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     

TARC and RANTES, but not CTACK, are induced in two models of allergic contact dermatitis. Effects of cilomilast and diflorasone diacetate on T-cell-attracting chemokines

BACKGROUND: Skin-infiltrating T cells play a predominant role in allergic and inflammatory skin diseases such as atopic dermatitis and allergic contact dermatitis. These T cells are attracted by chemotactic factors, e.g. RANTES (regulation on activation, normal T cell expressed and secreted; CCL5), TARC (thymus and activation regulated chemokine; CCL17) and CTACK (cutaneous T-cell attracting chemokine; CCL27). OBJECTIVES: To investigate which T-cell-attracting chemokines are involved in allergic contact dermatitis in mice. METHODS: Allergic contact dermatitis was induced by application of dinitrochlorobenzene (DNCB) or toluene-2,4-diisocyanate (TDI), and chemokine concentrations were determined by enzyme-linked immunosorbent assay. The effects on chemokine concentrations of the highly selective phosphodiesterase 4 inhibitor cilomilast and the glucocorticoid diflorasone diacetate were studied in mouse ears. RESULTS: RANTES and TARC were elevated in both models of allergic contact dermatitis 24 h after challenge, whereas CTACK remained unchanged. The increase in RANTES was diminished in mouse ears pretreated with cilomilast or diflorasone diacetate. TARC was reduced by diflorasone diacetate in the DNCB model but was highly induced in the TDI model; in contrast, TARC was not influenced by cilomilast. CONCLUSIONS: TARC and RANTES, but not CTACK, are involved in these two models of allergic contact dermatitis.     

Extended DNFB-induced contact hypersensitivity models display characteristics of chronic inflammatory dermatoses

Despite recent developments, there is a high medical need for new treatment options for chronic inflammatory dermatoses like allergic contact dermatitis (ACD) and psoriasis. Particularly, more predictive skin inflammation models are required to facilitate the process of drug discovery. Murine contact hypersensitivity (CHS) models adequately reflect ACD and are also used to characterize therapeutic approaches for psoriasis. Using the hapten 2,4-dinitrofluorobenzene (DNFB), we established new subacute and subchronic DNFB-induced CHS models in C57BL/6 mice, which more closely reflect the characteristics of chronic T-cell-dependent inflammatory dermatoses as pronounced keratinocyte proliferation, strong hypervascularization, immune cell infiltration and overexpression of T cell and inflammatory cytokines. For the subacute DNFB model, we demonstrated anti-inflammatory activity of the glucocorticoid, prednisolone, as well as of neutralization of TNFα, IL-12/IL-23 or IL-18. In the subchronic DNFB-induced CHS model, deficiency for MyD88 and IL-12/IL-35 p35 chain but not IL-12/IL-23 p40 chain led to decreased skin inflammation. Furthermore, as exemplified by the dose-dependently effective therapeutic prednisolone treatment, the subchronic model allows the continuous therapy of a pre-established stable contact dermatitis. Altogether, prolonged DNFB-induced mouse CHS models closely reflect ACD sensitive to glucocorticoids as standard therapy, reveal a more chronic skin inflammation and are responsive to cytokine antagonization.     

CCR4 and CCR10 ligands play additive roles in mouse contact hypersensitivity

Abstract:  Psoriasis, atopic dermatitis and allergic contact dermatitis are T-cell-mediated inflammatory skin diseases; chemokine receptors (CCR) 4 and 10 play an important role in the ligand-mediated recruitment of T cells into the skin in mice and humans, specifically with regards to tethering, firm adhesion and subsequent extravasation to the sight of injury. We utilized established murine models of dinitrofluorobenzene-, trimellitic acid anhydride- or oxazalone-induced contact hypersensitivity, to reflect the various Th-polarizations of different skin diseases, and investigated the functional effect of antibody blocking of single CCR ligands or combination therapy to block all CCR4 and CCR10 ligands. Our results indicate a greater reduction in inflammatory response – measured by oedema formation, myeloid cell and neutrophil infiltration and activity and CD3+ cell infiltration at the site of injury – with combination antibody therapy to CCR4 and CCR10 ligands versus controls, in nearly every tested condition. We conclude that blocking CCR4 and CCR10 simultaneously, or their ligands, should be beneficial in the treatment of T-cell-mediated skin diseases.     

Periorbital dermatitis: Causes,differential diagnoses and therapy

Periorbital dermatitis is common and frequently difficult to treat. Patients with periorbital dermatitis often suffer severely because their disease is in such a visible location. Because of the variety of clinical appearance, the differential diagnostic considerations are often difficult. We examined the causes of periorbital dermatitis and compared the data of 88 patients from the Department of Dermatology, University Hospital Erlangen to those of the German IVDK (Information Network of the Departments of Dermatology). Between 1999 and 2004, predominant causes of periorbital dermatitis were allergic contact dermatitis (Erlangen 44 %, IVDK 32 %), atopic eczema (Erlangen 25 %, IVDK 14 %), airborne contact dermatitis (Erlangen 10 %, IVDK 2 %) and irritant contact dermatitis (Erlangen 9 %, IVDK 8 %). Less frequent causes for secondary eczematous periocular skin lesions were periorbital rosacea, allergic conjunctivitis or psoriasis vulgaris. Female gender, atopic skin diathesis and age of 40 years and older were identified as risk factors for periocular dermatitis. Common elicitors of periorbital allergic contact dermatitis were leave‐on cosmetic products (face cream, eye shadow) and eye drops with the usual allergens being fragrances, preservatives and drugs. Exact identification of relevant contact allergens and allergen elimination are essential for successful treatment. Calcineurin inhibitors are the first‐line therapy for facial atopic eczema. They may be also effective in periocular eczematous lesions of other origins although they are not approved for such use.     

Haptenos,proteínas y dermatitis atópica

Atopic dermatitis is a chronic inflammatory disease that is multifactorial in nature. Allergic contact dermatitis and protein contact dermatitis are allergic conditions that may occur in the context of atopic dermatitis and be the cause of exacerbations. Although the prevalence of allergic contact dermatitis is similar in atopic patients and the general population, these 2 conditions are frequently associated because atopic inflammation disrupts the skin barrier. Skin tests are therefore recommended in atopic individuals. Dupilumab could be useful for treating allergic contact dermatitis if it is mediated by type 2 helper T cells but could exacerbate inflammation if mediated by T_H1 cells: further study is needed before conclusions can be drawn. Although the mechanism by which exposure to environmental proteins exacerbates atopic dermatitis remains under discussion, such exacerbations are routinely seen in clinical practice. Prick testing is recommended in symptomatic atopic dermatitis. When prick-test findings are positive, patients should be advised to avoid the culprit substances.     

The presence of surface CD30 on T cells in atopic dermatitis

Atopic dermatitis (AD) has cellular immunohistochemical features similar to those of allergic contact dermatitis (ACD) and there is plenty of evidence for T-cell activation in this disease. The involvement of CD30+ T cells in acute stages of atopic dermatitis might establish CD30 as a helpful marker in differentiating those two diseases. Tissue sections from the skin of 12 patients with active atopic dermatitis and 13 with allergic contact (nickel-induced) dermatitis were immunohistochemically analyzed for cell-surface antigens, including CD30, CD3, CD4, and CD45RO. The severity of the disease was graded by the SCORAD clinical scoring system. The analysis of CD30+, CD45RO+, CD3+, and CD4+ cells in the dermis and epidermis showed a much wider range of values and statistically higher median (p<0.01) in the inflammatory infiltrate of acute atopic dermatitis compared with that of allergic contact dermatitis. Our results showed an association of CD30 expression with atopic dermatitis, but not allergic contact dermatitis. CD30 expression in AD might be helpful in histologic differentiation of these disorders and further characterization of atopy patch testing. The results suggested a specific regulatory function of CD30+ T cells in acute AD. Abundant CD45R0+ cells were detected in both AD and ACD lesions.     

外用茶油对变应性接触性皮炎发生的影响

目的 观察茶油对小鼠变应性接触性皮炎发生的影响。方法 建立二硝基氟苯致小鼠变应性接触性皮炎模型,外用药物进行治疗,观察发生皮炎的小鼠耳片的组织学变化（HE染色）,RT-PCR检测组织中炎症细胞因子IL-2、IFN-γ mRNA的表达水平。结果 成功建立二硝基氟苯致小鼠变应性接触性皮炎的动物模型,且皮肤中IL-2、IFN-γ mRNA的表达显著增高。哈西奈德溶液组和茶油组的耳片组织肿胀明显减轻,炎症反应轻微,炎性细胞浸润数目少,组织病理变化轻。在茶油和哈西奈德溶液的干预下,炎性组织IL-2、IFN-γ的mRNA表达均不同程度下降。结论 茶油减轻二硝基氟苯致小鼠变应性接触性皮炎的病理损害,下调了炎症因子的表达。     

[Translated article] Haptens,Proteins, and Atopic Dermatitis

Atopic dermatitis is a chronic inflammatory disease that is multifactorial in nature. Allergic contact dermatitis and protein contact dermatitis are allergic conditions that may occur in the context of atopic dermatitis and be the cause of exacerbations. Although the prevalence of allergic contact dermatitis is similar in atopic patients and the general population, these 2 conditions are frequently associated because atopic inflammation disrupts the skin barrier. Skin tests are therefore recommended in atopic individuals. Dupilumab could be useful for treating allergic contact dermatitis if it is mediated by type 2 helper T cells but could exacerbate inflammation if mediated by T_H1 cells: further study is needed before conclusions can be drawn. Although the mechanism by which exposure to environmental proteins exacerbates atopic dermatitis remains under discussion, such exacerbations are routinely seen in clinical practice. Prick testing is recommended in symptomatic atopic dermatitis. When prick-test findings are positive, patients should be advised to avoid the culprit substances.     

Cilomilast, tacrolimus and rapamycin modulate dendritic cell function in the elicitation phase of allergic contact dermatitis

BACKGROUND: Cilomilast and tacrolimus as well as rapamycin are potential drugs for the treatment of allergic skin diseases like atopic dermatitis and allergic contact dermatitis. OBJECTIVES: To compare the in vitro and in vivo immunomodulatory effects of the phosphodiesterase 4 inhibitor cilomilast with those of tacrolimus and rapamycin. METHODS: The in vitro action of cilomilast, tacrolimus and rapamycin were tested in a mixed leucocyte reaction (MLR). In vivo, the inhibitory action of the immunomodulatory drugs was compared in the toluene-2,4-diisocyanate (TDI)-induced allergic inflammatory response with particular focus on dendritic cell (DC) function. RESULTS: Cilomilast, tacrolimus and rapamycin were all able to inhibit DC-mediated T-cell activation in a MLR. But it was demonstrated for cilomilast that the target cells are T cells rather than DC. In vivo, a combination of systemic and topical administration of each of these three substances significantly inhibited swelling in the murine ear 16 h after TDI challenge. There was also a reduction in the weight of the draining auricular lymph node, in lymphocyte cell count, and in the number of emigrated DC. The density of Langerhans cells in the epidermis was correspondingly higher in mice treated with cilomilast, tacrolimus and rapamycin than in those treated with vehicle. All three substances were found to inhibit DC migration ex vivo in a skin DC migration assay performed on ear tissue after TDI challenge. CONCLUSIONS: DC migration into the draining lymph node also takes place in the elicitation phase of allergic contact dermatitis and this migration can be influenced by tacrolimus and rapamycin, and, to a lesser extent, by cilomilast.     

Increased “in vivo” lymphocyte blastogenesis in the peripheral blood of patients with atopic dermatitis and allergic contact dermatitis

Summary The spontaneous ³H-thymidine (³HT) labelling of some lymphocyte subpopulations has been studied in the peripheral blood of five patients with atopic dermatitis and five with widespread allergic contact dermatitis and compared with that in 10 healthy subjects. One hour after addition of ³HT to heparinized blood, lymphocytes were separated and processed with two different rosetting techniques (E-rosette test and Active-E-rosette test). The cell suspensions were cytocentrifuged and autoradiography undertaken.An increased number of ³HT labelled lymphocytes was observed in the peripheral blood of patients with dermatitis as compared to controls. These labelled lymphocytes were E-rosette-forming cells (T cells) and E-non-rosetteforming cells (non-rosette-forming T cells and non-T cells). The ratio between the labelling index (LI) of E-rosette- to the LI of non-E-rosette-forming cells was in favour of T cells in allergic contact dermatitis (ratio=3.09) whereas in atopic dermatitis (ratio=0.93) the DNA synthesis was relatively greater in the non-rosette-forming cells.It is suggested that this increased LI of peripheral blood lymphocytes could be related to the increased dermal mononuclear cell ³HT-labelling that has been reported previously in these inflammatory skin diseases.D. Van Neste is recipient of a grant from INSERM, Paris and Administration des relations culturelles internationales (ARCI), Bruxelles     

Strong induction of AIM2 expression in human epidermis in acute and chronic inflammatory skin conditions

Absent in melanoma 2 (AIM2) is a double‐stranded DNA receptor, and its activation initiates an interleukin‐1 beta processing inflammasome. AIM2 is implicated in host defense against several pathogens, but could hypothetically also contribute to autoinflammatory or autoimmune diseases, such as is the case for NLRP3. Using thoroughly characterised antibodies, we analysed AIM2 expression in human tissues and primary cells. A strong epidermal upregulation of AIM2 protein expression was observed in several acute and chronic inflammatory skin disorders, such as psoriasis, atopic dermatitis, venous ulcera, contact dermatitis, and experimental wounds. We also found AIM2 induction by interferon‐gamma in submerged and three‐dimensional in vitro models of human epidermis. Our data highlight the dynamics of epidermal AIM2 expression, showing Langerhans cell and melanocyte‐restricted expression in normal epidermis but a pronounced induction in subpopulations of epidermal keratinocytes under inflammatory conditions.     

Scratching behavior in spontaneous- or allergic contact-induced dermatitis in NC/Nga mice

NC/Nga mice have pathological and behavioral features similar to those seen in human atopic dermatitis. There are two known dermatitis models in NC/Nga mice, one being spontaneous-induced dermatitis under conventional conditions and the other 2,4,6-trinitrochlorobenzene (TNCB)-induced allergic contact dermatitis. However, there are significant differences in time course on development of dermatitis. We studied the role of scratching behavior (sign of itch) on the development of dermatitis on spontaneous- and TNCB-induced dermatitis. We measured scratching counts, transepidermal water loss (TEWL), and skin inflammation score, under conventional conditions or by applying 5% TNCB once a week for 6 weeks in NC/Nga mice. In spontaneous-induced dermatitis, scratching counts increased with the passage of time. The scratching counts were significantly increased only 1 week after housing the mice under conventional conditions, but no changes were observed in cases of TNCB-induced dermatitis. In spontaneous-induced dermatitis, TEWL and skin-inflammation score were gradually increased, time-dependently. On the other hand, in TNCB-induced dermatitis, these dependent values rapidly increased and reached a maximum only after 24 h TNCB application. These data suggest that pathogenesis of spontaneous- and allergic contact-induced dermatitis was clearly different. It will be of major interest to identify the pruritic mediators causing profound scratching behavior and scratching-induced aggravation of inflammation in the spontaneous-induced dermatitis, as opposed to the inflammatory mediators that cause contact allergic dermatitis without major scratching.     

Sites of dermatitis in a patch test population: hand dermatitis is associated with polysensitization

Background  Sites of dermatitis in larger series of contact allergic patients are rarely reported. Increased risk of polysensitization has been linked only to stasis dermatitis and leg ulcers. However, a large proportion of polysensitized individuals may have dermatitis in other skin areas.
Objectives  To examine the site of dermatitis at time of first appearance in contact allergic individuals with special focus on the distribution of dermatitis in polysensitized individuals and to examine if widespread dermatitis is more frequent in polysensitized than in single/double-sensitized patients.
Methods  A matched case–control study was carried out including 394 polysensitized and 726 single/double-sensitized patients who responded to a postal questionnaire. All subjects were recruited from a hospital patch test population.
Results  The hands were the most frequent and the anogenital region was the least frequent skin area affected with dermatitis. Dermatitis on the hands/wrists [odds ratio (OR) 1·58], in the armpits (OR 1·56) and on the back (OR 1·91) was positively associated with polysensitization. The hands were the only skin area with dermatitis which maintained the association to polysensitization in two subpopulations consisting of, respectively, individuals with and without atopic eczema. Dermatitis on the scalp was negatively associated with polysensitization (OR 0·66) primarily for individuals without atopic eczema. The dermatitis did not seem to be more widespread in polysensitized compared with single/double-sensitized patients.
Conclusions  Special awareness in patients with hand dermatitis seems justified either to prevent development of multiple contact allergies or to document polysensitization as an aetiological factor.     

Dendritic cells: biology of the skin

Allergic contact dermatitis results from a T-cell-mediated, delayed-type hypersensitivity immune response induced by allergens. Skin dendritic cells (DCs) play a central role in the initiation of allergic skin responses. Following encounter with an allergen, DCs become activated and undergo maturation and differentiate into immunostimulatory DCs and are able to present antigens effectively to T cells. The frequency of allergic skin disorders has increased in the past decades. Therefore, the identification of potential sensitizing chemicals is important for skin safety. Traditionally, predictive testing for allergenicity has been conducted in animal models. For regulatory reasons, animal use for sensitization testing of compounds for cosmetic purposes is shortly to be prohibited in Europe. Therefore, new non-animal-based test methods need to be developed. Several DC-based assays have been described to discriminate allergens from irritants. Unfortunately, current in vitro methods are not sufficiently resilient to identify allergens and therefore need refinement. Here, we review the immunobiology of skin DCs (Langerhans' cells and dermal dendritic cells) and their role in allergic and irritant contact dermatitis and then explore the possible use of DC-based models for discriminating between allergens and irritants.     

复方氟米松软膏对慢性变应性接触性皮炎模型鼠的治疗作用

目的探讨复方氟米松软膏治疗小鼠慢性变应性接触性皮炎的疗效及机制。方法用0.5%2,4二硝基氯苯(DNCB)制备小鼠慢性变应性接触性皮炎模型40只,随机分为治疗组(复方氟米松软膏)、治对照组(地塞米松)、空白对照组(模型组)和对照组(冷霜)。除空白对照组外,余三组在小鼠背部均匀涂抹实验药物,2次/d,连续2周。观察各组干预后皮肤组织病理及组织IL-4水平。结果复方氟米松治疗组小鼠较对照组皮损处角质层明显变薄,表皮厚度恢复正常;炎症细胞明显减少,IL-4含量显著降低(P<0.05)。结论复方氟米松软膏治疗慢性变应性接触性皮炎,具有一定的效果,其机制可能与下调局部皮损炎性因子有关。