Disease Endotypes Predict the Severity of Mucous Membrane Pemphigoid.

Mucous membrane pemphigoid is an autoimmune disease with variable clinical presentation and multiple autoantigens. To determine whether disease endotypes could be identified on the basis of the pattern of serum reactivity, the clinical and diagnostic information of 70 patients with mucous membrane pemphigoid was collected, and reactivity to dermal or epidermal antigens, using indirect immunofluorescence, and specific reactivity to bullous pemphigoid (BP) autoantigens BP180 and BP230, collagen VII, and laminin 332 were evaluated. Most patients had lesions at multiple mucosae, with the most prevalent being oropharyngeal (mouth, gingiva, pharynx; 98.6%), followed by ocular (38.6%), nasal (32.9%), genital or anal (31.4%), laryngeal (20%), and esophageal (2.9%) sites and skin (45.7%). Autoantigen profiling identified BP180 (71%) as the most common autoantigen, followed by laminin 332 (21.7%), collagen VII (13%), and BP230 IgG (11.6%). Reactivity to dermal antigens predicted a more severe disease characterized by a higher number of total sites involved, especially high-risk sites, and a decreased response to rituximab. In most cases, identification of dermal indirect immunofluorescence reactivity is an accurate predictor of disease course; however, confirmation of laminin 332 reactivity is important, with dermal indirect immunofluorescence positivity because of an increased risk of solid tumors. In addition, the ocular mucosae should be monitored in patients with IgA on direct immunofluorescence.

Eosinophil localization to the basement membrane zone is autoantibody- and complement-dependent in a human cryosection model of bullous pemphigoid.

Bullous pemphigoid (BP) is an autoimmune blistering disease characterized by antibodies (IgG and IgE) targeting cell-substrate adhesion proteins. A variety of BP models suggest that autoantibody-dependent neutrophil degranulation is essential for blister formation. However, lesional biopsies reveal a predominance of eosinophils and few neutrophils. Our goal was to evaluate the role of antibodies and complement in eosinophil localization, degranulation and split formation at the dermo-epidermal junction (DEJ) utilizing a human skin cryosection model of BP paired with a human eosinophilic cell line, 15HL-60. Expression of receptors for IgG (FcγRII), IgE (FcεRI) and complement (CR1 and CR3) was confirmed on 15HL-60 cells using flow cytometry. 15HL-60 expression of granule protein [eosinophil derived neurotoxin (EDN) and eosinophil peroxidase (EPO)] mRNA and their degranulation in vitro was confirmed using RT-PCR and ELISA, respectively. For cryosection experiments, BP or control sera or IgG and IgE antibodies purified from BP sera were utilized in combination with 15HL-60 cells ± fresh complement. Both BP serum and fresh complement were required for localization of 15-HL60 cells to the DEJ. Interestingly, eosinophil localization to the DEJ was dependent on IgG, but not IgE, and complement. However, no subepidermal split was observed. Additionally, the 15HL-60 cells did not degranulate under any experimental conditions and direct application of cell lysate to cryosections did not result in a split. Our observation that eosinophil localization to the DEJ is dependent on IgG mediated complement fixation provides additional insight into the sequence of events during the development of BP lesions.

Human eosinophils express the high affinity IgE receptor, FcεRI, in bullous pemphigoid.

Bullous pemphigoid (BP) is an autoimmune blistering disease mediated by autoantibodies targeting BP180 (type XVII collagen). Patient sera and tissues typically have IgG and IgE autoantibodies and elevated eosinophil numbers. Although the pathogenicity of the IgE autoantibodies is established in BP, their contribution to the disease process is not well understood. Our aims were two-fold: 1) To establish the clinical relationships between total and BP180-specific IgE, eosinophilia and other markers of disease activity; and 2) To determine if eosinophils from BP patients express the high affinity IgE receptor, FcεRI, as a potential mechanism of action for IgE in BP. Our analysis of 48 untreated BP patients revealed a correlation between BP180 IgG and both BP180 IgE and peripheral eosinophil count. Additionally, we established a correlation between total IgE concentration and both BP180 IgE levels and eosinophil count. When only sera from patients (n = 16) with total IgE ≥ 400 IU/ml were analyzed, BP180 IgG levels correlated with disease severity, BP230 IgG, total circulating IgE and BP180 IgE. Finally, peripheral eosinophil count correlated more strongly with levels of BP180 IgE then with BP180 IgG. Next, eosinophil FcεRI expression was investigated in the blood and skin using several methods. Peripheral eosinophils from BP patients expressed mRNA for all three chains (α, ß and γ) of the FcεRI. Surface expression of the FcεRIα was confirmed on both peripheral and tissue eosinophils from most BP patients by immunostaining. Furthermore, using a proximity ligation assay, interaction of the α- and ß-chains of the FcεRI was observed in some biopsy specimens, suggesting tissue expression of the trimeric receptor form in some patients. These studies provide clinical support for the relevance of IgE in BP disease and provide one mechanism of action of these antibodies, via binding to the FcεRI on eosinophils.

Erythema migrans: a spectrum of histopathologic changes.

Early cutaneous Lyme disease, erythema migrans, manifests as a gyrate erythema at the site of a tick bite. The standard histopathologic description is that of a superficial and deep perivascular lymphocytic infiltrate in which plasma cells are identified at the periphery of the lesion and eosinophils in the center. Deviation from these commonly accepted histopathologic findings may lead to an erroneous diagnosis. Herein, we describe 4 cases of erythema migrans, all biopsied at the periphery of the lesion and confirmed by serologic studies, demonstrating a variety of unconventional histopathologic patterns. These findings include eosinophils and neutrophils at the periphery of the expanding annular plaque of erythema migrans, focal interface change, spongiosis, involvement of the superficial vascular plexus alone, and an absence of plasma cells in all cases. These cases highlight the varied and nonspecific histopathologic changes that can be seen in erythema migrans, including the absence of plasma cells and the presence of focal interface change. Based on these findings, the dermatopathologist should always consider erythema migrans as a diagnostic possibility in a biopsy specimen from an expanding gyrate or annular erythema despite the presence of unusual features. In atypical clinical cases, serologic confirmation may be required for diagnosis in the presence of histopathologic findings considered unconventional for erythema migrans.

IgG anti-laminin-332 autoantibodies are present in a subset of patients with mucous membrane, but not bullous, pemphigoid.

BACKGROUND: Antiepiligrin cicatricial pemphigoid is a mucosal-predominant subepidermal blistering disease associated with an increased relative risk of cancer. In contrast to prior reports showing that anti-laminin (L)-332 autoantibodies are a reliable marker for patients with antiepiligrin cicatricial pemphigoid, a recent report suggested that as many as 40% of patients with bullous pemphigoid (BP) have IgG reactive with this laminin isoform. OBJECTIVE: We sought to determine whether patients with BP possess circulating IgG anti-L-332 autoantibodies. METHODS: Sera from 100 adults with BP were analyzed by indirect immunofluorescence testing of intact skin, immunoblot studies of human keratinocyte (HK) extracts, and a new L-332 enzyme-linked immunosorbent assay. Sera showing reactivity suggestive of anti-L-332 autoantibodies in these assays were further analyzed in immunoblot studies of HK extracellular matrix and immunoprecipitation studies of biosynthetically radiolabeled HK extracts. RESULTS: IgG from all patients with BP bound intact epidermal basement membrane by indirect immunofluorescence microscopy and immunoblotted bullous pemphigoid antigen-1, -2, or both in HK extracts. None of these sera immunoblotted L-332 in HK extracts, although 13 did score above the cut point of a new IgG(4) L-332 enzyme-linked immunosorbent assay (sensitivity = 0.91, specificity = 0.98, Youden index = 0.89). Further analysis of sera from these 13 patients found: (1) all had IgG that bound the epidermal side of 1 mol/L NaCl split skin by indirect immunofluorescence microscopy; (2) none immunoblotted L-332 purified from HK extracellular matrix; and (3) none immunoprecipitated L-332 from biosynthetically radiolabeled HK extracts. LIMITATIONS: The basis of false-positive enzyme-linked immunosorbent assay determinations for anti-L-332 IgG among patients with BP is unknown. CONCLUSION: Anti-L-332 autoantibodies remain a reliable marker for patients with antiepiligrin cicatricial pemphigoid.

Voriconazole-induced blistering in the setting of graft versus host disease: A report of 2 patients.

Voriconazole is a newer triazole antifungal agent with a wide spectrum of activity against yeast, fungi and molds including many Candida, Aspergillus, and Fusarium species. Its use continues to increase, particularly in immunocompromised patients, owing to its broad coverage, availability in both intravenous and oral preparations, and safety profile. The detection of adverse events in these patients may be complicated by their preexisting comorbidities and polypharmacy. We describe 2 patients with hematologic malignancies status post allogeneic bone marrow transplantation who developed blistering eruptions on the extremities related to voriconazole use. A history of graft versus host disease in each patient confounded and delayed the diagnosis. It is imperative to recognize voriconazole-induced blistering as a separate and distinct entity in such patients with a history of graft versus host disease, since delayed withdrawal of voriconazole use could result in unnecessary and potentially dangerous increases in immunosuppressive therapy.

Pemphigus vulgaris presenting in a radiation portal.

We report a case of mucocutaneous pemphigus vulgaris in a patient with squamous cell carcinoma of the lung. The cutaneous involvement was limited to the skin within his therapeutic radiation portal. The diagnosis of pemphigus vulgaris was confirmed by histopathology and immunologic studies. Direct immunofluorescence demonstrated IgG and C3 in the intercellular spaces and indirect immunofluorescence was positive on monkey esophagus at a titer of 1:160. Enzyme-linked immunosorbent assay of the patient's serum detected autoantibodies only to desmoglein (Dsg)3, with no reactivity to Dsg1. Immunomapping of perilesional skin from the irradiated field illustrated decreased Dsg1 expression compared with a control sample from an area that was not exposed to radiation. This case provides support for the Dsg compensation hypothesis and may also suggest a mechanism by which irradiation may induce skin lesions.

Macrophages, but not T and B lymphocytes, are critical for subepidermal blister formation in experimental bullous pemphigoid: macrophage-mediated neutrophil infiltration depends on mast cell activation.

Bullous pemphigoid (BP) is a subepidermal blistering disease associated with autoantibodies against two hemidesmosomal proteins, BP180 and BP230. Numerous inflammatory cells infiltrate the upper dermis in BP. We have previously shown by passive transfer studies that Abs to the ectodomain of murine BP180 are capable of triggering blisters in mice that closely mimic human BP. Experimental BP depends on complement activation and neutrophil infiltration. In the present study, we investigated the relative contribution of neutrophils, mast cells (MCs), macrophages (Mphi), and lymphocytes and their functional relationship in the immunopathogenesis of this disease model by using mice deficient in these cells. Wild-type, T cell-deficient, and T and B cell-deficient mice injected intradermally with pathogenic anti-murine BP180 IgG exhibited extensive subepidermal blisters. In contrast, mice deficient in neutrophils, MCs, and Mphi were resistant to experimental BP. MCs play a major role in neutrophil recruitment into the dermis. Furthermore, Mphi-mediated neutrophil infiltration depends on MC activation/degranulation.

The epidermolysis bullosa acquisita antigen (type VII collagen) is present in human colon and patients with crohn's disease have autoantibodies to type VII collagen.

Epidermolysis bullosa acquisita is an autoimmune blistering disease of the skin characterized by IgG autoantibodies against type VII collagen. Systemic diseases are often associated with epidermolysis bullosa acquisita, Crohn's disease being the most frequent. This study sought to determine if type VII collagen, the epidermolysis bullosa acquisita autoantigen, was present in normal human colon by western blotting and immunofluorescence. The 290 kDa type VII collagen alpha chain was demonstrated by western blotting in four normal intraoperative colon specimens. Antibodies to type VII collagen labeled the junction between the intestinal epithelium and the lamina propria. We also used an enzyme-linked immunosorbent assay to test sera from patients with Crohn's disease (n = 19), ulcerative colitis (n = 31), celiac disease (n = 17), rheumatoid arthritis (n = 15), and normal controls (n = 16). It was found that 13 of 19 patients with Crohn's disease and four of 31 patients with ulcerative colitis demonstrated reactivity to type VII collagen. Sera from control subjects, patients with celiac disease or rheumatoid arthritis were negative. The sera from Crohn's disease patients also reacted with type VII collagen by immunoblot analysis. It was concluded that patients with inflammatory bowel disease may have IgG autoantibodies to type VII collagen, which exists in both the skin and the gut.