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Guo HW, Lai HJ, Long BQ, Xu LX, Wang EHC, Shapiro J, McElwee KJ. Increased CRHR1 expression on monocytes from patients with AA enables a pro-inflammatory response to corticotrophin-releasing hormone. Exp Dermatol 2024; 33:e15182. [PMID: 39367575 DOI: 10.1111/exd.15182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 08/19/2024] [Accepted: 09/06/2024] [Indexed: 10/06/2024]
Abstract
Stress may play a key role in alopecia areata (AA), though the exact interactions of stress with AA remain undefined. Corticotropin-releasing hormone (CRH), the proximal regulator of the stress axis, has been recognized as an immunomodulatory factor in tissues and peripheral blood mononuclear cells (PBMCs). We used multicolour flow cytometry to identify receptor CRHR1 expression on PBMC subsets in AA patients (n = 54) and controls (n = 66). We found that CRHR1 was primarily expressed by circulating monocytes. CRHR1 expression on monocytes was enhanced in AA compared with controls (3.17% vs. 1.44%, p = 0.002, chi-squared test). AA incidence was correlated to elevated CD14+ monocyte numbers (R = 0.092, p = 0.036) and markedly independently correlated with increased CRHR1 expression (R = 0.215, p = 0.027). High CRHR1 expression was significantly related to chronic AA (disease duration >1 year; p = 0.003, chi-squared test), and large lesion area (AA area >25%; p = 0.049, chi-squared test). We also observed enhanced percentages of active monocytes and reduced CD16+ CD3- NK cell numbers in AA patients' PBMCs (p = 0.010; 0.025, respectively). In vitro CRH treatment of PBMCs and human monocyte cell line THP-1 promoted CD86 upregulation. The findings imply that stress-related factors CRH and CRHR1 contribute to AA development and progression where higher CRHR1 expression is associated with chronic AA and larger lesions.
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Affiliation(s)
- Hong-Wei Guo
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Dermatology, The Second Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Hui-Jun Lai
- Department of Dermatology, The Second Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Bo-Quan Long
- Department of Dermatology, The Second Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Li-Xin Xu
- Flow Core Facility, Children and Family Research Institute, Vancouver, British Columbia, Canada
| | - Eddy Hsi Chun Wang
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jerry Shapiro
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, British Columbia, Canada
- The Ronald O. Perelman Department of Dermatology, New York University Grossman School of Medicine, New York, New York, USA
| | - Kevin J McElwee
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Skin Sciences, University of Bradford, Bradford, West Yorkshire, UK
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Ly S, Manjaly P, Kamal K, Shields A, Wafae B, Afzal N, Drake L, Sanchez K, Gregoire S, Zhou G, Mita C, Mostaghimi A. Comorbid Conditions Associated with Alopecia Areata: A Systematic Review and Meta-analysis. Am J Clin Dermatol 2023; 24:875-893. [PMID: 37464249 DOI: 10.1007/s40257-023-00805-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2023] [Indexed: 07/20/2023]
Abstract
BACKGROUND Alopecia areata (AA) is a complex autoimmune condition resulting in nonscarring hair loss. In recent years, many studies have provided new evidence on comorbid diseases present in patients with AA. However, some studies have conflicting results, and analyses conducting a comprehensive approach are lacking. OBJECTIVE The aim of our study was to provide an updated systematic review and meta-analysis of medical comorbidities associated with AA. METHODS We searched PubMed, Embase, and Web of Science for case-control, cross-sectional, and cohort studies investigating medical comorbidities in AA published from inception through 1 February 2023. RESULTS We screened 3428 abstracts and titles and reviewed 345 full text articles for eligibility. Ultimately, 102 studies were analyzed, comprising 680,823 patients with AA and 72,011,041 healthy controls. Almost all included studies (100 of 102 studies) were of satisfactory to high quality (Newcastle-Ottawa scale score ≥ 4). Among patients with AA, comorbidities with the highest odds ratios (OR) compared with healthy controls and data available from more than one study included vitamin D deficiency (OR 10.13, 95% CI 4.24-24.20), systemic lupus erythematous (OR 5.53, 95% CI 3.31-9.23), vitiligo (OR 5.30, 95% CI 1.86-15.10), metabolic syndrome (OR 5.03, 95% CI 4.18-6.06), and Hashimoto's thyroiditis (OR 4.31, 95% CI 2.51-7.40). AA may be a protective factor for certain disorders, for which the AA group had lower odds compared with healthy controls, such as irritable bowel syndrome (OR 0.38, 95% CI 0.14-0.99) and colorectal cancer (OR 0.61, 95% CI 0.42-0.89). CONCLUSION These findings corroborate and contextualize the risks across comorbidities for patients with AA. Further work should be done to identify the underlying pathophysiology and understand appropriate screening criteria.
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Affiliation(s)
- Sophia Ly
- College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, USA
- Department of Dermatology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA
| | - Priya Manjaly
- Department of Dermatology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA
- Boston University School of Medicine, Boston, MA, USA
| | - Kanika Kamal
- Department of Dermatology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, USA
| | - Ali Shields
- Department of Dermatology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA
- Drexel University College of Medicine, Philadelphia, PA, USA
| | - Bruna Wafae
- Department of Dermatology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, USA
| | - Najiba Afzal
- Department of Dermatology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA
- University of California, Davis School of Medicine, Sacramento, CA, USA
| | - Lara Drake
- Department of Dermatology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA
- Tufts University School of Medicine, Boston, MA, USA
| | - Katherine Sanchez
- Department of Dermatology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA
- Lake Erie College of Osteopathic Medicine, Erie, PA, USA
| | - Samantha Gregoire
- Department of Dermatology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA
- University at Buffalo Jacobs School of Medicine, Buffalo, NY, USA
| | - Guohai Zhou
- Department of Dermatology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA
| | - Carol Mita
- Countway Library of Medicine, Harvard University, Boston, MA, USA
| | - Arash Mostaghimi
- Department of Dermatology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA, 02115, USA.
- Harvard Medical School, Boston, MA, USA.
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3
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Chanprapaph K, Mahasaksiri T, Kositkuljorn C, Leerunyakul K, Suchonwanit P. Prevalence and Risk Factors Associated with the Occurrence of Autoimmune Diseases in Patients with Alopecia Areata. J Inflamm Res 2021; 14:4881-4891. [PMID: 34588794 PMCID: PMC8473714 DOI: 10.2147/jir.s331579] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/10/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Increased rates of autoimmune diseases (ADs) have been reported in association with alopecia areata (AA); however, the risk factors for coexisting ADs in AA patients have been poorly investigated. OBJECTIVE To evaluate the prevalence and factors associated with AD comorbidities in patients with AA. METHODS This case-control study included patients diagnosed with AA between January 2000 and March 2020. Individuals with AA, both with and without concomitant ADs, were statistically compared. Variables significantly associated with coexisting ADs were identified using univariate and multivariate logistic regression analyses. Multinomial logistic regression analysis was performed to identify the specific risk factors for each concomitant AD. RESULTS Among the 615 patients with AA, comorbid ADs were found in 76 (12.4%). Autoimmune thyroid disease (AITD) exhibited the highest frequency (n = 42, 6.8%), followed by vitiligo (n = 15, 2.4%), and systemic lupus erythematosus (SLE) (n = 12, 2.0%). Logistic regression analyses revealed that female sex (odds ratio [OR] = 2.45, 95% confidence interval [CI] = 1.24-4.82; P = 0.011), nail abnormalities (OR = 2.49, 95% CI = 1.14-5.46; P = 0.023), and atopic diseases (OR = 1.98, 95% CI = 1.09-2.43; P < 0.001) were significantly associated with coexisting ADs. Regarding each concomitant AD, nail abnormalities were an associated factor for AITD (OR = 4.65, 95% CI = 1.96-7.24; P = 0.01), whereas coexisting atopic diseases were demonstrated as a predictor of vitiligo (OR = 2.48, 95% CI = 1.43-4.58; P = 0.02). Female sex (OR = 1.61, 95% CI = 1.18-4.27; P = 0.04) and family history of AD (OR = 1.85, 95% CI = 1.26-4.19; P = 0.03) were predictors of SLE. CONCLUSION This study suggests that female AA patients with nail abnormalities and atopic diseases have increased rates of AD comorbidities. A thorough review of systems for associated factors can help physicians screen for concomitant ADs.
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Affiliation(s)
- Kumutnart Chanprapaph
- Division of Dermatology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Thipprapai Mahasaksiri
- Division of Dermatology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Chaninan Kositkuljorn
- Division of Dermatology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Kanchana Leerunyakul
- Division of Dermatology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Poonkiat Suchonwanit
- Division of Dermatology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
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Suchonwanit P, Kositkuljorn C, Pomsoong C. Alopecia Areata: An Autoimmune Disease of Multiple Players. Immunotargets Ther 2021; 10:299-312. [PMID: 34350136 PMCID: PMC8328385 DOI: 10.2147/itt.s266409] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 07/17/2021] [Indexed: 12/12/2022] Open
Abstract
Alopecia areata (AA) is an autoimmune disease of the hair follicles. It is characterized by a well-defined non-scarring alopecic patch or patches that may extend to the entire scalp or lead to total body hair loss. Due to its unpredictable clinical course, AA causes substantial psychological harm. Despite the high prevalence of this disease and extensive research, its exact pathomechanism is unclear, and current treatments have a high relapse rate that has deemed AA incurable. Over the past few decades, researchers have investigated multiple potential factors that may help alleviate its pathogenesis and provide effective treatment. Given its complex immunopathogenesis, AA is considered an autoimmune disease with multiple factors. This review gathers current evidence that emphasizes molecular mechanisms, possible causative etiologies, and targeted immunotherapies for AA. Understanding its underlying mechanisms may shed light on new strategies to effectively manage AA in the future.
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Affiliation(s)
- Poonkiat Suchonwanit
- Division of Dermatology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Chaninan Kositkuljorn
- Division of Dermatology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Cherrin Pomsoong
- Division of Dermatology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
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Reolid A, Muñoz-Aceituno E, Abad-Santos F, Ovejero-Benito MC, Daudén E. Epigenetics in Non-tumor Immune-Mediated Skin Diseases. Mol Diagn Ther 2021; 25:137-161. [PMID: 33646564 DOI: 10.1007/s40291-020-00507-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2020] [Indexed: 02/08/2023]
Abstract
Epigenetics is the study of the mechanisms that regulate gene expression without modifying DNA sequences. Knowledge of and evidence about how epigenetics plays a causative role in the pathogenesis of many skin diseases is increasing. Since the epigenetic changes present in tumor diseases have been thoroughly reviewed, we believe that knowledge of the new epigenetic findings in non-tumor immune-mediated dermatological diseases should be of interest to the general dermatologist. Hence, the purpose of this review is to summarize the recent literature on epigenetics in most non-tumor dermatological pathologies, focusing on psoriasis. Hyper- and hypomethylation of DNA methyltransferases and methyl-DNA binding domain proteins are the most common and studied methylation mechanisms. The acetylation and methylation of histones H3 and H4 are the most frequent and well-characterized histone modifications and may be associated with disease severity parameters and serve as therapeutic response markers. Many specific microRNAs dysregulated in non-tumor dermatological disease have been reviewed. Deepening the study of how epigenetic mechanisms influence non-tumor immune-mediated dermatological diseases might help us better understand the role of interactions between the environment and the genome in the physiopathogenesis of these diseases.
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Affiliation(s)
- Alejandra Reolid
- Dermatology Department, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria La Princesa (IIS-IP), Diego de León, 62, 28006, Madrid, Spain.
| | - E Muñoz-Aceituno
- Dermatology Department, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria La Princesa (IIS-IP), Diego de León, 62, 28006, Madrid, Spain
| | - F Abad-Santos
- Clinical Pharmacology Department, Hospital Universitario de la Princesa, Instituto Teófilo Hernando, Universidad Autónoma de Madrid (UAM), Instituto de Investigación Sanitaria la Princesa (IIS-IP), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid, Spain
| | - M C Ovejero-Benito
- Clinical Pharmacology Department, Hospital Universitario de la Princesa, Instituto Teófilo Hernando, Universidad Autónoma de Madrid (UAM), Instituto de Investigación Sanitaria la Princesa (IIS-IP), Madrid, Spain
| | - E Daudén
- Clinical Pharmacology Department, Hospital Universitario de la Princesa, Instituto Teófilo Hernando, Universidad Autónoma de Madrid (UAM), Instituto de Investigación Sanitaria la Princesa (IIS-IP), Madrid, Spain
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6
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Bertolini M, McElwee K, Gilhar A, Bulfone‐Paus S, Paus R. Hair follicle immune privilege and its collapse in alopecia areata. Exp Dermatol 2020; 29:703-725. [DOI: 10.1111/exd.14155] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/18/2020] [Accepted: 07/10/2020] [Indexed: 12/11/2022]
Affiliation(s)
| | - Kevin McElwee
- Monasterium Laboratory Münster Germany
- Centre for Skin Sciences University of Bradford Bradford UK
- Department of Dermatology and Skin Science University of British Columbia Vancouver British Columbia Canada
| | - Amos Gilhar
- Laboratory for Skin Research Rappaport Faculty of Medicine Technion‐Israel Institute of Technology Haifa Israel
| | - Silvia Bulfone‐Paus
- Monasterium Laboratory Münster Germany
- Centre for Dermatology Research University of Manchester and NIHR Manchester Biomedical Research Centre Manchester UK
| | - Ralf Paus
- Monasterium Laboratory Münster Germany
- Centre for Dermatology Research University of Manchester and NIHR Manchester Biomedical Research Centre Manchester UK
- Dr. Philip Frost Department of Dermatology & Cutaneous Surgery University of Miami Miller School of Medicine Miami FL USA
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7
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Alopecia areata susceptibility variant in MHC region impacts expressions of genes contributing to hair keratinization and is involved in hair loss. EBioMedicine 2020; 57:102810. [PMID: 32580135 PMCID: PMC7317227 DOI: 10.1016/j.ebiom.2020.102810] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 05/07/2020] [Accepted: 05/09/2020] [Indexed: 01/08/2023] Open
Abstract
Background Alopecia areata (AA) is considered a highly heritable, T-cell-mediated autoimmune disease of the hair follicle. However, no convincing susceptibility gene has yet been pinpointed in the major histocompatibility complex (MHC), a genome region known to be associated with AA as compared to other regions. Methods We engineered mice carrying AA risk allele identified by haplotype sequencing for the MHC region using allele-specific genome editing with the CRISPR/Cas9 system. Finally, we performed functional evaluations in the mice and AA patients with and without the risk allele. Findings We identified a variant (rs142986308, p.Arg587Trp) in the coiled-coil alpha-helical rod protein 1 (CCHCR1) gene as the only non-synonymous variant in the AA risk haplotype. Furthermore, mice engineered to carry the risk allele displayed a hair loss phenotype. Transcriptomics further identified CCHCR1 as a novel component interacting with hair cortex keratin in hair shafts. Both, these alopecic mice and AA patients with the risk allele displayed morphologically impaired hair and comparable differential expression of hair-related genes, including hair keratin and keratin-associated proteins (KRTAPs). Interpretation Our results implicate CCHCR1 with the risk allele in a previously unidentified subtype of AA based on aberrant keratinization in addition to autoimmune events. Funding This work was supported by JSPS KAKENHI (JP16K10177) and the NIHR UCLH Biomedical Research center (BRC84/CN/SB/5984).
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8
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Chen Q, Tao Y, Wang L, Zhang J, Sun B, Yang X. A randomized controlled clinical study of acupuncture therapy for Seborrheic alopecia in young and middle ages: Study protocol clinical trial (SPIRIT compliant). Medicine (Baltimore) 2020; 99:e19842. [PMID: 32332635 PMCID: PMC7220544 DOI: 10.1097/md.0000000000019842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 03/12/2020] [Indexed: 01/04/2023] Open
Abstract
INTRODUCTION Seborrheic alopecia (SA) has clinical manifestations, duration of disease, and priorities. In the current situation where there are many and complicated clinical treatments, Western medicine treatment can delay and control the development of the disease and promote hair regeneration. However, some patients may aggravate symptoms after taking the drug, and the condition is easy to repeat after stopping the drug. Acupuncture is an important method for non-surgical treatment of SA, and it has various methods, low side effects, high safety, and simple and economical. Therefore, we will use a clinical randomized controlled study to explore the effect of acupuncture on SA, and provide a new idea and reference for the treatment of this disease. METHODS/DESIGN We will select 60 patients diagnosed with SA. They will be randomly divided into intervention group and control groups. The control group will be given conventional treatment measures. The intervention group will receive acupuncture. Efficacy will be evaluated by comparing the skin lesion score and dermatological quality of life index before and after treatment. DISCUSSION This trial may provide evidence regarding the clinical effectiveness, safety, and cost-effectiveness of acupuncture for patients with SA. TRIAL REGISTRATION NUMBER CTR2000030430.
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Affiliation(s)
| | - Yun Tao
- Department of Dermatology,Huabei Petroleum General Hospital
| | - Longjun Wang
- Graduate Student of Hebei University of Chinese medicine
| | - Jinfang Zhang
- Department of Dermatology, The First Hospital of Hebei Medical University
| | - Bichen Sun
- Department of Traditional Chinese Medicine, Huabei Petroleum General Hospital
| | - Xiaoli Yang
- Qin Huang Dao Hospital of Traditional Chinese Medicine of HeBei North University,China
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9
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Sung CT, Choi FD, Juhász M, Mesinkovska NA. The Immunological Association between Alopecia Areata and Respiratory Diseases: A Systematic Review. Skin Appendage Disord 2019; 5:230-237. [PMID: 31367601 DOI: 10.1159/000496445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 12/14/2018] [Indexed: 11/19/2022] Open
Abstract
Background While alopecia areata (AA) has been associated with atopy, the immunological relationship is unclear, with the association of specific atopic and systemic respiratory diseases not established. The relationship between T-helper (Th)1-mediated AA and Th2-mediated atopy challenges the conventional Th1/Th2 paradigm of autoimmune disease categorization. Objectives To determine the association between AA and atopic respiratory diseases in adults and children, and respiratory diseases in general. Method All primary literature, excluding case reports, were identified within PubMed/MEDLINE, CINAHL, and Web of Science in May 2018 using the following search terms: "(alopecia OR hair loss) AND (respiratory OR pulmonary OR lungs OR asthma OR rhinitis OR bronchitis OR COPD OR atopy OR atopic)." Information from 32 articles meeting the inclusion and exclusion criteria was reviewed. Results Among the 32 articles identified for inclusion, the prevalence of AA was more strongly associated with allergic rhinitis compared to asthma among pediatric and adult populations. While a significant association was identified between AA, allergic rhinitis, and a late age of onset, the association of AA and asthma remains controversial despite asthma's prevalence among AA patients. No significant difference was identified with regard to the association of AA and non-atopic respiratory diseases between adult and pediatric patients. Conclusions Adult and pediatric patients with AA warrant further workup for atopic respiratory diseases such as allergic rhinitis. AA may have an underlying Th2-mediated immunological component, which supports its association with atopic respiratory diseases and provides a new avenue for targeted therapies in select cases.
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Affiliation(s)
- Calvin T Sung
- Department of Dermatology, University of California, Irvine, Irvine, California, USA.,School of Medicine, University of California, Riverside, Riverside, California, USA
| | - Franchesca D Choi
- Department of Dermatology, University of California, Irvine, Irvine, California, USA.,School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Margit Juhász
- Department of Dermatology, University of California, Irvine, Irvine, California, USA
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10
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Rajabi F, Drake LA, Senna MM, Rezaei N. Alopecia areata: a review of disease pathogenesis. Br J Dermatol 2018; 179:1033-1048. [PMID: 29791718 DOI: 10.1111/bjd.16808] [Citation(s) in RCA: 153] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2018] [Indexed: 12/12/2022]
Abstract
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.
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Affiliation(s)
- F Rajabi
- Department of Dermatology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - L A Drake
- Massachusetts General Hospital, Harvard Medical School, MA, U.S.A
| | - M M Senna
- Massachusetts General Hospital, Harvard Medical School, MA, U.S.A
| | - N Rezaei
- Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Sheffield, U.K
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11
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Jalili RB, Kilani RT, Li Y, Khosravi-Maharlooie M, Nabai L, Wang EHC, McElwee KJ, Ghahary A. Fibroblast cell-based therapy prevents induction of alopecia areata in an experimental model. Cell Transplant 2018; 27:994-1004. [PMID: 29871523 PMCID: PMC6050905 DOI: 10.1177/0963689718773311] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Alopecia areata (AA) is an autoimmune hair loss disease with infiltration of
proinflammatory cells into hair follicles. Current therapeutic regimens are unsatisfactory
mainly because of the potential for side effects and/or limited efficacy. Here we report
that cultured, transduced fibroblasts, which express the immunomodulatory molecule
indoleamine 2,3-dioxygenase (IDO), can be applied to prevent hair loss in an experimental
AA model. A single intraperitoneal (IP) injection of IDO-expressing primary dermal
fibroblasts was given to C3H/HeJ mice at the time of AA induction. While 60–70% of mice
that received either control fibroblasts or vehicle injections developed extensive AA,
none of the IDO-expressing fibroblast-treated mice showed new hair loss up to 20 weeks
post injection. IDO cell therapy significantly reduced infiltration of CD4+ and
CD8+ T cells into hair follicles and resulted in decreased expression of
TNF-α, IFN-γ and IL-17 in the skin. Skin draining lymph nodes of IDO fibroblast-treated
mice were significantly smaller, with more CD4+ CD25+
FoxP3+ regulatory T cells and fewer Th17 cells than those of control
fibroblast and vehicle-injected mice. These findings indicate that IP injected
IDO-expressing dermal fibroblasts can control inflammation and thereby prevent AA hair
loss.
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Affiliation(s)
- Reza B Jalili
- 1 Department of Surgery, ICORD (international collaboration on regenerative discoveries), University of British Columbia, Canada
| | - Ruhangiz T Kilani
- 1 Department of Surgery, ICORD (international collaboration on regenerative discoveries), University of British Columbia, Canada
| | - Yunyuan Li
- 1 Department of Surgery, ICORD (international collaboration on regenerative discoveries), University of British Columbia, Canada
| | - Mohsen Khosravi-Maharlooie
- 1 Department of Surgery, ICORD (international collaboration on regenerative discoveries), University of British Columbia, Canada
| | - Layla Nabai
- 1 Department of Surgery, ICORD (international collaboration on regenerative discoveries), University of British Columbia, Canada
| | - Eddy Hsi Chun Wang
- 2 Department of Dermatology and Skin Science, University of British Columbia, Canada
| | - Kevin J McElwee
- 2 Department of Dermatology and Skin Science, University of British Columbia, Canada
| | - Aziz Ghahary
- 1 Department of Surgery, ICORD (international collaboration on regenerative discoveries), University of British Columbia, Canada
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Loh SH, Moon HN, Lew BL, Sim WY. Role of T helper 17 cells and T regulatory cells in alopecia areata: comparison of lesion and serum cytokine between controls and patients. J Eur Acad Dermatol Venereol 2018; 32:1028-1033. [PMID: 29283462 DOI: 10.1111/jdv.14775] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 12/05/2017] [Indexed: 01/01/2023]
Abstract
BACKGROUND Alopecia areata (AA) is an organ-specific autoimmune disease with T-cell-mediated attack of hair follicle autoantigens. As T helper 17 (Th17) cells and T regulatory (Treg) cells are crucially involved in the pathogenesis, the role of Th17 and Treg cytokines has not been studied yet. OBJECTIVE To determine whether AA is associated with alterations in lesional and serum Th17 and Treg cytokines and studied whether they were associated with clinical type. METHODS Scalp skin samples from 45 patients and eight normal controls were obtained for PCR specific for IFN-γ, TNF-α, TGF-β, IL-1, IL-2, IL-4, IL-10, IL-12A, IL-13, IL-17, IL-22 and IL-23. Serum cytokines were measured from 55 patients and 15 normal controls using ELISA. RESULTS Lesional IL-17 and IL-22 were significantly increased in patient group. Moreover, positive correlations were shown between lesional IL-17, IL-22 and disease severity. Serum IL-1, IL-17, TNF-α and TGF-β were significantly increased, and positive correlation was shown between serum IL-17 and disease severity. CONCLUSION These results showed significantly high Th17 cytokines in both lesion and serum in AA patients, which may highlight a functional role of these cytokines in the pathogenesis of AA.
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Affiliation(s)
- S-H Loh
- Department of Dermatology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - H-N Moon
- Department of Biochemical Science, Graduate School, Kyung Hee University, Seoul, Korea
| | - B-L Lew
- Department of Dermatology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - W-Y Sim
- Department of Dermatology, College of Medicine, Kyung Hee University, Seoul, Korea
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14
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Atwa MA, Youssef N, Bayoumy NM. T-helper 17 cytokines (interleukins 17, 21, 22, and 6, and tumor necrosis factor-α) in patients with alopecia areata: association with clinical type and severity. Int J Dermatol 2016; 55:666-72. [PMID: 26235375 DOI: 10.1111/ijd.12808] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 05/30/2014] [Accepted: 07/07/2014] [Indexed: 12/21/2022]
Abstract
BACKGROUND Alopecia areata (AA) is an organ-specific autoimmune disease characterized by T-cell infiltrates and cytokine production. T-helper 17 (Th17) cells are crucially involved in the pathogenesis of autoimmune diseases. OBJECTIVES Our aim was to assess the association of Th17 with AA. We examined interleukin (IL)-17, IL-21, IL-22, IL-6, and tumor necrosis factor-alpha (TNF-α) levels in the serum of patients with AA and studied their association with clinical type and severity of AA. SUBJECTS AND METHODS The serum concentrations of IL-17, IL-21, IL-22, IL-6, and TNF-α were measured in 47 patients with AA and 40 healthy controls. The clinical type of AA was determined, and the severity of hair loss was assessed in accordance with the Alopecia Areata Investigational Assessment Guideline criteria. RESULTS The serum concentrations of IL-17, IL-21, IL-22, IL-6, and TNF-α were significantly higher in patients with AA as compared with healthy controls (mean: IL-17 33.23 ± 11.58 vs. 4.62 ± 1.88 pg/ml; P = 0.000, IL-21 62.10 ± 6.11 vs. 48.38 ± 3.31 pg/ml; P = 0.000, IL-22 19.27 ± 3.36 vs. 7.09 ± 1.62 pg/ml; P = 0.000, IL-6 17.18 ± 3.08 vs. 4.59 ± 1.66 pg/ml; P = 0.000, TNF-α 19.94 ± 3.59 vs. 9.95 ± 2.42 pg/ml; P = 0.000, respectively). There were significant positive correlations between serum IL-17, TNF-α, and disease severity. There was also significant positive correlation between serum IL-22 and duration of AA. CONCLUSION Our results showed high serum levels of Th17 cytokines among patients with AA that may suggest a functional role of these cytokines in the pathogenesis of this important skin disease. It could also provide the rationale for new treatment strategies in AA.
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Affiliation(s)
- Mona A Atwa
- Department of Dermatology and Venereology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Nahed Youssef
- Department of Clinical Pathology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Nervana M Bayoumy
- Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
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Gilhar A, Schrum AG, Etzioni A, Waldmann H, Paus R. Alopecia areata: Animal models illuminate autoimmune pathogenesis and novel immunotherapeutic strategies. Autoimmun Rev 2016; 15:726-35. [PMID: 26971464 DOI: 10.1016/j.autrev.2016.03.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 03/02/2016] [Indexed: 01/13/2023]
Abstract
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.
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Affiliation(s)
- Amos Gilhar
- Skin Research Laboratory, Faculty of Medicine, Technion - Israel Institute of Technology, Flieman Medical Center, PO Box 9649, Haifa, Israel.
| | - Adam G Schrum
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Amos Etzioni
- Ruth Children Hospital, Haifa, Israel; Rappaport Medical School, Technion, Haifa, Israel
| | - Herman Waldmann
- Therapeutic Immunology Group, Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Ralf Paus
- Centre for Dermatology Research, Inst. of Inflammation and Repair, University of Manchester, Manchester, UK; Department of Dermatology, University of Münster, Münster, Germany
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16
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Sundberg JP, McElwee K, Brehm MA, Su L, King LE. Animal Models for Alopecia Areata: What and Where? J Investig Dermatol Symp Proc 2015; 17:23-6. [PMID: 26551940 PMCID: PMC4722955 DOI: 10.1038/jidsymp.2015.35] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Disease is not limited to humans. Rather, humans are but another mammal in a continuum, and as such, often share similar if not identical diseases with other mammalian species. Alopecia areata (AA) is such a disease. Natural disease occurs in humans, nonhuman primates, many domestic animals, and laboratory rodents. However, to be useful as models of human disease, affected animals need to be readily available to the research community, closely resemble the human disease, be easy to work with, and provide reproducible data. To date, the laboratory mouse (most if not all of the C3H substrains) and the Dundee experimental bald rat fit these criteria. Manipulations using full-thickness skin grafts or specific immune cell transfers have improved the models. New mouse models that carry a variety of genetic-based immunodeficiencies can now be used to recapitulate the human immune system and allow for human full-thickness skin grafts onto mice to investigate human-specific mechanistic and therapeutic questions. These models are summarized here including where they can currently be obtained from public access repositories.
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Affiliation(s)
- John P. Sundberg
- The Jackson Laboratory, Bar Harbor, ME
- Department of Medicine, Division of Dermatology, Vanderbilt University, Nashville, TN
| | - Kevin McElwee
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC, Canada
| | - Michael A. Brehm
- Program in Molecular Medicine, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA
| | - Lishan Su
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC
| | - Lloyd E. King
- Department of Medicine, Division of Dermatology, Vanderbilt University, Nashville, TN
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17
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Guo H, Cheng Y, Shapiro J, McElwee K. The role of lymphocytes in the development and treatment of alopecia areata. Expert Rev Clin Immunol 2015; 11:1335-51. [PMID: 26548356 DOI: 10.1586/1744666x.2015.1085306] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
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.
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Affiliation(s)
- Hongwei Guo
- a 1 Department of Dermatology and Skin Science, University of British Columbia, Vancouver, Canada.,b 2 Department of Dermatology, Affiliated Hospital of Guangdong Medical College, Zhanjiang, Guangdong, China
| | - Yabin Cheng
- a 1 Department of Dermatology and Skin Science, University of British Columbia, Vancouver, Canada
| | - Jerry Shapiro
- a 1 Department of Dermatology and Skin Science, University of British Columbia, Vancouver, Canada.,c 3 Department of Dermatology, New York University, Langone Medical Center, New York, USA
| | - Kevin McElwee
- a 1 Department of Dermatology and Skin Science, University of British Columbia, Vancouver, Canada.,d 4 Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
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Abstract
INTRODUCTION Hair loss or alopecia affects the majority of the population at some time in their life, and increasingly, sufferers are demanding treatment. Three main types of alopecia (androgenic [AGA], areata [AA] and chemotherapy-induced [CIA]) are very different, and have their own laboratory models and separate drug-discovery efforts. AREAS COVERED In this article, the authors review the biology of hair, hair follicle (HF) cycling, stem cells and signaling pathways. AGA, due to dihydrotesterone, is treated by 5-α reductase inhibitors, androgen receptor blockers and ATP-sensitive potassium channel-openers. AA, which involves attack by CD8(+)NK group 2D-positive (NKG2D(+)) T cells, is treated with immunosuppressives, biologics and JAK inhibitors. Meanwhile, CIA is treated by apoptosis inhibitors, cytokines and topical immunotherapy. EXPERT OPINION The desire to treat alopecia with an easy topical preparation is expected to grow with time, particularly with an increasing aging population. The discovery of epidermal stem cells in the HF has given new life to the search for a cure for baldness. Drug discovery efforts are being increasingly centered on these stem cells, boosting the hair cycle and reversing miniaturization of HF. Better understanding of the molecular mechanisms underlying the immune attack in AA will yield new drugs. New discoveries in HF neogenesis and low-level light therapy will undoubtedly have a role to play.
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Affiliation(s)
- Zenildo Santos
- Massachusetts General Hospital, Wellman Center for Photomedicine , Boston, MA 02114 , USA +1 617 726 6182 ; +1 617 726 6643 ;
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19
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Ataseven A, Saral Y, Godekmerdan A. Serum cytokine levels and anxiety and depression rates in patients with alopecia areata. Eurasian J Med 2015; 43:99-102. [PMID: 25610172 DOI: 10.5152/eajm.2011.22] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 07/01/2011] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE Alopecia areata (AA) is a disease characterized by patchy hair loss. Although the etiopathogenesis of AA is still unclear, it has been hypothesized that immune system dysfunction and stress are involved. The aim of this study was to evaluate possible associations between AA and depression, anxiety and serum levels of cytokines interleukin (IL)-1β, IL-6, IL-8 and IL-10. MATERIALS AND METHODS Forty-three patients who were diagnosed with AA were prospectively enrolled into the study. Thirty age- and sex-matched healthy individuals were included as the control group. The Hamilton Rating Scale for Depression and the Hamilton Rating Scale for Anxiety were used. For children between the ages of 7 and 16, the Children's Depression Inventories was completed. Serum levels of the cytokines IL-1 β, IL-6, IL-8, and IL-10 were analyzed by ELISA. RESULTS No significant differences were observed between patients and controls with respect to serum cytokine levels (p>0.05). Depression rates were found to be 50% and 30% in AA patients and controls, respectively (p<0.05). Similarly, anxiety rates were found to be 63% and 23.3% in AA patients and controls, respectively (p<0.05). CONCLUSION Depression and anxiety were found more frequent in AA patients than healthy individuals. Therefore, when considering management therapy, an entire psychiatric evaluation should also be performed. However, no differences were found in serum cytokine levels of patients and controls.
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Affiliation(s)
- Arzu Ataseven
- Department of Dermatology, Konya Education and Research Hospital, Konya, Turkey
| | - Yunus Saral
- Department of Dermatology, Faculty of Medicine, Rize University, Rize, Turkey
| | - Ahmet Godekmerdan
- Department of Immunology, Faculty of Medicine, Firat University, Elazig, Turkey
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20
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Takahashi T, Asano Y, Ichimura Y, Toyama T, Taniguchi T, Noda S, Akamata K, Tada Y, Sugaya M, Kadono T, Sato S. Amelioration of Tissue Fibrosis by Toll-like Receptor 4 Knockout in Murine Models of Systemic Sclerosis. Arthritis Rheumatol 2014; 67:254-65. [DOI: 10.1002/art.38901] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 09/30/2014] [Indexed: 01/19/2023]
Affiliation(s)
| | - Yoshihide Asano
- University of Tokyo Graduate School of Medicine; Tokyo Japan
| | - Yohei Ichimura
- University of Tokyo Graduate School of Medicine; Tokyo Japan
| | - Tetsuo Toyama
- University of Tokyo Graduate School of Medicine; Tokyo Japan
| | | | - Shinji Noda
- University of Tokyo Graduate School of Medicine; Tokyo Japan
| | - Kaname Akamata
- University of Tokyo Graduate School of Medicine; Tokyo Japan
| | - Yayoi Tada
- University of Tokyo Graduate School of Medicine; Tokyo Japan
| | - Makoto Sugaya
- University of Tokyo Graduate School of Medicine; Tokyo Japan
| | - Takafumi Kadono
- University of Tokyo Graduate School of Medicine; Tokyo Japan
| | - Shinichi Sato
- University of Tokyo Graduate School of Medicine; Tokyo Japan
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21
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Gu ME, Song XM, Zhu CF, Yin HP, Liu GJ, Yu LP, Yang WW, Ni LF, Zhang YL, Wu BJ. Breeding and preliminarily phenotyping of a congenic mouse model with alopecia areata. DONG WU XUE YAN JIU = ZOOLOGICAL RESEARCH 2014; 35:249-55. [PMID: 25017742 DOI: 10.13918/j.issn.2095-8137.2014.4.249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
In the current study, the alopecia areata gene was introduced into the C57BL/6 (B6) mouse through repeated backcrossing/intercrossing, and the allelic homozygosity of congenic AA(tj)mice (named B6.KM-AA) was verified using microsatellites. The gross appearance, growth characteristics, pathological changes in skin, and major organs of B6.KM-AA mice were observed. Counts and proportions of CD4⁺ and CD8⁺ T lymphocytes in peripheral blood were determined by flow cytometry. Results show that congenic B6.KM-AA mice were obtained after 10 generations of backcrossing/intercrossing. B6.KM-AA mice grew slower than B6 control mice and AA skin lesions were developed by four weeks of age. The number of hair follicles was reduced, but hair structures were normal. Loss of hair during disease progression was associated with CD4⁺ and CD8⁺ T lymphocytes infiltration peri-and intra-hair follicles. No pathological changes were found in other organs except for the skin. In the peripheral blood of B6.KM-AA mice, the percentage of CD4⁺ T cells was lower and percentage of CD8⁺ T cells higher than in control mice. These findings indicate that B6.KM-AA mice are characterized by a dysfunctional immune system, retarded development and T-cell infiltration mediated hair loss, making them a promising new animal model for human alopecia areata.
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Affiliation(s)
- Mei-Er Gu
- Laboratory of Experimental Animal Science, Hangzhou Normal University, Hangzhou 310036, China
| | - Xiao-Ming Song
- Laboratory of Experimental Animal Science, Hangzhou Normal University, Hangzhou 310036, China
| | - Chun-Feng Zhu
- Laboratory of Experimental Animal Science, Hangzhou Normal University, Hangzhou 310036, China
| | - Hong-Ping Yin
- Laboratory of Experimental Animal Science, Hangzhou Normal University, Hangzhou 310036, China
| | - Gui-Jie Liu
- Laboratory of Experimental Animal Science, Hangzhou Normal University, Hangzhou 310036, China
| | - Li-Ping Yu
- Laboratory of Experimental Animal Science, Hangzhou Normal University, Hangzhou 310036, China
| | - Wei-Wei Yang
- Laboratory of Experimental Animal Science, Hangzhou Normal University, Hangzhou 310036, China
| | - Li-Feng Ni
- Laboratory of Experimental Animal Science, Hangzhou Normal University, Hangzhou 310036, China
| | - Yan-Li Zhang
- Laboratory of Experimental Animal Science, Hangzhou Normal University, Hangzhou 310036, China
| | - Bao-Jin Wu
- Laboratory of Experimental Animal Science, Hangzhou Normal University, Hangzhou 310036, China.
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22
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Abstract
Noninflammatory, nonpruritic alopecias are uncommonly encountered in the horse. Alopecia areata, an apparently autoimmune hair follicle bulbitis produces focal, multifocal to widespread hair loss. The skin is otherwise normal. Diseases that can mimic the widespread hair loss associated with alopecia areata include telogen and anagen effluvium, seasonal alopecias, follicular dysplasias (including color dilution alopecia), various nutritional deficiencies and chemical toxicosis, and diseases that result in defective hair shafts (eg, trichorrhexis nodosa and piedra). These problems are differentiated by history, physical examination, trichography, and skin biopsy. Most are cosmetic diseases that do not have predictably effective therapies.
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Affiliation(s)
- Rod A W Rosychuk
- Department of Clinical Sciences, Colorado State University, 300 West Drake, Fort Collins, CO 80523, USA.
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23
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McElwee KJ, Gilhar A, Tobin DJ, Ramot Y, Sundberg JP, Nakamura M, Bertolini M, Inui S, Tokura Y, Jr LEK, Duque-Estrada B, Tosti A, Keren A, Itami S, Shoenfeld Y, Zlotogorski A, Paus R. What causes alopecia areata? Exp Dermatol 2013; 22:609-26. [PMID: 23947678 PMCID: PMC4094373 DOI: 10.1111/exd.12209] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The pathobiology of alopecia areata (AA), one of the most frequent autoimmune diseases and a major unsolved clinical problem, has intrigued dermatologists, hair biologists and immunologists for decades. Simultaneously, both affected patients and the physicians who take care of them are increasingly frustrated that there is still no fully satisfactory treatment. Much of this frustration results from the fact that the pathobiology of AA remains unclear, and no single AA pathogenesis concept can claim to be universally accepted. In fact, some investigators still harbour doubts whether this even is an autoimmune disease, and the relative importance of CD8(+) T cells, CD4(+) T cells and NKGD2(+) NK or NKT cells and the exact role of genetic factors in AA pathogenesis remain bones of contention. Also, is AA one disease, a spectrum of distinct disease entities or only a response pattern of normal hair follicles to immunologically mediated damage? During the past decade, substantial progress has been made in basic AA-related research, in the development of new models for translationally relevant AA research and in the identification of new therapeutic agents and targets for future AA management. This calls for a re-evaluation and public debate of currently prevalent AA pathobiology concepts. The present Controversies feature takes on this challenge, hoping to attract more skin biologists, immunologists and professional autoimmunity experts to this biologically fascinating and clinically important model disease.
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Affiliation(s)
- K. J. McElwee
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC, Canada
| | - A. Gilhar
- Laboratory for Skin, Research, Rappaport Faculty of Medicine, Technion–Israel Institute of Technology, Haifa, Israel Marta Bertolini
| | - D. J. Tobin
- Centre for Skin Sciences, School of Life Sciences, University of Bradford, Bradford, West Yorkshire, BD7 1DP, UK
| | - Y. Ramot
- Department of Dermatology, Hadassah- Hebrew University Medical Center, Jerusalem 91120, Israel
| | - J. P. Sundberg
- The Jackson Laboratory, Bar Harbor, ME, USA; Division of Dermatology, Skin Disease Research Center, Vanderbilt University, Nashville, TN, USA
| | - M. Nakamura
- Department of Dermatology, University of Occupational and Environmental Health, Kitakyushu, Japan Yoshiki Tokura
| | - M. Bertolini
- Department of Dermatology, University of Lübeck, Germany Yehuda Shoenfeld
| | - S. Inui
- Department of Regenerative Dermatology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Y. Tokura
- Department of Dermatology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - L. E. King Jr
- The Jackson Laboratory, Bar Harbor, ME, USA; Division of Dermatology, Skin Disease Research Center, Vanderbilt University, Nashville, TN, USA
| | - B. Duque-Estrada
- Instituto de Dermatologia Prof. Rubem David Azulay, Rio de Janeiro, Brazil Antonella Tosti
| | - A Tosti
- Department of Dermatology, University of Miami, Miami, FL, USA
| | - A. Keren
- Laboratory for Skin, Research, Rappaport Faculty of Medicine, Technion–Israel Institute of Technology, Haifa, Israel Marta Bertolini
| | - S. Itami
- Department of Regenerative Dermatology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Y. Shoenfeld
- Center for Autoimmune Diseases, Sheba Medical Center, Tel Hashomer and Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
| | - A. Zlotogorski
- Department of Dermatology, Hadassah- Hebrew University Medical Center, Jerusalem 91120, Israel
| | - R. Paus
- Department of Dermatology, University of Lübeck, Germany; Institute of Inflammation and Repair, University of Manchester, Manchester, UK ,
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24
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Tembhre M, Sharma V. T-helper and regulatory T-cell cytokines in the peripheral blood of patients with active alopecia areata. Br J Dermatol 2013; 169:543-8. [DOI: 10.1111/bjd.12396] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2013] [Indexed: 12/22/2022]
Affiliation(s)
- M.K. Tembhre
- Department of Dermatology and Venereology; All India Institute of Medical Sciences; Ansari Nagar; New Delhi; 110029; India
| | - V.K. Sharma
- Department of Dermatology and Venereology; All India Institute of Medical Sciences; Ansari Nagar; New Delhi; 110029; India
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25
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Hoolahan DE, White SD, Outerbridge CA, Shearer PL, Affolter VK. Equine alopecia areata: a retrospective clinical descriptive study at the University of California, Davis (1980-2011). Vet Dermatol 2013; 24:282-e64. [DOI: 10.1111/vde.12013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2012] [Indexed: 11/26/2022]
Affiliation(s)
- Danielle E. Hoolahan
- William R. Pritchard Veterinary Medical Teaching Hospital; University of California; Davis; CA; 95616; USA
| | - Stephen D. White
- Department of Medicine and Epidemiology; School of Veterinary Medicine; University of California; Davis; CA; 95616; USA
| | - Catherine A. Outerbridge
- Department of Medicine and Epidemiology; School of Veterinary Medicine; University of California; Davis; CA; 95616; USA
| | | | - Verena K. Affolter
- Department of Pathology, Microbiology and Immunology; University of California; Davis; CA; 95616; USA
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26
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Pi LQ, Jin XH, Hwang ST, Lee WS. Effects of calcitonin gene-related peptide on the immune privilege of human hair follicles. Neuropeptides 2013; 47:51-7. [PMID: 22975462 DOI: 10.1016/j.npep.2012.07.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 06/19/2012] [Accepted: 07/16/2012] [Indexed: 10/27/2022]
Abstract
The hair follicle is a widely available and instructive miniature organ in the human body that experiences major histocompatibility complex (MHC) class I dependent immune privilege (IP). There are various regulation factors that act on the generation, maintenance, and collapse of hair follicle IP. Neuropeptides such as calcitonin gene-related peptide (CGRP) are created in many organs, including skin, and display various immune regulation effects. The purpose of this study was to investigate the phenotypic effect of CGRP on the hair follicle's IP. First, we used interferon-γ (IFN-γ) to generate ectopic MHC antigen expression model in cultured human hair follicles as previously described. Then, we examined the effects of CGRP on the regulation of ectopic MHC antigen expression in cultured human hair follicles using reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemical staining techniques. IFN-γ (75 IU/ml) induced ectopic MHC expression. CGRP down-regulated INF-γ-induced ectopic MHC class I mRNA expression. These down-regulated effects were especially evident in 10(-8)M. In addition, CGRP also suppressed the staining intensity related to the expression of MHC class I and MHC class I-pathway related molecules (β2-microglobulin), but had no effect on MHC class II antigen expression. Taken together, these results indicate that CGRP might be an important regulatory factor for IP maintenance and restoration of IP via suppression of MHC class I antigen.
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Affiliation(s)
- Long-Quan Pi
- Department of Dermatology and Institute of Hair and Cosmetic Medicine, Yonsei University, Wonju College of Medicine, Wonju, Republic of Korea
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Avci P, Sadasivam M, Gupta A, De Melo WC, Huang YY, Yin R, Chandran R, Kumar R, Otufowora A, Nyame T, Hamblin MR. Animal models of skin disease for drug discovery. Expert Opin Drug Discov 2013; 8:331-55. [PMID: 23293893 DOI: 10.1517/17460441.2013.761202] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
INTRODUCTION Discovery of novel drugs, treatments, and testing of consumer products in the field of dermatology is a multi-billion dollar business. Due to the distressing nature of many dermatological diseases, and the enormous consumer demand for products to reverse the effects of skin photodamage, aging, and hair loss, this is a very active field. AREAS COVERED In this paper, we will cover the use of animal models that have been reported to recapitulate to a greater or lesser extent the features of human dermatological disease. There has been a remarkable increase in the number and variety of transgenic mouse models in recent years, and the basic strategy for constructing them is outlined. EXPERT OPINION Inflammatory and autoimmune skin diseases are all represented by a range of mouse models both transgenic and normal. Skin cancer is mainly studied in mice and fish. Wound healing is studied in a wider range of animal species, and skin infections such as acne and leprosy also have been studied in animal models. Moving to the more consumer-oriented area of dermatology, there are models for studying the harmful effect of sunlight on the skin, and testing of sunscreens, and several different animal models of hair loss or alopecia.
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Affiliation(s)
- Pinar Avci
- Harvard Medical School, Massachusetts General Hospital, Wellman Center for Photomedicine, Department of Dermatology, Boston MA, USA
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Zhao M, Liang G, Wu X, Wang S, Zhang P, Su Y, Yin H, Tan Y, Zhang J, Lu Q. Abnormal epigenetic modifications in peripheral blood mononuclear cells from patients with alopecia areata. Br J Dermatol 2012; 166:226-73. [PMID: 21936853 DOI: 10.1111/j.1365-2133.2011.10646.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Alopecia areata (AA) is a hair loss disease caused by T-cell-mediated autoimmune reactions against anagen-stage hair follicles. Although the exact aetiology is poorly understood, there is evidence to suggest that both genetic and environmental factors are involved in AA pathogenesis. OBJECTIVES To analyse DNA methylation and histone modification patterns in peripheral blood mononuclear cells (PBMCs) of patients with AA. METHODS PBMC samples were obtained from 25 patients with AA and 20 healthy controls. Global DNA methylcytosine levels, as well as histone acetylation and methylation levels, were measured by enzyme-linked immunosorbent assay. mRNA expression levels were determined using real-time quantitative reverse transcription-polymerase chain reaction. RESULTS Genomic DNA methylation in PBMCs of patients with AA was increased relative to controls. DNMT1, MBD1 and MBD4 expression levels were significantly higher in AA PBMCs than in controls, and DNMT1 transcription levels positively correlated with global DNA methylation levels in patient samples. Histone H3 acetylation was significantly increased and histone H3 lysine 4 methylation was significantly decreased in patient PBMCs compared with healthy controls. Histone H3 acetylation levels were positively correlated with AA disease severity, and with RANTES (CCL5) mRNA expression in PBMCs of patients with AA. These changes were accompanied by increased p300 (EP300), histone deacetylase 1 (HDAC1), myeloid/lymphoid or mixed lineage leukemia (MLL), SET7/9 (SETD7), G9A (EHMT2), JMJD2C (KDM4C) and JARID1A (KDM5A) expression, as well as reduced HDAC2, HDAC7, LSD1 (KDM1A), JMJD2A (KDM4A) and JMJD2B (KDM4B) expression. CONCLUSIONS DNA methylation and histone modification status are altered in PBMCs of patients with AA, possibly due to the deregulation of epigenetic regulatory genes. These changes may contribute to the activation of pathological immune responses in AA.
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Affiliation(s)
- M Zhao
- Hunan Key Laboratory of Medical Epigenomics, Department of Dermatology, Second Xiangya Hospital, Central South University, 139 Renmin Middle Road, Changsha, Hunan 410011, China
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Abstract
Alopecia areata (AA) is a nonscarring, inflammatory skin disease that results in patchy hair loss. AA is unpredictable in its onset, severity, and duration making it potentially very stressful for affected individuals. Currently, the treatment options for AA are limited and the efficacy of these treatments varies from patient to patient. The exact etiology of AA is unknown. This article provides some insights into the etiopathogenesis of AA and why some people develop it. The current knowledge on the pathogenesis of AA is summarized and some of the recent hypotheses and studies on AA are presented to allow for a fuller understanding of the possible biological mechanisms of AA.
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Affiliation(s)
- Eddy Wang
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, Canada
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Effects of the Lexington LaserComb on hair regrowth in the C3H/HeJ mouse model of alopecia areata. Lasers Med Sci 2011; 27:431-6. [PMID: 21739260 DOI: 10.1007/s10103-011-0953-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 06/20/2011] [Indexed: 02/08/2023]
Abstract
Alopecia areata (AA) is a common autoimmune disease that presents with non-scarring alopecia. It is characterized by intra- or peri-follicular lymphocytic infiltrates composed of CD4+ and CD8+ T-cells on histology. To this day, few treatments are effective for AA. Here we present findings of using a low-level laser comb to alleviate the symptoms of AA in a C3H/HeJ mouse model for AA. Fourteen C3H/HeJ mice with induced AA were used in this study. Two were killed to confirm AA through histology. The remaining 12 mice were randomized into two groups; group I received HairMax LaserComb (wavelength: 655 nm, beam diameter <5 mm; divergence 57 mrad; nine lasers) for 20 s daily, three times per week for a total of 6 weeks; group II was treated similarly, except that the laser was turned off (sham-treated). After 6 weeks of LaserComb treatment, hair regrowth was observed in all the mice in group I (laser-treated) but none in group II (sham-treated). On histology, increased number of anagen hair follicles was observed in laser-treated mice. On the other hand, sham-treated mice demonstrated hair follicles in the telogen phase with no hair shaft. LaserComb seems to be an effective and convenient device for the treatment of AA in the C3H/HeJ mouse model. Human studies are required to determine the efficacy and safety of this device for AA therapy.
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Chu SY, Chen YJ, Tseng WC, Lin MW, Chen TJ, Hwang CY, Chen CC, Lee DD, Chang YT, Wang WJ, Liu HN. Comorbidity profiles among patients with alopecia areata: the importance of onset age, a nationwide population-based study. J Am Acad Dermatol 2011; 65:949-56. [PMID: 21616562 DOI: 10.1016/j.jaad.2010.08.032] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2010] [Revised: 08/26/2010] [Accepted: 08/30/2010] [Indexed: 02/08/2023]
Abstract
BACKGROUND Alopecia areata (AA) is considered an autoimmune disease with undetermined pathogenesis. Age at onset predicts distinct outcomes. A nationwide study of the relationship of AA with associated diseases stratified by onset age has rarely been reported. OBJECTIVE We sought to clarify the role of atopic and autoimmune diseases in AA, thereby better understanding its pathogenesis. METHODS A total of 4334 patients with AA were identified from the National Health Insurance Database in Taiwan from 1996 to 2008. A national representative cohort of 784,158 persons served as control subjects. RESULTS Among patients with AA, there were significant associations with vitiligo, lupus erythematosus, psoriasis, atopic dermatitis, autoimmune thyroid disease, and allergic rhinitis. Different ages at onset resulted in disparate comorbidities. Increased risk of atopic dermatitis (odds ratio [OR] 3.82, 95% confidence interval 2.67-5.45) and lupus erythematosus (OR 9.76, 95% confidence interval 3.05-31.21) were found in childhood AA younger than 10 years. Additional diseases including psoriasis (OR 2.43) and rheumatoid arthritis (OR 2.57) appeared at onset age 11 to 20 years. Most atopic and autoimmune diseases were observed at onset ages of 21 to 60 years. With onset age older than 60 years, thyroid disease (OR 2.52) was highly related to AA. Moreover, patients with AA had higher risk for more coexisting diseases than control subjects. LIMITATIONS We could not differentiate hypothyroidism from hyperthyroidism. CONCLUSIONS AA is related to various atopic and autoimmune diseases. Different associated diseases in each onset age group of AA can allow clinician to efficiently investigate specific comorbidities.
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Affiliation(s)
- Szu-Ying Chu
- Department of Dermatology, Taipei Veterans General Hospital, Taipei, Taiwan
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Wikramanayake TC, Alvarez-Connelly E, Simon J, Mauro LM, Guzman J, Elgart G, Schachner LA, Chen J, Plano LR, Jimenez JJ. Heat treatment increases the incidence of alopecia areata in the C3H/HeJ mouse model. Cell Stress Chaperones 2010; 15:985-91. [PMID: 20582641 PMCID: PMC3024057 DOI: 10.1007/s12192-010-0209-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2009] [Revised: 06/10/2010] [Accepted: 06/11/2010] [Indexed: 01/31/2023] Open
Abstract
Alopecia areata (AA) is a common autoimmune disease characterized by non-scarring hair loss. Previous studies have demonstrated an association between AA and physiological/psychological stress. In this study, we investigated the effects of heat treatment, a physiological stress, on AA development in C3H/HeJ mice. Whereas this strain of mice are predisposed to AA at low incidence by 18 months of age, we observed a significant increase in the incidence of hair loss in heat-treated 8-month-old C3H/HeJ mice compared with sham-treated mice. Histological analysis detected mononuclear cell infiltration in anagen hair follicles, a characteristic of AA, in heat-treated mouse skin. As expected, increased expression of induced HSPA1A/B (formerly called HSP70i) was detected in skin samples from heat-treated mice. Importantly, increased HSPA1A/B expression was also detected in skin samples from C3H/HeJ mice that developed AA spontaneously. Our results suggest that induction of HSPA1A/B may precipitate the development of AA in C3H/HeJ mice. For future studies, the C3H/HeJ mice with heat treatment may prove a useful model to investigate stress response in AA.
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Affiliation(s)
- Tongyu Cao Wikramanayake
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, 1600 NW 10th Avenue, RMSB 2023A, Miami, FL 33136 USA
| | - Elizabeth Alvarez-Connelly
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, 1600 NW 10th Avenue, RMSB 2023A, Miami, FL 33136 USA
| | - Jessica Simon
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, 1600 NW 10th Avenue, RMSB 2023A, Miami, FL 33136 USA
| | - Lucia M. Mauro
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 1011 NW 15th Street, Gautier 328, Miami, FL 33136 USA
| | - Javier Guzman
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, 1600 NW 10th Avenue, RMSB 2023A, Miami, FL 33136 USA
| | - George Elgart
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, 1600 NW 10th Avenue, RMSB 2023A, Miami, FL 33136 USA
| | - Lawrence A. Schachner
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, 1600 NW 10th Avenue, RMSB 2023A, Miami, FL 33136 USA
| | - Juan Chen
- Departments of Pediatrics and Microbiology & Immunology, University of Miami Miller School of Medicine, 1600 NW 10th Avenue, RMSB 3087, Miami, FL 33136 USA
| | - Lisa R. Plano
- Departments of Pediatrics and Microbiology & Immunology, University of Miami Miller School of Medicine, 1600 NW 10th Avenue, RMSB 3087, Miami, FL 33136 USA
| | - Joaquin J. Jimenez
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, 1600 NW 10th Avenue, RMSB 2023A, Miami, FL 33136 USA
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Hunter N, Shaker O, Marei N. Diphencyprone and topical tacrolimus as two topical immunotherapeutic modalities. Are they effective in the treatment of alopecia areata among Egyptian patients? A study using CD4, CD8 and MHC II as markers. J DERMATOL TREAT 2010; 22:2-10. [PMID: 20524872 DOI: 10.3109/09546630903410182] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE To evaluate the efficacy of two topically applied immunomodulative agents through the detection of lymphocyte subsets using monoclonal antibodies against CD4, CD8 and MHC II. METHODS Fifty patients from the Departments of Medical Biochemistry, Dermatology and Pathology at Cairo University with different degrees of alopecia areata (AA) were included in this study. They were classified into two groups each of 25 patients. Each patient was treated with the immunomodulative agent on one side of the scalp and the other side was left as a control. Biopsies were taken from all patients at the beginning of treatment and at the end of the study. Tissue specimens were prepared for histologic and immunophenotypic analysis. The main outcome measures were the uses of diphencyprone (DPCP) and topical tacrolimus as two topical immunotherapeutic modalities in the treatment of AA. RESULTS A clinical response of 68% was achieved in group A (treated with DPCP) while group B (treated with 0.1% tacrolimus) showed an insignificant clinical response. Decreased expression of CD4 and increased expression of CD8 and MHC II was detected in the post-treated areas compared with pretreated areas in cases treated with DCPC. In tacrolimus-treated cases, there was a decrease in CD4 and MHC II, with no change in CD8 between the pre- and post-treated areas. CONCLUSION DCPC is one of the most accepted therapeutic modalities in the treatment of AA, with a favourable prognosis among patchy hair loss. MHC II expression was the one correlating with clinical response. Tacrolimus, though beneficial in other dermatoses, could not be considered effective in the treatment of AA.
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Affiliation(s)
- Nahla Hunter
- Department of Dermatology, Faculty of Medicine, Cairo University, Egypt.
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Barahmani N, Lopez A, Babu D, Hernandez M, Donley SE, Duvic M. Serum T helper 1 cytokine levels are greater in patients with alopecia areata regardless of severity or atopy. Clin Exp Dermatol 2010; 35:409-16. [DOI: 10.1111/j.1365-2230.2009.03523.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Barahmani N, Schabath MB, Duvic M. History of atopy or autoimmunity increases risk of alopecia areata. J Am Acad Dermatol 2009; 61:581-91. [PMID: 19608295 DOI: 10.1016/j.jaad.2009.04.031] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 04/01/2009] [Accepted: 04/03/2009] [Indexed: 12/21/2022]
Abstract
BACKGROUND The association between a history of atopy or autoimmune diseases and risk of alopecia areata (AA) is not well established. OBJECTIVE The purpose of this study was to use the National AA Registry database to further investigate the association between history of atopy or autoimmune diseases and risk of AA. METHODS A total of 2613 self-registered sporadic cases (n = 2055) and controls (n = 558) were included in this analysis. RESULTS Possessing a history of any atopic (odds ratio = 2.00; 95% confidence interval 1.50-2.54) or autoimmune (odds ratio = 1.73; 95% confidence interval 1.10-2.72) disease was associated with an increased risk of AA. There was no trend for possessing a history of more than one atopic or autoimmune disease and increasing risk of AA. LIMITATIONS Recall, reporting, and recruiting bias are potential sources of limitations in this analysis. CONCLUSION This analysis revealed that a history of atopy and autoimmune disease was associated with an increased risk of AA and that the results were consistent for both the severe subtype of AA (ie, alopecia totalis and alopecia universalis) and the localized subtype (ie, AA persistent).
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Affiliation(s)
- Nazila Barahmani
- Department of Dermatology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
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Sun J, Silva KA, McElwee KJ, King LE, Sundberg JP. The C3H/HeJ mouse and DEBR rat models for alopecia areata: review of preclinical drug screening approaches and results. Exp Dermatol 2009; 17:793-805. [PMID: 18798913 DOI: 10.1111/j.1600-0625.2008.00773.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The C3H/HeJ inbred mouse strain and the Dundee Experimental Bald Rat (DEBR) strain spontaneously develop adult onset alopecia areata (AA), a cell-mediated disease directed against actively growing hair follicles. The low frequency of AA and the inability to predict the stage of AA as it evolves in the naturally occuring C3H/HeJ model of AA can be converted into a highly predictable system by grafting full thickness skin from AA-affected mice to normal haired mice of the same strain. The rat DEBR model develops spontaneous AA at a higher frequency than in the mouse model but they are more expensive to use in drug studies owing to their larger size. Regardless of the shortcomings of either model, these rodent models can be used succesfully to screen novel or approved drugs for efficacy to treat human AA. As the pathogenesis of AA follows the canonical lymphocytic co-stimulatory cascade in the mouse AA model, it can be used to screen compounds potentially useful to treat a variety of cell-mediated diseases. Efficacy of various agents can easily be screened by simply observing the presence, rate, and cosmetic acceptability of hair regrowth. More sophisticated assays can refine how the drugs induce hair regrowth and evaluate the underlying pathogenesis of AA. Some drugs commonly used to treat human AA patients work equally as well in both rodent models validating their usefulness as models for drug efficacy and safety for humanAA.
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Affiliation(s)
- Jing Sun
- The Jackson Laboratory, Bar Harbor, ME 04609-1500, USA
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Bruet V, Degorce-Rubiales F, Abadie J, Bourdeau P. Severe alopecia areata and onychodystrophy on all four feet of a French trotter mare. Vet Rec 2008; 162:758-60. [PMID: 18540038 DOI: 10.1136/vr.162.23.758] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- V Bruet
- Dermatology, Parasitology and Mycology Unit, Ecole Nationale Vétérinaire de Nantes, Route de Gachet, 44307 Nantes, France
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Abstract
Alopecia areata (AA) is a nonscarring, autoimmune, inflammatory, hair loss on the scalp, and/or body. Etiology and pathogenesis are still unknown. The most common site affected is the scalp. Histopathology is characterized by an increased number of the catagen and telogen follicles, the presence of inflammatory lymphocytic infiltrate in the peribulbar region ("swarm of bees"). Corticosteroids are the most popular drugs for the treatment of this disease. Etiologic and pathogenic mechanisms, as well as other current treatments available will be discussed in this article.
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Affiliation(s)
- Dan Wasserman
- Department of Dermatology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina, 27157, USA
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Siebenhaar F, Sharov AA, Peters EMJ, Sharova TY, Syska W, Mardaryev AN, Freyschmidt-Paul P, Sundberg JP, Maurer M, Botchkarev VA. Substance P as an Immunomodulatory Neuropeptide in a Mouse Model for Autoimmune Hair Loss (Alopecia Areata). J Invest Dermatol 2007; 127:1489-97. [PMID: 17273166 DOI: 10.1038/sj.jid.5700704] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Alopecia areata (AA) is an autoimmune disorder of the hair follicle characterized by inflammatory cell infiltrates around actively growing (anagen) hair follicles. Substance P (SP) plays a critical role in the cutaneous neuroimmune network and influences immune cell functions through the neurokinin-1 receptor (NK-1R). To better understand the role of SP as an immunomodulatory neuropeptide in AA, we studied its expression and effects on immune cells in a C3H/HeJ mouse model for AA. During early stages of AA development, the number of SP-immunoreactive nerve fibers in skin is increased, compared to non-affected mice. However, during advanced stages of AA, the number of SP-immunoreactive nerves and SP protein levels in skin are decreased, whereas the expression of the SP-degrading enzyme neutral endopeptidase (NEP) is increased, compared to control skin. In AA, NK-1R is expressed on CD8+ lymphocytes and macrophages accumulating around affected hair follicles. Additional SP supply to the skin of AA-affected mice leads to a significant increase of mast cell degranulation and to accelerated hair follicle regression (catagen), accompanied by an increase of CD8+ cells-expressing granzyme B. These data suggest that SP, NEP, and NK-1R serve as important regulators in the molecular signaling network modulating inflammatory response in autoimmune hair loss.
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Affiliation(s)
- Frank Siebenhaar
- Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Goh C, Finkel M, Christos PJ, Sinha AA. Profile of 513 patients with alopecia areata: associations of disease subtypes with atopy, autoimmune disease and positive family history. J Eur Acad Dermatol Venereol 2007; 20:1055-60. [PMID: 16987257 DOI: 10.1111/j.1468-3083.2006.01676.x] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Several lines of evidence support a genetic component to alopecia areata (AA), including differences in patients based on severity of AA, associated diseases and family history. OBJECTIVE We aimed to examine clinical and genetic features of patients with AA with a focus on associated diseases, especially atopy, and family history of AA in the USA. METHODS From 1998 to 2001, 513 patients with AA completed interviews consisting of demographic information, patient's medical history, and family history of AA. RESULTS Forty per cent of respondents had alopecia totalis and/or universalis (AT/AU). These patients were younger at the age of onset than those with patchy AA (P < 0.001), were more likely to have associated autoimmune or atopic disease (P = 0.047), most notably atopic dermatitis (P = 0.021) and thyroid disease (P = 0.012). They also had a greater number of relatives affected by AA (P < 0.05). CONCLUSIONS Our findings show marked associations between severity of AA, atopic dermatitis, thyroid disease and other autoimmune diseases, and extensive family history of AA, suggesting two clinically distinct subtypes of AA with the severe subtype possibly associated with greater familial autoimmunity. Further research exploring the possibility of a genetic basis to explain these clinical findings will be helpful in clarifying our understanding of AA, leading to improvements in diagnosis and treatment.
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Affiliation(s)
- C Goh
- Department of Dermatology, Weill Medical College of Cornell University, New York, NY, USA.
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Ricciardi A, Ruberto A, García-Hernández MJ, Kotzalidis GD, Trevisi M, Persechino S, Tatarelli R, Ruiz-Doblado S. Alopecia areata with comorbid depression: early resolution with combined paroxetine-triamcinolone treatment. J Eur Acad Dermatol Venereol 2006; 20:1000-1. [PMID: 16922952 DOI: 10.1111/j.1468-3083.2006.01592.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Hong SB, Jin SY, Park HJ, Jung JH, Sim WY. Analysis of the monocyte chemoattractant protein 1 -2518 promoter polymorphism in Korean patients with alopecia areata. J Korean Med Sci 2006; 21:90-4. [PMID: 16479072 PMCID: PMC2733986 DOI: 10.3346/jkms.2006.21.1.90] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Monocyte chemoattractant protein-1 (MCP-1) levels are increased in scalp lesions of patients with alopecia areata (AA), suggesting a role in the development of AA. Recently, a biallelic A/G polymorphism in the MCP-1 promoter at position -2518 has been found, influencing the level of MCP-1 expression in response to an inflammatory stimulus. We investigated whether the presence of these polymorphisms were associated with AA in Korean population. 145 Korean patients with AA, 246 healthy subjects without clinical evidence of AA were screened for genotype with a PCR-based assay. In the AA patients the frequency of the A and G alleles was 40.3 and 59.7%, respectively and the distribution of the A/A, A/G and G/G genotypes was 19.3, 42.1 and 38.6%, respectively. Amongst the controls the frequency of the A and G alleles was 39.8 and 60.2%, and the distribution of the A/A, A/G, G/G genotypes in the same group was 17.5, 44.7 and 37.8%, respectively. There was no significant difference in the allele frequencies and genotype distributions between the patients and the controls (p=0.889, p=0.848, respectively). Our data indicates that no association exists between the -2518A/G polymorphism of the MCP-1 gene and susceptibility to alopecia areata.
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Affiliation(s)
- Seok-Beom Hong
- Department of Dermatology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - Sheng-Yu Jin
- Department of Pharmacology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - Hae-Jeong Park
- Department of Pharmacology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - Joo-Ho Jung
- Department of Pharmacology, College of Medicine, Kyung Hee University, Seoul, Korea
| | - Woo-Young Sim
- Department of Dermatology, College of Medicine, Kyung Hee University, Seoul, Korea
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Freyschmidt-Paul P, McElwee KJ, Hoffmann R, Sundberg JP, Kissling S, Hummel S, Vitacolonna M, Kopp-Schneider A, Zöller M. Reduced expression of interleukin-2 decreases the frequency of alopecia areata onset in C3H/HeJ mice. J Invest Dermatol 2006; 125:945-51. [PMID: 16297194 DOI: 10.1111/j.0022-202x.2005.23888.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Alopecia areata (AA) is an autoimmune hair loss disease, that can be transferred between C3H/HeJ mice by skin grafting. We explored whether AA susceptibility is influenced by the availability of interleukin (IL)-2, a cytokine with leukocyte activating and regulatory properties. Mice heterozygous for a targeted deletion of IL-2 from the histocompatible C3.129P2(B6)-Il2(tm1Hor) substrain, that produce reduced levels of IL-2, were examined for AA development after grafting skin from AA-affected C3H/HeJ mice. After grafting, nine of 19 (47%) heterozygous IL-2+/-versus 16 of 18 (88%) IL-2+/+ wild-type littermates developed AA. Although dense follicular leukocyte infiltrates were apparent in AA affected wild-type mice, AA-developing IL-2+/- littermates had a reduced leukocyte infiltration, and AA-resistant IL-2+/- mice had no inflammation. Lymph node cell analysis revealed a reduction in leukocyte activation markers in AA-developing IL-2+/- mice. IL-2+/- mice presented with low level expression of cytokines (IL-4, IL-10, interferon-gamma, transforming growth factor-beta), upregulation of tumor necrosis factor receptors, and increased leukocyte apoptosis susceptibility independent of AA expression. In the skin, CD4+ cells and monocytes were reduced; activation markers were not upregulated and very few CD44v3+ or CD44v10+ leukocytes were recovered. Taken together, our data suggest that AA resistance of IL-2+/- mice is because of the failure of activated leukocyte recruitment, thus pointing toward an involvement of IL-2 in AA pathogenesis.
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McElwee KJ, Yu M, Park SW, Ross EK, Finner A, Shapiro J. What Can We Learn from Animal Models of Alopecia areata? Dermatology 2005; 211:47-53. [PMID: 15983437 DOI: 10.1159/000085580] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Alopecia areata (AA) is a hair loss disease marked by a focal inflammatory infiltrate of dystrophic anagen stage hair follicles by CD4+ and CD8+ lymphocytes. Although AA is thought to be an autoimmune disorder, definitive proof is lacking. Moreover, characterization of the primary pathogenic mechanisms by which hair loss is induced in AA is limited. In this context, animal models may provide a vital contribution to understanding AA. Recent research using animal models of AA has focused on providing evidence in support of a lymphocyte-mediated pathogenic mechanism consistent with AA as an autoimmune disease. In the future, research with both humans and animal models shall likely concentrate on identifying the primary antigenic epitopes involved in AA and the genetics of AA susceptibility. With a comprehensive understanding of the key elements in AA pathogenesis, new avenues for therapeutic research and intervention will be defined.
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Affiliation(s)
- Kevin J McElwee
- Division of Dermatology, University of British Columbia, Vancouver, Canada.
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Rosenblum MD, Olasz EB, Yancey KB, Woodliff JE, Lazarova Z, Gerber KA, Truitt RL. Expression of CD200 on epithelial cells of the murine hair follicle: a role in tissue-specific immune tolerance? J Invest Dermatol 2004; 123:880-7. [PMID: 15482475 DOI: 10.1111/j.0022-202x.2004.23461.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CD200 (OX-2) is a transmembrane glycoprotein that transmits an immunoregulatory signal through the CD200 receptor (CD200R) to attenuate inflammatory reactions and promote immune tolerance. CD200 expression in the skin has not been described previously. We now report that freshly isolated cells of the murine epidermis contain a subpopulation of major histocompatibility complex (MHC) class II-negative, CD3-negative keratinocytes that are CD200-positive. CD200 expression was accentuated in keratinocytes comprising the outer root sheath of the murine hair follicle (HF). When syngeneic skin grafts were exchanged between gender-matched wild-type (WT) and CD200-deficient C57BL/6 mice, significant perifollicular and intrafollicular inflammation was observed, eventually leading to the destruction of virtually all HF (alopecia) without significant loss of the CD200-negative grafts. Minimal and transient inflammation was observed in WT grafts, which persisted long term with hair. There was a 2-fold increase in graft-infiltrating T cells in CD200-deficient skin at 14 d. Alopecia and skin lesions were induced in CD200-deficient hosts by adoptive transfer of splenocytes from WT mice previously grafted with CD200-negative skin, but not from mice grafted with WT skin. Collectively, these results suggest that the expression of CD200 in follicular epithelium attenuates inflammatory reactions and may play a role in maintaining immune tolerance to HF-associated autoantigens.
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Affiliation(s)
- Michael D Rosenblum
- Department of Pediatrics, Medical College of Wisonsin, Milwaukee, Wisconsin, USA
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Colombo S, Keen JA, Brownstein DG, Rhind SM, McGorum BC, Hill PB. Alopecia areata with lymphocytic mural folliculitis affecting the isthmus in a thoroughbred mare. Vet Dermatol 2004; 15:260-5. [PMID: 15305934 DOI: 10.1111/j.1365-3164.2004.00392.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A 13-year-old, thoroughbred mare was presented with an 8-year history of multifocal, generalized, noninflammatory alopecia and a 3-month history of alopecia, erythema and scaling of the white star on the forehead and muzzle. Histopathological examination of biopsy samples from multiple sites on the body (mane, neck, shoulder, flank and gluteal region) showed a subtle lymphocytic inflammatory infiltrate affecting and surrounding the anagen hair bulbs, consistent with a diagnosis of alopecia areata. The biopsy sample from the star on the forehead showed atrophic hair follicles with perifollicular and mural mononuclear folliculitis affecting the isthmus. Immunohistochemical staining with a CD3 marker confirmed the T-lymphocytic origin of the inflammatory infiltrate in all the samples. The concurrent presence of lymphocytic infiltration at the bulbar and isthmic level of the hair follicles in the same horse is unusual. This finding may represent a variation of the histological appearance of alopecia areata.
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Affiliation(s)
- Silvia Colombo
- Hospital for Small Animals, The University of Edinburgh, The Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Center, Roslin, Midlothian, EH25 9RG, UK
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Zöller M, McElwee KJ, Vitacolonna M, Hoffmann R. The progressive state, in contrast to the stable or regressive state of alopecia areata, is reflected in peripheral blood mononuclear cells. Exp Dermatol 2004; 13:435-44. [PMID: 15217364 DOI: 10.1111/j.0906-6705.2004.00179.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alopecia areata (AA) is a putative autoimmune disease of the skin with an inflammatory component that can be treated by the local application of contact sensitizers. Here, we explored whether responsiveness toward diphenylcyclopropenone (DPCP) is reflected by the composition and the activation state of peripheral blood mononuclear cells (PBMCs). PBMCs of 43 AA patients, 26 treated and 17 untreated, and of 31 healthy volunteers were tested. AA patients' PBMCs differed from that of healthy donors by a slight increase in CD16- and tumor necrosis factor-alpha (TNF-alpha)-expressing cells. These features were independent of the disease state and treatment. Additional changes in the activation state of PBMCs, upregulation of the costimulatory molecules CD40 and CD80, of the accessory molecule CD154, and of interferon-gamma expression were identified only in AA patients where the disease was advancing, i.e. these changes were independent of the extent of hair loss and were not seen in patients with spontaneous or DPCP treatment-induced, regressing AA. Thus, the progressive state of AA is accompanied by a systemic activation of T cells, and the therapeutic efficacy of treatment can be estimated by restoration of the non-activated state. Furthermore, an increase in CD16(+)- and TNF-alpha-expressing cells may contribute to AA susceptibility.
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Affiliation(s)
- Margot Zöller
- Department of Tumor Progression and Tumor Defense, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany.
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McElwee KJ, Freyschmidt-Paul P, Zöller M, Hoffmann R. Alopecia areata susceptibility in rodent models. J Investig Dermatol Symp Proc 2004; 8:182-7. [PMID: 14582670 DOI: 10.1046/j.1087-0024.2003.00806.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
With our current view of alopecia areata as an autoimmune disease, it is probable that disease development in an individual is dependent on multiple genetic and environmental factors interacting in a complex system. Rodent models afford the opportunity to investigate alopecia areata development and to define the significance of the different factors involved. Recently, rodent model characterization has been conducted using flow cytometry, microarray analysis, and functional studies. From these a pattern of events in alopecia areata development has emerged. Although the preliminary activation events for the onset of alopecia areata remain unknown, the response of the immune system is characterized by antigen presentation and costimulation of lymphocytes in the lymph nodes and skin, a deficiency of CD4+/CD25+ regulatory cells, and an action of activated lymphocytes on hair follicles via Fas/FasL signaling and cytokines. Thus, onset of disease may require appropriate (or inappropriate) expression of stimulatory antigens within the hair follicle, the breakdown of the putative hair follicle immune privilege, the presentation of antigens to the immune system, a failure of immune system regulation, and the ability of the activated immune system to disrupt anagen-stage hair follicles. Once the sequence of events is initiated, it may become a self-perpetuating cycle, with epitope spreading leading to a wider range of targets in chronic alopecia areata. Rodent model studies have provided significant insight into alopecia areata, but much more remains to be explained about the mechanisms of disease development.
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Affiliation(s)
- Kevin J McElwee
- Department of Dermatology, Philipp University Marburg, Marburg, Germany.
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Martinez-Mir A, Zlotogorski A, Ott J, Gordon D, Christiano AM. Genetic linkage studies in alopecia areata. J Investig Dermatol Symp Proc 2004; 8:199-203. [PMID: 14582673 DOI: 10.1046/j.1087-0024.2003.00809.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Alopecia areata affects approximately 4.6 million individuals in the United States alone. It is typified by patchy hair loss on the scalp that can progress to cover the entire scalp (alopecia totalis) and eventually the entire body (alopecia universalis). Despite the high incidence of this condition, its genetic basis is largely unknown. It is now generally accepted, however, that it fits the paradigm of a complex trait, in which a combination of genetic and environmental factors results in the final phenotype. Genetic studies have been limited thus far to association analyses, which suggest that a permissive HLA status may potentiate the development of alopecia areata. A systematic screen for identifying the primary genetic mechanisms underlying this disorder has never before been undertaken, however. Here we discuss our approach to the identification of susceptibility genes for alopecia areata. In particular, we recently initiated a comprehensive genetic analysis by performing a genome-wide scan in a collection of alopecia families with multiple affected family members. There are currently a number of examples of complex diseases of the skin, such as psoriasis and atopic dermatitis, in which genetic studies are being undertaken that substantiate the timeliness of this approach. We anticipate that these studies will lead to the identification of the susceptibility genes and provide a foundation for understanding how they interact with each other and with other variables, such as the immune system and environmental factors.
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Affiliation(s)
- Amalia Martinez-Mir
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA
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