Mite-antigen-stimulated cytokine production by peripheral blood mononuclear cells of atopic dermatitis patients with positive mite patch tests

To investigate possible involvement of Th1-type immunoreaction in the development of skin lesions of atopic dermatitis (AD), we measured mite-antigen-stimulated production of IL-2, IL-4 and IFN-gamma, using peripheral blood mononuclear cells (PBMC) obtained from 23 patients with AD who developed positive patch test reactions to house dust mite antigens extracted from Dermatophagoides pteronyssinus (Dp). Incubation of these PBMC with the Dp antigen for 72 h produced marked secretion of IL-2 and IFN-gamma, but not IL-4, indicating that Dp-specific T cells were found in these patients' circulating peripheral blood and were capable of producing IL-2 and IFN-gamma, known as major mediators of the delayed-type allergic reaction. Our study suggests that Th1-type cells may be involved in the development of skin lesions of AD patients with positive patch test reactions to house dust mite antigen.

Reduced secretion of IgA to skin surface of patients with atopic dermatitis

To investigate whether the secretory form of immunoglobulin A (sIgA) was reduced on the skin surface in atopic dermatitis, the amount of sIgA present in sweat was measured in 40 patients with atopic dermatitis and in 50 healthy volunteers by attaching a cellulose membrane disk (10 x 10 mm) to the inner aspect of the upper arm skin for 24 hours. The secretory form of IgA, which was absorbed to the membrane and accumulated during the period of application, was revealed as dots by an enzyme immunoassay in which antibodies for IgA and for the secretory component were used. The density and number of dots (per mm2/day), which corresponded to the openings of eccrine excretory ducts, were determined with a densitometer. The mean amount of sIgA secreted by those patients was 3.86 +/- 0.71 pg/mm2/day (range, 0 to 21.17 pg/mm2/day), whereas that of the control subjects was significantly higher (p < 0.001), 16.79 +/- 2.80 pg/mm2/day (range, 0.79 to 133.77 pg/mm2/day). This may be related to the high incidence of bacterial and viral skin infections seen in patients with atopic dermatitis, and in addition, to the development of eczematous lesions through a defect in ridding the skin of allergens and/or microorganisms.

Deposition of basic fibroblast growth factor on surface of epidermal melanocytes suggesting the stromal control of epidermal pigmentation

Scanning electron microscopy with immunogold labeling was used to demonstrate the in vivo distribution of molecules of basic fibroblast growth factor (bFGF) that were expressed and/or present on the surface of the cells of the normal epidermis and dermal connective tissue of humans. We found that molecules of bFGF, seen as deposits of gold particles, were present densely on the surfaces of the melanocytes but not the epidermal keratinocytes. In connective tissue, these molecules were present exclusively on the surfaces of the fibroblasts, macrophages, vascular endothelial cells, and the basement membrane surrounding the endothelial tube. The selective deposition of bFGF molecules on the melanocytes suggests that the dermal connective tissue may be involved in controlling the proliferation of melanocytes by means of bFGF molecules in vivo, since these melanocytes require bFGF to proliferate in vitro. The latter is synthesized and stored exclusively in the connective tissue.

Epidermolysis bullosa herpetiformis (Dowling-Meara type) exhibits ultrastructural derangement of tonofilaments and desmosomes

Ultrastructural and immunohistochemical studies of clinically intact skin obtained from three severe neonatal cases of epidermolysis bullosa herpetiformis (Dowling-Meara type) demonstrated disorders in the assembly of keratin intermediate filaments and desmosomes of the keratinocytes. During mitosis, K5- and K14-positive and K1- and K10-negative tonofilaments were disrupted and formed spherical bodies associated with intracytoplasmic desmosomes by invagination of the desmosomes and the adjacent plasma membrane. During the invagination process, destructive changes in the internalized membrane were noted. These were accompanied by gradual loss of reactivity with a monoclonal antibody ZK31, which detected plasma membrane adjacent to the attachment plaques of desmosomes. However, the reactivity of the attachment plaques of the internalized desmosomes for desmoplakins and desmoglein did not decline during the process of internalization. In the suprabasal layers of the epidermis, filamentous substructures and K1 and K10 appeared at the periphery of the spherical bodies. Simultaneously, the desmosomes that were sparsely located in the lower epidermis, increased in number as cell differentiation progressed. Thus, the keratinocytes attained an almost normal appearance with respect to tonofilaments and desmosomes by the time they reached the upper layer of the epidermis. These findings may be relevant to the mechanism responsible for the clinical appearance of the herpetiform blisters in epidermolysis bullosa herpetiformis, which are also characterized by spontaneous involution during childhood or when exposed to high ambient temperatures.

Ultraviolet-B irradiation deforms the configuration of elastic fibers during the induction of actinic elastosis in rats

We used scanning electron microscopy combined with perfusion fixation, resin injection and a selective digestion procedure to determine the effects of ultraviolet-B (UVB) radiation on the three-dimensional architecture of elastic fibers of rat skin. Chronic irradiation with a suberythematous dose of UVB (3 times/week for 12 weeks) produced a tortuous deformation of the superficial elastic fibers in the skin of the rat sole which normally are linearly arranged. Using computer analysis, we evaluated 40 individuals elastic fibers every 3 weeks for 12 weeks following the irradiation. This procedure confirmed the increasing tortuosity of the fibers, which was related to a decline in the elastic property of the skin in situ. Fine elastic branches developed among the deformed fibers and eventually anastomosed to produce an irregular network in the superficial dermal connective tissue, which may correspond to the development of actinic elastosis, that is, the UV-related accumulation of elastic fiber material.

Cellular mechanisms of the steroid-induced vascular responses in the rabbit ear artery

1. In anesthetized rabbits, topical application of dexamethasone to the ear produced an initial vasodilation followed by a vasoconstriction with long delay (120 min). Diphenhydramine inhibited the former, but not the latter. 2. In isolated rabbit ear arteries, dexamethasone reduced the amplitude of contractions of smooth muscles produced by nerve stimulation, noradrenaline and high-K solution, only at high concentrations (> 10(-5) M). 3. The initial vasodilation induced by topical application of dexamethasone may be related to endogenous histamine, while the delayed constriction response may not be direct actions of steroid to smooth muscles.

Three neonatal cases of epidermolysis bullosa herpetiformis (Dowling-Meara type) with severe erosive skin lesions

We describe three neonates who had large eroded areas of skin on their extremities. The clinical course and ultrastructural findings were consistent with a diagnosis of epidermolysis bullosa herpetiformis (Dowling-Meara type). In each case blisters developed around eroded areas after birth and enlarged centrifugally in a herpetiform fashion. One patient died of sepsis at 8 days of age. In the two survivors blister formation subsided gradually within 1 year. Ultrastructural studies confirmed intraepidermal blister formation associated with spheric aggregates of tonofilaments in the lower epidermis. Spheric aggregates were also found in clinically uninvolved skin.

Secretion of IL-2, IL-4, and IFN-gamma for dust mite antigens in a patient with atopic dermatitis

In a 21-year-old female with severe atopic dermatitis, the secretion of interleukin-2 (IL-2), interleukin-4 (IL-4), and interferon-gamma (IFN-gamma) by her peripheral blood mononuclear cells (PBMC) was measured after incubation with/without antigens extracted from Dermatophagoides pteronyssinus (Dp), to which the patient had developed a positive patch-test reaction. Incubation with Dp antigen produced marked secretion of IL-2 and IFN-gamma, but not IL-4. This may suggest that Dp-specific T lymphocytes present in the circulating blood cells are capable of producing IL-2 and IFN-gamma, which may be relevant to the delayed-type allergic reaction occurring in the skin lesion.

An AIDS patient with atopic dermatitis-like eruption responsive to systemic anti-fungal treatment

Patients with the acquired immunodeficiency syndrome (AIDS) often develop unusual skin complications. We describe a case of a 58-year-old man with AIDS who had a history of multiple transfusions with anti-hemophilic factor A. He developed papulovesicular and lichenified skin lesions on his head, face, neck and the extensor aspects of his extremities accompanied by severe pruritus. Atopic dermatitis was suspected; however, intensive treatment with a potent topical corticosteroid and a systemic antihistamine failed. In addition to the decreased subset of CD4-positive lymphocytes characteristic of AIDS, this patient showed an elevated level of serum IgE particularly specific for Candida albicans, probably because he had a chronic candidial infection of the digestive tract. Oral administration of anti-fungal agents Diflucan and Fungizone produced almost complete relief from the atopic dermatitis-like skin disease within 2 weeks.

Combination of patch test and IgE for dust mite antigens differentiates 130 patients with atopic dermatitis into four groups

BACKGROUND

Patients with atopic dermatitis sometimes have positive responses to patch testing (PT) with dust mite antigens, which is believed to correlate with the elevated levels of specific IgE for those antigens.

OBJECTIVE

The purpose of this study is to identify the correlation between the PT and serum IgE concerning the mite antigens.

METHODS

We studied 130 patients with atopic dermatitis by the PT reaction and the serum level of specific IgE for Dermatophagoides pteronyssinus antigens.

RESULTS

Fifty-one of the 130 patients assessed as PT-positive had either high (32 of 130 patients; 24.6%) or low or no (19 of 130 patients; 14.6%) levels of mite-specific IgE; there was a significant difference between the groups with elevated and low IgE. Similarly, a total of 79 PT-negative patients also showed an elevated or low mite-specific IgE (42 of 130 patients [32.3%] or 37 of 130 patients [28.5%], respectively). It was noted that clinical morphologic findings were peculiar to three of the four groups; however, the patients who were PT-negative with a low IgE (37 of 130 patients) showed no particular clinical lesions.

CONCLUSION

Comparing the results from our 130 patients, there was no correlation between the serum IgE level and the PT reaction for dust mite antigens. Conversely, the results of PT and mite-specific IgE could be used to divide these patients into four distinct groups, each with its own particular clinical morphology, suggesting the heterogeneity of this disease.

A histopathological and ultrastructural study of eccrine porocarcinoma with special reference to its subtypes

Five cases of eccrine porocarcinoma were studied by light and electron microscopy. Histopathologically, these could be classified into two types; the common and the giant cell type. The common type was characterized by almost uniform medium-sized cuboidal tumour cells and a formation of well-developed intracytoplasmic lumina. A broad diversity of histopathological and ultrastructural features was seen in these tumours. The tumours of the giant cell type consisted of mononuclear polygonal cells and bizarre giant cells. This type was considered to be an undifferentiated form of porocarcinoma.

Identification of a cell layer containing alpha-smooth muscle actin in the connective tissue sheath of human anagen hair

Immunohistochemical and immunoelectron microscopy studies revealed the presence of alpha-smooth muscle (alpha-SM) actin in fibroblasts located in the connective tissue sheath (CTS) of human anagen hair follicles. Immunostaining was positive from the base of the bulb to the upper part of the lower portion of the mature anagen hair follicles. The late catagen hair follicles did not stain. Ultrastructurally, alpha-SM actin was detected only in the fibroblasts located in the innermost layer of the transverse collagenous fibres. Since alpha-SM actin is located in cells with contractile potential, this newly identified layer may play an important role in the morphological changes of the lower portion of the hair follicle during the hair growth cycle.

Differing cell surface distribution of human leukocyte antigen-DR molecules on epidermal Langerhans cells and eccrine duct cells

Scanning electron microscopy (SEM) with immunogold labeling was employed to observe the undersurface of the human epidermis after it was split from dermal connective tissue, in an attempt to localize the molecules actually expressed on cell/tissue surfaces. We found that human leukocyte antigen-DR (HLA-DR) molecules were expressed on the surfaces of eccrine duct cells as well as those of epidermal Langerhans cells (LC) in normal skin. HLA-DR molecules, visualized by the deposition of gold particles, were distributed evenly on the LC surface but were present only along the interdigitating borders of the individual duct cells, thus producing a meshwork pattern on the duct surface. Transmission electron microscopy confirmed that the gold particles labeling cell surface HLA-DR molecules were seen only on the portions of duct cell membranes the interdigitated with neighboring duct cells. These findings suggest that the function of HLA-DR molecules may vary with their location and distribution. On the LC surface, the evenly distributed molecules seem to be well suited for promoting "accessory cell" functions. On duct cell surfaces, the HLA-DR molecules present along the intercellular spaces may be involved in trapping various peptide antigens that pass into the sweat gland filtrate and then are reabsorbed by the excretory duct, since these molecules have a highly permissive capacity for binding various peptides.

Differential localization of ICAM-1 and HLA-DR expression on epidermal basal surface in mycosis fungoides and lichenoid reaction

Scanning electron microscopy with immunogold labeling revealed that epidermal keratinocytes expressed ICAM-1 (intercellular adhesion molecule-1) and HLA-DR molecules on their surfaces in patterns that differed in mycosis fungoides (MF) and lichenoid reaction (LR). ICAM-1 molecules, visualized as deposits of gold particle, were visualized as clusters adjacent to the junctions interconnecting the keratinocytes of MF lesions. LFA-1 (leukocyte function-associated antigen-1) molecules were seen as granules on the surfaces of all infiltrates, most of which also expressed ICAM-1. HLA-DR molecules were seen continuously along the borders of the individual keratinocytes, thus producing a cobblestone appearance on the epidermal undersurface. In contrast, ICAM-1 and HLA-DR were found only sparsely on the undersurface of the epidermis from LR. These findings may help to explain the differing histological features of MF and LR: ICAM-1 molecules present on the intercellular junctions of MF epidermis lead the LFA-1-bearing cells to migrate into the interspaces, thus producing epidermotropism. These cells aggregate by means of co-expressed ICAM-1 to thus produce Pautrier's microabscess. In LR, the minimal expression of ICAm-1 on the epidermal undersurface leaves most infiltrates within the dermis, thus producing a band-like infiltrate.

Melanocyte chemotactic factor produced by skin metastases of a breast carcinoma

A 65-year-old woman underwent right modified radical mastectomy for a malignant lesion which had developed just below the right nipple. Two years after the operation, skin lesions composed of dark brown to black, pigmented, papular lesions developed in the precordia. A biopsy revealed this to be a cutaneous metastasis of the previous breast carcinoma. However numerous pigment blockade melanocytes were also found in the tumor nests, located in and/or beneath the epidermis. Although a black-colored breast carcinoma has been reported, the presence of pigment blockade melanocytes was not determined. Culture of the tumor nest recovered a population of melanocytes as well as the carcinoma cells. Boyden chamber analysis revealed the presence of a chemotactic factor for melanocytes in the culture medium. This seems to be the first documentation of melanocyte incorporation in breast carcinoma tissue.

Localization of herpes simplex virus type 1 in sebaceous glands of mice

The distribution of HSV-1 during the development of zosteriform skin lesions in SCID mice was analyzed by immunofluorescence and electron microscopy. The virus initially appeared within certain keratinocytes, sometimes surrounded by keratinocytes whose surfaces were also positive for the antigens, in the lower epidermal layers including the hair follicles, and then extended upward to the entire epidermis and downward to the sebaceous glands 1-2 days later, when no macroscopic skin lesion was seen. The affected epidermal cells subsequently degenerated and lost their viral antigens within a day, when the zosteriform lesion then became evident. This was followed by a degeneration of the dermis. The sebaceous glands eventually degenerated in 10 days, but some glands in the necrotic skin areas preferentially retained HSV-1. The horizontal spread of the virus in the epidermis beyond the first invaded dermatome occurred much later. In mice passively immunized with specific immune serum, viral antigens were observed even 20 days after the infection in sebaceous glands in necrotized areas. Therefore, HSV-1 appears to spread first via the extracellular fluid among the keratinocytes after being shed from nerve endings, and then produces a successive degeneration of the affected keratinocytes which may prevent any further extension of horizontal viral spread. The pilosebaceous apparatus is possibly acting as a site not only for the replication of HSV-1 with a delayed cytopathic effect, but also as an area that is temporarily sheltered from host defense mechanisms.

Reduction of environmental mites improved atopic dermatitis patients with positive mite-patch tests

During a series of studies on the involvement of house dust mite antigens in 183 cases of atopic dermatitis, we observed an improvement in two patients following the removal of mites from their environment by means of a thorough housecleaning and replacement of the mattress. Both patients manifested the typical clinical skin lesions of atopic dermatitis and had similar laboratory findings. Although the serum IgE concentrations and specific IgE to Dermatophagoides pteronyssinus and Dermatophagoides farinae were each relatively low, the results of patch tests with these antigens were positive. Thus, a regimen aimed at reducing the presence of house dust mites can produce clinical improvement in a subset of patients with atopic dermatitis who show contact hypersensitivity to mite antigens on skin testing, but negative results on IgE (RAST; radioallergosorbent technique) testing.

Spindle cell hemangioendothelioma exhibits the ultrastructural features of reactive vascular proliferation rather than of angiosarcoma

A patient with spindle cell hemangioendotheliomas was followed from 1964 to the present time, allowing the authors the opportunity to examine the lesions in the early, mature, and old phases. Organizing thrombi of different stages associated with slit-like vascular proliferation were always observed, whereas cavernous vascular spaces predominated as the lesions became older. Each spindle cell hemangioendothelioma initially developed relatively rapidly and was sometimes painful but then persisted as a silent nodule for decades. Transmission and scanning electron microscopic studies revealed that endothelial cells tended to digitate into the slit-like proliferating channels, became attached to other cells by means of tight junctions, and thus obstructed the channels at sites where thrombi developed repeatedly. The vascular spaces, ranging in nature from slit-like to cavernous, were outlined further by a relatively sparse mantle of ramified or dendritic interstitial cells that corresponded to spindle cells. Most of the cells appeared simply to be fibroblasts, but they developed the features of pericytes when they were close to the endothelial lining of well-developed vascular lumens. Large vascular spaces and phleboliths were surrounded by smooth muscle cells. Approximately 20% of the interstitial cells were dendritic macrophages characterized by phagocytic activity, presence of many lysosomes, and Factor XIIIa expression. The long and characteristic clinical course, the histologic evidence that thrombosis and its organization was continually occurring within the lesions, and the ultrastructural finding that spindle cell hemangioendotheliomas were composed of different microvascular segments from capillaries to veins, suggest that spindle cell hemangioendotheliomas may develop from a cycle of recanalization after thrombosis that occurs repeatedly because of the unique endothelial growth that was noted. This is in contrast with the previous conception that they were low-grade angiosarcomas.