斑秃合并特应性皮炎免疫学特性及治疗研究进展

目前大多数研究认为斑秃是Th1细胞介导的自身免疫性疾病,特应性皮炎是经典的Th2细胞主导的炎症性疾病。但最近的研究也显示了Th2轴在斑秃发病中的潜在作用,在斑秃患者的头皮和血清中发现Th2相关生物标志物显著升高。此外,GWAS也在斑秃中鉴定出了Th2的易感性位点(IL-4和IL-13)。同时合并FLG突变的患者更容易发展成重度斑秃。度普利尤单抗和JAK抑制剂在合并特应性皮炎的斑秃患者中的治疗效果,进一步阐明了不同细胞因子通路对斑秃表型的影响,有助于未来斑秃靶向治疗的选择。     

斑秃发病机制的实验研究进展

斑秃是一种发生于毛囊的非瘢痕性、炎症性疾病,尽管临床无明显炎症表现,但组织病理学检查显示,生长期毛囊有淋巴细胞浸润和炎症介质增多,临床用免疫调节或抑制剂治疗有效。斑秃发病与自身免疫有关,是炎症细胞介导的、器官特异性疾病。啮齿类动物有自发脱发现象,其发病机制与人类斑秃相似,文中就啮齿类动物(C3H/HeJ小鼠和DEBR鼠)的秃发特征和发病机制研究现状作一综述。     

T细胞因子在斑秃发病中的作用

目的研究T细胞因子与斑秃发病的关系,比较活动期和稳定期斑秃患者血清T细胞因子的变化情况,并探讨斑秃患者的Th1和Th2免疫功能状况。方法107例斑秃患者,根据临床表现分为活动期和稳定期,采用夹心抗体酶联免疫吸附试验法(Sandwich,ELISA)检测活动期和稳定期组斑秃患者血清的IFN-γ、IL-2、IL-4、IL-10和IL-16水平,并分析脱发严重程度与血清细胞因子的关系,采用单因素方差分析和LSD检验。结果稳定期组血清IFN-γ水平显著高于健康对照组(P<0.05),活动期组血清IFN-γ水平与健康对照组间的差异无统计学意义(P>0.05);IL-2、IL-16水平比较,活动期组、稳定期组、健康对照组间的差异无统计学意义(P>0.05);IL-4、IL-10水平比较,稳定期组显著低于对照组,活动期组显著低于稳定期组,组间差异均有统计学意义(P<0.05);随着脱发面积占头皮面积百分比增加,患者血清IFN-γ升高(P均<0.05),IL-2、4、10、16水平的改变无明显统计学意义(P>0.05)。结论IFN-γ参与斑秃稳定期免疫反应,可能与诱导斑秃发病无关;IL-4和IL-10与病情活动有关;IL-2和IL-16可能与斑秃发病无关;IFN-γ可能与斑秃的严重程度有关。     

Successful treatment of alopecia areata-like hair loss with the contact sensitizer squaric acid dibutylester (SADBE) in C3H/HeJ mice.

A type of hair loss closely resembling human alopecia areata has been described in C3H/HeJ mice. In order to test the assumed analogy with human alopecia areata, we investigated the efficacy of treatment with the contact allergen squaric acid dibutylester. In 12 C3H/HeJ mice with alopecia areata an allergic contact dermatitis was induced and elicited weekly on one side of the back by topical applications of squaric acid dibutylester. Overt hair regrowth was observed only on the treated side of the back in nine of 12 mice. Histopathologic examination revealed a change in the distribution of the inflammatory infiltrate from a dense perifollicular lymphocytic infiltrate around the mid and lower regions of hair follicles in untreated skin to a uniform presence in the upper dermis in treated skin. Immunohistomorphometric studies revealed that treatment with squaric acid dibutylester increased the CD4+/CD8+ ratio from approximately 1:2 in untreated alopecia areata to 1:1 in treated alopecia areata. Additional immunohistochemical investigations showed an aberrant expression of major histocompatibility complex class I, major histocompatibility complex class II and intercellular adhesion molecule 1 on keratinocytes of the mid and lower parts of hair follicles in untreated alopecia areata. In successfully treated skin ectopic major histocompatibility complex class I and II expression was clearly reduced, whereas intercellular adhesion molecule 1 expression showed only minor changes. In conclusion, alopecia areata-like hair loss in C3H/HeJ mice responded to treatment with the contact sensitizer squaric acid dibutylester analogous to human alopecia areata. Moreover, successful treatment changes the aberrant expression of major histocompatibility complex class I and II in a way similar to that observed in human alopecia areata. These observations support the concept that alopecia areata-like hair loss in C3H/HeJ mice can be utilized as an appropriate model for the study of human alopecia areata.     

MicroRNA-1246 Inhibits NFATc1 Phosphorylation and Regulates T Helper 17 Cell Activation in the Pathogenesis of Severe Alopecia Areata

BackgroundWe found microRNA (miR)-1246 to be significantly differentially expressed between severe active alopecia areata (AA) patients and healthy individuals.ObjectiveTo explore the role and mechanism of miR-1246 in severe AA.MethodsExpression of miR-1246, dual-specific tyrosine phosphorylation-regulated kinase 1A (DYRK1A), and nuclear factor of activated T cells 1c (NFATc1) in peripheral CD4⁺ T cells and in scalp tissues of patients were detected using RT-qPCR, Western blot, and immunohistochemistry assays. Peripheral CD4⁺ T cells from the AA patients were transfected with lentiviral vectors overexpressing miR-1246. RT-qPCR and Western blot analysis were used to measure mRNA or protein expression of retinoic-acid-receptor-related orphan nuclear receptor gamma (ROR-γt), interleukin (IL)-17, DYRK1A, NFATc1, and phosphorylated NFATc1. Flow cytometry was used to assay the CD4⁺IL-17⁺ cells proportion. ELISA was used to measure cytokine levels.ResultsmiR-1246 levels decreased and DYRK1A and NFATc1 mRNA levels significantly increased in the peripheral CD4⁺ T cells and scalp tissues of severe active AA samples. NFATc1 protein expression was also significantly increased in the peripheral CD4⁺ T cells but not in the scalp tissues. NFATc1 positive cells were mainly distributed among infiltrating inflammatory cells around hair follicles. In peripheral CD4⁺ T cells of severe active AA, overexpression of miR-1246 resulted in significant downregulation of DYRK1A, NFATc1, ROR-γt, and IL-17 mRNA and phosphorylated NFATc1 protein, as well as a decrease in the CD4⁺IL-17⁺ cells proportion and the IL-17F level.ConclusionmiR-1246 can inhibit NFAT signaling and Th17 cell activation, which may be beneficial in the severe AA treatment.     

Normalisation of hair follicle morphology in C3H/HeJ alopecia areata mice after treatment with squaric acid dibutylester

Alopecia areata is a non-scarring, reversible disorder, presumably caused by an autoimmune attack on anagen hair follicles. Treatments are numerous, and most of these are ineffective. However, the elicitation of contact dermatitis on the affected skin is commonly associated with hair regrowth. A major advance in the study of alopecia areata has been the introduction and characterisation of the C3H/HeJ mouse model that exhibits many features of the human disease. In this study we examined the effects of squaric acid dibutylester treatment on hair follicles and the associated leukocyte infiltrate in alopecia areata mice by light and transmission electron microscopic analysis. This was compared with unaffected normal mice and alopecic untreated mice. Experimental mice were treated unilaterally with the contact allergen squaric acid dibutylester and the skin was assessed after hair regrowth. The characteristic pathological picture of alopecia areata was observed in alopecic but not normal mice. Nine of eleven experimental mice regrew hair on the treated side only and this was associated with a reduction in peri/intrafollicular inflammatory cell infiltrates, hair follicle dystrophy, melanin incontinence/clumping, and an increase in the numbers of hair follicles in full anagen. This normalisation of hair follicle status after treatment reflects the successful reversal of disease in these mice. The mechanism of action of topical immunotherapy with a potent contact allergen such as squaric acid dibutylester still needs to be elucidated, but an altered immune milieu is suspected. This study further validates the C3H/HeJ mouse model of alopecia areata in the search for therapeutic interventions in this common hair follicle disorder.     

IL-17 and its role in inflammatory,autoimmune, and oncological skin diseases: state of art

Recent data support the theory of the involvement of IL-17 in the pathogenesis of several chronic inflammatory skin diseases (psoriasis, atopic dermatitis, acne, hidradenitis suppurativa) and autoimmune skin diseases (alopecia areata, vitiligo, bullous diseases). Even if the role of IL-17 in inflammatory and autoimmune diseases has been reported extensively, its role in tumor is still controversial. Some reports show that Th17 cells eradicate tumors, while others reveal that they promote the initiation and early growth of tumors. Herein, we review the role of IL-17 in the involvement of some common dermatologic diseases: psoriasis, atopic dermatitis, hidradenitis suppurativa, acne, vitiligo, melanoma, and nonmelanoma skin cancers.     

In situ lymphocyte subsets in alopecia areata before and during treatment with a contact allergen

In situ lymphocyte subsets in 12 patients with patchy alopecia areata or alopecia universalis were estimated using monoclonal antibodies and immunoperoxidase technique. The majority of the inflammatory cells around the hair bulbs and follicles where leu 4⁺ T-cells with the subphenotypes of either leu 2a⁺ (suppressor/cytotoxic T-cells) or leu 3a⁺ (helper/inducer T-cells). Many of the T-cells expressed HLA-DR class II antigen. In about half of the patients, the hair bulbs and follicles were also infiltrated with T-cells. Eight of the 12 patients were treated with dinitroch-loro-benzene. Six of these patients were biopsied during treatment. The number of T-cells around the hair bulbs and follicles increased during; treatment and niam T-cells were seen in the hair bulbs and follicles. In five of the six patients treated with dinitrochlorobenzene, an increase in the percentage of leu 2a+ cells around the bulbs and follicles was noticed. The increase in leu 2a⁺ cells may be of importance for the DNCB-induced re-growth of hair.     

Serum T helper 1 cytokine levels are greater in patients with alopecia areata regardless of severity or atopy

Background. Alopecia areata (AA) is an organ‐specific autoimmune disease characterized by folliculotropic T‐cell infiltrates around anagen‐stage hair follicles. The role of T helper (Th)1 and Th2 cytokines in the pathogenesis of AA have not been established. Aim. To determine whether serum cytokine profiles define the severity of the AA phenotype or are affected by co‐existent atopy. Methods. In total, 17 serum cytokines were measured and compared in 269 patients with AA of varying severity with and without atopy and 18 unrelated controls. Results. Of the 269 patients with AA, 96% had active disease and 54% were atopic. The disease phenotype was transient patchy AA in 27 patients, persistent patchy AA in 89 and alopecia totalis or alopecia universalis in 153. Levels of Th1, interleukin (IL)‐1 receptor antagonist (ra) and IL‐8 levels were higher in all patients with AA than in controls. IL‐1α, IL‐12 and tumour necrosis factor‐α levels were higher in patients with AA and atopy than in patients with AA without atopy. Conclusions. Increased Th1 serum cytokines (IL‐2, IL‐12 and interferon‐γ) and IL‐1ra levels are associated with AA regardless of disease severity or the presence of atopy.     

Altered polyamine profiling in the hair of patients with androgenic alopecia and alopecia areata

Hair follicles are among the most highly proliferative tissues. Polyamines are associated with proliferation, and several polyamines including spermidine and spermine play anti‐inflammatory roles. Androgenic alopecia results from increased dihydrotestosterone metabolism, and alopecia areata is an autoimmune disease. This study aimed to investigate differences in polyamine profiles in hair samples between patients with androgenic alopecia and alopecia areata. Polyamine concentrations were determined through high‐performance liquid chromatography‐mass spectrometry. Hair samples were derivatized with isobutyl chloroformate. Differences in polyamine levels were observed between androgenic alopecia and alopecia areata compared with normal controls. In particular, polyamine levels were higher in alopecia areata patients than in normal controls. Certain polyamines displayed different concentrations between the androgenic alopecia and alopecia areata groups, suggesting that some polyamines, particularly N‐acetyl putrescine (P = 0.007) and N‐acetyl cadaverine (P = 0.0021), are significantly different in androgenic alopecia. Furthermore, spermidine (P = 0.021) was significantly different in alopecia areata. Our findings suggest that non‐invasive quantification of hair polyamines may help distinguish between androgenic alopecia and alopecia areata. Our study provides novel insights into physiological alterations in patients with androgenic alopecia and those with alopecia areata and reveals some differences in polyamine levels in hair loss diseases with two different modes of action.     

Interleukin-1 receptor antagonist allele 2 and familial alopecia areata

Alopecia areata affects 1%-2% of the population and is hypothesized to be an autoimmune, organ specific T-cell mediated reaction directed against the human hair follicle. It is characterized by loss of hair in patches (alopecia areata) with progression in some individuals to total loss of scalp hair (alopecia totalis) or to loss of all scalp and body hair (alopecia universalis). The interleukin-1 receptor antagonist (IL-1RN) gene was found to be associated with more severe clinical outcome in several chronic inflammatory diseases, including alopecia areata. The IL-1RN*2 allele was found to be associated with alopecia areata severity in a British case-control study. In this paper, we analyzed alopecia areata probands in a family-based sample (n = 131 parent-offspring trios) to study the association between alleles of the IL-1RN and various phenotypes of alopecia areata. In considering all patients with any form of alopecia areata, no association was found with IL-1RN. IL-1RN*2 allele was not associated with alopecia totalis and alopecia universalis. A borderline association was observed between IL-1RN and patchy alopecia areata but it was not statistically significant (p =0.06). We also observed an association between IL1-RN*1 allele and patchy alopecia areata (p =0.045).     

Cytokines and growth factors influence hair growth in vitro. Possible implications for the pathogenesis and treatment of alopecia areata

Factors that influence the growth of the anagen hair follicle or initiate the switch to a catagen growth pattern have so far not been definitely determined, but there is increasing evidence that cytokines and growth factors play an important role during these processes. Recently we detected an aberrant in situ expression pattern of cytokines of the Th1 type (IFNγ, IL-2) plus IL-1β expression in untreated alopecia areata (AA), and a switch to high levels of IL-10 TGF-β1 expression after successful treatment with the contact allergen diphenylcyclopropenone (DCP). Hence the question arose as to whether cytokines are able to arrest hair growth and whether IL-10 or TGFβ1 have the capacity to antagonize this process. Using whole-organ cultures of microdissected human hair follicles we studied the effect of a panel of cytokines and growth factors on hair growth and on the gross morphology of the hair follicles in vitro. IL-2, IL-10 and IFN-γ had no effect in this regard, whereas TGFβ1 partially inhibited hair growth and EGF, TNFα and IL-1β completely abrogated it. EGF and TNFα induced the formation of a club-like hair follicle, similar to catagen morphology of the hair bulb, whereas hair follicles grown in the presence of IL-1β or TGFβ1 showed no particular morphological changes. We conclude that cytokines and growth factors are pivotal regulators of hair growth at least in vitro. IL-1 is suggested as playing an important role during the pathogenesis of AA. Possible mediators of therapeutic contact dermatitis (IL-10, TGFβ1, TNFα, PGE₂) are, at least in vitro, not able to antagonize the IL-1β-triggered hair growth inhibition. Therefore, we infer that these mediators rather ‘modulate’ the immune response in AA.     

Treatment of alopecia areata: “What is new on the horizon?”

New drug treatment opportunities based on the results of a genome-wide association study, which implicate T cell and natural killer (NK)-cell activation pathways, are leading to new approaches in future clinical trials of alopecia areata. Special attention is being given to the UL 16-binding protein (ULBP3) gene cluster on chromosome 6q25, as these genes make the NKG2D-activating ligand or signal that can trigger the NKG2D receptor, initiating an autoimmune response. A greater expression of ULBP3 has also been found in hair follicles in scalp biopsy specimens from patients with active disease. It is now postulated that the characteristic T cell "swarm of bees" infiltrate seen in alopecia areata is the result of T cells being attracted to the hair follicle by NKG2D-activating ligands. Future treatment approaches for alopecia areata include use of drugs that: (i) block the NKGD-activating ligand and NKG2D receptor interaction, (ii) halt activated T cells, or (iii) modification of the inflammatory cytokine network. Many drugs currently being used or being evaluated for other autoimmune diseases that work through these mechanisms might prove to be very effective in alopecia areata.     

Biomarkers of alopecia areata disease activity and response to corticosteroid treatment

Alopecia areata (AA) is a common inflammatory disease targeting the anagen‐stage hair follicle. Different cytokines have been implicated in the disease profile, but their pathogenic role is not yet fully determined. We studied biopsies of pretreatment lesional and non‐lesional (NL) scalp and post‐treatment (intra‐lesional steroid injection) lesional scalp of 6 patchy patients with AA using immunohistochemistry and gene expression analysis. Immunohistochemistry showed increases in CD3⁺, CD8⁺ T cells, CD11c⁺ dendritic cells and CD1a⁺ Langerhans cells within and around hair follicles of pretreatment lesional scalp, which decreased upon treatment. qRT‐PCR showed in pretreatment lesional scalp (compared to NL) significant increases (P < 0.05) in expression of inflammatory markers (IL‐2, IL‐2RA, JAK3, IL‐15), Th1 (CXCL10 and CXCL9), Th2 (IL‐13, CCL17 and CCL18), IL‐12/IL‐23p40 and IL‐32. Among these, we observed significant downregulation with treatment in IL‐12/IL‐23p40, CCL18 and IL‐32. We also observed significant downregulation of several hair keratins in lesional scalp, with significant upregulation of KRT35, KRT75 and KRT86 in post‐treatment lesional scalp. This study shows concurrent activation of Th1 and Th2 immune axes as well as IL‐23 and IL‐32 cytokine pathways in lesional AA scalp and defined a series of response biomarkers to corticosteroid injection. Clinical trials with selective antagonists coupled with cytokine‐pathway biomarkers will be necessary to further dissect pathogenic immunity.     

The therapeutic role of contact sensitization in alopecia areata: What,how, and why?

The immunologic pathways by which a contact dermatitis is able to induce hair regrowth in alopecia areata are not completely understood. Novel studies, however, provided evidence that cytokines may play a pivotal role during the pathogenesis of alopecia areata, and a counteracting cytokine pattern induced by the contact dermatitis may be responsible for the inhibition of the immune response giving rise to alopecia areata. Such counteracting activities are most likely mediated by cytokines such as interleukin 10 or transforming growth factor β1. This hypothesis is as yet unproven, but the effectiveness of allergic contact dermatitis in the treatment of alopecia areata would be compatible with this concept.     

Potential future dermatological indications for tacrolimus ointment

Tacrolimus ointment is a steroid-free topical immunomodulator developed for the treatment of atopic dermatitis, a common, chronic inflammatory skin disease. By inhibiting T-cell activation and cytokine production, topically applied tacrolimus modulates inflammatory responses in the skin. Numerous clinical trials have shown that it is effective and well tolerated for the treatment of atopic dermatitis, its licensed indication. In addition, numerous publications suggest that tacrolimus ointment may provide effective treatment for a variety of other inflammatory skin disorders, many of which are very difficult to manage with standard therapy. This paper reviews currently available evidence regarding the use of tacrolimus ointment in a range of dermatological disorders, including psoriasis, lichen planus, pyoderma gangrenosum, lichen sclerosus, contact dermatitis, leg ulcers in rheumatoid arthritis, steroid-induced rosacea and alopecia areata. It also provides recommendations for future clinical studies with tacrolimus ointment.     

Expression of CD30 on T helper cells in the inflammatory infiltrate of acute atopic dermatitis but not of allergic contact dermatitis

Abstract  The CD30 molecule has been proposed as a marker for a subset of CD4⁺CD45RO⁺ (memory) T cells with potent B cell helper activity producing IL-5 and IFN-γ and as a specific marker for Th2 cells. Recently, an association has been demonstrated between elevated serum levels of soluble CD30, which is shed by CD30⁺ cells in vitro and in vivo, and atopic dermatitis but not respiratory atopic disorders or allergic contact dermatitis. We studied the expression of CD30 in the inflammatory infiltrate of atopic dermatitis compared with that of allergic contact dermatitis, with special regard to skin disease activity (acute vs subacute/ chronic). Biopsies were obtained from 16 patients suffering from atopic dermatitis (acute n = 6, subacute/ chronic n = 10), from 7 patients with acute allergic contact dermatitis and from 5 positive patch-test reactions. Paraffin-embedded as well as snap-frozen material was stained with anti-CD30 and anti-CD45RO mAbs according to standard procedures. Double-staining procedures for CD30CD3, CD30CD4, CD30CD45RO and CD30CD68 were also performed. Abundant CD45RO⁺ cells were detected both in atopic dermatitis and in allergic contact dermatitis lesions. We found scattered CD30⁺ cells in only one of six formalin-fixed paraffin-embedded acute atopic dermatitis biopsies, but in all of the respective snap-frozen specimens, possibly because CD30 expression on atopic dermatitis infiltrating cells is weak and sensitive to formalin fixation and paraffin embedding. CD30CD3 and CD30CD4 double staining identified CD30⁺ cells to be helper T lymphocytes. No significant CD30 expression (either in paraffin-embedded or in frozen material) could be found in subacute/chronic atopic dermatitis lesions or in any of the specimens of allergic contact dermatitis. The results suggest a specific regulatory function of CD30⁺ T cells in acute atopic dermatitis. With respect to the view that CD30 is a marker for Th2 cells, our observations confirm previous findings that Th2 cells predominate in the infiltrate particularly of acute atopic dermatitis. CD30 expression in acute atopic dermatitis but not in acute allergic contact dermatitis might be helpful in the histological differentiation of these disorders and in the further characterization of atopy patch testing. Received: 1 April 1998 / Received after revision: 28 May 1998 / Accepted: 3 July 1998     

Type 1 interferon signature in the scalp lesions of alopecia areata

Background Autoimmune attack of the bulbar region of anagen phase hair follicles by CD8+ T cells and Th1 cytokines has been proposed to result in hair loss in alopecia areata (AA). The initiating stimuli are unknown. As interferon‐α therapy may trigger AA, we propose that type 1 interferons are involved in the induction of disease. Objectives To compare lesional scalp from patients with AA with scalp lesions of cutaneous diseases associated with local type 1 interferon‐related protein expression. Methods Lesional scalp of patients with AA, discoid lupus erythematosus, lichen planopilaris and androgenetic alopecia was examined by immunohistochemistry for expression of the type 1 interferon‐inducible myxovirus protein A (MxA), the chemokine receptor CXCR3, and the cytotoxic proteins granzyme B (GrB) and T‐cell intracytoplasmic antigen 1 (TiA‐1). Results MxA was expressed in the intradermal and subcutaneous compartments of the hair follicle including sebaceous glands in inflammatory AA similar to lesions of cicatricial alopecia (discoid lupus erythematosus, lichen planopilaris) but not in the epidermal compartment of AA, and not at all in noninflammatory AA or androgenetic alopecia. The location of CXCR3‐expressing cells correlated with MxA expression. The inflammatory cells around the hair follicle in AA included a lower number of GrB+ and TiA‐1+ cells compared with cicatricial alopecia and demonstrated predominant TiA‐1+ expression. Conclusions We demonstrate the expression of type 1 interferon‐related proteins in the inflammatory lesions of AA. The distribution pattern of the interferon signature and cytotoxicity‐associated proteins in AA differs from cicatricial alopecia.     

斑秃的治疗现状

斑秃是一种累及生长期毛囊的免疫相关性疾病.斑秃的治疗主要是依据患者的年龄、疾病的严重程度及持续时间来选择合适的治疗方法,包括糖皮质激素、米诺地尔、免疫疗法、生物制剂及试验性治疗和疾病管理措施等,但至今尚无确切有效的治疗和预防的方法,有些疗法也没有系统的随机、对照试验证据,其治疗方面仍是一大挑战.目前认为,斑秃是一种毛囊免疫赦免破坏的自身免疫性疾病,免疫抑制可控制病情,进一步重建免疫状态成为斑秃治疗的理想观念.     

Trichostasis spinulosa of the scalp mimicking Alopecia Areata black dots

Alopecia areata is a common autoimmune disorder that leads to nonscarring hair loss. Black dots, also called comedo-like cadaver hairs, can be found in almost 50% of alopecia areata patients and indicate disease activity. Trichostasis spinulosa is a follicular disorder resulting from the retention of numerous hairs surrounded by a keratinous sheath in dilated follicles. Trichostasis spinulosa is a relatively common but underdiagnosed disorder of hair follicles. Here, we describe a man with alopecia areata of the eyebrows, androgenetic alopecia and trichostasis spinulosa at the vertex and show how dermoscopy can be useful in distinguishing black dots from Trichostasis spinulosa lesions.