Number Of Langerhans Research Articles

Comparative characteristics of osmolarity, tear production and state of the corneal epithelium after instillations of the preparations Visomitin and hypromellose

Introduction. Dry eye syndrome (DES) is a multifactorial disease of the ocular surface, characterized by changes in its homeostasis and accompanied by ocular symptoms, the etiology of which is associated with destabilization of the tear film, hyperosmolarity, inflammation, damage to the structures of the ocular surface and neurosensory disorders.Objective. To study the effect of a drug containing plastoquinonyldecyltriphenylphosphonium bromide (PDTP, SkQ1) on dynamics of osmolarity and reparative properties of the cornea.Materials and methods. The study included 23 patients (46 eyes) aged 23 to 49 years. All patients presented complaints of dryness, burning sensation, cramps and discomfort in the eyes, increased sensitivity with instillation of drops, periodic blurred vision. Patients underwent standard and special ophthalmic examinations. The patients were divided into two groups comparable in gender and quantitative composition.Results. Based on the results of the examination at the starting visit, all patients were diagnosed with DES mild or moderate study. After one week of therapy, a significant decrease in subjective complaints was noted patients who received the drug with PDTF. All patients tolerated the drug well. In the group of patients who received a tear replacement therapy with hypromellose, in most patients, while complaints of dryness persist, decreased a feeling of pain in the eyes. A month later, complaints persisted only in patients of this group, but their intensity was known significantly reduced compared to the visit after a week. Against the background of therapy with the drug with PDTP, significant improvement of the Schirmer test, Norn test and corneal staining, as well as with the help of a in vivo confocal microscopy shows a decrease in the number of Langerhans cells.Conclusion. The results obtained indicate a positive effect of PDTP on the structure of the ocular surface even with its short-term use due to its keratoprotective and anti-inflammatory action.

Pulmonary histiocytosis

Introduction. Langerhans cell histiocytosis encompasses a group of disorders of unknown origin with different clinical presentations and outcomes. It is characterized by infiltration of the involved tissues by large numbers of Langerhans cells, often organized into granulomas. The accumulation of these cells causes the classic lytic bone lesions, skin rashes, lymphadenopathy, splenomegaly, and dysfunction of organ such as the pituitary gland, lungs, liver, and bone marrow. Pulmonary histiocytosis. Adult pulmonary Langerhans cell histiocytosis is a rare disorder of unknown etiology. It occurs predominantly in male smokers, with an incidence peak between 20 and 40 years of age. High-resolution computed tomography of the chest can show nodules, cavitated nodules, and thickand thin-walled cysts. The definite diagnosis of pulmonary Langerhans cell histiocytosis requires identification of Langerhans? cell granulomas infiltrating and destroying distal bronchioles, which is usually achieved by lung biopsy at a site selected by chest high-resolution computed tomography. Treatment. Treatment options for adults have never been clarified by a clinical trial. The published literature provides minimal data on the comparative efficacy of various treatment options which include surgery/curettage, steroids, radiation, and various chemotherapy regimens. The improved understanding of the mechanisms involved in the pathogenesis of pulmonary Langerhans cell histiocytosis should help in the development of specific therapeutic strategies and effective treatment.

Influência do uso de anticoncepcionais hormonais orais sobre o número de células de Langerhans em mulheres com captura híbrida negativa para papilomavírus humano

PURPOSE: to study the influence of the use of oral contraceptives (OC) on the number of Langerhans' cells in women without cervical infection by human papillomavirus (HPV). METHODS: thirty women who presented abnormal cervical cytology and colposcopy-guided biopsy with samples of uterine cervix negative for HPV were selected. The absence of HPV DNA was confirmed by hybrid capture. Langerhans' cells were identified by immunohistochemistry using anti-S100 antigens. The cells visualized in light microscopy were counted using the Cytoviewer software. The nonparametric Wilcoxon rank sum test was employed for statistical analysis. RESULTS: the average number of Langerhans' cells in OC users was 320.7/mm2 and in non-users 190.7/mm2, this difference being statistically nonsignificant. In the intermediary layer of the cervical epithelium a tendency towards the increase of these cells was observed, with the averages 192.1/mm2 for OC users and 93.4/mm2 for non-users (p=0.05). CONCLUSIONS: the present study reports a tendency towards the increase in the number of the Langerhans' cells among OC users. This result suggests the OC may induce alterations in the number of Langerhans' cells, but considering the limited number of cases, more studies should be developed for a definitive conclusion.

Fatores biocomportamentais e as alterações no número das células de Langerhans

OBJECTIVE: to study the relationship of biobehavioral factors, such as age, menarche, number of gestations, and age of first sexual intercourse, with changes in Langerhans'cells in women with negative hybrid capture for HPV. METHODS: thirty women referred due to abnormal cervical cytology or premalignant cervical lesions were studied and underwent colposcopy, guided biopsy and histopathological exams. The Langerhans' cells were identified by immunohistochemical (S100+) exams. Langerhans' cells visualized in brown color were counted using the software Cytoviewer. The nonparametric Wilcoxon rank-sum test was employed for statistical analysis. RESULTS: the number of Langerhans' cells in women who had menarche after 13 years old presented statistically significant difference (173.34 cell/mm2) compared to the group whose menarche occurred before 13 (271.41 cell/mm2). The age at the first sexual intercourse was associated with the low number of Langerhans' cells, 127.15 cell/mm2 and 250.14 cell/mm2, respectively, for the beginning of the sexual activity up to 17 years old and after 17 (p=0.03). Previous cauterizations of the uterine cervix have been related to a lower number of Langerhans' cells in the epithelium, with the average 120.30 cell/mm2 as compared to 236.06 cell/mm2 for those women who never underwent that procedure (p=0.05). Other factors such as the patient's age and the number of gestations showed no statistically significant differences in the density of Langerhans' cells. CONCLUSIONS: the present study reports the association of biobehavioral factors with decrease in the number of Langerhans' cell.

The number and distribution of immune cells in the cervicovaginal mucosa remain constant throughout the menstrual cycle of rhesus macaques.

A number of studies have shown that the ovarian hormone cycle affects genital tract immunoglobulin (Ig) levels and T cell function in both humans and rhesus monkeys. We hypothesized that shifts in immune cell populations occurring in response to hormone cycles are involved in the observed changes in genital tract immunity. To test this hypothesis, we characterized the type, number, and distribution of immune cells in the cervicovaginal mucosa at different stages of the menstrual cycle. Tissues from 18 normal female rhesus macaques were studied by immunohistochemistry and computerized morphometric analysis. The number and distribution of CD1a+ Langerhans' cells, CD2+, CD3+, CD4+, and CD8+ T cells, CD20+ B cells, and surface Ig+ plasma cells did not change in samples collected at the different stages of the cycle. However, in no relation to the stage of the menstrual cycle, the number of Langerhans' cells and other immune cell types was different in the various regions of the cervicovaginal mucosa examined. In addition, variation in thickness of the ectocervical and vaginal epithelium during a normal menstrual cycle of rhesus macaques is not accompanied by changes in intraepithelial immune cell populations. We conclude that steroid hormones do not influence genital mucosal immunity by changing the number or distribution of immune cells in the lower reproductive tract.

Cosmetics for the elderly

Aging remains an enigma and the visible modifications that slowly appear in aging skin are provided by a gradual reduction in the size and number of cells and a decrease in the rate of many organic functions. Skin aging is the result of a programmed multistep, time-dependent continuous phenomenon at the cellular and molecular level.1,2 Little attention has been given to the issue of appearance in the elderly until recently. Skin functions that decline with age are cell replacement, injury response, barrier function, chemical clearance, sensory perception, immune and vascular responsiveness, thermoregulation, sweat production, sebum production, and vitamin D production.3 Successful aging is characterized by good mental health, adaptative psychosocial functioning, and life satisfaction.4 In the United States in 1998, the older population (65 years or older) represented 12.7% of the total: approximately one in every eight Americans. Since 1900, the percentage of Americans older than 65 years of age has more than tripled (4.1% in 1900 to 12.7% in 1998), and the number has increased eleven times (from 3.1 million to 34.4 million). By 2030, the estimate is that there will be approximately 70 million senior citizens, more than twice the number in 1998. People over 65 years of age are expected to represent 13% of the population in the year 2000 but will be 20% by 2030. The 40 million “baby boomers” born in the United States between 1946 and 1963 are approaching that stage of life in which, unfortunately, youthful good looks are becoming more of a memory than a reality. They obviously cannot remain forever young, but cosmetic innovations through scientific research are progressing very rapidly. Patients are able to significantly delay the visible aging process by practicing preventive skin care and taking advantage of the many chemical treatments available for facial rejuvenation.5 Cutaneous aging provides a visible model of the interaction between endogenous and exogenous (UV light) factors. Recently, much interest has been directed toward defining the aging processes in the skin, aiming to highlight areas such as environmental changes and their influence in skin aging and carcinogenesis.6,7 Clinically detectable, age-associated cutaneous changes result from two independent processes: chronologic aging and actinic irradiation (Fig 1). Several lines of evidence suggest that these two processes have different biologic, biochemical, and molecular mechanisms.8 Understanding these events at all these levels has unfortunately not been paralleled by clinical and therapeutic advances about common, troublesome skin problems of old age, such as cancer, xerosis, and pruritus. These conditions remain major causes of morbidity and are yet poorly explained.6,7 The main skin functions include protection, excretion, secretion, absorption, thermoregulation, pigmentogenesis, accumulation, sensory perception, and regulation of immunological processes; all of these functions are altered with the passing of time. Physiological changes include impairment of the barrier function, decreased turnover of epidermal cells, reduced numbers of keratinocytes and fibroblasts, and a reduced vascular network particularly around hair bulbs and glands, leading to fibrosis and atrophy, decrease of hair and nail growth, retardation in vitamin D synthesis, decline of Langerhans’ cells density, and impairment of the immune response.9–12 There is also a decrease in the function of Meissner’s and Pacinian corpuscles. Increased production of free radicals is observed and cutaneous permeability to chemical substances also changes, while water-binding capacity of the stratum corneum is reduced.8,13–15 Epidermal changes associated with aging involve the flattening of its underside, a reduction in the number of Langerhans’ cells and of melanocytes, and a decline in the number of synthesized melanosomes, leading to reduced pigmentation. Dermal changes are represented by a reduction in collagen and elastic fibers, fibroblasts, mast cells and macrophages, and dilation of the lymphatic channels. The most affected cells in the senescence process are keratinocytes and fibroblasts. The dermal–epidermal junction is flattened and the number of hair follicles decrease with age, although their structure remains unchanged.10,11,16–20 Colorimetric measurements show that elderly skin is darker than young skin even in areas not exposed to the sun. Epidermal atrophy and increased transparency From the Sector of Dermatology, HUCFF-UFRJ and School of Medicine, Universidade Federal do Rio de Janeiro, (MRS and SCSC) and the HUPEUERJ and Sector of Dermatology, School of Medicine, Universidade do Estado do Rio de Janeiro, (SCSC) Rio de Janeiro, Brazil. Address correspondence to Marcia Ramos-e-Silva, MD, Rua Sorocaba 464/205, 22271-110-Rio de Janeiro, Brazil. E-mail address: ramos.e.silva@dermato.med.br.

Rod-shaped bodies resembling birbeck granule-like structures in endothelial cells of dermal capillaries in generalized granuloma annulare.

A previous study demonstrated that, in generalized granuloma annulare in the epidermis, the Langerhans' cell section area and the number of Langerhans' cell granules or Birbeck granules per cell section were increased, suggesting an active state of these Langerhans' cells. Reexamination by transmission electron microscopy of the same tissue, but in samples also containing dermal tissue, from the same subjects revealed endothelial cells with rod-shaped bodies resembling Birbeck granules or Birbeck granule-like structures. This finding has not been previously described in blood vessels of human skin and is described here.

Intracutaneous injection of lysophosphatidylcholine induces skin inflammation and accumulation of leukocytes.

Various cell stimuli act through activation of phospholipase A2, which hydrolyses fatty acids from membrane phospholipids, resulting in the formation of fatty acids and lysophospholipids. One of the lysophospholipid classes, lysophosphatidylcholine, is a chemoattractant for monocytes and T-lymphocytes and induces the expression of adhesion molecules on cultured endothelial cells. The purpose of the present study was to determine whether lysophosphatidylcholine possesses proinflammatory properties in vivo. This was assessed clinically and histologically by intracutaneous injection of 200-800 nmol lysophosphatidylcholine in healthy volunteers. Lysophosphatidylcholine elicited a dose- and time-dependent local erythema and oedema. The erythema disappeared within 4 h, while the induration lasted for up to 48 h. HE-stained biopsies taken after 24 h showed a leukocytoclastic vasculitis in 2 of the 6 subjects. Microscopic examination of immunohistochemically stained biopsies taken 24 h after the injection showed a significant increase in the number of T-lymphocytes, monocytes and neutrophils, whereas the number of Langerhans' cells was unchanged after lysophosphatidylcholine injection. In addition, the number of intercellular cell adhesion molecule-1 and -3-positive cells was increased approximately 3-fold after injection of lysophosphatidylcholine. In conclusion, the phospholipase A2 hydrolysis product lysophosphatidylcholine can induce erythema, oedema, a mixed cellular infiltrate and the expression of adhesion molecules.

Pityrosporum species as a cause of allergy and infection.

Pityrosporum species as a cause of allergy and infection.

Paracortical hyperplasia of superficial lymph nodes in a new mutant strain of hairless rats (ISh): a lesion similar to human dermatopathic lymphadenopathy.

The dermal histology and the regional draining superficial lymph node of a new mutant strain of hairless rats (ISh) were investigated. The homozygote ISh rat was characterized as having naked and wrinkled skin. The comedo-like cysts in the skin resembled human acne and vulgaris. Histopathologically, many Langerhans' cells positive for anti-protein kinase C type II antibody (PKC-II) were recognized in the epidermis. The superficial lymph nodes were significantly larger than those of the heterozygote. The paracortex of these lymph nodes was expanded and the number of Langerhans' cells mainly increased in these areas. These lymph node lesions were similar to those of human dermatopathic lymphadenopathy. The ISh rats should be a very useful animal model for studying dermatopathic lymphadenopathy in humans. Furthermore, they may be a valuable animal model for investigating the mechanisms of not only maturation, movement and migration of Langerhans' cells, but also of their function for antigen presentation.

Langerhans' cells are depleted in chronic graft versus host disease.

AIMS: To measure Langerhans' cells in skin of patients treated by bone marrow transplantation who developed chronic graft versus host disease (GvHD); to determine whether the reduction in Langerhans' cells...

Local immune response in endometrial carcinomas.

To determine whether Langerhans cells act as antigen-presenting cells in endometrial carcinomas and their related lesions. Frozen endometrial samples were obtained from 13 women with normal menstrual cycles, 3 postmenopausal women, 11 women with hyperplasia (simple 4, complex 4 and atypical 3) and 32 women with endometrial carcinomas. Langerhans cells (CD1), T lymphocytes (CD4 and CD8), B lymphocytes (CD22), natural killer (NK) cells (CD57) and HLA-DR were all quantitatively assessed in endometrial samples using immunohistochemical method. The numbers of Langerhans, CD4+, CD8+ and B cells were higher in the secretory phase than in the proliferative endometrium. The CD8+ cells appeared to be more plentiful than the CD4+ cells. When compared with the proliferative endometrium, the numbers of Langerhans cells were higher in hyperplasias and carcinomas. Most of Langerhans cells were HLA-DR+, showing a strong correlation with CD4+ cells in carcinomas. This suggests that MHC class II antigen restricted lymphocytes in carcinomas are activated by HLA-DR+ Langerhans cells. However, epithelial expression of HLA-DR in carcinomas did not show on association with high numbers of Langerhans and CD4+ cells. No correlation was observed between Langerhans cells and clinicopathologic features of carcinomas. In contrast, the number of NK cells significantly decreased in noninvasive carcinomas but increased in Grade 3 tumours. Based on the above findings, Langerhans cells are considered to act as antigen-presenting cells in carcinomas, but it was not shown that they were activated by epithelial expression of HLA-DR in carcinomas.

The role of CD4 molecules in the induction phase of contact hypersensitivity cytokine profiles in the skin and lymph nodes

We have previously demonstrated that CD4 gene-targeted mutant mice (CD4- mice) demonstrate hyporesposiveness in contact hypersensitivity (CHS) suggesting that CD4 molecules are required for optimal induction of CHS. In the present study, we wished to examine the mechanisms of this hyporesponsiveness, in particular, we examined whether cytokines were altered in the skin and lymph nodes of CD4- mice following exposure to the contact allergen dinitrofluorobenzene (DNFB). Cytokine mRNA in the ear skin and draining lymph nodes (DLN) were examined by reverse transcription-polymerase chain reaction (RT-PCR) at various times after sensitization. Skin cytokine patterns revealed that in normal mice, interleukin (IL)-2, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha mRNA levels increased at 12 hr sensitization, whereas these cytokines were below the level of detection in CD4- mice. In the DLN of normal mice following the hapten application, sequential upregulation of cytokine mRNA including IL-1 alpha, IL-1 beta, IL-2, IL-4, IL-10, IFN-gamma and TNF-alpha was found. No change was seen for IL-1 alpha, IL-1 beta, IL-10 and TNF-alpha and IL-2, IL-4 and IFN-gamma mRNA levels were below the level of detection in DLN from CD4- mice following the hapten application. However, IL-1 beta, IL-2 and TNF-alpha mRNA levels of lymph node cells from CD4- mice could be upregulated by phorbol myristate acetate in vitro. Flow cytometry study has revealed that the number of Langerhans' cells (LC) in DLN of CD4- mice was similar to that of normal mice, thus, inferring that the alterations of cytokine milieu in the ear skin did not have a significant effect on LC migration to DLN. These results suggest that CD4 molecules are crucial for the induction of certain cytokines in the skin and in inducing sequential cytokine signals in DLN required for optimal development of CHS, but that these changes in cytokines do not effect LC migration.

EFFECT OF TOPICAL TRETINOIN ON EPIDERMAL LANGERHANS’CELLS IN PHOTODAMAGED SKIN

Topical tretinoin has been successfully applied to treat photoaging; however, a decrease in the number of Langerhans' cells (LC) has been reported after its topical application in Macaque skin. A study was performed to evaluate the possible effect of topical tretinoin on the number of LC in human beings. Eight patients were studied. Topical tretinoin was applied in progressively increasing concentrations: 0.025% for 1 month, 0.05% for one month and 0.1% for 4 months. A skin biopsy from the malar area was taken before this therapy and 6 months later. To study LC, 4 mu frozen sectionswere stained with the anti-CD1 antibody. The number of CD1+ cells did not change when they were counted per unit of epidermal length, but they decreased when they were counted per unit of epidermal surface. These results indicate that topical tretinoin might damage epidermal Langerhans' cells, when it is applied for long periods of time; future studies are necessary to clarify this point.

Dendritic cells in cutaneous lupus erythematosus: a clue to the pathogenesis of lesions.

In view of the critical role of dendritic cells in immune mediated skin diseases, we have investigated the membrane antigen patterns and ultrastructure of cutaneous dendritic cells in eight patients with chronic discoid lupus erythematosus and five with subacute cutaneous lupus erythematosus. In the lesional epidermis, the expression of HLA-DR antigens by epidermal dendritic cells was reduced, as compared with perilesional, clinically normal skin. In addition, only few CD1a+ dendritic cells (Langerhans' cells), along with some CD11c+ and CD14+ cells (presumable precursors of Langerhans' cells), were found in atrophic areas of lesional epidermis. In contrast, the number of Langerhans' cells in non-atrophic areas of lesional epidermis was similar to that in perilesional skin. On electronmicroscopy, epidermal Langerhans' cells appeared depleted of organelles and dendrites and contained tubuloreticular inclusions. In the lesional dermis, both CD1a+ and CD36+ dendritic cells were found, associated with CD4+ and CD8+ T-cells, respectively. Moreover, CD11c+ and CD14+ cells were found around capillaries in the papillary dermis on electronmicroscopy. Indeterminate cells (dendritic cells with features of Langerhans' cell lineage, but apparently without Birbeck granules) and dendritic macrophages were found, associated with lymphocytes and mast cells. No cells with intermediate/transitional features between these two dendritic cell types were found. Conversely, peculiar dendritic cells--with short and blunt dendrites and cytoplasm containing many flat, rough cisternae, moderately well developed Golgi apparatus and no lysosomes--were found in the same location as the CD11c+ and CD14+ cells identified by light microscopy. These findings might be interpreted as follows: 1 the alterations in cytological differentiation and expression of functionally meaningful molecules by epidermal Langerhans' cells in cutaneous lupus erythematosus lesions suggest an impairment of their immunological efficiency; 2 in the lesional dermis of cutaneous lupus erythematosus, a CD4+ T-cell/CD1a+ dendritic cell-based, delayed-type immune response is possibly modulated by a suppressor T-cell circuit in which CD36+ dendritic cells may act as accessory cells; 3 CD11c+ and CD14+ cells with peculiar ultrastructure are possible precursors of both CD1a+ indeterminate cells and CD36+ dermal dendrocytes in the dermis.

Langerhans' cells of elderly patients with decubital ulcers.

An ultrastructural and morphometric study compared Langerhans' cells in sacral epidermis, 8-10 cm from the lesion of patients (mean age 70) with decubital ulcers, with those in the patients' own normal epidermis from the upper leg and with those in the epidermis from the upper leg of normal age-matched volunteers. The Langerhans' cell section area was significantly lower in patients' control leg epidermis (25.86 +/- 2.29 microns2) than in that from normal controls (35.74 +/- 3.76 microns2) or that from patients' sacral epidermis near the lesion (41.26 +/- 3.45). The number of Langerhans' cell granules was higher in control leg epidermis of patients (10.22 +/- 1.26) and was significantly higher in lesioned sacral epidermis (12.94 +/- 1.90) than in normal controls (6.97 +/- 1.47). In Langerhans' cells in patients' epidermis, formative stages of Langerhans' cell granules were observed. The findings may indicate that Langerhans' cells in patients' epidermis are in an active state.

UV-related skin conditions and Langerhans' cell populations in human skin.

Chronic sun exposure and cumulative exposures to PUVA are associated with a risk of development of non-melanoma skin cancer. Acute UV irradiation reduces the number of epidermal antigen-presenting Langerhans' cells in the skin. Alterations in the Langerhans' cell population could be relevant to a disturbance in the cutaneous immune response in UV-exposed skin. Therefore the density of CDla+ and ATPase+ Langerhans' cells in epidermal sheets from the hand, buttock and in some cases face was examined in PUVA-treated patients (n = 8) and in patients with actinic keratosis (n = 13) or basal cell carcinoma (n = 16). The number of Langerhans' cells was significantly lower on the hand compared with that on the face and buttock (p < 0.05). There was no difference in Langerhans' cell distribution between the different diagnostic groups and controls, and there was no age-related change in Langerhans' cell density. These results indicate that patients who develop actinic keratosis or multiple basal cell carcinomas do not differ in Langerhans' cell density from healthy controls and that cumulative sunlight or PUVA exposure does not lead to a persistent reduction in Langerhans' cell numbers.

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.

In situ characterization of the cutaneous immune response in Ethiopian cutaneous leishmaniasis.

Cryostat sections from 10 patients with localized cutaneous leishmaniasis (LCL) and eight patients with diffuse cutaneous leishmaniasis (DCL) from Ethiopia were studied with immunofluorescence methods for the phenotypic characterization of cells in the lesions. Higher numbers of Leu 2+ and Leu 3+ cells (P less than 0.005) were found in LCL than in DCL, while the Leu 3a + b/Leu 2a ratios were the same. No differences were found in the numbers of transferrin receptor, HLA-DR, and HLA-DQ expressing cells in the granulomas. Significantly (P less than 0.0001) lower numbers of IL-2 receptors expressing (Tac+) cells were found in DCL than LCL lesions, suggesting interference in the activation of the T cells. IL-2-containing cells were absent in DCL and were found in LCL lesions. Epidermal keratinocytes above the LCL but not the DCL lesions expressed HLA-DR (but not HLA-DQ) antigen, suggesting a lower gamma-interferon production in the DCL granulomas. The number of Langerhans' cells (Leu 6+) was higher in the epidermis of DCL (P less than 0.005) than in LCL, while a lower number of Leu 6+ cells were seen in the dermal lesions (P less than 0.001). These observations could account for some of the mechanisms responsible for the disturbed immunostimulation and immunoregulation observed in the lesions of DCL.

Possible Functional Impairment of Langerhans' Cells in Vitiliginous Skin

• We used patch testing to compare the ability to elicit contact sensitivity to dinitrochlorobenzene (DNCB) of uninvolved with vitiliginous skin of 31 patients with vitiligo. The induction of DNCB contact sensitivity was possible in the vitiliginous skin in the same way as in normal skin. The DNCB contact sensitivity reactions, however, were generally diminished in vitiliginous skin, although the number of cases showing similar DNCB contact reactivity between normal and vitiliginous skin increased when the sensitization procedure was performed in vitiliginous skin instead of normal skin. On the other hand, delayed skin reactions to intradermally injected<i>Candida albicans</i>antigen were not suppressed in vitiliginous skin. The number of Langerhans' cells was not decreased in vitiliginous skin as compared with that of normal skin. The epidermal cells derived from vitiligonous skin, however, tended to show a lower stimulatory effect in the allogeneic mixed skin cell lymphocyte culture reaction than those from normal skin. These results suggest a possibility of functional impairment of Langerhans' cells in vitiliginous skin. (<i>Arch Dermatol</i>1987;123:51-54)