Respective contribution of neutrophil elastase and matrix metalloproteinase 9 in the degradation of BP180 (type XVII collagen) in human bullous pemphigoid.

Bullous pemphigoid is a blistering disorder associated with autoantibodies directed against two components of hemidesmosomes, BP180 and BP230. Autoantibodies to the extracellular collagenous domain of BP180 are thought to play a key role in the pathogenesis of the disease. In a murine model of bullous pemphigoid, neutrophil elastase and 92 kDa gelatinase (matrix metalloproteinase 9) have been implicated in subepidermal blister formation via proteolytic degradation of BP180. In this study we sought to elucidate the contribution of these two enzymes to subepidermal blister formation by assessing the expression, localization, and activity of the two proteases in lesional skin, serum samples, and blister fluids obtained from 17 patients with bullous pemphigoid. The results indicate that (i) neutrophil elastase is found in skin biopsy specimens from bullous pemphigoid lesions and is recovered as active enzyme in blister fluids, and (ii) although proform of matrix metalloproteinase 9 is present in lesional skin, it is present only as proenzyme in blister fluids, which also contain high levels of tissue inhibitor of metalloproteinase-1. Next, the capacity of matrix metalloproteinase 9 and neutrophil elastase to degrade a recombinant protein corresponding to the extracellular collagenous domain of the BP180 was studied. Our data illustrate that (i) recombinant matrix metalloproteinase 9, neutrophil elastase, and blister fluid from bullous pemphigoid patients are all able to hydrolyze recombinant BP180; (ii) the pattern of recombinant BP180 proteolysis with blister fluid was similar to that obtained with neutrophil elastase; and (iii) recombinant BP180 degradation by blister fluid could be inhibited by chloromethylketone, a specific elastase inhibitor, but not by batimastat, a wide spectrum matrix metalloproteinase inhibitor. Our results confirm the importance of neutrophil elastase but not matrix metalloproteinase 9 in the direct cleavage of BP180 autoantigen and subepidermal blister formation in human bullous pemphigoid.

Value of standard laboratory tests for the early recognition of group A beta-hemolytic streptococcal necrotizing fasciitis.

The laboratory data for 17 patients with group A beta-hemolytic streptococcal necrotizing fasciitis (GAS NF) were compared with data for 145 patients hospitalized for cellulitis during the same period. Admission values of C-reactive protein and creatine kinase were higher for patients in the group with GAS NF than for patients in the group with cellulitis (P<.001), suggesting that standard laboratory tests may be useful for the early differential diagnosis of GAS NF and cellulitis.

[Linear radiodermatitis following total body electron beam therapy]. / Radiodermite linéaire de superposition, secondaire à une électronthérapie corporelle totale.

BACKGROUND: We describe herein a peculiar clinical presentation of a linear overlapping radiodermatitis, localized on the internal side of the limbs, following a total body electron beam therapy. CASE REPORT: A 68-year-old-man was treated in April 1998 by a total body electron beam therapy, for a stage I mycosis fungoides. Few days after the last irradiation, the patient suffered from a linear eruption localized on the internal side of the limbs and the external side of the abdominal wall. DISCUSSION: Total body electron beam therapy can be proposed in early stage mycosis fungoides with localized or generalized cutaneous lesions. Because penetration depth of electron is well controlled and is limited to the skin, usual side effects of total body electron beam therapy do not concern internal organs (bone marrow,.). We report here a peculiar clinical presentation of a linear radiodermatitis in frontal plane which has not been reported to date, to our knowledge. This radiodermatitis corresponds to overlapping of posterior and anterior fields of irradiation.

[Phototoxic contact phytodermatitis: clinical and biological aspects]. / Phytodermatite phototoxique de contact: aspects clinique et biologique.

We report the case of a 39-year-old patient, gardener, who develops, during a beautiful sunny summerday, an erythemato-bullous eruption of the forearms. The diagnosis is a Contact Phototoxic Phytodermatitis (dermite des prés, dermatitis bullosa striata) with a classical presentation. This clinical observation gives us the opportunity to remind of the clinical and biological aspects of this dermatosis, whose frequency is probably underestimated, related to an often rapidly favourable evolution.

Characterization of the nuclear deoxyribonucleic acid content and nuclear morphometry in 71 primary cutaneous melanomas.

BACKGROUND: While the determination of nuclear deoxyribonucleic acid (DNA) content (DNA ploidy level) and nuclear morphometry characterization has proved to be of prognostic value in melanocytic lesions, there are several ways of performing these determinations. OBJECTIVE: To identify which of 9 DNA ploidy- and 2 nuclear morphometry-related variables are of prognostic and/or diagnostic value in 71 primary melanomas. METHODS: Histological typing, Breslow depth determination, the evaluation of Clark's level of invasion and the 11 quantitative variables (calculated in Feulgen-stained nuclei using computer-assisted microscope analysis) determined for each melanoma were submitted to discriminant analysis. RESULTS: The discriminant analysis of image cytometric variables enabled specific cell subpopulations to be identified in histological and the Breslow-related groups, but not in the Clark-related ones. CONCLUSION: The characterization of melanoma heterogeneity by means of the identification of specific DNA ploidy level-related cell subpopulations in specific Breslow-related groups enables the problem of intra- and interobserver variability in Breslow depth determination to be reduced and therefore can help dermatologists in their daily routine.

[Alopecia areata: diagnostic and therapeutic approach]. / Alopecia Areata: approche diagnostique et thérapeutique.

Alopecia Areata is a frequent cause of alopecia. This benign pathology can be psychologically very disabling; it is very important to give these patients a good support. The exact aetiology is unknown; there are several hypotheses, but the most likely seems to be the autoimmune mechanism. The importance of the symptoms can vary from a very small bald area to a complete loss of hair and influences the psychological impact, the prognosis and the therapeutic strategy. Several kinds of treatments can be proposed; they should be used in accordance with the type and the extent of the lesion, with the side effects and with the possible associated risk factors. A psychological support can be necessary in the management of an Alopecia Areata.