Immunohistochemical localization of epidermal basement membrane laminin and type IV collagen in bullous lesions of dermatitis herpetiformis

Hemidesmosomal molecular changes in dermatitis herpetiformis; decreased expression of BP230 and plectin/HD1 in uninvolved skin

Recent BP230-knockout experiments with subsequent blistering and recently identified plectin/HD1 mutations in epidermolysis bullosa simplex patients suggest that defective expression of BP230 and plectin/HD1 may predispose to blister formation in human skin. We have studied the expression of the epithelial adhesion complex as well as the basement membrane and anchoring fibril antigens in uninvolved dermatitis herpetiformis skin to find out if alterations can be detected in these structures predisposing to the blister formation typical of the disease. Ten uninvolved dermatitis herpetiformis skin specimens, which all showed clear granular deposits of IgA under the basement membrane in direct immunofluorescence and five normal skin specimens, were studied by indirect immunofluorescence technique. Six uninvolved dermatitis herpetiformis skin specimens showed distinctly decreased immunoreaction for BP230 and four uninvolved dermatitis herpetiformis skin specimens showed distinctly decreased immunoreaction for plectin/HD1. All five skin controls showed strong immunoreactions for BP230 and plectin/HD1. Other hemidesmosomal proteins including BP180 and integrin alpha6beta4, as well as basement membrane proteins laminin-5, laminin-1, nidogen and type IV collagen, and the anchoring fibril protein type VII collagen showed a normal strong expression. Our results suggest that alterations in BP230 and plectin/HD1 may contribute or predispose to blister formation in dermatitis herpetiformis skin.

A case of nonscarring inflammatory epidermolysis bullosa acquisita: characterization of IgG autoantibodies by immunofluorescence, immunoblotting and immunogold electron microscopy

We report a case of nonscarring inflammatory epidermolysis bullosa acquisita in a 59-year-old Japanese woman. She developed blisters and erosions on her lip, trunk and extremities. Sodium aurothiomalate was effective for the skin lesions. The patient had been free from bullous skin lesions for the last 13 years and had shown no scarring. Indirect immunofluorescence (IF) study on 1 M NaCl-split skin revealed IgG autoantibodies against the dermal side of the split skin. Immunoblotting using normal human dermal extracts disclosed IgG autoantibodies reactive with the 290 and 145 kD antigens. Circulating IgG autoantibodies were deposited on the lamina densa by immunoelectron microscopy. IF mapping using several antibodies for the components of the basement membrane zone revealed blister formation at the lamina densa. These results suggest that the cleavage at the lamina lucida does not necessarily exclude the diagnosis of EBA and that the definite diagnosis of EBA should be confirmed by immunoblotting or immunoelectron microscopic study.

Urokinase plasminogen activator is expressed by basal keratinocytes before interstitial collagenase, stromelysin-1, and laminin-5 in experimentally induced dermatitis herpetiformis lesions

We studied the temporal expression of interstitial collagenase, stromelysin-1 and -2, and urokinase plasminogen activator (uPA) mRNAs by in situ hybridization in eight patients with dermatitis herpetiformis. To induce blisters, 50% potassium iodide patch tests were performed, and serial biopsy specimens were taken at 4, 12, and 24 h. Additional samples were taken from occasional spontaneous blisters. Components of the basement membrane, laminin-5, laminin-1, and type VII collagen, were examined immunohistochemically in relation to matrix metalloproteinase expression. At 12 h, when no blisters were seen, uPA mRNA was present in basal keratinocytes in five of eight samples, whereas interstitial collagenase and stromelysin-1 mRNA were not detected. At this time, immunohistochemistry failed to show changes in the basement membrane. At 24 h, uPA, collagenase, and stromelysin-1 mRNAs were present in basal keratinocytes, suggesting an activation of latent forms of the two latter enzymes by the uPA-plasmin pathway. Signal for stromelysin-2 was not detected. Furthermore, disruptions of laminin-1 and type VII collagen were evident. The data suggest that stromelysin-1 and interstitial collagenase may contribute to the degradation of basement membrane in dermatitis herpetiformis. Intracellular staining for laminin-5 co-localized with collagenase mRNA in basal keratinocytes. Because laminin-5 is essential for adhesion of keratinocytes to basement membrane and for establishment of focal adhesions on migrating cells, its production may reflect a regenerative response after the destruction of basement membrane components.

Enhanced expression of interstitial collagenase, stromelysin-1, and urokinase plasminogen activator in lesions of dermatitis herpetiformis

Because dermatitis herpetiformis is characterized by neutrophilic inflammation and destructive changes in the basement membrane zone, we studied the in situ expression of interstitial collagenase and stromelysin-1 in 11 lesions. A prominent signal for collagenase mRNA was consistently detected in the basal keratinocytes of rete ridges surrounding the neutrophilic abscesses in 10 of 11 lesions, and the expression was independent of the age of the lesion and the migratory state of the basal keratinocytes. Expression of stromelysin-1 was detected in seven of 11 lesions and co-localized with collagenase. No expression of the 92-kDa gelatinase mRNA or matrilysin protein was found in the vicinity of neutrophilic accumulations or the damaged basement membrane. Urokinase-type plasminogen activator mRNA was found in basal keratinocytes in seven of nine samples. Collagenase, stromelysin-1, and urokinase-type plasminogen activator were not expressed in normal-appearing skin of patients with dermatitis herpetiformis. Our results suggest that in lesions of dermatitis herpetiformis, collagenase and stromelysin-1 may be induced in basal keratinocytes by neutrophil cytokines or by altered cell-matrix interactions through contact of keratinocytes with the matrix due to damaged basement membrane. Stromelysin-1, in particular, may contribute to formation of blisters by degrading basement membrane components.

Location of basement membrane type IV collagen beneath subepidermal bullous diseases

Using standard immunohistochemical methods, routinely processed sections, and a polyclonal antibody to Type IV collagen, we have determined the location of Type IV collagen, a substance located in the lamina densa of basement membrane, in a spectrum of acquired subepidermal bullous diseases. Type IV collagen was attached to the blister roof in five cases of well-established epidermolysis bullosa acquisita and to the blister base in 25 cases of bullous pemphigoid, four cases of dermatitis herpetiformis and 12 cases of porphyria cutanea tarda. Immunohistochemical localization of Type IV collagen in epidermal-dermal basement membrane is a simple, rapid and reliable technique which can be utilized to exclude and possibly to confirm the diagnosis of epidermolysis bullosa acquisita in routinely fixed paraffin-embedded tissues.

The presence of intra-lamina lucida blister formation in epidermolysis bullosa acquisita: possible role of leukocytes

In evaluating patients we have noted disparity between the locations of bound immunoreactants and the level of blistering in epidermolysis bullosa acquisita (EBA). We examined 10 consecutive EBA patients by routine histology, direct (DIF) and indirect (IIF; intact and NaCl-split skin) immunofluorescence, immunofluorescence mapping (IM), and/or direct immunoelectron microscopy (DIEM). DIF was positive in each. IIF was positive in 3/8 and 6/7 patients when intact and split skin were used as substrates. DIEM revealed immunoreactants within the lamina densa (LD) in 6/10, sub-LD in 1/10, and both LD and sub-LD in 3/10 patients. In contrast, by DIEM and IM, blister formation was noted within the lamina lucida (LL) in 7/9 and 8/10, sub-LD in 1/9 and 1/10, and within both LL and sub-LD in 1/9 and 1/10, respectively. In the presence of neutrophils within the upper dermis (n = 6), cleavage occurred within the LL in 5 specimens; in one additional specimen containing predominantly neutrophils, cleavage occurred within both LL and sub-LD. In the presence of mononuclear cells (n = 2), intra-LL cleavage occurred. In the presence of eosinophils, cleavage occurred within both LL and sub-LD. In the one specimen lacking any infiltrate, the cleavage plane was exclusively sub-LD. Intra-LL cleavage planes are more common than sub-LD ones in at least early cases of EBA. These findings likely represent the intra-LL-separating effect of leukocyte-derived proteolytic enzymes, when such cells are chemoattracted to the dermoepidermal junction by bound immuno-reactants.

An immunohistochemical study of laminin, type-IV collagen and type-III pN-collagen with relation to reticular fibres in Hodgkin's disease

The distribution of aminoterminal propeptides of type-III procollagen (indicating the presence of type-III pN-collagen, i.e., type-III collagen molecule with a non-cleaved aminoterminal propeptide), laminin and type-IV collagen was studied by immunohistochemical methods. The results were compared with the distribution of reticular fibres using Gomori's reticulin stain. Lymph nodes from 20 cases of Hodgkin's disease (HD) and 3 spleens affected by nodular sclerosis HD were studied. The reticular fibres stained for all the antigens investigated, the strongest reaction being for pN type-III collagen. Thick fibres stained mainly for type-III pN-collagen, the BM proteins being located in a fragmented rim on the surface. The distribution and composition of fibres was similar in both nodal and extranodal infiltrations. The morphological alterations noted in the fibres comprised (1) compression between nodules in the nodular type of lymphocyte-predominant HD, and (2) fragmentation, present in collections of histiocytes in lymphocyte-predominant HD. BM proteins and type-III pN-collagen were present in the walls of the sinuses and vessels. The marginal sinuses were often partially spared in spite of extracapsular invasion. Our results suggest that laminin, type-IV collagen and type-III pN-collagen are important components of reticular fibres in HD and that the composition of the fibres is similar to that seen in the normal lymph node.

Basement membrane formation by malignant mouse keratinocyte cell lines in organotypic culture and transplants: correlation with degree of morphologic differentiation

Six malignant C3H mouse epidermal cell lines (HEL-30, HEL-37, HELP I, HELP IV, HD II, H3L), with different capacities for epidermal differentiation, were analyzed for their organized growth behavior and basement membrane (BM) formation in organotypical cultures in vitro and after transplantation into syngeneic mice. Expression and deposition of five BM components (type IV collagen, laminin, bullous pemphigoid antigen, fibronectin, heparan sulfate proteoglycan) were determined on frozen sections by indirect immunofluorescence. Additionally, synthesis and secretion of BM components by the line HEL-30 (in submersed cultures) were identified by metabolic labeling and immunoprecipitation. Morphologic differentiation features and formation of a structured BM were studied by electron microscopy. All cell lines were tumorigenic and invasive but nevertheless able to synthesize BM constituents in vitro and in vivo, although pronounced variations in the expression and the polarity and continuity of deposition were found. Irrespective of the amount of BM components synthesized, none of the cell lines formed a structured BM in organotypical cultures in vitro. After transplantation the production of BM components was improved and the newly formed epithelia were separated from the mesenchyme by a structured BM. The formation of BM occurred whether the epithelial cells were in immediate contact with the mesenchyme or separated by a 1 to 2 mm thick native collagen gel. Deposition of BM constituents and formation of BM structures occurred both at the superficial epithelium and around invading cell cords. The studies clearly demonstrated that malignant epidermal cells maintain their capacity to synthesize BM components. The extent of production and the polarity of deposition of the constituents and the quality of BM formation were usually higher in well differentiated cell lines and obviously correlated well with their preserved degree of differentiation. Comparable to normal keratinocytes, formation of structured BM requires interaction with living mesenchyme but occurs independently of direct epidermal-mesenchymal contact.

Altered basement membrane structure of the spleen in hairy cell leukaemia. Demonstration of laminin in hairy cells

Changes in five spleens affected by hairy cell leukaemia were characterized using immunohistochemical staining for the basement membrane (BM) components laminin and type IV collagen. The ring fibres had not been totally destroyed, and were well preserved in places. The spaces filled by abnormal blood or hairy cells were assigned to the categories of altered sinus and two types of pseudosinus. In an altered sinus the staining pattern of the ring fibres had gained attenuations and the sinus was sometimes lined by a continuous BM of uneven thickness. The number of altered sinuses was related to the size of the spleen. The pseudosinuses were larger than normal sinuses and usually also larger than altered sinuses. One of the two types seemed to be derived from ruptured Billroth's cords and entailed spaces of irregular size and shape bounded by strips of fibres containing BM proteins. No ring fibres were seen in the wall. The other type of pseudosinus occurred in those spleens where no white pulp remained. These spaces were large, located around arteries and bounded by irregular strips of BM material. In three cases a number of hairy cells could be demonstrated which showed positive staining for laminin either in the surface or in the cytoplasm. Adhesive properties of hairy cells would be conceivable on the basis of the presence of laminin on the surface of the cells.

Basement membrane proteins and reticulin in a normal thymus and the thymus in myasthenia gravis

The distribution of basement membrane (BM) proteins, laminin and type IV collagen were studied immunohistochemically in a series of 12 normal thymuses representing different age groups (0-52 years) and in 10 cases of myasthenia gravis (age 7-53 years). The staining pattern was compared with that of conventional reticulin staining. BM proteins were present at the capsule-parenchyma interface and scantily distributed in the medullary stroma, where they were closely associated with reticulin fibres. The extrathymic perivascular space was effectively visualized by the staining of the BM's marginal to it. The fiber network present in this space stained with reticulin stain and, less continuously, in BM stainings. Lymph node like tissue with germinal centers was occasionally present in the perivascular spaces in normal thymuses and commonly in the myasthenia gravis cases, where the perivascular spaces were often dilated. The BM's of the perivascular space were mostly continuous in normal cases, but discontinuities were observed in cases of myasthenia gravis, especially in the spaces which were widely dilated. Immunohistochemical detection of BM proteins seems to be useful in the study of thymic structure, particularly in the demonstration of the characteristic changes of the perivascular space in myasthenia gravis. It is suggested that the reticulin fibres present in the medulla and in the perivascular space contain laminin and type IV collagen.

Distribution of basement membrane laminin and type IV collagen in human reactive lymph nodes

The location of two basement membrane components, laminin and the 7-S domain of type IV collagen, was studied in human lymph nodes using the peroxidase-antiperoxidase method. Basement membrane antigens were present on the walls of blood vessels and of marginal, trabecular and medullary sinuses. Thin, fragmented fibre-like staining was present also in parenchyma outside the germinal centres, in a pattern overlapping with reticular fibres as seen on conventional reticulin stains. This finding suggests that basement membrane components are a part of the reticular fibres of lymph nodes, or are closely associated with them.