Explanations for the clinical and microscopic localization of lesions in pemphigus foliaceus and vulgaris.
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Patients with pemphigus foliaceus (PF) have blisters on skin, but not mucous membranes, whereas patients with pemphigus vulgaris (PV) develop blisters on mucous membranes and/or skin. PF and PV blisters are due to loss of keratinocyte cell-cell adhesion in the superficial and deep epidermis, respectively. PF autoantibodies are directed against desmoglein (Dsg) 1; PV autoantibodies bind Dsg3 or both Dsg3 and Dsg1. In this study, we test the hypothesis that coexpression of Dsg1 and Dsg3 in keratinocytes protects against pathology due to antibody-induced dysfunction of either one alone. Using passive transfer of pemphigus IgG to normal and DSG3(null) neonatal mice, we show that in the areas of epidermis and mucous membrane that coexpress Dsg1 and Dsg3, antibodies against either desmoglein alone do not cause spontaneous blisters, but antibodies against both do. In areas (such as superficial epidermis of normal mice) where Dsg1 without Dsg3 is expressed, anti-Dsg1 antibodies alone can cause blisters. Thus, the anti-desmoglein antibody profiles in pemphigus sera and the normal tissue distributions of Dsg1 and Dsg3 determine the sites of blister formation. These studies suggest that pemphigus autoantibodies inhibit the adhesive function of desmoglein proteins, and demonstrate that either Dsg1 or Dsg3 alone is sufficient to maintain keratinocyte adhesion. (+info)
Feasibility and safety of a new technique of extracorporeal photochemotherapy: experience of 240 procedures.
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BACKGROUND AND OBJECTIVE: Extracorporeal photochemotherapy (ECP) is a therapeutic approach based on the biological effects of ultraviolet light (UV) - A and psoralens on mononuclear cells collected by apheresis. Recently, ECP has been under investigation as an alternative treatment for various immune and autoimmune diseases. The aim of this study was to evaluate the safety and feasibility of a new three-step ECP technique, in terms of reproducibility, acceptance, tolerability, and short and long term side effects. DESIGN AND METHODS: Seventeen patients affected by acute or chronic graft-versus-host disease (GvHD), pemphigus vulgaris, or interferon-resistant chronic hepatitis C and one patient being treated for prevention of heart transplant rejection underwent 240 ECP procedures. MNC collection and processing parameters were recorded, biological effects of UV-A/8 methoxy-psoralen (8-MOP) were evaluated, and short and long term side effects were monitored. RESULTS: At a mean follow up of 7 months (range 2-19) 240 ECP had been completed, a mean of 7,136 mL (range 1,998-10,591) of whole blood having beenprocessed per procedure. The mean of total nucleated cells collected per procedure was 6.5x109 (range 0.65-23.8), with a mean MNC percentage of 85% (41. 4-98%) in a mean final volume of 115.5 mL (37-160). No severe side effects were documented and no infectious episodes occurred throughout the course of the treatment. INTERPRETATION AND CONCLUSIONS: The new ECP technique was highly reproducible as regards the collection and each processing step. Short and long term side effects were mild. No increase in infectious episodes was recorded. All patients willingly underwent ECP, demonstrating an excellent tolerability for the procedure even after several courses. (+info)
The anti-desmoglein 1 autoantibodies in pemphigus vulgaris sera are pathogenic.
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Pemphigus vulgaris and pemphigus foliaceus are two closely related, but clinically and histologically distinct, autoimmune skin diseases. The autoantigens for pemphigus vulgaris and pemphigus foliaceus are desmoglein 3 and desmoglein 1, respectively. The anti-desmoglein 1 antibodies in pemphigus foliaceus and anti-desmoglein 3 antibodies in pemphigus vulgaris are pathogenic as determined by immunoglobulin G passive transfer animal models. More than 50% of pemphigus vulgaris sera also contain anti-desmoglein 1 autoantibodies; however, the pathogenicity of the anti-desmoglein 1 autoantibodies in pemphigus vulgaris remains unknown. In this study, we used soluble recombinant extracellular domains of desmoglein 1 and desmoglein 3 to obtain affinity-purified anti-desmoglein 1 and anti-desmoglein 3 autoantibodies from pemphigus vulgaris sera and examined the pathogenicity of each fraction separately using the passive transfer mouse model. By immunoprecipitation, the purified anti-desmoglein 1 and anti-desmoglein 3 showed no cross-reactivity. The anti-desmoglein 1 autoantibodies in pemphigus vulgaris induced typical pemphigus foliaceus lesions in neonatal mice, whereas the anti-desmoglein 3 fraction induced pemphigus vulgaris-like lesions. In addition, the pathogenic anti-desmoglein 1 and anti-desmoglein 3 autoantibodies in pemphigus vulgaris had predominant IgG4 subclass specificity. These findings suggest that the anti-desmoglein 1 antibodies in pemphigus vulgaris are pathogenic. (+info)
Envoplakin and periplakin are the paraneoplastic pemphigus antigens.
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Paraneoplastic pemphigus (PNP) sera have been reported to immunoprecipitate multiple proteins, including the 250 kDa and 210 kDa proteins believed to correspond to desmoplakins I/II, BP230, and two unidentified proteins of 190 kDa and 170 kDa. We have recently provided evidence that the presence of the 210 kDa and 190 kDa proteins is the most prominent feature of PNP, and have suggested that the major 210 kDa antigen may not correspond to desmoplakin II. Using immunoprecipitation and immunoblotting, we found that some PNP sera identified a doublet protein migrating at 210 kDa, with the larger protein corresponding to desmoplakin II, and the smaller protein corresponding to envoplakin, a recently described precursor of the keratinocyte cornified envelope. In contrast to desmoplakin II, envoplakin was detected by all PNP sera analyzed. Using immunoblotting and immunoprecipitation, we further showed that the 190 kDa PNP antigen is identical to periplakin, another recently identified envelope precursor that can form complexes with envoplakin. Like desmoplakin and BP230, envoplakin and periplakin belong to the plakin family of proteins. (+info)
Constrictive bronchiolitis obliterans and paraneoplastic pemphigus.
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Constrictive bronchiolitis obliterans is rare, and the pathogenesis of the disease often remains unknown. This study reports on the case of a 38 yr-old female with constrictive bronchiolitis obliterans and paraneoplastic pemphigus associated with malignant lymphoma. The patient developed progressive obstructive lung disease. The chest radiograph showed almost normal lungs. Paraneoplastic pemphigus is a newly described syndrome in which patients have autoantibodies binding to some epithelia, including in the respiratory tract. The disease develops in association with non-Hodgkin's lymphomas or other malignant neoplasms. The case presented here suggests that constrictive bronchiolitis obliterans associated with paraneoplastic pemphigus may be one of the facets of autoimmune responses in this context. (+info)
Pemphigus vulgaris and pemphigus foliaceus antibodies are pathogenic in plasminogen activator knockout mice.
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Previous studies have suggested that urokinase plasminogen activator is required for blister formation in pemphigus vulgaris and pemphigus foliaceus. Other studies, however, have shown that downregulation of plasminogen activator does not inhibit blisters induced by pemphigus immunoglobulin G. To eliminate the possibility that small amounts of urokinase plasminogen activator might be sufficient for blister formation, we passively transferred pemphigus immunoglobulin G to urokinase plasminogen activator knockout neonatal mice. Pemphigus foliaceus and pemphigus vulgaris immunoglobulin G caused gross blisters and acantholysis in the superficial and suprabasal epidermis, respectively, to the same degree in knockout and control mice, demonstrating that urokinase plasminogen activator is not absolutely required for antibody-induced blisters. Some studies have shown elevated tissue-type plasminogen activator in pemphigus lesions. Tissue-type plasminogen activator, however, is not necessary for blister formation, because pemphigus foliaceus and pemphigus vulgaris immunoglobulin G caused blisters to the same degree in tissue-type plasminogen activator knockout and control mice. To rule out that one plasminogen activator might compensate for the other in the knockout mice, we bred urokinase plasminogen activator, tissue-type plasminogen activator double knockouts. After passive transfer of pemphigus foliaceus and pemphigus vulgaris immunoglobulin G these mice blistered to the same degree as the single knockout and control mice, and histology indicated blisters at the expected level of the epidermis. These data definitively demonstrate that plasminogen activator is not necessary for pemphigus immunoglobulin G to induce acantholysis in the neonatal mouse model of pemphigus. (+info)
Common human leukocyte antigen alleles in pemphigus vulgaris and pemphigus foliaceus Italian patients.
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Pemphigus refers to a group of autoimmune blistering skin diseases, mainly identified as pemphigus vulgaris and pemphigus foliaceus, both characterized by the presence of autoantibodies against keratinocyte adhesion molecules, leading to loss of cell-cell adhesion with consequent blister formation. Pemphigus vulgaris is reported to be associated with human leukocyte antigen DR4 and/or DR6 whereas no data are available on pemphigus foliaceus, except for the endemic Brazilian form (fogo selvagem), which is reported to be associated with DR1 and DR4. We here report human leukocyte antigen molecular typing on a total of 87 patients, 61 with pemphigus vulgaris and 26 with pemphigus foliaceus, versus 128 healthy matched controls. Generic typing showed an increase of DRB1*04 and DRB1*14 and a decrease of DRB1*07 in both pemphigus vulgaris and pemphigus foliaceus patients. Molecular subtyping of DR4+ and DR14+ subjects showed a highly significant association between the DRB1*1401 and both pemphigus vulgaris (p < 0.0001) and pemphigus foliaceus patients (p < 0.0001) together with a significant increase of the linked DQB1*0503 (pemphigus vulgaris p < 0.0001; pemphigus foliaceus p < 0.0001). Moreover, whereas the association between DRB1*0402 and pemphigus vulgaris (p < 0.0001) has been confirmed, no significant association between a specific allele of the DR4 group and pemphigus foliaceus, has been found. Therefore, at least in Italian patients, pemphigus vulgaris and pemphigus foliaceus share DRB1*1401 and DQB1*0503, as susceptible human leukocyte antigen alleles, whereas DRB1*0402 is only found associated with pemphigus vulgaris. The observation that both diseases, pemphigus vulgaris and pemphigus foliaceus, carry the same susceptible human leukocyte antigen alleles has been interpreted as a common genetic background predisposing to pemphigus as, like in other autoimmune disorders, it is not sufficient to explain the onset of the disease on the basis of the sole aforementioned alleles. Other linked genes and/or environmental factors should play a facilitating role in the outbreak of pemphigus, either pemphigus vulgaris or pemphigus foliaceus. (+info)
The role of antibody to human beta4 integrin in conjunctival basement membrane separation: possible in vitro model for ocular cicatricial pemphigoid.
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PURPOSE: To demonstrate the specific binding of autoantibodies present in the sera of patients with ocular cicatricial pemphigoid (OCP) to human beta4 integrin present in the normal human conjunctiva (NHC) and to study the role of OCP autoantibodies and antibody to human beta4 integrin in the pathogenesis of subepithelial lesion formation in OCP. METHODS: Indirect immunofluorescence assay and in vitro organ culture method using NHC were used. Sera and IgG fractions from 10 patients with OCP; immunoaffinity-purified OCP autoantibody; antibodies to human beta4, beta1, alpha6, and alpha5 integrins; and sera from patients with pemphigus vulgaris, bullous pemphigoid (BP), and chronic atopic and chronic ocular rosacea cicatrizing conjunctivitis; and normal human serum (NHS) were used. RESULTS: Nine of 10 OCP sera or IgG fractions, immunoaffinity-purified OCP autoantibody, antibodies to human beta4 and alpha6 integrins, and sera from patients with BP showed homogenous, smooth linear binding along the basement membrane zone (BMZ) of the NHC. NHS, antibodies to other integrins, and sera from patients with chronic cicatrizing conjunctivitis from other causes showed no such binding. When NHC was first absorbed with OCP sera and then reacted with anti-beta4 antibodies or vice versa, the intensity of the BMZ binding was dramatically reduced or completely eliminated, indicating that there were autoantibodies in OCP sera specific for the beta4 integrin. BMZ separation developed 48 to 72 hours after addition of total OCP sera, IgG fractions from OCP sera, immunoaffinity-purified autoantibodies from sera of patients with OCP, or anti-beta4 antibodies to the NHC cultures, but not after addition of normal control sera, sera from patients with chronic cicatrizing conjunctivitis from causes other than OCP, or sera from patients with OCP in clinical remission. CONCLUSION: Circulating anti-beta4 integrin antibody may have an important role in the pathogenesis of OCP. (+info)