Blister fluid from epidermolysis bullosa letalis induces dermal-epidermal separation in vitro

Dermal eosinophilic infiltrate in junctional epidermolysis bullosa

Junctional epidermolysis bullosa (JEB) is a rare genodermatosis characterized by a split in the lamina lucida usually because of mutations in LAMA3, LAMB3 and LAMC2 resulting in absence or reduction of laminin-332. Rare subtypes of JEB have mutations in COL17A1, ITGB4, ITGA6 and ITGA3 leading to reduction or dysfunction of collagen XVII, integrin α6β4 and integrin α3. The classic finding under light microscopy is a paucicellular, subepidermal split. We describe the unusual presence of an eosinophilic infiltrate in the bullae and subjacent dermis in a neonate with JEB, generalized intermediate (formerly known as non-Herlitz-type JEB), discuss the histologic differential diagnosis for a subepidermal blister in a neonate, review the literature regarding cases of epidermolysis bullosa (EB) presenting with inflammatory infiltrates, and discuss mechanisms to explain these findings. This case highlights that eosinophils can rarely be seen in EB and should not mislead the dermatopathologist into diagnosing an autoimmune blistering disorder.

Dystrophic epidermolysis bullosa associated with eosinophilic infiltrate and elevated serum IgE

An infiltrate of eosinophils is rarely seen in epidermolysis bullosa. We describe a child with dystrophic epidermolysis bullosa associated with a marked eosinophilic tissue infiltrate and elevated serum IgE.

Junctional epidermolysis bullosa keratinocytes in culture display adhesive, structural, and functional abnormalities

An unusual, elongated, refractile cell morphology was observed in keratinocytes cultured from three patients with non-lethalis forms of junctional epidermolysis bullosa (JEB). To determine whether these changes might be related to altered cell adhesion, keratinocyte strains established from one patient were examined for adhesive, structural, and functional characteristics. JEB keratinocytes expressed keratin tonofilaments, as determined by staining with AE1 monoclonal antibodies and direct observation of tonofilaments by electron microscopy. JEB keratinocytes showed diminished cell-substratum adhesions, judged by interference reflection microscopy. Areas of diminished cell-substratum adhesion corresponded to F-actin-rich cell adhesions (focal adhesions) and not to cellular areas that abundantly express hemidesmosomal antigens. Analysis of cell-substratum adhesion by electron microscopy revealed extensive areas of cell-substratum separation in JEB keratinocytes that were not present in normal keratinocytes maintained in serum-free medium. Normal keratinocytes displayed numerous regions of focal contact between the ventral plasma membrane and the culture substratum, but these structures were not seen in JEB keratinocytes. Bundled actin filaments (stress fibers) were greatly diminished in expected regions of cell-substratum adhesion in JEB keratinocytes and, instead, displayed disorganized individual filaments. The growth rate of JEB keratinocytes was quite slow in culture, with a population doubling time of 2.7 d versus 1.5 d for normal keratinocytes under identical conditions. JEB keratinocytes also displayed a reduced ability to aggregate into colonies upon exposure to medium with increased extracellular calcium. JEB keratinocytes thus display adhesive, structural, and functional abnormalities that suggest this cell type may be central to the pathogenesis of junctional epidermolysis bullosa. Study of affected keratinocytes could be important to characterize associated molecular pathologies.

Effect of sulfur exposure on protease activity in human peripheral blood lymphocytes

Sulfur mustard is a chemical warfare blistering agent for which neither the mechanism of action nor an antidote is known. Papirmeister et al. (1985) have postulated a biochemical hypothesis for mustard-induced cutaneous injury involving a sequelae of DNA alkylation, metabolic disruption and activation of protease. Human peripheral blood lymphocytes in cell cultures were employed as an in vitro model for alkylating agent toxicity. A chromogenic peptide substrate assay was used for detection of protease in lymphocytes treated with sulfur mustard or chloroethyl ethyl sulfide. Exposure of human peripheral blood lymphocytes from normal donors to these alkylating agents resulted in an increase in cell associated protease activity. This increase in protease activity may contribute to the pathology or act as an indicator to predict methods of therapeutic intervention for sulfur mustard toxicity.

Induction of lesions of dermatitis herpetiformis by autologous serum

In the present study various factors which contribute to the initiation of lesions in dermatitis herpetiformis (DH) were examined. Thirty-one patients with DH, seven with bullous pemphigoid, two with linear IgA disease and two healthy subjects were studied either before starting treatment or after stopping dapsone for up to 5 days. Intradermal inoculation of freshly prepared autologous serum was followed after 18-24 h by the formation of DH-like lesions in 24/31 DH patients. The lesions were erythematous papules, often with vesicles and microscopically showed papillary tip microabscesses. Serum-induced formation of lesions only occurred in patients with active DH with some spontaneous lesion formation: it did not occur in any of the non-DH controls. The formation of lesions was dose-related, declining proportionately with dilution of the serum down to 1/16. Plasma prepared by various methods of anticoagulation (heparin, citrate, EDTA) caused lesser reactions, while addition of heparin or epsilon-amino caproic acid (EACA), but not citrate, to serum substantially inhibited the formation of lesions. This suggested the responsible factor might be a protease. Other vasoactive agents including histamine (1-4 micrograms) and compound 48/80 (1-5 micrograms) caused normal immediate wealing. DH-like lesions occurred in only one of 13 subjects challenged with histamine and two of nine challenged with 48/80. In all these, autologous serum elicited large vesicular responses. There is a factor(s) in serum in DH which can initiate the formation of lesions. This factor appears to be activated by clotting and can be inhibited by heparin and EACA, suggesting it may be a protease.

Epidermolysis bullosa atrophicans generalisata mitis--report of a case with renal dysfunction

A male adult epidermolysis bullosa atrophicans generalisata mitis (EBAGM) patient with renal dysfunction is described. The abnormal urological findings were improved together and healing of the generalized skin erosions occurred. To our best knowledge, he is the 3rd EBAGM patient with urological abnormalities in the world.