Alterations in distribution of tenascin, fibronectin and fibrinogen in vulval lichen sclerosus

BACKGROUND: The pathophysiology of lichen sclerosus remains uncertain. The clinical features, including increased fragility and scarring, and the histology suggest that significant reorganisation of the extracellular matrix is occurring. Tenascin, fibrinogen and fibronectin are extracellular matrix components that play a significant role in tissue remodelling, for example during wound repair. Aim: To examine the distribution of tenascin, fibrinogen and fibronectin in vulval lichen sclerosus. MATERIALS AND METHODS: Immunohistochemical staining was performed to study the distribution of tenascin, fibronectin and fibrinogen in 16 specimens of untreated vulval lichen sclerosus and 1 specimen of extragenital lichen sclerosus. Haematoxylin and eosin staining of the specimens was also performed to identify the position of the pale staining homogenous zone/zone of sclerosis and the inflammatory infiltrate below this. The control tissues studied included biopsies taken from the uninvolved thigh of 13 of the lichen sclerosus patients and 6 samples of normal vulva tissue obtained during gynaecological procedures from women of similar age to the lichen sclerosus women. RESULTS: All the lichen sclerosus specimens demonstrated increased immunostaining of tenascin in the upper dermis and comparing this with the haematoxylin and eosin staining this corresponded to the zone of sclerosis with relatively little tenascin staining associated with the inflammatory band. In 14 out of the 16 vulval lichen sclerosus specimens and the extragenital lichen sclerosus specimen fibrinogen immunostaining was increased in the upper dermis which corresponded--in haematoxylin and eosin staining --to the zone of sclerosis. There was also slightly increased fibrinogen staining in the mid dermis which corresponded to the inflammatory band. Fibronectin staining was reduced in the upper dermis of 12 of the vulval lichen sclerosus specimens and the extragenital lichen sclerosus specimen which corresponded to the zone of sclerosis. However, in 14 of the vulval lichen sclerosus specimens and the extragenital lichen sclerosus specimen, fibronectin was slightly increased in the mid and deeper dermis which corresponded to the zone of inflammatory cells and the area below this. There was also increased fibronectin staining around blood vessel walls both in the mid dermis and within the zone of sclerosis. CONCLUSION: The distribution of tenascin, fibrinogen and fibronectin is altered in lichen sclerosus and the alteration in these extracellular matrix components may be relevant to the initiation of scarring in lichen sclerosus and the associated increased skin fragility.     

Fibrillin microfibrils are reduced in skin exhibiting striae distensae

Striae distensae (striae: stretch marks) are a common disfiguring condition associated with continuous and progressive stretching of the skin—as occurs during pregnancy. The pathogenesis of striae is unknown but probably relates to changes in those structures that provide skin with its tensile strength and elasticity. Such structures are components of the extracellular matrix, including fibrillin, elastin and collagens. Using a variety of histological techniques, we assessed the distribution of these extracellular matrix components in skin affected by striae. Pregnant women were assessed for the presence of striae, and punch biopsies were obtained from lesional striae and adjacent normal skin. Biopsies were processed for electron microscopy, light microscopy and immunohistochemistry. For histological examination, 7 μm frozen sections were stained so as to identify the elastic fibre network and glycosaminoglycans. Biopsies were also examined with a panel of polyclonal antibodies against collagens I and III, and fibrillin and elastin. Ultrastructural analysis revealed alterations in the appearance of skin affected by striae compared with that of normal skin in that the dermal matrix of striae was looser and more floccular. Light microscopy revealed an increase in glycosaminoglycan content in striae. Furthermore, the number of vertical fibrillin fibres subjacent to the dermal–epidermal junction (DEJ) and elastin fibres in the papillary dermis was significantly reduced in striae compared with normal skin. The orientation of elastin and fibrillin fibres in the deep dermis showed realignment in that the fibres ran parallel to the DEJ. However, no significant alterations were observed in any other extracellular matrix components. This study identifies a reorganization and diminution of the elastic fibre network of skin affected by striae. Continuous strain on the dermal extracellular matrix, as occurs during pregnancy, may remodel the elastic fibre network in susceptible individuals and manifest clinically as striae distensae.     

Investigation of intercellular matrix macromolecules involved in lichen sclerosus

Dermal changes of the vulva in lichen sclerosus were compared with control vulvar samples using ultrastructural and immunofluorescence techniques. Collagen degeneration and regeneration were observed ultrastructurally in the superficial dermis of lichen sclerosus with increased amounts of ground substance. These processes appeared to alter the affinity of collagen fibres for the anticollagen antisera types I, III, IV. A decrease in elastin content was observed by electron microscopy. A loss of fibronectin was discovered at the dermo-epidermal junction, which looked normal ultrastructurally. The linear laminin pattern at the dermo-epidermal junction was also altered. These results suggested an enzymatic process in the pathogenesis of lichen sclerosus. Amidase activity could be determined in 6 normal and 6 pathological biopsies, though higher in the pathological samples (p less than 0.01).     

Elastolysis in lichen ruber planus.

The dermal elastic fiber network was studied in specimens from five patients with lichen ruber planus, using a standard elastin staining procedure (orcein), results being compared with those for the elastin-associated microfibrillar network stained using anti-fibrillin antibodies in an immunofluorescence and an avidin-biotin-peroxidase complex technique. Additional specimens of healed apparently normal skin were taken from two of the patients. Orcein-stained fibers were scarce or absent in the inflammatory zone in all the lesions. In contrast, an extensive fibrillin immunoreactive network was present in the papillary zone in all the specimens, in a pattern similar to that of normal skin. In specimens from healed lesions of lichen ruber planus, dermal orcein-stained fibers were present in the papillary dermis. The findings indicate that the amorphous component of elastic fibers is destroyed during the acute phase of lichen ruber planus. Hypothetically, the elastolysis is caused by elastases released from macrophages known to be present in the lichenoid infiltrate. In contrast, the fibrillin fiber network seems to be less or not at all affected by proteolytic events during the inflammatory phase of lichen ruber planus.     

Immunohistochemical studies on fibrillin in amyloidosis, lichen ruber planus and porphyria.

The pathogenesis of macular amyloidosis and lichen amyloidosis remains unsolved and the primary amyloid fibril protein(s) has not yet been identified. Ultrastructural association of skin amyloid with elastin associated microfibrils has been noted earlier. The presence of fibrillin in conjunction with such microfibrils was recently demonstrated immunohistochemically. The presence of fibrillin immunoreactivity in the amyloid deposits in skin biopsies from 3 patients with macular amyloidosis and 3 patients with lichen amyloidosis was studied, using monoclonal anti-fibrillin antibodies. For comparison, skin specimens were studied from five patients with lichen ruber planus, four patients with erythropoietic protoporphyria and from a patient with myeloma-associated cutaneous amyloidosis. Renal specimens from two cases of the amyloid A type of renal amyloidosis also were investigated. There was no immunostaining either of the keratin bodies in specimens of lichen ruber planus, the cutaneous PAS-positive vascular deposits in patients with erythropoietic protoporphyria, or the amyloid deposits in specimens of systemic amyloidosis and it was faint or absent in amyloid deposits in the specimens from patients with lichen amyloidosis. In contrast, distinct fibrillin immunoreactivity could be demonstrated in amyloid deposits in specimens from patients with macular amyloidosis. It was sometimes absent in deposits located in the upper part of the papillary dermis, close to the dermal epidermal junction zone, while consistently strong in deposits located lower down in the dermis. The results suggest that fibrillin or part of the fibrillin molecule may be present in some of the amyloid deposits in specimens of macular amyloidosis.     

Immunochemistry of elastotic material in sun-damaged skin

The nature of elastotic material in sun-damaged human skin was investigated by indirect immunofluorescence. Antibodies were used against the following components of the dermis: type I and type VI collagens, aminopropeptide of type I and type III procollagens, fibronectin, elastin, microfibrillar proteins, and basement membrane represented by the 7S domain of type IV collagen, laminin, and nidogen. The elastotic material exhibited marked fluorescence for elastin and microfibrillar proteins which codistributed with fibronectin. The presence of type I and VI collagens and procollagen type III were demonstrated to a lesser extent within the elastotic material. These results suggest that solar elastosis is primarily derived from elastic fibers and not from preexisting or newly synthesized collagens.     

The basement membrane zone in lichen sclerosus: an immunohistochemical study

The alteration in expression of basement membrane zone (BMZ) components in lichen sclerosus was investigated by immunohistochemical staining of skin biopsies from seven patients with histologically confirmed disease compared with controls. Monoclonal antibodies and polyclonal sera directed against proteins of the hemidesmosomes, anchoring fibrils, lamina lucida, lamina densa and BMZ collagens were used. Characteristic histological appearances at the dermo-epidermal junction were reflected in widespread alterations in antigen expression in the epidermal basement membrane and the papillary dermis. Expression of the proteins which constitute the structural scaffold (collagen IV and VII) were increased in lichen sclerosus. Expression of hemidesmosomal proteins which mediate adhesion and cell to matrix interaction (α6/β4 and hullous pemphigoid antigen) and expression of anchoring filament components were markedly reduced, suggesting that the epidermal cells are exposed to selective damage.     

An infective aetiology for vulval lichen sclerosus re-addressed

Although there is evidence to support an autoimmune basis for lichen sclerosus, there have also been some studies which suggest an infective aetiology. These include reports of the presence of spirochaetal forms with Steiner silver stains and purplish coccoid forms with Fite stains. We have repeated these studies on vulval biopsies obtained from 16 patients with vulval lichen sclerosus. Using the Steiner silver method we found no evidence of spirochaetal forms in any of the specimens. With the Fite stain we observed purple-staining coccoid forms within the dermis of 13 of the 16 lichen sclerosus specimens. However, these coccoid forms also stained strongly positive with toluidine blue, suggesting they were mast cell granules rather than micro-organisms. We were therefore unable to demonstrate evidence for an infective aetiology in vulval lichen sclerosus, although this cannot yet be excluded. Further work is also needed to understand the significance of mast cells in lichen sclerosus.     

Psoriasis associated with vulval scarring

Psoriasis is a chronic inflammatory skin disorder which is generally not associated with scarring. We report two patients with long-standing severe anogenital psoriasis, that was associated with loss of the labia minora, thus clinically mimicking the scarring associated with lichen sclerosus. Histopathological finding were however, consistent with psoriasis with no evidence of lichen sclerosus. Elastic fibres were present and there was no evidence of abnormal collagen or fibrous tissue. The association of vulval psoriasis with scarring has not been reported previously.     

Angiokeratoma-like changes in extragenital and genital lichen sclerosus

Hemorrhagic blisters have rarely been described developing in the background of either genital or extragenital lichen sclerosus and have invariably been designated clinically as telangiectatic, hemorrhagic or bullous lichen sclerosus. We describe three patients with extragenital and genital lichen sclerosus, who presented clinically with hemorrhagic plaques and/or papules. In addition to the classical histology of lichen sclerosus, dilated, congested and focally thrombosed vascular channels lined by flat endothelium were seen within the sclerotic dermal collagen. They were in close proximity to and even in contact with the overlying epidermis and thus mimicked an angiokeratoma. Angiokeratoma-like changes in lichen sclerosus represent secondary features because of damage to the dermis by lichen sclerosus and are characterized histologically by ectatic thin-walled vascular spaces in the papillary dermis intimately associated with the epidermis. Increased venous pressure, local trauma, degenerative changes in the elastic tissue of the vessel wall and/or surrounding supportive tissue, as well as abnormalities in the extracellular protein network, appear to be implicated in their pathogenesis.     

Case Report: Vulvar Lichen Sclerosus in a Premenarchal Girl with a Complicated Biopsy

Abstract:  Lichen sclerosus is a T-lymphocyte mediated chronic cutaneous disorder with predilection for the vulva. In prepubertal girls, lichen sclerosus presents as vulvar discomfort, pruritus, bruising/bleeding, discharge, dysuria, or painful defecation. Diagnosis and treatment of lichen sclerosus is of utmost importance in the prevention of complications such as scarring, adhesions, atrophy, or long-term sexual dysfunction. We discuss a case of a 4-year-old female with an atypical presentation of genital lichen sclerosus and a complicated biopsy.     

A study of clinical and aetiological factors and possible associations of lichen sclerosus in males

Lichen sclerosus is a chronic skin condition with a predilection for the genital area. In the present study, 35 male patients with lichen sclerosus were interviewed and examined. Blood screens were performed and histology was requested if not already performed. The findings indicate that lichen sclerosus in males exists as a spectrum of disease, ranging from a mild form with white plaques and few symptoms to a severe form with inflammation, atrophy and scarring with possible urological consequences. In many areas it differs from the condition in females; the association with autoimmune disease is weaker and there is less perianal and extragenital involvement The association with malignancy in males is of lesser significance than initially believed.     

Monoclonal antibodies to collagens for immunofluorescent examination of human skin

Monoclonal antibodies, specific for each of human types I, III, IV and V collagens, were produced and shown to be suitable for immunofluorescent studies of human skin. The antibodies showed that types I and III collagens were abundant and distributed throughout the dermis. The distribution of type III collagen appeared different in the papillary compared with the reticular dermis, although an increased concentration of type III collagen in the papillary dermis could not be unambiguously established. Type V collagen, which could be visualised only after acid-pretreatment of sections, was also distributed throughout the dermis, but appeared to be in higher concentrations around cells. Type IV collagen was observed specifically in the basement membrane associated with the dermal/epidermal junction.     

Cytokine alterations in lichen sclerosus: an immunohistochemical study

BACKGROUND: Although the histology of lichen sclerosus is characteristic, the precise nature of the inflammatory changes and the signals provoking them is uncertain. OBJECTIVES: To delineate the inflammatory changes in lichen sclerosus more accurately by studying cytokine changes. METHODS: An immunohistochemical study of 12 specimens of genital lichen sclerosus and one specimen of extragenital lichen sclerosus was undertaken using monoclonal antibodies to interferon (IFN)-gamma, IFN-gamma receptor, tumour necrosis factor (TNF)-alpha, interleukin (IL)-1alpha, IL-2 receptor (CD25), intercellular adhesion molecule-1 (ICAM-1) and its ligand CD11a. Control specimens were seven specimens of normal vulva obtained during gynaecological procedures, three specimens of normal skin, adjacent uninvolved thigh from three of the patients with lichen sclerosus, five specimens of nonvulval psoriasis, four specimens of nonvulval lichen planus and two specimens from chronic wounds. RESULTS: The lichen sclerosus specimens demonstrated slightly increased staining for IFN-gamma within the epidermis compared with the normal vulva and nonvulval skin. There was increased dermal staining for IFN-gamma both within the pale zone of the upper dermis and within the inflammatory zone below this. We confirmed our previous demonstration that in lichen sclerosus HLA-DR immunostaining is increased in association with vascular endothelium, the inflammatory cell infiltrate and around the keratinocytes. The areas of the epidermis with the strongest immunostaining for HLA-DR generally also had the strongest staining for IFN-gamma. In the lichen sclerosus specimens the zone of inflammation also demonstrated increased immunostaining for TNF-alpha, IL-1alpha, IFN-gamma receptor, CD25, CD11a and ICAM-1 while the zone of sclerosus demonstrated a smaller increase in immunostaining for IFN-gamma receptor, TNF-alpha, CD11a and ICAM-1, and the epidermis demonstrated increased staining for ICAM-1. CONCLUSIONS: The increased staining for IFN-gamma, TNF-alpha, IL-1alpha, IFN-gamma receptor, CD25, CD11a and ICAM-1 suggest that the cytokine response in lichen sclerosus shares characteristics of the cytokine response in lichen planus and chronic wounds.     

Effect of topical tretinoin on photoaged facial skin: a histometric, immunohistochemical and ultrastructural study

Background Topical tretinoin is a recognized treatment for photoageing. Aim To evaluate the microscopic changes induced by topical tretinoin used to treat mild to moderate photodamage in dark‐skinned patients aged 30 to 50 years. Patients and methods Biopsy specimens were obtained from the facial skin of 11 patients before and after treatment with topical tretinoin. Routine histopathology coupled with histometric computer‐assisted image analysis was used to assess epidermal changes. Alcian blue stain was used to measure changes in glycosaminoglycans (GAGs). Immunoperoxidase technique for type I and III collagens and elastin, as well as transmission electron microscopy, were used to measure changes in collagen and elastic fibres. Results Epidermal hyperplasia occurs following tretinoin application, which is reversible with continued therapy. GAGs decreased (p < 0.05) after 6 months of tretinoin application but with no significant change thereafter. Quantitatively, there was an insignificant decrease of type I (p = 0.7) and III (p = 0.3) collagens during the first 6 months of tretinoin usage. However, biopsies taken after 10 months revealed a statistically significant increase in collagen I from a mean of 75.2% ± 9.6 before treatment to 94.2% ± 4.1 after treatment (p = 0.05). Similarly, the amount of type III collagen increased from a mean of 74.6% ± 9.96 to 90.6% ± 2.1 after 10 months of treatment (p = 0.05). On the other hand, the amount of elastin significantly (p = 0.02) decreased from a mean of 54.5% ± 3.68 before treatment to 43.4% ± 4.42 after 6 months of tretinoin application but with no significant change thereafter. Such changes were associated ultrastructurally with new collagen deposition and improvement of the quality of elastic fibres. Conclusion Topical tretinoin benefits facial skin, mainly by increasing collagen I and III and also by improving the morphological appearance of collagen and elastic fibres.     

沿Blaschko线分布的硬化性萎缩性苔藓合并局限性硬皮病1例

患者女,57岁。右颈部及腰部出现沿Blaschko线分布的条状硬化性白斑8月。皮损与Blaschko线分布区域相吻合。皮损组织病理示:基底细胞灶状液化变性,真皮乳头层均一化变性,真皮中深层胶原纤维增粗融合,皮肤附属器数目减少。诊断:硬化性萎缩性苔藓;局限性硬皮病。     

Spirochetal forms in the dermal lesions of morphea and lichen sclerosus et atrophicus

Morphea and lichen sclerosus et atrophicus are cutaneous diseases that are manifest by an early edematous stage, followed later by sclerosis and atrophy. They share features with acrodermatitis chronica atrophicans and erythema chronicum migrans, diseases that have been linked to infection by the spirochete Borrelia burgdorferi. A modified silver stain was used to identify the presence of spirochetes in skin biopsy specimens of patients with morphea and lichen sclerosus et atrophicus. Spirochetal forms were identified in the lesional skin of 10 of 25 patients with morphea and in 10 of 21 cases of lichen sclerosus et atrophicus. These spiral forms of bacteria had a significant tendency to occur in early and fully developed lesions of morphea and in early lesions of lichen sclerosus et atrophicus, whereas they tended to be absent in lesions demonstrating late pathological changes.     

Histology of lichen sclerosus varies according to site and proximity to carcinoma.

To investigate why vulvar but not extragenital lichen sclerosus is associated with squamous cell carcinoma, we performed a histologic study of extragenital lichen sclerosus, vulvar lichen sclerosus without carcinoma, and vulvar lichen sclerosus with carcinoma adjacent to and distant from the carcinoma. We compared epidermal thickness, rete ridge length, mitotic activity, atypia, dermal collagen change, dermal inflammation, and presence of other dermatoses in 30 women in each group. Extragenital lichen sclerosus showed thinner epidermis (mean thickness of 0.13 mm versus 0.41 mm; P < 0.0005), shorter rete ridges (P = 0.0001), more dermal edema (P = 0.16), and absence of associated dermatoses of spongiotic dermatitis and lichen planus (P < 0.005) compared with vulvar lichen sclerosus. The epidermal thickening seen in vulvar lichen sclerosus was indistinguishable from lichen simplex chronicus. Vulvar lichen sclerosus without carcinoma was generally similar to that distant from carcinoma. Vulvar lichen sclerosus adjacent to carcinoma showed increased epidermal thickness (0.61 mm versus 0.26 mm; P < 0.005), more dermal fibrosis (P < 0.0005), more inflammation (P < 0.0005), and more simplex (differentiated) vulvar intraepithelial neoplasia (18 cases versus 1 case; P < 0.0005) compared with that distant from carcinoma. We concluded that (1) the classic histologic features of lichen sclerosus are seen in both vulvar and extragenital sites; (2) vulvar lichen sclerosus without associated carcinoma has a mean epidermal thickness more than three times that of extragenital lichen sclerosus; (3) the epidermal thickening is histologically indistinguishable from lichen simplex chronicus; (4) there is a tendency for vulvar lichen sclerosus to have a more sclerotic and inflamed dermis; (5) lichen sclerosus 10 mm from cancer is more similar to vulvar lichen sclerosus without carcinoma than lichen sclerosus 1 mm from carcinoma; and (6) lichen sclerosus adjacent to carcinoma tends to show exaggerated epidermis thickness, basal atypia, and loss of the edematous-hyaline layer.     

Expression of basement membrane proteins and interstitial collagens in dermal papillae of human hair follicles

The expression of basement membrane molecules and interstitial collagens in human hair follicle mesenchyme was studied by immunohistochemical staining of tissue sections and of cells cultured from dermal papillae. Type I and type III collagens were found in the dermal sheath and in the dermal papilla throughout the hair cycle. Laminin and type IV collagen were expressed at the outer root sheath basement membrane and in the extracellular matrix of the dermal papilla of anagen and catagen follicles. In telogen follicles, where the volume of the dermal papilla extracellular matrix is much reduced, outline staining of dermal papilla cells for laminin and type IV collagen was still apparent. Staining for bullous pemphigoid antigen was also seen at the outer root sheath basement membrane extending to the lower tip of the hair bulb. In anagen follicles, there was no staining for bullous pemphigoid antigen at the interface between hair bulb epithelium and the dermal papilla and no staining within the dermal papilla. However, linear staining for bullous pemphigoid antigen became continuous around hair follicle epithelium during catagen and telogen. Cells cultured from human dermal papillae also stained for interstitial collagens, type IV collagen and laminin. However, similar results were obtained when cultured dermal fibroblasts were stained with the same antibodies. The expression of basement membrane proteins in human dermal papillae resembles that seen in follicles from other mammalian species and suggests that this is relevant to dermal papilla function. Cultured dermal papilla cells express a similar pattern of interstitial collagens and basement membrane proteins to those seen in tissue sections but this finding is not specific to dermal papilla cells.