Alopecia areata: A psychodermatological perspective

Single-cell transcriptome profiling reveals cell type-specific variation and development in HLA expression of human skin

Skin, the largest organ of body, is a highly immunogenic tissue with a diverse collection of immune cells. Highly polymorphic human leukocyte antigen (HLA) molecules have a central role in coordinating immune responses as recognition molecules. Nevertheless, HLA gene expression patterns among diverse cell types within a specific organ, like the skin, have yet to be thoroughly investigated, with stromal cells attracting much less attention than immune cells. To illustrate HLA expression profiles across different cell types in the skin, we performed single-cell RNA sequencing (scRNA-seq) analyses on skin datasets, covering adult and fetal skin, and hair follicles as the skin appendages. We revealed the variation in HLA expression between different skin populations by examining normal adult skin datasets. Moreover, we evaluated the potential immunogenicity of multiple skin populations based on the expression of classical HLA class I genes, which were well represented in all cell types. Furthermore, we generated scRNA-seq data of developing skin from fetuses of 15 post conception weeks (PCW), 17 PCW, and 22 PCW, delineating the dynamic expression of HLA genes with cell type-dependent variation among various cell types during development. Notably, the pseudotime trajectory analysis unraveled the significant variance in HLA genes during the evolution of vascular endothelial cells. Moreover, we uncovered the immune-privileged properties of hair follicles at single-cell resolution. Our study presents a comprehensive single-cell transcriptomic landscape of HLA genes in the skin, which provides new insights into variation in HLA molecules and offers a clue for allogeneic skin transplantation.

Parenting styles and psychological effects on children with alopecia areata: exploring family dynamics, anxiety, and depression

Alopecia areata (AA) is an autoimmune disease that develops due to inflammation and causes sudden hair loss. Ithas been observed that family circumstances may contribute to the development of AA. This study aims to assessthe relationship between the development of alopecia areata in children, family functions, and depression andanxiety levels in their parents.Thirty-nine participants diagnosed with AA and 41 healthy controls (HC), agedbetween 8 and 18 years, and their parents participated in the study. The assessment of the children included thecompletion of a socio-demographic data form, the Parenting Style Scale (PSS), and the Revised Children's Anxietyand Depression Scale (RCADS). The parents provided information on a sociodemographic form, the BeckDepression Inventory (BDI), and the Beck Anxiety Inventory (BAI). The children in the control group scoredsignificantly higher on the PSS acceptance/ involvement subscale than those with AA. In the AA group, the numberof authoritative and indulgent (PSS) families was statistically significantly lower than that of the families in the HC,and the number of neglectful families was statistically significantly higher than those of the control group. Totalanxiety and depression t scores (RCADS) were statistically significantly higher in the AA children than in theHC. Our study demonstrates the importance of considering familial factors and parental mental health tounderstand and address alopecia areata in children. Our findings support the psychosomatic component of AA.Implementing comprehensive treatment strategies that target psychological well-being and family dynamics couldprove crucial.

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.

Platelet-rich plasma efficacy in alopecia areata patients with normal and elevated levels of antibodies against thyroglobulin and thyroid peroxidase

AIM

To evaluate and compare the efficacy of platelet-rich plasma (PRP) therapy in alopecia areata (AA) patients with normal and with elevated levels of anti-thyroglobulin antibodies and/or anti-thyroid peroxidase antibodies.

Treatments for Moderate-to-Severe Alopecia Areata: A Systematic Narrative Review

Treatments for alopecia areata (AA) have traditionally been prescribed off-label, and there has been no universal agreement on how to best manage the condition. Baricitinib is the first oral selective Janus kinase (JAK) inhibitor approved for the treatment of adults with severe AA. As a better understanding of the evidence supporting the management of AA in clinical practice is needed, we conducted a systematic literature review and subsequent narrative review to describe available evidence pertaining to the efficacy and tolerability of treatments currently recommended for adults with moderate-to-severe forms of AA. From 2557 identified records, a total of 53 records were retained for data extraction: 9 reported data from 7 randomized controlled trials (RCTs) versus placebo, and 44 reported data from unique RCTs with no placebo arm, non-randomized trials, or observational studies. Across drug classes, data were reported heterogeneously, with little consistency of data collection or clinical endpoints used. The most robust evidence was for the JAK inhibitor class, in particular the JAK1/JAK2 inhibitor baricitinib. Five RCTs (three for baricitinib) demonstrated a consistent benefit of JAK inhibitor therapy over placebo across various clinical outcomes in adult patients with at least 50% scalp hair loss. Overall, hair regrowth varied widely for the other drug classes and was generally low for patients with moderate-to-severe AA. Relapses were commonly observed during treatment and upon discontinuation. Adverse effects were generally consistent with the known safety profile of each intervention. The heterogeneity observed prevented the conduct of a network meta-analysis or an indirect comparison of different treatments. We found that the current management of patients with moderate-to-severe AA often relies on the use of treatments that have not been well evaluated in clinical trials. The most robust evidence identified supported the use of baricitinib, and other oral JAK inhibitors, in patients with severe AA.

Psychological Stress-Induced Pathogenesis of Alopecia Areata: Autoimmune and Apoptotic Pathways

Alopecia areata (AA) is an autoimmune dermatological disease with multifactorial etiology and is characterized by reversible hair loss in patches. AA may be closely related to emotional stress and influenced by psychological factors as part of its pathophysiology; however, its etiology remains predominantly unknown. This review aimed to elucidate the association between AA occurrence and the neuropeptide substance P (SP) and corticotropin-releasing hormone (CRH), which are secreted during emotional stress, and have been understood to initiate and advance the etiopathogenesis of AA. Therefore, this review aimed to explain how SP and CRH initiate and contribute to the etiopathogenesis of AA. To assess the etiopathogenesis of AA, we conducted a literature search on PubMed and ClinicalTrials.gov. Overall, several authors described interactions between the hair follicles (HFs) and the stress-associated signaling substances, including SP and CRH, in the etiology of AA; this was attributed to the understanding in that AA can occur without the loss of HFs, similar to that observed in hereditary hair loss with age. Most studies demonstrated that the collapse of "immune privilege" plays a crucial role in the development and exacerbation of the AA; nonetheless, a few studies indicated that substances unrelated to autoimmunity may also cause apoptosis in keratocytes, leading to the development of AA. We investigated both the autoimmune and apoptotic pathways within the etiology of AA and assessed the potential interactions between the key substances of both pathways to evaluate potential therapeutic targets for the treatment of AA. Clinical trials of marketed/unreviewed intervention drugs for AA were also reviewed to determine their corresponding target pathways.

"Mens Sana in Cute Sana"-A State of the Art of Mutual Etiopathogenetic Influence and Relevant Pathophysiological Pathways between Skin and Mental Disorders: An Integrated Approach to Contemporary Psychopathological Scenarios

The negative socioeconomic impact of mental health disorders and skin diseases has increased in part due to the conflict between Russia and Ukraine, which has been a fertile ground for the emergence of psychopathologies. It is firmly established that there is a direct thread of etiopathogenetic communication between skin diseases and neuropsychiatric disorders, and the literature has tried to reveal the pathophysiological mechanisms governing such bidirectionality. This paper discusses this complex network of molecular pathways that are targeted by conventional and biological pharmacological agents that appear to impact two pathological spheres that previously seemed to have little connection. This molecular discussion is supplemented with a literature review, from a clinical viewpoint, regarding skin-brain etiopathogenetic bidirectionality. We focus on post-traumatic stress disorder (PTSD), which can be considered for all intents and purposes a systemic inflammatory disease that also affects the skin. A brief overview is also provided on the diagnostic-therapeutic and follow-up potential of oxidative and inflammatory markers potentially involved in the pathophysiological mechanisms treated. The aim is to clarify how these mechanisms may be useful in defining different stress-coping strategies and thus individual phenotypes of stress sensitivity/resistance in order to promote personalized medicine in the field of psychodermatology.

Peripheral control of psychiatric disorders: Focus on OCD. Are we there yet?

"We are all in this together" - we often hear this phrase when we want to flag up a problem that is not for a single individual but concerns us all. A similar reflection has been recently made in the field of mental disorders where brain-centric scientists have started to zoom out their brain-focused graphical representations of the mechanisms regulating psychiatric diseases to include other organs or mediators that did not belong historically to the world of neuroscience. The brain itself - that has long been seen as a master in command secluded in its fortress (the blood brain barrier), has now become a collection of Airbnb(s) where all sorts of cells come in and out and sometimes even rearrange the furniture! Under this new framework of reference, mental disorders have become multisystem pathologies where different biological systems - not just the CNS -contribute 'all together' to the development and severity of the disease. In this narrative review article, we will focus on one of the most popular biological systems that has been shown to influence the functioning of the CNS: the immune system. We will specifically highlight the two main features of the immune system and the CNS that we think are important in the context of mental disorders: plasticity and memory.

What's being recommended to patients on social media? A cross-sectional analysis of alopecia treatments on YouTube®

Our study shows that treatment recommendations provided through social media are based on evidence of variable quality. However, on Youtube®, there was no significant difference between viewership numbers between physicians and nonphysicians. Therefore, Dermatologists with expertise in alopecia should consider utilizing social media to promote evidence-based treatment options for all alopecia subtypes.