Diminished contact sensitivity response in vitiliginous skin

Thirty patients with vitiligo (ten of the segmental type and 20 of the generalized type) were sensitized with dinitrochlorobenzene (DNCB) in a normal skin site on the upper medial aspect of the arm. Challenge tests with dinitrochlorobenzene were performed in vitiliginous patches and in normal skin sites. In vitiliginous patches diminished contact sensitivity reactions to dinitrochlorobenzene were noted in both patient groups, while in normal skin sites a normal delayed hypersensitivity response to the same antigen developed in the same patients. Tuberculin reactivity was not suppressed in vitiliginous lesions. We suggest that diminished contact reactivity in vitiliginous skin might be due to functional changes in Langerhans' cells, or to an alteration of carrier (skin) proteins in the lesions.     

Langerhans' cell population studies with OKT6 and HLA-DR monoclonal antibodies in vitiligo patients treated with oral phenylalanine loading and UVA irradiation

In vitiligo patients, treated with oral phenylalanine loading combined with UVA irradiation (Phe-UVA), Langerhans' cells (LC) were counted in pigmented and depigmented skin. The LC, which were labelled with OKT6 and HLA-DR monoclonal antibodies, were expressed per linear mm epidermis. Before treatment the number of OKT6(+) cells was significantly increased in vitiliginous skin especially in the basal layer. Under treatment the number went down and was comparable to normal skin. When using HLA-DR labelling the number of LC increased in vitiliginous skin which had been treated with Phe-UVA. The influence of Phe-UVA on the shift of LC subpopulations is discussed.     

Photoepicutaneous testing UV-induced protection against photoxic reactions in normal and vitiliginous skin: A clinical and histological study

The effect of erythemic UV irradiation on the phototoxic reactions caused by topical methoxsalen + UVA exposure was studied on normal skin, normal-looking skin of vitiligo patients, and vitiliginous skin. Although only slight histological changes were detectable 9 days after irradiation with 5 MED of erythemic UV, this pre-irradiation did induce protection against photoxic reactions in all skin types. This protection was clinically equal in all skin types; the slight differences were not statistically significant. Histological evaluation, however, showed a most conspicuous protective effect on vitiliginous skin. In all skin types the influence of UV pre-irradiation was confined to epidermal protection; the dermal phototoxic changes were unaffected.     

Reduced density of T6-positive epidermal Langerhans' cells in uninvolved skin of patients with psoriasis

The Langerhans' cell (LC) density is known to be reduced in skin lesions as compared to uninvolved skin in patients with psoriasis. It is, however, still unsettled whether the LC density in uninvolved psoriatic skin differs from the density in normal skin. We have enumerated epidermal LC in uninvolved skin from 15 patients with stable psoriasis and in 15 healthy subjects. Punch biopsies from non-sunexposed skin from the buttock were taken. Epidermal sheets were separated by EDTA and LC then stained with an indirect immunoperoxidase technique using the mouse monoclonal antibody OKT6. The LC density was significantly reduced in uninvolved skin of patients with psoriasis (mean +/- SD: 375 +/- 37/mm2) as compared to healthy controls (544 +/- 168/mm2) (p less than 0.01). A reduced number of LC in uninvolved psoriatic skin is in accordance with previous reports demonstrating an impaired DNCB reactivity in patients with psoriasis. Whether the reduction in LC density is of pathogenic importance for psoriasis is unknown.     

Effect of depletion of epidermal dendritic cells on the induction of contact sensitivity in the guinea-pig

Guinea pig skin was depleted of Langerhans cells (LC) as assessed by ATPase and Ia staining using several techniques. The LCs were depleted either by tape-stripping or exposure of the animals to UV-B or UV-C radiation. Guinea-pigs were sensitized to 2,4-dinitrochlorobenzene (DNCB) by application of the sensitizer to the epidermis depleted of LC. Minimally suppressed contact reactions were found in animals exposed to both wavelengths of radiation, but this was shown to be a systemic rather than a local effect. Tape-stripping did not alter the degree of contact sensitivity when guinea-pigs were sensitized with a large dose of DNCB. When a non-sensitizing dose of DNCB was applied to the ear depleted of LC by tape-stripping, contact sensitivity resulted. Although the depletion of LCs was 97% following UV-B, 93% with UV-C and 78% after tape-stripping, at no time were LCs completely absent from the epidermis.     

Increased anthralin irritation response in vitiliginous skin

Summary The irritation response to anthralin was studied using the chamber-testing technique in 17 patients with vitiligo. Anthralin concentrations of 0.1%, 0.5%, 1%, and 5% in lanette wax were applied to both vitiliginous and adjacent pigmented skin for 24 h. The extent of the erythematous reaction was evaluated on the 2nd day after application. The visual assessment of the paired anthralin patches indicated that the erythema was more intense in pigmented skin than in vitiliginous skin in 15 out of 17 patients. Chromometer readings, however, clearly indicated that the erythematous response was stronger in the vitiliginous skin than in the pigmented skin, confirming the known fact that the human eye is not accurate in the quantitative assessment of complex colors. Immunophenotypification of cellular infiltrates, using the combination of different monoclonal antibodies and the peroxidase technique, showed that inflammatory cell infiltrates caused by the anthralin exposure contained increased numbers of granulocytes and monocytes in vitiliginous skin when compared with normal skin. The percentage of T-cell subsets, Langerhans cells, and mast cells in the same infiltrates of both types of skin were similar. Our results are discussed in accordance with the view that anthralin-induced radical species of the pigmented skin can be neutralized by the scavenging properties of melanin.Part of this work was presented at the annual meeting of the European Society for Dermatological Research, 1987, at Amsterdam, The Netherlands     

The suppressive effect of tape-stripping treatment of guinea-pig skin on the induction of contact sensitivity by intradermal injection of haptenated epidermal cells

Summary Contact sensitivity (CS) to 2,4-dinitrochlorobenzene (DNCB) was produced in inbred JY1-strain guinea pigs by the intradermal injection of epidermal cells (ECs) prepared from DNCB-painted skin (DNP-ECs). When the site of DNP-EC-induced CS was pretreated by tape stripping, the rate and intensity of the challenge reactions to DNCB were diminished. The ability of DNP-ECs to induce CS returned to normal when normal peritoneal macrophages together with DNP-ECs were administered into the stripped skin. Normal ECs had a similar effect. Using either anti-Ia antiserum and complement or allogeneic ECs (strains 2 and 13), Ia-positive cells among the ECs (presumably Langerhans cells) were found to be essential for the recovery of CS. Tape-stripping treatment also resulted in the development of immunological tolerance, as assessed by subsequent painting with a sensitizing dose of DNCB. These findings suggest that the immunological function of the mononuclear-phagocyte system in the dermis may be impaired when the epidermal surface is markedly disturbed by tape-stripping treatment.     

Studies on the retest reaction in contact sensitivity to DNCB

DNCB-sensitized guinea pigs demonstrated an accelerated reactivity on retest of DNCB at the site of prior contact reaction, though presenting normal contact sensitivity at the virgin site. The retest reaction reached maximal at 9 h and waned at 24 h after antigenic challenge. Massive accumulation of eosinophils in either the epidermis or dermis was its distinguishing histologic feature. The reaction was induced at the site of delayed skin reaction to DNP-GPE in the animals sensitized with DNCB or DNP-GPE. A retest reaction in delayed sensitivity to DNP-GPE was also elicited at the site of contact reaction to DNCB in the animals. The significance of these findings is discussed.     

Variations in the number and morphology of Langerhans' cells in the epidermal component of squamous cell carcinomas

We investigated the number and morphology of Langerhans' cells in the epidermal component of squamous cell carcinomas located on the sun-exposed skin of 10 patients. Using adenosine triphosphatase-stained epidermis from the tumors, we compared the Langerhans' cells in squamous cell carcinoma with those in nontumorous skin specimens from the same patient. The nontumorous skin specimen was obtained from either sun-exposed perilesional or non-sun-exposed sites. In three patients a normal number and almost normal morphology of Langerhans' cells were observed within the epidermal component of the tumor. One patient showed a normal number but a profound alteration of the morphology of the cells. In the remaining six patients, a significant decrease in the number of Langerhans' cells was observed. Langerhans' cells within the epidermal component of the tumors of these patients exhibited morphologic alterations in that they were mainly round or oval rather than highly dendritic. In none of our patients was the number of Langerhans' cells in the tumor increased. We conclude that a decreased number and altered morphology of Langerhans' cells occur in some, but not all, squamous cell carcinomas of the skin, and that there is no apparent difference between the number of Langerhans' cells in sun-exposed vs unexposed skin from the same individual.     

Immunological studies in psoriasis. The quantitative evaluation of cell-mediated immunity in patients with psoriasis by experimental sensitization to 2,4-dinitrochlorobenzene.

Quantitative techniques of sensitization to 2,4-dinitrochlorobenzene (DNCB) was used to determine in psoriasis the intensity and frequency of allergic reactions to DNCB following primary challenge with 2,000 microgram allergen and secondary challenge with decreasing doses of DNCB. 56 patients with psoriasis and 23 healthy volunteers were examined. Frequency of positive reactions to DNCB was similar in both groups, since all normal controls were sensitized, whereas only 8 of 56 psoriasis cases failed to develop delayed hypersensitivity to DNCB. However, the intensity of acquired contact allergy was significantly diminished in psoriasis in comparison with controls. The patients with stationary skin lesions resembled the normal population in the intensity of reaction to DNCB. Decreased intensity of DNCB sensitization seemed to be related to the activity of the disease, but not correlated with the extent of the lesions. A relationship was found between reduced reactivity to DNCB and decrease in E rosette-forming lymphocytes. The data suggest that the impaired function of T lymphocytes in active psoriasis could be responsible for both, defective recognition of contact antigens, such as DNCB, and the alteration of secondary response to DNCB.     

Study of the skin of a new hairless rat mutant

Histological and immunological examinations were performed on the skin of a newly established strain of hairless rat (Hirosaki hairless rat; HHR). The appearance of the mutant rat skin was marked by resembles to human skin with wrinkles and scarce vellus hair. The presence of scattered dilated follicular cysts in the mid-dermis was the most predominant microscopic change. Electron microscopically, some of the basal cells contained many oval organelles in the cytoplasm, although their role was not clear. Langerhans cells were observed, but melanocytes were lacking in the epidermis. Immunofluorescence technique demonstrated Ia-positive cells (presumably Langerhans cells) in epidermal sheets from the soles of the mutants, which also developed contact sensitivity to dinitrochlorobenzene (DNCB). HHRs may be a useful experimental model for studies of allergic as well as nonallergic dermatitis requiring gross observation and wrinkled skin.     

Susceptibility to effects of UVB radiation on induction of contact hypersensitivity as a risk factor for skin cancer in humans

Normal, healthy human volunteers and patients with proved history of non-melanoma skin cancer have been tested for their capacity to develop contact hypersensitivity to dinitrochlorobenzene (DNCB) following exposure of buttock skin to acute, low-dose ultraviolet B (UVB) radiation. Using a radiation protocol that achieves virtually complete depletion of normal-appearing Langerhans cells from irradiated skin, it was learned that approximately 60% of healthy volunteers developed vigorous contact hypersensitivity (CH) when 2000 micrograms DNCB was painted on the irradiated site. These individuals were designated UVB-resistant, and were distinguished from other individuals, designated UVB-susceptible, who failed to develop contact hypersensitivity following an identical treatment protocol. It was then discovered that virtually all (92%) skin cancer patients exposed to UVB and DNCB failed to develop CH, i.e., were UVB-susceptible. In subsequent experiments, epicutaneous application of 2000 micrograms DNCB to unirradiated skin of UVB-susceptible individuals revealed a further distinction between normal persons and skin cancer patients. Approximately 45% of the latter (and none of the former) remained unresponsive (failed to develop contact hypersensitivity following this second attempt at sensitization), implying that they had been rendered immunologically tolerant. These tolerant individuals responded normally to the unrelated hapten, diphencyprone. We conclude that human beings resemble inbred strains of laboratory mice in that some individuals are UVB-susceptible, whereas others are UVB-resistant. Because the incidence of UVB-susceptibility was significantly higher in skin cancer patients, and as specific unresponsiveness could be demonstrated only in these patients, we propose that UVB-susceptibility, as we define it in this hapten system, may be a risk factor for the development of skin cancer.     

白癜风患者调节性T细胞及单核细胞趋化蛋白-1及可溶性细胞问黏附分子-1的检测

目的 探讨稳定期白癜风患者白斑与非白斑处皮肤单核细胞趋化蛋白-1（MCP-1）及可溶性细胞间黏附分子-1（sICAM-1）的变化以及血液中调节性T细胞的表达变化。方法 稳定期白癜风患者进行负压吸疱移植治疗，收集白斑及正常皮肤的疱液，用ELISA法检测皮肤组织液中MCP-1及sICAM-1的水平；收集稳定期白癜风患者血液与正常人比较，流式细胞仪观察调节性T细胞的变化。结果 稳定期白癜风患者，血液中调节性T细胞的表达与正常人差异无统计学意义：寻常型白癜风患者局部白斑与非白斑处皮肤吸引疱疱液MCP-1及sICAM-1水平比较均显著增高，经统计学分析，差异有统计学意义。节段型白癜风白斑与非白斑处MCP-1及sICAM-1的水平差异无统计学意义。结论 寻常型稳定期白癜风患者局部白斑皮肤微环境仍处于免疫异常状态，移植治疗的失败可能与局部微环境异常有关。     

Reactive changes in the Langerhans' cells of human skin caused by occlusion with water and sodium lauryl sulphate

Human skin was patch tested with sodium lauryl sulphate or with water only for 48 h and biopsied immediately and after 24 h, then analyzed by immunocytochemistry and electron microscopy. Sodium lauryl sulphate produced a decrease in the number of epidermal Langerhans' cells and an increase in dermal Langerhans' cells, with individual variations. The 48-h water occlusion controls showed only slight reactions. Unexpectedly, quite pronounced reactive changes were seen 24 h after termination of water occlusion. Thus, dermal Langerhans' cells were commonly increased and epidermal Langerhans' cells tended to decrease in number. The results indicate that the 24-h interval is not a period of recovery but a period in which more pronounced reactive changes occur. Hydration over 48 h followed by dehydration leading to temporary damage to the epidermal barrier may explain the present findings. Some of the reactive changes observed after sodium lauryl sulphate exposure probably represent the additive effects of occlusion and sodium lauryl sulphate treatment.     

Immunohistologic studies in Schamberg's disease. Evidence for cellular immune reaction in lesional skin

We studied eight cases of Schamberg's disease immunohistologically by using monoclonal antibodies. The dermal infiltrate was composed of Leu-1-reactive T cells, OKT6-reactive Langerhans' cells, and Leu-M5-reactive (Leu-M5+) macrophages. Among them, the major population consisted of T cells with the predominance of Leu-3a-reactive (Leu-3a+) T cells over Leu-2a-reactive (Leu-2a+) T cells. On the other hand, the epidermotropic mononuclear cells consisted of Leu-2a+ and Leu-3a+ T cells without any predominant pattern, and Leu-M5+ macrophages. Furthermore, note that a pemphiguslike intercellular staining pattern was observed in the epidermis in most of the cases, when the sections were stained either with anti-HLA-DR antibody or with OKT6, suggesting the HLA-DR antigen expression on the keratinocyte surface and possibly an enlargement of Langerhans' cells. Based on these immunohistologic findings, we think that Langerhans' cells play an important role in the pathomechanism of Schamberg's disease, and that cellular immune reactions are taking place in the lesional skin.     

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.     

白癜风患者调节性T细胞及单核细胞趋化蛋白-1及可溶性细胞间黏附分子-1的检测

目的 探讨稳定期白癜风患者白斑与非白斑处皮肤单核细胞趋化蛋白-1(MCP-1)及可溶性细胞间黏附分子-1(sICAM-1)的变化以及血液中调节性T细胞的表达变化.方法 稳定期白癜风患者进行负压吸疱移植治疗,收集白斑及正常皮肤的疱液,用ELISA法检测皮肤组织液中MCP-1及sICAM-1的水平;收集稳定期白癜风患者血液与正常人比较,流式细胞仪观察调节性T细胞的变化.结果 稳定期白癜风患者,血液中调节性T细胞的表达与正常人差异无统计学意义;寻常型白癜风患者局部白斑与非白斑处皮肤吸引疱疱液MCP-1及sICAM-1水平比较均显著增高,经统计学分析,差异有统计学意义.节段型白癜风白斑与非白斑处MCP-1及sICAM-1的水平差异无统计学意义.结论 寻常型稳定期白癜风患者局部白斑皮肤微环境仍处于免疫异常状态,移植治疗的失败可能与局部微环境异常有关.     

Langerhans' cells in seborrheic keratosis. A clinical and ultrastructural study

Skin biopsies from 10 patients with seborrheic keratoses were examined by electron microscopy for the presence of Langerhans' cells. Comparing seborrheic keratoses with normal skin of the same patient and with normal skin from controls, neither an increased number of Langerhans' cells nor an increased number of specific granules, Birbeck granules, nor abnormal Langerhans' cells, was found. Melanosomes in a Langerhans' cell were observed in 2 seborrheic keratoses, suggesting phagocytic activity of the Langerhans' cell.     

Langerhans' cells in hair follicles of the depigmenting C57Bl/Ler-vit.vit mouse. A model for human vitiligo

The C57Bl/Ler-vit.vit mouse grows a black pelage after birth. During successive hair molts, the fur loses its pigmentation. By 6 months of age, most of the fur of the animal is white. The epidermis of the ears and tail also loses its pigmentation. Histologic studies confirm that in the epidermis and hair follicles there is an absence of pigment cells identifiable by various histochemical or electron microscopic techniques. This mouse may be an excellent model in which to study the role of Langerhans' cells and the immune response in the pathogenesis of vitiligo, a study not easily done in humans. From results of prior studies, we postulated that if Langerhans' cells were involved in the destruction of melanocytes, they would be abnormal (either more or less numerous) in number during the active phase of depigmentation and normal in number after depigmentation was complete. To determine whether the Langerhans cell (Ia+/adenosine triphosphatase dendritic epidermal cell) might be involved in destruction of pigment cells, we quantified the number of Ia+ and adenosine triphosphatase dendritic cells in the hair follicles in skin from the ear, abdomen, back, and tail from male C57Bl/Ler-vit.vit mice while the fur and skin were depigmenting and after depigmentation was almost completed. We found that Langerhans' cells were normal in number during depigmentation and were most numerous after depigmentation. Previous studies indicate that Langerhans' cells in these mice are functionally defective and respond poorly to some contact allergens. From these morphologic and functional data, we conclude that Langerhans' cells probably are uninvolved in causing depigmentation in these mice. We also observed that the epithelium of hair follicles has a significantly higher (up to 1600/mm2) population density of Langerhans' cells than interfollicular skin.     

Clinical and histopathologic characteristics of trichrome vitiligo

BACKGROUND: The term trichrome vitiligo describes lesions that have a tan zone of varying width between normal and totally depigmented skin, which exhibits an intermediate hue. However, the pathogenesis and the histopathologic characteristics of trichrome vitiligo are unknown. OBJECTIVE: Our purpose was to investigate the clinical and histopathologic characteristics and the pathogenesis of trichrome vitiligo. METHODS: Four punch biopsy specimens were taken from 21 patients with trichrome vitiligo; they were from vitiliginous skin, light brown skin, perilesional normal skin, and normal skin as far as 5 cm from the nearest vitiligo spot. The sections were stained with hematoxylin-eosin; in selected cases, we performed immunohistochemical staining with S-100 protein and CD1a. RESULTS: Trichrome vitiligo occurred most frequently on the trunk in active vitiligo vulgaris. Focal vacuolar degeneration of the basal cell layer and mild inflammatory cell infiltration of the epidermis and dermis were more prominent in light brown skin and perilesional normal skin than in vitiliginous skin and normal skin. The number of melanocytes was decreased in light brown skin compared with perilesional normal skin (P <.05) and in vitiliginous skin compared with light brown skin (P <.05); a few melanocytes were observed even in skin affected by trichrome vitiligo. The number of Langerhans cells was increased in the epidermis of light brown skin and perilesional normal skin compared with vitiliginous and normal skin (P <.05). PUVA therapy yielded excellent repigmentation. CONCLUSION: Trichrome vitiligo is a variant of active vitiligo. The changes of melanocytes, keratinocytes, and Langerhans cells may be involved in the pathogenesis of depigmentation in trichrome vitiligo.