Fibroproliferative genes are preferentially expressed in central centrifugal cicatricial alopecia

Proteomic Profiling of Central Centrifugal Cicatricial Alopecia Reveals Role of Humoral Immune Response Pathway and Metabolic Dysregulation

Proteomic profiling on other primary cicatricial alopecias, such as frontal fibrosing alopecia and lichen planopilaris, have suggested a T helper 1-mediated inflammatory pathway, but in central centrifugal cicatricial alopecia (CCCA), the protein expression patterns are unknown. In this study, we sought to characterize protein expression patterns in CCCA to identify biomarkers of disease activity that will identify potential therapeutic avenues for treatment. Scalp protein quantification was performed to understand protein expression patterns in affected versus unaffected scalps in CCCA. A total of 5444 proteins were identified, of which 148 proteins were found to be differentially expressed in CCCA-affected scalp, with upregulation of adaptive immune pathways (IGHG3, P = .034; IGHG4, P = .01; IGG1, P = .026) and markers of fibrosis (ITGA1, P = .016; SFRP2, P = .045; TPM2, P = .029; SLMAP, P = .016) and downregulation of metabolic proteins (ALOX15B, P = .003; FADS2, P = .006; ELOVL5, P = .007; FA2H, P = .017; FAR2, P = .011; SC5D, P < .001). Our analysis revealed, to our knowledge, previously unknown humoral immune canonical pathways, notably IgG, implicated in CCCA and additionally confirmed aberrant lipid metabolism pathways implicated in diabetes mellitus, suggesting unique mechanisms of disease in patients with CCCA.

Updates on disorders in curly hair

Hair disorders, including central centrifugal cicatricial alopecia (CCCA), traction alopecia (TA), and acquired trichorrhexis nodosa (ATN), commonly occur in individuals with curly textured hair. Curly textured hair in individuals of African descent has unique properties and can present diagnostic and therapeutic challenges. CCCA has been linked to uterine leiomyoma and type 2 diabetes mellitus, as well as fibroproliferation. TA often presents with a fringe sign and can arise from high-tension hairstyles presumed to be protective. Trichoscopy is useful in establishing a diagnosis; perifollicular halos are more commonly seen than perifollicular erythema or scale in CCCA. In TA, miniaturized follicles, hair casts, and "flambeau sign" can be seen. Hairstyling practices likely contribute to TA and ATN; however, the data are mixed on the role of chemical relaxers and heat styling in CCCA. Unique considerations in the presentation of frontal fibrosing alopecia in curly textured hair have also been published recently. This review provides a comprehensive, up-to-date summary of these disorders with an emphasis on their unique properties, as well as considerations in hair care for curly textured hair.

Risk factors and comorbidities associated with central centrifugal cicatricial alopecia

Central centrifugal cicatricial alopecia (CCCA) is the most common form of scarring alopecia that most often affects Black women. The disease typically begins with hair loss in the center scalp, which progresses in a centripetal fashion. Both environmental insult and genetics have been implicated in CCCA etiology, although the exact pathophysiology remains unknown. Nevertheless, it is important that providers feel comfortable educating their patients on risk factors (RFs) for the development or worsening of CCCA, and potential comorbidities associated with the condition. Thus, the goal of this review was to summarize these factors. A comprehensive literature search was performed, and studies were included if they reported research on RFs for or comorbidities associated with, CCCA. A total of 15 studies were included: n = 5 researching RFs for CCCA and n = 10 researching comorbidities associated with CCCA. There was an association suggesting an increased risk of CCCA with traction hairstyles in n = 2/3 studies, previous pregnancies in n = 1/1 studies, and use of chemical hair relaxers in n = 1/3 studies. Additionally, age and total years of hair loss were associated with increased CCCA severity in n = 2/2 studies. Type 2 diabetes was positively associated with CCCA in n = 3/5 studies, uterine leiomyomas in n = 1/2 studies, hyperlipidemia in n = 1/2 studies, and vitamin D deficiency in n = 1/1 studies. Conflicting results regarding RFs and comorbidities associated with CCCA exist within the literature. Thus, further investigation in larger cohorts must be done, and future research into genes implicated in CCCA and their potential role in the development of other diseases is recommended.

Clinical factors and hair care practices influencing outcomes in central centrifugal cicatricial alopecia

Central centrifugal cicatricial alopecia (CCCA) is the most common form of primary scarring alopecia in women of African descent, negatively impacting their quality of life. Treatment is often challenging, and we usually direct therapy to suppress and prevent the inflammation. However, factors affecting clinical outcomes are still unknown. To characterize medical features, concurrent medical conditions, hair care practices, and treatments used for patients with CCCA and assess their relationship with treatment outcomes. We analyzed data from a retrospective chart review of 100 patients diagnosed with CCCA who received treatment for at least one year. Treatment outcomes were compared with patient characteristics to determine any relationships. P-values were calculated using logistic regression and univariate analysis with 95% CI P < 0.05 was considered significant. After one year of treatment, 50% of patients were stable, 36% improved, and 14% worsened. Patients without a history of thyroid disease (P = 0.0422), using metformin for diabetes control (P = 0.0255), using hooded dryers (P = 0.0062), wearing natural hairstyles (P = 0.0103), and having no other physical signs besides cicatricial alopecia (P = 0.0228), had higher odds of improvement after treatment. Patients with scaling (P = 0.0095) or pustules (P = 0.0325) had higher odds of worsening. Patients with a history of thyroid disease (P = 0.0188), not using hooded dryers (0.0438), or not wearing natural hairstyles (P = 0.0098) had higher odds of remaining stable. Clinical characteristics, concurrent medical conditions, and hair care practices may affect clinical outcomes after treatment. With this information, providers can adjust proper therapies and evaluations for patients with Central centrifugal cicatricial alopecia.

Granzyme B in Autoimmune Skin Disease

Autoimmune diseases often present with cutaneous symptoms that contribute to dysfunction, disfigurement, and in many cases, reduced quality-of-life. Unfortunately, treatment options for many autoimmune skin diseases are limited. Local and systemic corticosteroids remain the current standard-of-care but are associated with significant adverse effects. Hence, there is an unmet need for novel therapies that block molecular drivers of disease in a local and/or targeted manner. Granzyme B (GzmB) is a serine protease with known cytotoxic activity and emerging extracellular functions, including the cleavage of cell-cell junctions, basement membranes, cell receptors, and other structural proteins. While minimal to absent in healthy skin, GzmB is markedly elevated in alopecia areata, interface dermatitis, pemphigoid disease, psoriasis, systemic sclerosis, and vitiligo. This review will discuss the role of GzmB in immunity, blistering, apoptosis, and barrier dysfunction in the context of autoimmune skin disease. GzmB plays a causal role in the development of pemphigoid disease and carries diagnostic and prognostic significance in cutaneous lupus erythematosus, vitiligo, and alopecia areata. Taken together, these data support GzmB as a promising therapeutic target for autoimmune skin diseases impacted by impaired barrier function, inflammation, and/or blistering.

Beyond the Hot Comb: Updates in Epidemiology, Pathogenesis, and Treatment of Central Centrifugal Cicatricial Alopecia from 2011 to 2021

Central centrifugal cicatricial alopecia (CCCA) is a form of scarring alopecia that predominantly affects middle-aged women of African descent. Recent data suggest a multifactorial etiology of CCCA that is influenced by environmental and genetic factors. Emerging evidence regarding the genetic basis of the condition may elucidate new therapies. While topical and intralesional steroids and tetracycline antibiotics are the mainstay of treatment, refractory cases may be considered for hair transplantation. Emerging therapies using platelet-rich plasma, botanical formulas, and cosmetic procedures have shown promising results for the future management of CCA. As recent notable advances in CCCA have been achieved, this review provides an update on the epidemiology, pathophysiology, and management of CCCA.

Primary cicatricial alopecias are characterized by dysregulation of shared gene expression pathways

The primary forms of cicatricial (scarring) alopecia (PCA) are a group of inflammatory, irreversible hair loss disorders characterized by immune cell infiltrates targeting hair follicles (HFs). Lichen planopilaris (LPP), frontal fibrosing alopecia (FFA), and centrifugal cicatricial alopecia (CCCA) are among the main subtypes of PCAs. The pathogenesis of the different types of PCAs are poorly understood, and current treatment regimens yield inconsistent and unsatisfactory results. We performed high-throughput RNA-sequencing on scalp biopsies of a large cohort PCA patients to develop gene expression-based signatures, trained into machine-learning-based predictive models and pathways associated with dysregulated gene expression. We performed morphological and cytokine analysis to define the immune cell populations found in PCA subtypes. We identified a common PCA gene signature that was shared between LPP, FFA, and CCCA, which revealed a significant over-representation of mast cell (MC) genes, as well as downregulation of cholesterogenic pathways and upregulation of fibrosis and immune signaling genes. Immunohistological analyses revealed an increased presence of MCs in PCAs lesions. Our gene expression analyses revealed common pathways associated with PCAs, with a strong association with MCs. The indistinguishable differences in gene expression profiles and immune cell signatures between LPP, FFA, and CCCA suggest that similar treatment regimens may be effective in treating these irreversible forms of hair loss.

Immune-mediated alopecias and their mechanobiological aspects

Alopecia is a non-specific term for hair loss clinically diagnosed by the hair loss pattern and histological analysis of patient scalp biopsies. The immune-mediated alopecia subtypes, including alopecia areata, lichen planopilaris, frontal fibrosing alopecia, and central centrifugal cicatricial alopecia, are common, significant forms of alopecia subtypes. For example, alopecia areata is the most common autoimmune disease with a lifetime incidence of approximately 2% of the world's population. In this perspective, we discuss major results from studies of immune-mediated alopecia subtypes. These studies suggest the key event in disease onset as the collapse in immune privilege, which alters the hair follicle microenvironment, e.g., upregulation of major histocompatibility complex molecules and increase of cytokine production, and results in immune cell infiltration, inflammatory responses, and damage of hair follicles. We note that previous studies have established that the hair follicle has a complex mechanical microenvironment, which may regulate the function of not only tissue cells but also immune cell infiltrates. This suggests a potential for mechanobiology to contribute to alopecia research by adding new methods, new approaches, and new ways of thinking, which is missing in the existing literature. To fill this a gap in the alopecia research space, we develop a mechanobiological hypothesis that alterations in the hair follicle microenvironment, specifically in the mechanically responsive tissues and cells, partially due to loss of immune privilege, may be contributors to disease pathology. We further focus our discussion on the potential for applying mechanoimmunology to the study of T cell infiltrates in the hair follicle, as they are considered primary contributors to alopecia pathology. To establish the connection between the mechanoimmunological hypothesis and immune-mediated alopecia subtypes, we discuss what is known about the role of T cells in immune-mediated alopecia subtypes, using the most extensively studied AA as our model.

Treatment-Refractory Central Centrifugal Cicatricial Alopecia Responsive to a Novel Botanical Treatment

Purpose

Central centrifugal cicatricial alopecia (CCCA) is the most common cause of scarring alopecia in women of African descent. However, current treatments for CCCA, such as immunosuppressants and immunomodulatory pharmaceutical agents, have suboptimal efficacy and undesirable side effects. This case series reports the therapeutic effect of a new botanical formulation (Dr. UGro Gashee) in four patients with histologically supported diagnoses of CCCA. The formulations contain at least three phytoactive ingredients that affect multiple targets in the cascade of pathophysiologic events contributing to CCCA. Possible mechanisms of action include anti-inflammatory effects, inhibiting proinflammatory cytokines, and the net antifibrotic effect of inhibiting transforming growth factor-beta while upregulating AMP-activated protein kinase and peroxisome proliferator-associated receptor-gamma activity.

Patients and Methods

Four African American women with treatment-refractory CCCA were treated with a new topical botanical formula (cosmeceutical) alone or in combination with its oral formulation (nutraceutical) for 8 weeks to 1 year. The cosmeceutical and nutraceutical treatments contain similar phytoactive ingredient profiles. Treatment outcomes were collected using documented patient reports and images and by direct observation.

Results

In all patients, scalp pruritus cessation occurred within 2 weeks of treatment, and significant hair regrowth was observed within 2 months. All patients reported a high satisfaction level without adverse effects.

Conclusion

Patients with treatment-refractory CCCA responded to the novel botanical treatment reported in this study. Further evaluations in a controlled trial with more patients are warranted.

Presence of Uterine Leiomyomas Has No Significant Impact on Gene Expression Profile in the Scalp of Patients with Central Centrifugal Cicatricial Alopecia

Central centrifugal cicatricial alopecia (CCCA) is associated with increased expression of genes implicated in fibroproliferative disorders and a higher prevalence of uterine leiomyomas (ULs) among affected individuals. We sought to examine the effect of UL status on the gene expression profile of the lesional scalp in patients with CCCA. Scalp biopsy was obtained from 16 patients with a confirmed diagnosis of CCCA between 2017 and 2020. Microarray analysis was used to identify differential gene expression between patients with CCCA with a history of UL and those without the history. Of more than 20,000 genes analyzed, 23 of 25 genes with the highest expression in patients with CCCA with UL held no statistical significance. No genes previously implicated in fibroproliferative disorders were found among the upregulated transcripts. Of all genes analyzed, only eight upregulated genes and zero downregulated genes had a fold change in expression >2 in patients with CCCA with UL compared with those in patients with CCCA without UL. Our findings highlight similar gene expression patterns in the lesional scalp of patients with CCCA with and without a history of UL. This analysis is key in highlighting no evidence of causational or linked mechanobiology that accounts for the increased prevalence of UL seen in patients with CCCA that previous studies have not addressed.

Gene expression profiling suggests severe, extensive central centrifugal cicatricial alopecia may be both clinically and biologically distinct from limited disease subtypes

The natural history of central centrifugal cicatricial alopecia (CCCA) is widely variable. Some patients experience rapid progression to extensive, end-stage disease while others never approach extensive involvement over decades, suggesting heterogeneity in CCCA disease phenotype. To better characterize clinically severe disease in CCCA, tissue samples were obtained from the peripheral, hair bearing lesional scalp of women with clinically focal, limited, and extensive CCCA disease involvement. A microarray analysis was conducted to identify differential expression of genes previously identified to be preferentially expressed in the lesional scalp vs non-lesional scalp of CCCA patients. Clinically extensive, severe CCCA was characterized by increased expression of MMP9, SFRP4, and MSR1 when directly compared with focal and limited disease. These biomarkers correspond to dysregulated pathways of fibrosis, Wnt signaling, and macrophage-mediated inflammatory processes, respectively. These findings hold significance for both possible targets for future study of prognostic markers of disease severity and new potential therapeutic targets. In summary, this study suggests clinically extensive, severe CCCA may have a differential gene expression pattern in the lesional scalp of affected patients, in addition to its clinical distinction.

New Diagnostic Tools to Evaluate Hair Loss

The precise and reliable diagnosis of hair loss disorders is essential for developing a successful management plan. It is, thus, the responsibility of the dermatologist to select the appropriate diagnostic tools to effectively evaluate patients presenting with hair loss concerns. Fortunately, there is a growing body of noninvasive and invasive diagnostic resources, each with advantages and disadvantages. For the practicing dermatologist, tactile assessments and direct visualization are enhanced with scoring instruments, questionnaires, handheld trichoscopy, and scalp biopsy. For research and clinical study purposes, the more precise, high-resolution tools such as videodermoscopy, optical coherence tomography, and phototrichograms, may be useful.

Central Centrifugal Cicatricial Alopecia: Challenges and Treatments

Central centrifugal cicatricial alopecia (CCCA) is the most common form of primary scarring alopecia diagnosed in women of African descent. Although the etiology was originally attributed exclusively to hairstyling practices common among women of African descent, more recent research on CCCA supports the concept that there are several contributing factors, including variants in gene expression, hair grooming practices that increase fragility on the hair follicle, and associations with other systemic conditions. Treatment of CCCA involves a combination of patient counseling and education on alternative hairstyles, medical therapies, and procedural methods when necessary.

Increased Association between Previous Pregnancies and Use of Chemical Relaxers in 74 Women with Central Centrifugal Cicatricial Alopecia

Background:

Central centrifugal cicatricial alopecia (CCCA) is a type of scarring alopecia exclusively seen in women of African descent. The etiology is unknown and epidemiologic studies including data on comorbidities in patients with CCCA are limited. Our primary objective was to identify possible etiologic and lifestyle associations in patients with CCCA.

Materials and Methods:

A retrospective chart review was conducted for patients diagnosed with CCCA between January 1, 2013, and January 1, 2018, at a university dermatology outpatient clinic. Controls consisted of age-, sex-, and race-matched African–American women diagnosed with other hair loss conditions. Data from 74 cases and 96 controls were collected and analyzed via logistic regression. In addition, a phone survey was conducted in the CCCA cohort asking specific questions related to their condition and quality of life.

Results:

A significant relationship was found between CCCA and previous pregnancies as well as the use of chemical relaxers: patients with CCCA were 11.71 times more likely to have had a previous pregnancy (P < 0.001) and 12.37 times more likely to have used chemical relaxers in the past (P < 0.001). Association with uterine fibroids was found not statistically significant (P > 0.05).

Conclusion:

We identified an association between previous pregnancies and use of chemical relaxers in patients diagnosed with CCCA when compared to controls. These findings may help to plan prospective studies aiming at establishing a more concrete link between hormones and CCCA.

Mitochondrial Sirtuins in Skin and Skin Cancers

Mammalian sirtuins (SIRTs 1-7) are a family of NAD+-dependent deacetylases with distinct subcellular localization and biological functions that regulate various important cellular processes. Among these, SIRTs -3, -4 and -5 are located in the mitochondria and have been implicated in caloric restriction, oxidative stress, aging and various human diseases. Emerging evidence has found dysregulation of mitochondrial sirtuins in multiple dermatological conditions, including responses to ultraviolet radiation (UVR), suggesting their importance in maintaining skin health. In this review, we discuss the roles and implications of mitochondrial sirtuins in cutaneous cellular processes, and their emerging potential as a target for the management of skin diseases, including skin cancer. Among mitochondrial sirtuins, SIRT3 is the most studied and linked to multiple skin conditions and diseases (keratinocyte differentiation, wound healing, chronological aging, UVR and ozone response, systemic sclerosis, melanoma, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)). SIRT4 has been connected to keratinocyte differentiation, chronological aging, UVR response, alopecia, BCC and SCC. Further, SIRT5 has been associated with keratinocyte differentiation, melanoma, BCC and SCC. Overall, while there is compelling evidence for the involvement of mitochondrial sirtuins in skin, additional detailed studies are needed to understand their exact roles in skin and skin cancers.

Profiling the human hair follicle immune system in lichen planopilaris and frontal fibrosing alopecia: can macrophage polarization differentiate these two conditions microscopically?

BACKGROUND

Frontal fibrosing alopecia (FFA) is traditionally regarded as a variant of lichen planopilaris (LPP) based on histological features. Distinct clinical presentation, demographics and epidemiology suggest that differing pathogenic factors determine the final phenotype.

OBJECTIVES

To map the hair follicle immune system in LPP and FFA by systematically comparing key inflammatory markers in defined hair follicle compartments.

METHODS

Lesional scalp biopsies from LPP and FFA and healthy controls were stained with the following immunohistochemical markers: CD1a and CD209, CD4, CD8, CD56, CD68, CD123, CXCR3, forkhead box (FOX)P3, mast cell tryptase and cKit. Macrophage polarization was explored using CD206, CD163, CD86, receptor for advanced glycation end products (RAGE), interleukin (IL)-4 and IL-13 on paired lesional and nonlesional LPP and FFA samples.

RESULTS

Increased numbers of CD8⁺ , CXCR3⁺ and FOXP3⁺ T cells and CD68⁺ macrophages were identified in the distal hair follicle epithelium and perifollicular mesenchyme in both LPP and FFA compared with controls. In both LPP and FFA, total and degranulated mast cells and CD123⁺ plasmacytoid dendritic cells were increased in the perifollicular mesenchyme adjacent to the bulge and infundibulum, whereas numbers of CD1a⁺ and CD209⁺ dendritic cells were significantly reduced in the infundibulum connective tissue sheath. However, only with CD68 staining was a significant difference between LPP and FFA identified, with greater numbers of CD68⁺ cells in LPP samples. Furthermore, the identified macrophage polarization markers downregulated CD86 and upregulated CD163 and IL-4 expression in lesional LPP compared with FFA samples.

CONCLUSIONS

This comparative immunopathological analysis is the first to profile systematically the hair follicle immune system in LPP and FFA. Our analysis highlights a potential role of macrophages in disease pathobiology and suggests that macrophage polarization may differ between LPP and FFA, allowing microscopic differentiation. Linked Comment: Kinoshita-Ise. Br J Dermatol 2020; 183:419-420.