Foxp3+ regulatory T cells and related cytokines differentially expressed in plaque vs. guttate psoriasis vulgaris

Background Differences in the number of Foxp3+ regulatory T cells (Tregs) in lesional skin and peripheral blood and their functioning in plaque vs. guttate psoriasis have not been reported. Objectives To investigate whether there is a differential expression of Foxp3+ Tregs and a differential regulation of inflammatory cytokines in plaque vs. guttate psoriasis vulgaris. Methods The number and the percentage of Foxp3+ cells in different phases of skin lesions of patients with plaque and guttate psoriasis vulgaris were assessed by immunohistochemical staining. The expression of Foxp3 and interleukin (IL)‐17 protein in CD4 populations was measured by flow cytometry. Inflammatory cytokine production by transforming growth factor‐β1‐induced Foxp3+ Tregs was assessed in an in vitro study. The cytokines in supernatant and serum were determined by enzyme‐linked immunosorbent assay. Results The percentage of Foxp3+ CD3+ cells in the papillary layer was higher than in the reticular layer of dermis and in epidermis (P < 0·05). The numbers of Foxp3+ Tregs in skin lesions and peripheral blood were higher in plaque than in guttate psoriasis, whereas the percentage of IL‐17+ CD4+ cells was higher in guttate than in plaque psoriasis (P < 0·05). The numbers of Foxp3+ cells were positively correlated with the Psoriasis Severity Index score of skin lesions (P < 0·0001), and the percentages of Foxp3+ CD4+ cells in peripheral blood were positively correlated with the Psoriasis Area and Severity Index score of patients (P < 0·05). The inhibitory functions of Tregs to IL‐17 and IL‐6 in guttate psoriasis and to tumour necrosis factor‐α in plaque psoriasis were deficient. Conclusions Differential expression and regulatory functioning for inflammatory cytokine production by Foxp3+ Tregs may imply a different immunopathogenesis for plaque and guttate psoriasis.     

Regulatory T cells in atopic dermatitis: epidermal dendritic cell clusters may contribute to their local expansion

Background  Regulatory T cells (Tregs) have an essential role in tolerance and immune regulation. However, few and controversial data have been published to date on the role and number of these cells in atopic dermatitis (AD).
Objectives  To investigate the number of CD4+CD25+FOXP3+ Tregs and interleukin 10-producing T regulatory type 1 (Tr1) cells in patients with AD.
Methods  Peripheral blood and skin biopsy samples from atopy patch test (APT)-positive patients with acute- and chronic-phase AD were investigated. Immunohistochemistry was applied to identify CD4+CD25+FOXP3+ Tregs in the skin, while flow cytometry was used to detect CD4+CD25highFOXP3+ Tregs and Tr1 cells in the peripheral blood.
Results  In the peripheral blood samples of patients with AD significantly elevated numbers of Tr1 cells were found. Although neither the absolute number nor the percentage of CD4+CD25highFOXP3+ Tregs showed significant alteration in the peripheral blood of patients, increased numbers of FOXP3+ Tregs were detected in skin biopsy specimens. All of the APT-positive skin samples showed epidermal dendritic cell aggregates, morphologically consistent with so-called Langerhans cell microgranulomas, which also contained intermingled FOXP3+ Tregs.
Conclusions  Tr1 cell numbers were elevated in the peripheral blood and increased numbers of CD4+CD25highFOXP3+ Tregs were detected in the skin of patients with AD. The epidermal dendritic cell clusters in APT-positive lesional skin showed a close connection to the FOXP3+ Tregs.     

Distinctive dendritic cell subsets expressing factor XIIIa, CD1a, CD1b and CD1c in mycosis fungoides and psoriasis

The papillary dermis of psoriasis and mycosis fungoides (MF) lesions is characterized by prominent collections of cells with dendritic morphology. Immunophenotypically distinct populations of cutaneous dendritic cells have been identified as CD1a+, FXIIIa-Langerhans cells (LC) and CD1a-, FXIIIa+ dermal dendritic cells (DDC). In this study, antibodies against the human GDI cluster of antigens (i.e. CD1a, CD1b and CD1c) and the DDC) marker (FXIIIa) were used to further characterize the subsets of dendritic cells in normal skin as compared to neonatal foreskin, psoriasis and MF by both immunoperoxidase and double immunofluorescence techniques. Normal skin and foreskin epidermis and dermis contained few CD1b+ or CD1c+ cells along with normal numbers of CD1a+ LC and FXIIIa+ DDC. Both MF and psoriasis were characterized by CD1a+ cells in the epidermis and dermis. FXIIIa+ cells were greatly expanded in the upper dermis of MF lesions and to a lesser degree in psoriasis as has been previously described by our group. MF contained significantly increased epidermal and dermal CD1b+ (15.7/5 high power fields [HPF] and 59.7/5 HPF respectively) and CD1c+ dendritic cells (33.8/5 HPF and 95.9/5 HPF respectively), while in psoriasis these cells were not statistically different from normal skin. Double immunofluorescence studies revealed that some (<25%) FXIIIa+ cells co-expressed CD1b and CD1c in MF>psoriasis> foreskin, while FXIIIa+ DDC never co-expressed CD1a. Thus, in contrast to normal skin in which epidermal or dermal dendritic cells rarely express CD1b and CD1c antigens, these members of the CD1 family are upregulated on both LC and DDC in benign and malignant inflammatory states. Upregulation of CD1b and CD1c on MF epidermal and dermal dendritic cells, as compared to psoriasis, foreskin and normal skin, may be useful in the immunophenotypic recognition of MF, as well as in helping to understand its immunobiology.     

Comparison of the distribution and numbers of antigen-presenting cells among T-lymphocyte-mediated dermatoses: CD1a+, factor XIIIa+, and CD68+ cells in eczematous dermatitis,psoriasis, lichen planus and graft-versus-host disease

Antigen-presenting cells (APCs) participate in the initiation of the inflammatory process in various immune-mediated dermatoses through the activation of antigen-specific T lymphocytes. The skin contains several different subsets of APCs. To investigate the role of these APCs in T-cell immune-mediated inflammation, we examined the distribution and numbers of epidermal and dermal CD1a(+) dendritic cells (DCs), factor XIIIa(+) dermal DCs, and CD68(+) macrophages in five T-cell-mediated inflammatory skin diseases. Immunohistochemistry of CD1a, factor XIIIa, and CD68 was performed using paraffin-embedded tissue obtained from a total of 51 patients with eczematous dermatitis (histologically spongiotic dermatitis), psoriasis, lichen planus, acute graft-versus-host disease (GVHD), and chronic GVHD. The numbers of positive cells for each staining were compared with those in site-matched normal skin control specimens from aged-matched subjects. In spongiotic dermatitis and lichen planus, the numbers of epidermal and dermal CD1a(+) cells and factor XIIIa(+) cells were significantly greater than in normal control skin, while in psoriasis only factor XIIIa(+) cells were significantly increased in number. Acute and chronic GVHD showed a reduced number of dermal CD1a(+) cells. Interestingly, factor XIIIa(+) cells were decreased in acute GVHD while they were increased in chronic GVHD. There was a significant reduction in epidermal CD1a(+) cells in acute GVHD, but not in chronic GVHD. The differences in the numbers of APCs in lesional skin appeared to reflect differences in the pathophysiology of these inflammatory skin diseases.     

Ultraviolet-B phototherapy is successful in Japanese patients with early-stage mycosis fungoides

UVB phototherapy is widely used for the treatment of psoriasis and atopic dermatitis, however, only limited reports evaluate its usefulness in the treatment of mycosis fungoides. We introduced UVB phototherapy to five patients with early-stage mycosis fungoides. All of them were classified as stage IB (erythematous stage), and none had obtained a satisfactory response to other therapies. After initial treatment with UVB phototherapy, all the patients obtained significant improvement in their skin lesions leaving pigmentary changes. After this satisfactory response was achieved, the same dose of UVB was administrated as a maintenance therapy with longer intervals between exposures. Histopathological examination of three patients revealed decreased numbers of inflammatory cells in both the epidermis and the dermis after the treatment. Immunohistochemical study showed that CD1a+/HLA-DR+ dendritic cells were present throughout the lesional epidermis before the treatment. In contrast, after the treatment, the dendritic cells in the epidermis were CD1a+/HLA-DR-. Although it remains unclear why only the expression of HLA-DR antigen was eliminated after treatment, we presume that this loss of HLA-DR antigen expression by epidermal Langerhans cells was, in part, responsible for the improvement of skin lesions. This preliminary study suggests that UVB phototherapy is an effective treatment for patients with early-stage mycosis fungoides.     

Distribution of CD1a-positive cells in psoriatic skin during the evolution of the lesions

Normal skin and psoriatic lesions from 35 patients were investigated immunohistochemically with regard to the CD1a+ cell population (Langerhans' cells and indeterminate cells) in the epidermis as well as in the dermal infiltrate. In the normal-appearing skin, we found the regularly typical pattern of CD1a+ dendritic cells in suprabasal position, but in lesional skin of chronic psoriasis the CD1a+ cells were scattered in the acanthotic epidermis. In initial lesions, CD1a+ cells represent up to 50-60% of the infiltrating cells of the dermal compartment, in several cases being preferentially localized in the upper part of the papillar dermis close up to the epidermal CD1a+ cells in basal position, whereas in chronic psoriasis they represent less than 10%. These results suggest that in psoriasis vulgaris, CD1a+ cells actively migrate between the epidermis and the dermal vessels.     

Leu-8/CD7 antigen expression by CD3+ T cells: comparative analysis of skin and blood in mycosis fungoides/Sézary syndrome relative to normal blood values.

Deficiencies of Leu-8 and CD7 antigens are exhibited by CD3+ T cells in the skin lesions of most patients with mycosis fungoides/Sézary syndrome. To determine whether these antigenic abnormalities are limited to involved skin, we studied Leu-8/CD7 expression in 21 skin lesions of mycosis fungoides/Sézary syndrome obtained from 16 patients and compared them with their peripheral blood leukocytes obtained concurrently. There was no correlation between Leu-8/CD7 values in skin lesions versus blood. Blood values were relatively uniform; most patients had 50% or greater of CD3+, Leu-8+ T cells and CD3+, CD7+ T cells. In contrast, skin values were highly heterogeneous; most patients lacked expression of Leu-8 or CD7 by the majority of lesional CD3+ T cells. Furthermore, Leu-8/CD7 antigen deficiency was present in lesional skin in one patient with mycosis fungoides but not in her concurrently sampled pityriasis lichenoides chronica or blood. These findings suggest that Leu-8/CD7 antigen deficiencies in skin lesions of mycosis fungoides/Sézary syndrome do not represent generalized antigenic abnormalities of CD3+ T cells in other body compartments and that within the skin, these deficiencies are disease specific within individual patients with more than one dermatosis. Comparative peripheral blood immunophenotyping of the patients with mycosis fungoides/Sézary syndrome and of the control subjects indicated that the control ranges of CD3+/Leu-8+ and CD3+/CD7+ T cells (33% or greater) extend lower than reported previously (60% or greater) and suggested that leukemic involvement in patients with mycosis fungoides/Sézary syndrome may correlate with percentages of CD3+, Leu8+ and/or CD3+, CD7+ T cells that fall below the revised control range.     

几种皮肤病中角朊细胞表达ICAM－1(CD54)和HLA－DR抗原的研究

为了探讨皮肤病病损处角朊细胞表达ICAM-1(CD54)和HLA-DR抗原及其与病损内浸润细胞的关系,应用抗ICAM-1及HLA-DR单抗、连续冰冻切片法及ABC免疫组化技术,在寻常型银屑病(4/4)、扁平苔藓(5/6)、慢性湿疹(4/6)、孢子丝菌病(3/6)、基底细胞癌(6/6)、鳞状细胞癌(5/7)、及Ⅱ期(4/5)、Ⅲ期(1/4)蕈样肉芽肿中,观察到其病损处角朊细胞可分别表达CD54和HLA-DR抗原.我们还发现在部分扁平苔藓(1/6)、慢性湿疹(2/6)、孢子丝菌病(3/6)、鳞状细胞癌(2/7)及Ⅱ期(1/5)、Ⅲ期(1/4)蕈样肉芽肿中,虽然其病损处真皮内见大量的T淋巴细胞浸润,但其上方表皮内角朊细胞未见CD54抗原表达,却可见HLA-DR抗原表达.在蕈样肉芽肿中,随病程进展到Ⅲ期(2/4),其病损处角朊细胞不仅有失去表达CD54、同时也有失去表达HLA-DR抗原能力的趋势.并探讨了病损内浸润细胞免疫表型与角朊细胞表达CD54抗原的关系.     

Monocytopoiesis in chronic eczematous diseases, psoriasis vulgaris, and mycosis fungoides.

Monocytopoiesis and blood monocytes were examined in 8 patients with disseminated chronic eczematous diseases, 8 patients with disseminated psoriasis vulgaris, and 8 patients with mycosis fungoides in plaque or tumor stage. Monocytopoiesis was moderately stimulated in all these patients. The stimulation manifested itself by: (1) a rise in relative number of promonocytes in bone marrow in all patients with eczema, in 1 out of 8 patients with psoriasis, and in 7 out of 9 examinations in patients with mycosis fungoides; (2) a rise in [3H]thymidine labeling indices of medullar promonocytes (8/8 eczema, 7/7 psoriasis, 8/9 mycosis fungoides); and (3) a rise in the naphthol-AS-D-chloroacetate esterase activity of blood monocytes, indicating premature monocyte marrow egress (3/5 eczema, 7/8 psoriasis, 9/9 mycosis fungoides). In eczema and psoriasis the mean enhancement of monocytopoietic activity was similar but less pronounced than in mycosis fungoides. In the latter disease there was no correlation between measured parameters and visible skin lesions. The results were interpreted as indicative of increased monocyte consumption by pathologic, immunologic, and/or inflammatory processes.     

Lack of suppressive CD4+CD25+FOXP3+ T cells in advanced stages of primary cutaneous T-cell lymphoma

Mycosis fungoides and its leukemic variant, Sezary syndrome, are the most common primary cutaneous T-cell lymphomas (CTCLs). In an ex vivo study, we investigated the percentage, phenotype, and suppressive function of CD4+CD25+ regulatory T cells (Tregs) from peripheral blood of CTCL patients. The percentage of Tregs did not differ significantly between patients and controls. Functional assays demonstrated a dichotomy in Treg function: in four out of 10 patients CD4+CD25+ T cells were incapable of suppressing autologous CD4+CD25- T-cell proliferation, whereas suppressive function was intact in the other six patients. Suppressive activity of Tregs inversely correlated with the peripheral blood tumor burden. T-plastin gene expression, used as a Sezary cell marker, confirmed that Sezary cells were heterogeneous for CD25 expression. Mixed lymphocyte reactions demonstrated that CD4+CD25- T cells from patients who lacked functional Tregs were susceptible to suppression by Tregs from healthy controls, and had not become suppressive themselves. Furthermore, we found reduced expression of Foxp3 in the CD4+CD25+ Tregs of these patients relative to the other six CTCL patients and controls. Our findings thus indicate a dysfunction of peripheral Tregs in certain CTCL patients, which correlates with tumor burden.     

Plaque psoriasis vs. atopic dermatitis and lichen planus: a comparison for lesional T-cell subsets, epidermal proliferation and differentiation

BACKGROUND: T-cell infiltration in plaque psoriasis has recently been an important subject of investigation. Interestingly, comparative analyses of the disease-specific composition of the lesional T-cell infiltrate in plaque psoriasis and other inflammatory dermatoses have only sparsely been performed. OBJECTIVES: To compare plaque psoriasis vs. atopic dermatitis and lichen ruber planus with respect to T-cell subsets, epidermal proliferation and keratinization. PATIENTS AND METHODS: Biopsies were taken from untreated lesional skin of patients, six with psoriasis, six with atopic dermatitis and six with lichen planus. T-cell subsets (CD4+, CD8+, CD45RO+, CD45RA+, CD2+, CD25+), an epidermal proliferation (Ki-67) and a keratinization marker (K10) were stained immunohistochemically and quantified using image analysis. RESULTS: The high number of CD8+ T cells (52 +/- 13 cells mm(-1)) found in the psoriatic epidermis was not found in the epidermis of atopic dermatitis (9 +/- 4), nor in the epidermis of lichen planus (34 +/- 10). The other T-cell subsets in the epidermis and dermis showed no statistically significant differences between psoriasis and atopic dermatitis. In contrast to the limited presence of CD4+, CD8+ and CD2+ in the psoriatic dermis (110 +/- 19, 27 +/- 9, 127 +/- 41, cells mm(-1), respectively), more impressive numbers of these cells were observed in the dermis of lichen planus (300 +/- 53, 144 +/- 38, 272 +/- 48, respectively). CD45RO+ memory effector T-cell counts were significantly higher in the epidermis of lichen planus (39 +/- 10) than in psoriasis (19 +/- 5). Psoriatic epidermis proved to have major keratinocyte hyperproliferation (247 +/- 26 cells mm(-1) lamina basalis), as compared with atopic dermatitis (134 +/- 15) and lichen planus (128 +/- 20). Furthermore, a marked decreased expression of keratin 10 was observed in psoriasis (41% of epidermal area) contrary to atopic dermatitis (70%). CONCLUSIONS: Psoriatic epidermis exhibits a pronounced CD8+ epidermotropism with accompanying epidermal hyperproliferation and abnormal keratinization, which changes are only minimally expressed in atopic dermatitis and lichen planus. In plaque psoriasis, substantially fewer activated CD4+ and CD8+ T cells in the dermis and less CD45RO+ T cells in the epidermis are present in comparison with lichen ruber planus.     

Intraepidermal lymphocytes in psoriatic lesions are activated GMP-17(TIA-1)+CD8+CD3+ CTLs as determined by phenotypic analysis

The onset and persistence of psoriatic lesions are linked to the presence of an inflammatory infiltrate of CD3+ lymphocytes that includes CD4+ and CD8+ subsets. Since a primary susceptibility factor for psoriasis is the Class I HLA-Cw6 molecule, we set out to learn more about the features of the epidermal CD8+ lymphocytes. The markers tested were GMP-17, a cytotoxic granule protein found in activated cytotoxic lymphocytes (CTLs), and the alpha chain of the IL-2 receptor (CD25), a plasma membrane molecule found on activated T cells. Lymphocytes in lesional skin expressed the GMP-17 protein, whereas lymphocytes in non-lesional skin, resolving lesional skin and normal skin had little or no GMP-17. By flow cytometry analysis, lesional epidermal GMP-17+ cells were CD8+CD3+, with a subpopulation expressing the activation marker CD25+. Due to the abundance of activated GMP-17+CD8+CD3+ lymphocytes (the phenotype of activated cytotoxic cells) in psoriatic lesions compared to non-lesional and normal skin, we hypothesize that they are contributing directly to the psoriatic phenotype.     

蕈样肉芽肿与扁平苔藓、银屑病浸润细胞的免疫组化比较

目的 探讨免疫表型对蕈样肉芽肿与扁平苔藓、银屑病鉴别诊断的意义.方法 应用ABC免疫组化技术检测15例蕈样肉芽肿,17例银屑病和17例扁平苔藓,6例正常人皮肤的CD1a、CD4、CD8、ICAM-1、LFA-1、HLA-DR(树枝状细胞)、CD30和CD7的表达情况.结果 蕈样肉芽肿表皮CD1a,CD30,ICAM-1(单一核细胞P<0.001,树枝状细胞P<0.01)的阳性细胞密度明显高于扁平苔藓、银屑病、正常人皮肤.蕈样肉芽肿表皮CD4,CD8,HLA-DR的阳性细胞密度明显高于扁平苔藓.蕈样肉芽肿真皮中CD1a阳性细胞的线性密度(P<0.01),真皮内ICAM-1和LFA-1阳性细胞百分比亦较扁平苔藓增多(P<0.05).蕈样肉芽肿表皮CD7阳性细胞与扁平苔藓、银屑病比较差异无统计学意义.银屑病和扁平苔鲜真皮内CD7阳性细胞百分比高于蕈样肉芽肿和正常人皮肤.结论 蕈样肉芽肿和扁平苔藓、银屑病皮损CD1a、CD4、CD8、ICAM-1、LFA-1、HLA-DR、CD30和CD7免疫表型有差异,其结果可为探讨发病机制提供线索.     

Fc epsilon R11/CD23 receptor distribution in patch test reactions to aeroallergens in atopic dermatitis.

There is increasing evidence that exposure to organic allergens may induce or exacerbate lesional skin in patients with atopic dermatitis. In this study, patients with atopic dermatitis were patch tested to 11 common organic allergens and to control chambers containing 0.4% phenol and 50% glycerin in 0.9% saline. In biopsies from positive patch test reactions, patch test control skin, lesional eczematous and non-lesional skin from atopic individuals, and normal skin from non-atopic volunteers, the presence and distribution of macrophages (RFD7+), dendritic cells (RFD1+), and Langerhans cells, and the expression of the low-affinity receptor for IgE (CD23) were investigated. In patch test reactions and lesional skin samples, inflammatory infiltrates of diffusely distributed macrophages (RFD7+), dendritic cells (RFD1+), T lymphocytes (RFTmix+), and Langerhans cells (CD1+) were seen, the latter being present in both the epidermis and the dermis. The numbers of Langerhans cells were reduced in the epidermis and increased in the dermis in patch test reactions and lesional skin compared to their controls. Double staining revealed a change in the distribution of CD23 antigen. In patch test control and non-lesional biopsies many macrophages and only a few Langerhans cells within the dermal infiltrates expressed this antigen. In patch test reaction and lesional skin samples, however, the proportion of CD23+ dermal Langerhans cells had increased compared to macrophages. Furthermore, in these latter samples an increased proportion of dermal CD1+ cells expressed the dendritic cell (RFD1+) marker. These results show that following antigen challenge there are marked similarities between the phenotype of the cellular infiltrate in patch test reaction and lesional skin biopsies, and also demonstrate a changing distribution of CD23 on antigen-presenting cells.     

Increased expression of TRAIL and its death receptors DR4 and DR5 in plaque psoriasis

TNF-related apoptosis-inducing ligand (TRAIL) is recognized as an important regulator of immune responses during infections and various autoimmune-mediated pathologies. Its role in inflammatory dermatoses is largely unknown. We aimed to investigate the expression of TRAIL and its receptors DR4 and DR5 in psoriasis vulgaris. Immunohistochemistry for TRAIL, DR4 and DR5 was performed on samples of lesional (n = 10) and non-lesional (n = 10) skin of patients with plaque psoriasis and skin of healthy volunteers (n = 10). Expression of TRAIL and its receptors was further examined by means of double immunofluorescence staining and co-localization with CD4, CD8, CD11c, CD68, CD16 and CD56 markers. Immunohistochemical staining for TRAIL was significantly enhanced in psoriatic lesional as well as non-lesional epidermis compared to the epidermis of healthy skin. Lesional epidermis also showed increased immunoreactivity for DR5. In addition, expression of TRAIL and both of its receptors was significantly increased in the dermis of lesional skin. As evidenced by double immunofluorescence, TRAIL was readily expressed by most of the examined cells of the inflammatory infiltrate in psoriatic lesions. In contrast, the expression of DR4 was found mostly among CD4+ and CD8+ cells but was only nuclear, while DR5 showed cytoplasmic staining in rare CD16+, CD56+ and CD68+ cells. According to abundant in situ presence of TRAIL and its receptors in lesional psoriatic skin, it seems that this cytokine participates in the complex interplay between keratinocytes and cells of the dermal infiltrate and thus contributes to the inflammatory cycle in psoriasis vulgaris.     

Expression of T-cell receptor antigens in mycosis fungoides and inflammatory skin lesions

Using immunohistologic methods, we studied the expression of the T-cell receptor (TCR)-associated antigens CD3, TCR-beta, and TCR-delta by cutaneous T cells in mycosis fungoides (MF) (36 patients) and a variety of inflammatory diseases (16 patients). Most T cells in the inflammatory diseases and patch/plaque mycosis fungoides expressed the immunophenotype characteristic of the vast majority of mature peripheral T cells: CD3+ TCR-beta+ TCR-delta-. In contrast, abnormal CD3/TCR-beta antigen expression was seen in 3 of 6 cases (50%) of tumor stage mycosis fungoides. Furthermore, we were able to document its evolution from the normal pattern present in earlier patch/plaque lesions of the two cases in which serial biopsies were available for study. Divergence of epidermal versus dermal CD3/TCR-beta antigen expression was seen in 2 of 34 (6%) of biopsies of patch/plaque mycosis fungoides but not in inflammatory controls. The TCR-delta+ cells were generally rare regardless of diagnosis. We conclude that inflammatory skin diseases and most patch/plaque mycosis fungoides are typically composed of T lymphocytes that resemble mature peripheral T cells in regard to their expression of TCR-associated antigens. In contrast, aberrant patterns of TCR-associated antigen expression can be seen in tumor stage MF, and, more rarely in patch/plaque MF.     

Evaluation of Langerhans' cells in normal and eczematous dermatitis skin by CD1a protein immunohistochemistry: preliminary findings

Background:  Langerhans' cells (CD1a positive, bone marrow–derived cells), are the antigen presenting cells of the skin. Our knowledge about the status of these cells in eczematous dermatitis is incomplete.
Aim:  This study tests the hypothesis that 'the development of eczematous dermatitis is associated with alterations of Langerhans' cells'.
Materials and methods:  Biopsy specimens from patients with eczematous dermatitis and normal skin (20 cases, each) were studied. Langerhans' cells were stained for CD1a using imunoperoxidase-staining methods and mouse monoclonal antibodies.
Results:  In normal skin, CD1a+ Langerhans' cells were seen in suprabasal position. In eczematous dermatitis skin, CD1a positive cells were seen scattered in the acanthotic epidermis. Compared with normal skin, the mean values of the Langerhans' cells were statistically significantly higher in eczematous dermatitis [epidermal Langerhans' cells: 1.20 (standard error of mean, SEM, 0.13) vs. 2.50 (SEM, 0.16); and dermal Langerhans' cells: 1.30 (SEM, 0.15) vs. 2.7 (SEM, 0.15); for normal and eczematous skin, respectively; p < 0.05].
Conclusions:  The higher Langerhans' cell counts in eczematous dermatitis suggest a possible link between antigen presenting capabilities of these cells, and development of these lesions.