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C Prost

Publications and source records attributed to C Prost.

At least 37 records · Page 2Linked to original sources
PubMed1999

Immunoelectron microscopic study of the conjunctiva in cicatricial pemphigoid.

BACKGROUND: Immune deposits can be found on the conjunctival basement membrane zone of patients affected by cicatricial pemphigoid using immunofluorescence technique. The purpose of this study was to perform direct immunoelectron microscopy on the conjunctiva of patients with scarring conjunctivitis associated with cicatricial pemphigoid. METHODS: Conjunctival and skin biopsies were performed in six patients who presented with presumed autoimmune cicatrizing conjunctivitis associated with cicatricial pemphigoid. Specimens were processed for direct immunofluorescence and direct immunoelectron microscopy. RESULTS: Direct immunofluorescence was positive in all skin samples and in three of six conjunctival samples. Direct immunoelectron microscopy showed immune deposits in the lamina lucida and the lamina densa of all skin and conjunctival samples. CONCLUSIONS: Direct immunoelectron microscopy can be performed on the conjunctiva. It shows the precise localization of cicatricial pemphigoid target antigens within the conjunctival basement membrane zone.

Aged↗
PubMed1999

Pure ocular cicatricial pemphigoid. A distinct immunopathologic subset of cicatricial pemphigoid.

OBJECTIVE: To determine whether ocular cicatricial pemphigoid (OCP) may represent a distinct immunopathologic disease when it is pure ocular cicatricial pemphigoid (POCP) (e.g., only confined to the conjunctiva) or when it is associated with skin or extraocular mucous membrane lesions or both (OCP+). DESIGN: Prospective, immunologic, and immunopathologic study with special emphasis on direct immunoelectron microscopy. PARTICIPANTS: Six patients with POCP and seven patients with OCP+. INTERVENTION: After informed consent was obtained, a conjunctival biopsy was performed in all patients. Skin and extraocular mucosa biopsy specimens were harvested in selected cases only. MAIN OUTCOME MEASURES: Results of direct immunofluorescence and direct immunoelectron microscopy without freezing on conjunctival and skin biopsy specimens, indirect immunofluorescence, and Western immunoblotting analysis were analyzed. RESULTS: Results of direct immunoelectron microscopic examination of the conjunctiva showed the presence of immune deposits in the upper lamina lucida of the basement membrane zone in the six patients with POCP, whereas the immune reactants were located in the lower part of the lamina lucida and in the lamina densa of the basement membrane zone (conjunctiva, buccal mucosa, and skin) in the seven patients with OCP+. Direct immunofluorescence was positive in the biopsy specimens of three patients with POCP (50%) and the seven patients with OCP+ (100%). Results of indirect immunofluorescence study showed circulating autoantibody levels only in two patients with OCP+, and results of Western immunoblot analysis were negative. CONCLUSIONS: Results of direct immunoelectron microscopic examination of the conjunctiva support the hypothesis that POCP may be a disease entity distinct from mucocutaneous cicatricial pemphigoid.

Aged↗
PubMed1999

Autoantibodies in lichen planus pemphigoides react with a novel epitope within the C-terminal NC16A domain of BP180.

Lichen planus pemphigoides is an autoimmune subepidermal blistering disease. The finding of immunoglobulin G antibodies directed against the basement membrane zone differentiates it from bullous lichen planus. The aim of this study was to identify the target antigen of lichen planus pemphigoides autoantibodies. Sera from lichen planus pemphigoides patients (n = 4) stained the epidermal side of NaCl-split human skin in a pattern indistinguishable from that produced by bullous pemphigoid sera. In bullous pemphigoid, the autoimmune response is directed against BP180, a hemidesmosomal transmembrane collagenous glycoprotein. We previously demonstrated that bullous pemphigoid sera predominantly react with a set of four epitopes (MCW-0 through MCW-3) clustered within a 45 amino acid stretch of the major noncollagenous extracellular domain (NC16A) of BP180. By immunoblotting and enzyme-linked immunosorbent assay, lichen planus pemphigoides sera were also strongly reactive with recombinant bullous pemphigoid 180 NC16A. The lichen planus pemphigoides epitopes were further mapped using a series of overlapping recombinant segments of the NC16A domain. All lichen planus pemphigoides sera reacted with amino acids 46-59 of domain NC16A, a protein segment that was previously shown to be unreactive with bullous pemphigoid sera. Two lichen planus pemphigoides sera, in addition, reacted with the immunodominant antigenic region associated with bullous pemphigoid. In conclusion, there are now five bullous diseases that are associated with an autoimmune response to BP180: bullous pemphigoid; pemphigoid/herpes gestationis; cicatricial pemphigoid; linear immunoglobulin A disease; and lichen planus pemphigoides. In addition, we have identified a novel epitope within the BP180 NC16A domain, designated MCW-4, that appears to be uniquely recognized by sera from patients with lichen planus pemphigoides.

Adult↗
PubMed1999

Subepidermal autoimmune bullous skin diseases associated with B-cell lymphoproliferative disorders.

The development of several types of autoimmune disorders is well known in the course of B-cell lymphoproliferative diseases. In order to investigate whether these autoimmune diseases may target cutaneous antigens, especially those of the dermal-epidermal junction, we conducted a retrospective analysis of all cutaneous direct immunofluorescence studies performed in patients with B-cell neoplasia who presented with cutaneous lesions requiring a skin biopsy. Patients with linear deposits of immunoglobulin or C3 molecules at the dermal-epidermal junction were studied further, using immunoblotting and immunoelectron microscopy. Patients with no overt hematologic malignancies but with cutaneous lesions requiring direct immunofluorescence were studied as a control population. During the study period, the diagnosis of autoimmune blistering diseases of the dermal-epidermal junction was established in 9/102 (8.9% +/- 2%) patients with a B-cell lymphoid disorder, compared with 288/8,189 (3.5% +/- 0.04%) patients without underlying hemopathy (p < 0.01). Among the 9 patients, 7 were studied in detail. Immunologic studies demonstrated epidermolysis bullosa acquisita in 6 patients and cicatricial pemphigoid in 1. Autoimmune blistering diseases, especially epidermolysis bullosa acquisita, are part of the spectrum of autoimmune disorders associated with B-cell neoplasia.

Aged↗
PubMed1998

Transforming growth factor beta1, in the presence of granulocyte/macrophage colony-stimulating factor and interleukin 4, induces differentiation of human peripheral blood monocytes into dendritic Langerhans cells.

Langerhans cells (LCs) are dendritic cells (DCs) that are present in the epidermis, bronchi, and mucosae. Although LCs originate in bone marrow, little is known about their lineage of origin. In this study, we demonstrate that in vitro LCs may originate from monocytes. Adult peripheral blood CD14+ monocytes differentiate into LCs (CD1a+, E-cadherin+, cutaneous lymphocyte-associated antigen+, Birbeck granules+, Lag+) in the presence of granulocyte/macrophage colony-stimulating factor, interleukin 4, and transforming growth factor beta1 (TGF-beta1). This process occurs with virtually no cell proliferation and is not impaired by 30 Gy irradiation. Selection of monocyte subpopulations is ruled out since monocyte-derived DCs can further differentiate into LCs. Our data suggest that in vivo LC differentiation may be induced peripherally, from a nonproliferating myeloid precursor, i.e., the monocyte, in response to a TGF-beta1-rich microenvironment, as found in the skin and epithelia. Therefore, the monocyte may represent a circulating precursor critical to the immune response in vivo.

Cell Differentiation↗
PubMed1998

Evaluation of clinical criteria for diagnosis of bullous pemphigoid. French Bullous Study Group.

OBJECTIVE: To check the potential usefulness of clinical criteria for the diagnosis of bullous pemphigoid when state-of-the-art techniques such as Western immunoblotting, immunoprecipitation, and indirect immunofluorescence on salt-split skin or direct immunoelectron microscopy are not available. DESIGN: Comparison of the clinical criteria between 2 groups (with and without bullous pemphigoid) as defined by immunoelectron microscopy used as standard criterion, in a prospective study. Multivariate logistic regression analysis was carried out by including all items that were statistically significant (at P < .05 level) in univariate analysis. SETTING: Five dermatology departments in teaching hospitals. PATIENTS: The 231 patients studied had subepidermal autoimmune bullous diseases with linear IgG or C3 deposits in the basement membrane zone (157 with bullous pemphigoid, 33 with cicatricial pemphigoid, 30 with epidermolysis bullous acquisita, 5 with lupus erythematosus, and 6 others). A second set of patients was used to calculate predictive values. RESULTS: The multivariate logistic stepwise analysis resulted in a final set of predictors that included only 4 items: absence of atrophic scars, absence of head and neck involvement, absence of mucosal involvement, and age greater than 70 years. No additional variables met the .05 significance level to enter into the model. If 3 of these 4 characteristics were present, a diagnosis of bullous pemphigoid could be made with a sensitivity of 90% and a specificity of 83%; these predictive values were calculated on a sample of 70 new cases. CONCLUSIONS: With and estimated incidence of bullous pemphigoid among subepidermal autoimmune bullous diseases of 80%, the presence of 3 of the 4 significant criteria allows the diagnosis of bullous pemphigoid, with a positive predictive value of 95%. Our set of clinical criteria thus allows the diagnosis of bullous pemphigoid with good validity for both clinical practice and therapeutic trials.

Aged↗
PubMed1998

Acquired junctional epidermolysis bullosa associated with IgG autoantibodies to the beta subunit of laminin-5.

We report the case of a 72-year-old man with clinical features resembling those of non-lethal junctional epidermolysis bullosa associated with IgG autoantibodies to the beta chain of laminin-5. The patient presented with a sudden onset of blistering and severe fragility of the skin and mucous membranes resulting in atrophic scars. Electron microscopy showed that the blistering arose in the lamina lucida. Indirect immunofluorescence indicated that the autoantibodies bound to the dermal side of 1 mol/L NaCl-split skin, and both direct and indirect immunoelectron microscopy demonstrated antibody binding to the lamina densa. Postembedding immunogold electron microscopy also revealed labelling in the lamina lucida beneath the hemidesmosomes. On immunoblotting, we found the autoantibodies to comigrate with the beta chain of laminin-5. Following the nomenclature of inherited junctional epidermolysis bullosa with mutations of the laminin-5 gene, we propose the name acquired junctional epidermolysis bullosa for this newly recognized disease.

Aged↗
PubMed1998

Lichen planus pemphigoides is a heterogeneous disease: a report of five cases studied by immunoelectron microscopy.

Lichen planus pemphigoides (LPP) is a rare and controversial disease. It is characterized by bullae arising on lichen planus papules and on uninvolved skin, subepidermal bullae in histology, and linear deposits of IgG and C3 along the basal membrane zone on immunofluorescence of peribullous skin. Our goal was to identify the localization of the target antigen in cases of LPP. Five patients diagnosed with LPP on clinical, histological and immunofluorescence criteria were explored by immunoelectron microscopy and immunoblot. Our results show that the target antigen in LPP is not unique. The localization of the immune deposits was consistent with a diagnosis of bullous pemphigoid in two cases, of cicatricial pemphigoid in two cases and of epidermolysis bullosa acquisita in one case. Our study supports the view that LPP is a heterogeneous condition in which lichen planus may induce different subepidermal acquired bullous dermatoses.

Adolescent↗
PubMed1998

Deletions within COL7A1 exons distant from consensus splice sites alter splicing and produce shortened polypeptides in dominant dystrophic epidermolysis bullosa.

We describe two familial cases of dominant dystrophic epidermolysis bullosa (DDEB) that are heterozygous for deletions in COL7A1 that alter splicing, despite intact consensus splice-site sequences. One patient shows a 28-bp genomic deletion (6081del28) in exon 73 associated with the activation of a cryptic donor splice site within this exon; the combination of both defects restores the phase and replaces the last 11 Gly-X-Y repeats of exon 73 by a noncollagenous sequence, Glu-Ser-Leu. The second patient demonstrates a 27-bp deletion in exon 87 (6847del27), causing in-frame skipping of this exon; consensus splice sites, putative branch sites, and introns flanking exons 73 and 87 showed a normal sequence. Keratinocytes from the probands synthesized normal and shortened type VII collagen polypeptides and showed intracellular accumulation of type VII procollagen molecules. This first report of genomic deletions in COL7A1 in DDEB suggests a role for exonic sequences in the control of splicing of COL7A1 pre-mRNA and provides evidence that shortened type VII collagen polypeptides can alter, in a dominant manner, anchoring-fibril formation and can cause DDEB of differing severity.

Adult↗
PubMed1998

Immunohistopathologic testing in patients suspected of ocular cicatricial pemphigoid.

PURPOSE: Optimizing the sensitivity of immunopathologic methods in detecting target antigens in immune-mediated cicatrizing conjunctivitis. METHODS: Immunofluorescence was performed on normal and salt-split conjunctival biopsies in fifteen patients with clinical evidence of ocular cicatricial pemphigoid, and results were compared with immunoperoxidase, a technique thought to be more sensitive although more expensive and more difficult technically to perform. RESULTS: Ten of fifteen biopsies (67%) were positive when conventional and salt-split immunofluorescence results were combined. Four of eight patients with positive conventional immunofluorescence showed more marked immunofluorescence with the salt-split method. All patients were positive with immunoperoxidase (100%). CONCLUSION: Immunoperoxidase was more sensitive than conventional or salt-split immunofluorescence in detecting immunoreactant deposition along the basement membrane of the conjunctiva. Salt-split immunofluorescence demonstrated more intense staining of conjunctival samples when compared with conventional immunofluorescence, without however increasing the yield of positive biopsies. Finding solutions for the proper handling of conjunctival tissue in salt may improve the diagnostic yield of salt-split immunofluorescence.

Aged↗
PubMed1998

[Pretibial epidermolysis bullosa. A rare form of epidermolysis bullosa simplex].

INTRODUCTION: Pretibial epidermolysis bullosa had been classified as a rare localized form of autosomal dominant dystrophic epidermolysis bullosa. OBSERVATION: We report a sporadic case of a patient suffering from bullous lesions induced by minor trauma on pretibial skin. The lesions healed with atrophic scars. No milia formation was observed. The mapping of dermoepidermal junction by LH 7:2 and GB3 monoclonal antibodies was normal. By electron microscopy, numerous perinuclear vacuoles were observed and the cleavage occurred within the basal keratinocytes. DISCUSSION: This patient had clinical features in accordance with a diagnosis of pretibial epidermolysis bullosa. However, in contrast to previous case reports, the ultrastructural pattern was this of an epidermolysis bullosa of simplex type.

Adult↗
PubMed1997

Epidermolysis bullosa acquisita diagnosed by direct immunoelectron microscopy of the conjunctiva.

OBJECTIVE: To describe for the first time the direct immunoelectron microscopic pattern of immune deposits on the conjunctival basement membrane in epidermolysis bullosa acquisita (EBA). DESIGN: Case reports. PARTICIPANTS: Two patients. INTERVENTION: Epidermolysis bullosa acquisita associated with cicatrizing conjunctivitis. MAIN OUTCOME MEASURES: Direct immunofluorescence and direct immunoelectron microscopy without freezing on conjunctival and skin biopsy specimens, indirect immunofluorescence, Western immunoblot analysis. RESULTS: Results of direct immunoelectron microscopic examination of the conjunctiva showed the presence of immune deposits in the anchoring fibril zone, just beneath the lamina densa, in both patients. This finding was the same as the direct immunoelectron microscopic pattern shown in the skin of these patients, which is known to be very specific for EBA. Direct immunofluorescence was positive in the conjunctiva of only one patient. Indirect immunofluorescence and Western immunoblot analysis failed to detect circulating autoantibodies. CONCLUSIONS: Direct immunoelectron microscopy on the conjunctiva is a useful diagnostic tool to differentiate EBA from other related autoimmune mucocutaneous blistering diseases.

Adult↗
PubMed1997

An extract from cultured human keratinocytes that contains the major autoantigens related to autoimmune bullous skin diseases.

Autoantibodies characteristic of autoimmune bullous skin diseases (AIBDs) can be detected by immunoblotting on epidermal, dermal, or bovine muzzle extracts. However, none of those substrates contain all the autoantigens involved in AIBDs, and the diagnosis requires the use of various substrates. Human keratinocytes were cultured under such conditions that they expressed the major autoantigens associated with AIBDs. Forty-two sera with antiepidermal antibodies were immunoblotted on the keratinocyte extract. Bands corresponding to desmoglein III, desmoglein I, BPAg2, BPAg1, and type VII collagen were found in 38 sera. Desmoplakins I and II were revealed by specific monoclonal antibodies. A review of the patients' charts showed a perfect correlation between the blots and the diagnoses of pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, cicatricial pemphigoid, and epidermolysis bullosa acquisita. Four sera revealing no band typical of AIBD were from patients with no autoimmune skin disease. Therefore, a single extract of keratinocytes can be used for the differential diagnosis of AIBDs.

Animals↗
PubMed1997

IgA-epidermolysis bullosa acquisita in a child resulting in blindness.

Epidermolysis bullosa acquisita (EBA) is an acquired subepidermal bullous disease characterized by IgG autoantibodies directed against type VII collagen, the major component of anchoring fibrils. The classical phenotype of EBA is a non-inflammatory, mechanobullous disease resembling the dystrophic forms of inherited epidermolysis bullosa. Mucous membrane involvement is frequent but usually mild. We report a 1-year-old girl suffering from IgA-EBA, who presented with an initial eruption of disseminated urticarial lesions and tense blisters of the skin but subsequently developed severe oral and ocular lesions reminiscent of cicatricial pemphigoid. Direct immunofluorescence of the skin and buccal mucosa revealed linear IgA and C3 at the basement membrane zone (BMZ). IgA anti-BMZ autoantibodies stained the dermal side of salt-split skin by indirect immunofluorescence and recognized a dermal protein of 290 kDa co-migrating with type VII collagen by immunoblotting. Direct and indirect immunoelectron microscopy revealed IgA deposits overlying the anchoring fibrils. The ocular involvement led to total blindness in spite of intense treatment. This case of childhood IgA-EBA is particularly striking because of the cicatricial pemphigoid phenotype with severe ocular involvement which resulted in blindness. It reinforces the necessity to use modern immunological methods to classify autoimmune bullous diseases in order to allow early and appropriate treatment.

Autoantibodies↗
PubMed1997

Characterization of 18 new mutations in COL7A1 in recessive dystrophic epidermolysis bullosa provides evidence for distinct molecular mechanisms underlying defective anchoring fibril formation.

We have characterized 21 mutations in the type VII collagen gene (COL7A1) encoding the anchoring fibrils, 18 of which were not previously reported, in patients from 15 unrelated families with recessive dystrophic epidermolysis bullosa (RDEB). COL7A1 mutations in both alleles were identified by screening the 118 exons of COL7A1 and flanking intron regions. Fourteen mutations created premature termination codons (PTCs) and consisted of nonsense mutations, small insertions, deletions, and splice-site mutations. A further seven mutations predicted glycine or arginine substitutions in the collagenous domain of the molecule. Two mutations were found in more than one family reported in this study, and six of the seven missense mutations showed clustering within exons 72-74 next to the hinge region of the protein. Patients who were homozygous or compound heterozygotes for mutations leading to PTCs displayed both absence or drastic reduction of COL7A1 transcripts and undetectable type VII collagen protein in skin. In contrast, missense mutations were associated with clearly detectable COL7A1 transcripts and with normal or reduced expression of type VII collagen protein at the dermo/epidermal junction. Our results provide evidence for at least two distinct molecular mechanisms underlying defective anchoring fibril formation in RDEB: one involving PTCs leading to mRNA instability and absence of protein synthesis, the other implicating missense mutations resulting in the synthesis of type VII collagen polypeptide with decreased stability and/or altered function. Genotype-phenotype correlations suggested that the nature and location of these mutations are important determinants of the disease phenotype and showed evidence for interfamilial phenotypic variability.

Alleles↗