression and social isolation. Objectives In this article, we seek to review the pathophysiological mechanisms proposed in recent years in a narrative fashion.

METHODS

We searched MEDLINE and Scopus for articles related to alopecia areata, with a particular emphasis on its pathogenesis.

RESULTS

The main theory of alopecia areata pathogenesis is that it is an autoimmune phenomenon resulting from a disruption in hair follicle immune privilege. What causes this breakdown is an issue of debate. Some believe that a stressed hair follicle environment triggers antigen presentation, while others blame a dysregulation in the central immune system entangling the follicles. Evidence for the latter theory is provided by animal studies, as well investigations around the AIRE gene. Different immune-cell lines including plasmacytoid dendritic cells, natural killer cells and T cells, along with key molecules such as interferon-γ, interleukin-15, MICA and NKG2D, have been identified as contributing to the autoimmune process.

CONCLUSIONS

Alopecia areata remains incurable, although it has been studied for years. Available treatment options at best are beneficial for milder cases, and the rate of relapse is high. Understanding the exact mechanisms of hair loss in alopecia areata is therefore of utmost importance to help identify potential therapeutic targets.

Differential proteomics of lesional vs. non-lesional biopsies revealed non-immune mechanisms of alopecia areata

Alopecia areata (AA) is one of the common hair disorders for which treatment is frequently ineffective and associated with relapsing episodes. Better understanding of disease mechanisms and novel therapeutic targets are thus required. From 10 AA patients, quantitative proteomics using LTQ-Orbitrap-XL mass spectrometer revealed 104 down-regulated, 4 absent, 3 up-regulated and 11 newly present proteins in lesional vs. non-lesional biopsies. Among these, the decreased levels of α-tubulin, vimentin, heat shock protein 70 (HSP70), HSP90, annexin A2 and α-enolase were successfully confirmed by Western blotting. Protein-protein interactions network analysis using STRING tool revealed that the most frequent biological processes/networks of the down-regulated proteins included tissue development, cell differentiation, response to wounding and catabolic process, whereas those for the up-regulated proteins included biological process, metabolic process, cellular transport, cellular component organization and response to stimulus. Interestingly, only 5 increased/newly present proteins were associated with the regulation of immune system, which may not be the predominant pathway in AA pathogenic mechanisms as previously assumed. In summary, we report herein the first proteome dataset of AA demonstrating a number of novel pathways, which can be linked to the disease mechanisms and may lead to discovery of new therapeutic targets for AA.

Tofacitinib (Selective Janus Kinase Inhibitor 1 and 3): A Promising Therapy for the Treatment of Alopecia Areata: A Case Report of Six Patients

Background

Alopecia areata (AA) is a chronic autoimmune disorder characterized by patchy loss of hair from scalp, beard, eyebrows, or rarely even body hair. Rarely, the disease can be widespread and severe leading to loss of entire scalp and body hair causing apprehension and psychological stress in patients. Management of such cases is equally difficult with the available options of topical and systemic immunosuppressant. Tofacitinib, JAK3 inhibitor, is emerging as a promising drug for the management of severe and resistant cases of AA/totalis/universalis.

Objective

Our study aims to show the effectiveness of oral tofacitinib in the treatment of alopecia universalis (AU).

Methods

Six patients diagnosed with AU/alopecia totalis duration of disease 6 months-15 years refractory to other treatments were selected and were started on oral tofacitinib 5 mg twice daily up to 10 mg BID and were followed up every 4 weeks. The efficacy was measured by hair regrowth using photographic assessment, Severity of Alopecia Tool score, and physical examination. Patients will be followed up for 6 months after stopping treatment for assessing disease relapse.

Results

All our six patients showed dramatic response to oral tofacitinib. Patients were followed up every 4 weeks, and results were assessed. Significant hair regrowth was evident in all the patients by the end of 12 weeks. Currently, four of our patients are on oral tofacitinib 10 mg BID and are under follow-up. There was no relapse in one patient after stopping drug for 4 months. Another patient started developed AA patches in the eyebrows within 2 months of stopping tofacitinib. Acneiform eruptions were seen in two patients which were managed with topicals.

Conclusion

In our patients, tofacitinib successfully alleviated AU in the absence of significant adverse side effects. We recommend that further controlled studies be required to establish safety and confirm efficacy.

Alopecia Areata: Review of Epidemiology, Clinical Features, Pathogenesis, and New Treatment Options

Alopecia areata (AA) is a complex autoimmune condition that causes nonscarring hair loss. It typically presents with sharply demarcated round patches of hair loss and may present at any age. In this article, we review the epidemiology, clinical features, pathogenesis, and new treatment options of AA, with a focus on the immunologic mechanism underlying the treatment. While traditional treatment options such as corticosteroids are moderately effective, a better understanding of the disease pathogenesis may lead to the development of new treatments that are more directed and effective against AA. Sources were gathered from PubMed, Embase, and the Cochrane database using the keywords: alopecia, alopecia areata, hair loss, trichoscopy, treatments, pathogenesis, and epidemiology.

Complete Regrowth of Beard Hair with Ruxolitinib in an Alopecia Universalis Patient

While most alopecia areata (AA) cases resolve spontaneously, the more severe types of AA, alopecia totalis (AT) and alopecia universalis (AU), can be highly resistant to therapy. We report on a 33-year-old ultraorthodox Jewish man with an 11-year history of AA that resulted in complete loss of the scalp and body hair 7 years ago. Previous treatments with intralesional and systemic corticosteroids had only partial and temporary effects. The patient was treated with ruxolitinib, 20 mg twice daily, resulting in complete growth of the beard after 4 months of treatment. The beard has a special significance for ultraorthodox Jews, and loss of the beard hair can have marked social and psychological consequences in AA patients. The Janus kinase (JAK) inhibitors have recently emerged as an effective treatment modality in AA, including the more severe forms, such as AT or AU. This report highlights the beneficial effects of the JAK inhibitors, especially in populations where the hair has a special importance due to cultural and religious backgrounds.

Alopecia areata: What's new in epidemiology, pathogenesis, diagnosis, and therapeutic options?

Alopecia areata (AA) is a common and stressful disorder that results in hair loss, and resistant to treatment in some cases. Experimental and clinical evidence suggests that AA is caused by autoimmune attack against the hair follicles. The precise pathomechanism, however, remains unknown. Here, we focus on the recent progress in multidisciplinary approaches to the epidemiology, pathogenesis, and new treatments of AA in 996 publications from January 2010 to July 2016, and provide an overview of the current understanding in clinical management and research directions.

Beard alopecia areata: a multicentre review of 55 patients

BACKGROUND

Alopecia areata on the beard area (BAA) is a common clinical manifestation, but there are no studies about its characteristics.

OBJECTIVE

To describe the epidemiology, comorbidities, clinical presentation, evolution, diagnostic findings and therapeutic choices in a series of patients with BAA.

METHODS

This retrospective multicentre review included patients diagnosed with BAA as the first and unique clinical manifestation with at least 12 months of follow-up. Diagnosis was performed based on the typical clinical features. Extra-beard involvement was monitored in all cases.

RESULTS

Overall, 55 male patients with a mean age of 39.1 years (range 20-74) were included. Twenty-five patients (45.5%) developed alopecia of the scalp during follow-up and more than 80% of cases appeared in the first 12.4 months. Clinical presentation of AA on the scalp was patchy AA (less than 5 patches) (52%), multifocal AA (28%), AA totalis (12%) and AA universalis (8%). Multivariate analysis revealed a trend of association between scalp involvement and family history of AA without statistical significance.

CONCLUSIONS

According to this study, BAA may progress to scalp AA in a significant number of patients (45.5% of the patients with a follow-up interval of at least 12 months). In the group of patients who developed scalp AA, 80% of them did it within the first 12 months, so follow-up of patients with BAA is highly encouraged.

Alopecia Areata as a Manifestation of Systemic Lymphoma: Report of Two Cases

Alopecia areata is a common autoimmune disorder leading to hair loss. It usually affects individuals under the age of 40, and first appearance in older subjects is considered uncommon. Here, we report 2 cases of rapidly progressing alopecia areata, which appeared for the first time in adults. Patient 1 had alopecia universalis, which preceded the identification of hepatosplenic T-cell lymphoma, a rare form of lymphoma. Patient 2 suffered from the ophiasis type of alopecia areata, presenting for the first time following chemotherapy for non-Hodgkin B-cell lymphoma. These 2 cases highlight the need to screen for malignancies in patients who present with rapidly progressing alopecia areata for the first time after the age of 40.

Efficacy of tofacitinib in treatment of alopecia universalis in two patients

BACKGROUND

Autoimmune-triggered non-scarring hair loss is a feature of alopecia areata (AA). Initially patchy and often self-limited, severe hair loss forms include the complete loss of scalp hair or alopecia totalis (AT) and complete loss of all hair or alopecia universalis (AU). For AT and AU a reliable treatment has remained elusive. The targeted kinase inhibitor tofacitinib, in current use for treatment of other immune diseases, has been hypothesized as a viable option for AA, AT and AU therapy and a few case reports support this.

OBJECTIVE

Our study aims to provide evidence for the effectiveness of tofacitinib in the treatment of AU.

METHODS

Two patients diagnosed with long-term AU were prescribed tofacitinib citrate at a dosage of 5 mg twice daily and observed for eight months.

RESULTS

In the first patient, beard growth was significant by 3 months of treatment. By 6 months of treatment, hair growth was apparent throughout the entire body. By 8 months of treatment, scalp hair continued to grow longer and thicker. In addition, eyelashes and eyebrows were established. In the second patient, a noticeable increase in scalp hair was present just 1 month into treatment. By 4 months into treatment, significant scalp regrowth was observed as well as eyelash, eyebrow and beard regrowth. Axillary hair regrowth and isolated leg hair was noted by 8 months.

CONCLUSION

In our patients, tofacitinib successfully alleviated AU in the absence of significant adverse side-effects. We recommend that further study be required to establish safety and confirm efficacy.

Alopecia areata: Animal models illuminate autoimmune pathogenesis and novel immunotherapeutic strategies

One of the most common human autoimmune diseases, alopecia areata (AA), is characterized by sudden, often persisting and psychologically devastating hair loss. Animal models have helped greatly to elucidate critical cellular and molecular immune pathways in AA. The two most prominent ones are inbred C3H/HeJ mice which develop an AA-like hair phenotype spontaneously or after experimental induction, and healthy human scalp skin xenotransplanted onto SCID mice, in which a phenocopy of human AA is induced by injecting IL-2-stimulated PBMCs enriched for CD56+/NKG2D+ cells intradermally. The current review critically examines the pros and cons of the available AA animal models and how they have shaped our understanding of AA pathobiology, and the development of new therapeutic strategies. AA is thought to arise when the hair follicle's (HF) natural immune privilege (IP) collapses, inducing ectopic MHC class I expression in the HF epithelium and autoantigen presentation to autoreactive CD8+ T cells. In common with other autoimmune diseases, upregulation of IFN-γ and IL-15 is critically implicated in AA pathogenesis, as are NKG2D and its ligands, MICA, and ULBP3. The C3H/HeJ mouse model was used to identify key immune cell and molecular principles in murine AA, and proof-of-principle that Janus kinase (JAK) inhibitors are suitable agents for AA management in vivo, since both IFN-γ and IL-15 signal via the JAK pathway. Instead, the humanized mouse model of AA has been used to demonstrate the previously hypothesized key role of CD8+ T cells and NKG2D+ cells in AA pathogenesis and to discover human-specific pharmacologic targets like the potassium channel Kv1.3, and to show that the PDE4 inhibitor, apremilast, inhibits AA development in human skin. As such, AA provides a model disease, in which to contemplate general challenges, opportunities, and limitations one faces when selecting appropriate animal models in preclinical research for human autoimmune diseases.

The role of lymphocytes in the development and treatment of alopecia areata

Alopecia areata (AA) development is associated with both innate and adaptive immune cell activation, migration to peri- and intra-follicular regions, and hair follicle disruption. Both CD4(+) and CD8(+) lymphocytes are abundant in AA lesions; however, CD8(+) cytotoxic T lymphocytes are more likely to enter inside hair follicles, circumstantially suggesting that they have a significant role to play in AA development. Several rodent models recapitulate important features of the human autoimmune disease and demonstrate that CD8(+) cytotoxic T lymphocytes are fundamentally required for AA induction and perpetuation. However, the initiating events, the self-antigens involved, and the molecular signaling pathways, all need further exploration. Studying CD8(+) cytotoxic T lymphocytes and their fate decisions in AA development may reveal new and improved treatment approaches.

Alopecia areata profiling shows TH1, TH2, and IL-23 cytokine activation without parallel TH17/TH22 skewing

BACKGROUND

Alopecia areata (AA) is a common T cell-mediated disorder with limited therapeutics. A molecular profile of cytokine pathways in AA tissues is lacking. Although studies have focused on TH1/IFN-γ responses, several observations support a shared genetic background between AA and atopy.

OBJECTIVE

We sought to define the AA scalp transcriptome and associated biomarkers with comparisons with atopic dermatitis (AD) and psoriasis.

METHODS

We performed microarray and RT-PCR profiling of 27 lesional and 17 nonlesional scalp samples from patients with AA for comparison with normal scalp samples (n = 6). AA gene expression was also compared with samples from patients with lesional or nonlesional AD and those with psoriasis. A fold change of greater than 1.5 and a false discovery rate of less than 0.05 were used for differentially expressed genes (DEGs).

RESULTS

We established the AA transcriptomes (lesional vs nonlesional: 734 DEGs [297 upregulated and 437 downregulated]; lesional vs normal: 4230 DEGs [1980 upregulated and 2250 downregulated]), including many upregulated immune and downregulated hair keratin genes. Equally impressive as upregulation in TH1/interferon markers (IFNG and CXCL10/CXCL9) were those noted in TH2 (IL13, CCL18, CCL26, thymic stromal lymphopoietin, and periostin), TH9/IL-9, IL-23 (p40 and p19), and IL-16 mediators (all P < .05). There were no increases in TH17/TH22 markers. Hair keratin (KRT) expressions (ie, KRT86 and KRT85) were significantly suppressed in lesional skin. Greater scalp involvement (>25%) was associated with greater immune and keratin dysregulation and larger abnormalities in nonlesional scalp samples (ie, CXCL10 and KRT85).

CONCLUSIONS

Our data associate the AA signature with TH2, TH1, IL-23, and IL-9/TH9 cytokine activation, suggesting consideration of anti-TH2, anti-TH1, and anti-IL-23 targeting strategies. Similar to psoriasis and AD, clinical trials with selective antagonists are required to dissect key pathogenic pathways.