Search

Background: Bullous pemphigoid (BP) is a severe autoimmune sub-epidermal bullous disease. Exosomes are small extracellular vesicles secreted by most cell types. The exosomal membrane proteins are implicated in various biological and pathological pathways. This study aims to explore the potential roles of exosomes in BP pathomechanism., Research Design: We collected plasma samples from 30 BP patients and 31 healthy controls. Nanoparticle tracking analysis (NTA) was used to analyze the size and concentration of exosomes. The immunogold labelling experiment and extracellular vesicle (EV) array were performed to detect the content and distribution of exosomes., Results: The exosomes from both the BP and control groups' plasma were successfully extracted. EV Array showed that CD63 and CD9 levels were significantly higher in the BP group than in the control group ( p  < 0.05). Expression levels of the BP180 NC16A and intracellular domain (ICD) were higher in the anti-BP180 positive group versus the controls ( p  < 0.05). The active BP group exhibits higher CD63 and BP180 ICD protein concentrations than the control or inactive BP groups ( p  < 0.05)., Conclusion: BP180 autoantigen fragments were expressed on the exosomal membrane in BP patients. The BP180 ICD and CD63 on exosomes could potentially be novel biomarkers for monitoring disease activity.

Importance: The correlation between serum levels of autoantibodies against bullous pemphigoid (BP) antigens 180 (BP180) and 230 (BP230) with BP disease severity is unclear., Objective: To investigate the correlation of anti-BP180 and anti-BP230 immunoglobulin G (IgG) antibody levels with BP disease severity., Data Sources: A search was performed of the Cochrane Central Register of Controlled Trials, Embase, and PubMed databases from their respective inception to April 11, 2024., Study Selection: Studies evaluating the correlation between serum levels of anti-BP180 or anti-BP230 IgG measured using enzyme-linked immunosorbent assay (ELISA) and disease severity assessed per the Autoimmune Bullous Skin Disorder Intensity Score (ABSIS) or BP Disease Area Index (BPDAI) were included. No language or geographic restrictions were imposed. Nearly 0.4% of initially identified studies met the selection criteria., Data Extraction and Synthesis: One researcher extracted data and another researcher confirmed data. The risk of bias was independently assessed by these researchers using the Quality Assessment of Diagnostic Accuracy Studies 2 tool, with discrepancies resolved by discussion with a third researcher. A random-effects model meta-analysis and a subgroup analysis were conducted based on the ELISA kit manufacturers., Main Outcomes and Measures: Pooled correlation coefficients of antibody levels with ABSIS and BPDAI., Results: In all, 14 studies with 1226 participants were analyzed. The risk of bias of included studies was generally low. The meta-analysis found anti-BP180 autoantibody levels showed moderate correlation with objective BPDAI (r = 0.56; 95% CI, 0.46-0.64) at baseline, strong correlation (r = 0.63; 95% CI, 0.39-0.79) at 3-month follow-up, and moderate correlation (r = 0.53; 95% CI, 0.25-0.72) at 6-month follow-up. Anti-BP180 autoantibody levels also showed moderate correlation (r = 0.52; 95% CI, 0.39-0.62) with ABSIS at baseline, strong correlation (r = 0.62; 95% CI, 0.39-0.79) at 3-month follow-up, and moderate correlation (r = 0.53; 95% CI, 0.25-0.72) at 6-month follow-up. By contrast, anti-BP230 autoantibody levels showed no association with objective BPDAI and ABSIS at diagnosis and follow-up. The subgroup analysis found similar results when using different ELISA kits., Conclusions and Relevance: The findings of this systematic review and meta-analysis indicated that anti-BP180 autoantibody levels may serve as an adjunctive tool for monitoring BP disease severity and guiding clinical care for patients with BP.

Background: Bullous pemphigoid (BP), the most common subepidermal autoimmune blistering disease, is classically defined by the presence of IgG autoantibodies directed against the hemidesmosomal proteins BP180 (type XVII collagen) and BP230 and the predominance of skin lesions. Several studies have addressed the role of anti-BP180 IgE in patients and experimental models, while data on anti-BP230 IgE are scarce., Objective: To assess anti-BP230 IgE level by ELISA in BP sera and to correlate it with disease severity and clinical characteristics., Methods: BP sera underwent anti-BP230 IgE ELISA and Western blotting against human BP230 fragments., Results: We demonstrate that 36/154 (23%) of BP sera were positive for anti-BP230 IgE. Anti-BP230 IgE levels had no correlation with clinical phenotype or disease activity per se. Interestingly, anti-BP230 IgE was significantly associated with disease activity within individuals during the course of the disease. Additionally, anti-BP230 IgE and total IgE levels showed a significant correlation. Notably, anti-BP230 IgG correlated interindividually with disease activity. By Western blotting, the C-terminal domain of BP230 fragments (C2; amino acids 2024-2349 and C3; amino acids 2326-2649), provided the best serological assay for anti-BP230 IgE detection., Conclusion: As a complementary tool, IgE immunoblotting is recommended to obtain an optimal serological diagnosis, particularly in patients with severe disease without IgG reactivity by BP180- or BP230-specific ELISA. Although the detection of serum anti-BP230 IgE is not of major diagnostic significance, it may be relevant for therapeutic decisions, e.g., for anti-IgE-directed treatment, which has been successfully used in case series of BP., Competing Interests: Declaration of Competing Interest ES has research grants from Euroimmun. ES holds patents with Euroimmun. ES and NvB have a joint research project and a patent pending with Euroimmun. The other authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Importance: Mucous membrane pemphigoid (MMP) is a rare, heterogeneous subepithelial autoimmune bullous disease. The association between its clinical and immunological features is yet to be fully evaluated., Objectives: To characterize the clinical, immunoserological, and immunopathological characteristics of patients with MMP and to identify site- and autoantigen-specific characteristics., Design, Setting, and Participants: A retrospective cohort study encompassing all consecutive patients diagnosed with MMP from January 2007 through February 2020 in 2 tertiary referral centers in Germany., Main Outcomes and Measures: The clinical, immunoserological, and immunopathological features of eligible patients were evaluated. Associations of different anatomical sites and autoantigens were assessed using a multivariable logistic regression model., Results: The study encompassed 154 patients (96 [62.3%] women and 58 [37.7%] men; mean [SD] age at diagnosis, 66.2 [13.8] years) with MMP, of whom 125 (81.2%), 61 (39.6%), 34 (22.1%), and 16 (10.4%) presented with lesions involving the oral, ocular, nasal, and genital mucosae, respectively, and 35 (22.7%) presented with cutaneous involvement. Among the 154 patients, the most frequently targeted antigen was BP180 (90 patients [58.4%]), followed by laminin 332 (13 patients [8.4%]) and BP230 (3 patients [1.9%]). Ocular disease was inversely associated with oral (adjusted odds ratio [aOR], 0.02; 95% CI, 0.01-0.13) and nasal (aOR, 0.20; 95% CI, 0.04-0.91) involvement and was associated with a 13-fold increased risk of malignant neoplasm (aOR, 13.07; 95% CI, 1.56-109.36). Anti-laminin 332 reactivity was associated with malignant neoplasm (aOR, 23.27; 95% CI, 1.83-296.68), whereas anti-BP180 NC16A immunoglobulin G seropositivity was associated with absence of ocular lesions (aOR, 0.09; 95% CI, 0.01-0.99)., Conclusions and Relevance: In this cohort study of patients with MMP, malignant neoplasms were associated with ocular disease and anti-laminin 332 reactivity, suggesting potential benefit of malignant neoplasm screening in these patients.

Dermatitis herpetiformis (DH) is an extraintestinal manifestation of coeliac disease (CD). Patients with DH have an elevated risk of development of another autoimmune blistering skin disease, bullous pemphigoid (BP). In this study we investigated whether patients with DH and CD (mean age for both 49 years) have circulating autoantibodies against BP180, the major BP autoantigen. ELISA tests showed that only a few DH (3/46) and CD (2/43) patients had BP180-NC16A IgG autoantibodies. Immunoblotting found that more than half of the DH samples contained IgG autoantibodies against full-length BP180. Epitope mapping with 13 fusion proteins covering the BP180 polypeptide revealed that in DH and CD patients, IgG autoantibodies did not target the NC16A or other epitopes typical of BP but recognized other intracellular and mid-extracellular regions of BP180. None of the analyzed DH and CD patients with either ELISA or immunoblotting positivity had IgG or IgA reactivity against the cutaneous basement membrane in indirect immunofluorescence analysis or skin symptoms characteristic of BP. Although only a minority of middle-aged DH patients had IgG autoantibodies against the immunodominant epitopes of BP180, our results do not exclude the possibility that intermolecular epitope spreading could explain the switch from DH to BP in elderly patients., (Copyright © 2020 Nätynki, Tuusa, Hervonen, Kaukinen, Lindgren, Huilaja, Kokkonen, Salmi and Tasanen.)

Background: Bullous pemphigoid (BP) autoantibody levels are generally elevated in patients with BP but can be present nonspecifically in patients without BP., Objective: To analyze the clinical findings of patients with elevated BP180 or BP230 autoantibody levels and negative direct immunofluorescence (DIF) study findings., Methods: We retrospectively reviewed records of patients seen at our institution during January 1, 2005-December 31, 2015, who were positive for BP180 or BP230 autoantibodies and had a negative DIF study finding. These patients' demographic characteristics and BP180 and BP230 levels were compared with those of a BP control group who were positive for BP180 or BP230 autoantibodies and had positive DIF study findings., Results: We identified 208 patients with BP autoantibodies but without positive DIF study findings. These patients' mean age and enzyme-linked immunosorbent assay values were significantly lower than those of the control group. Dermatitis was the most common final clinical diagnosis. Of the 208 patients, 41 (19.7%) had at least 2 years' follow-up. Four patients had positive DIF results upon repeating the test and ultimately received pemphigoid diagnoses., Limitations: Retrospective design with limited follow-up., Conclusion: Patients might harbor serum BP autoantibodies in the context of a wide range of dermatoses. Low positive BP180 and BP230 autoantibody levels should not be overinterpreted as evidence for BP in the setting of a negative DIF., (Copyright © 2019 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Background: Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering skin disease. Two antigens have been identified as targets of circulating autoantibodies (autoAbs) - BP180 and BP230 - with BP180 being a critical transmembrane adhesion protein of basal keratinocytes of the epidermis. The noncollagenous domain 16A (NC16A) of BP180 is the immunodominant epitope in patients with BP, and anti-BP180-NC16A IgG antibodies (Abs) correlate to disease activity. Routine serological testing and follow-up of BP relies on indirect immunofluorescence (IIF) of serum Abs, commonly performed on monkey oesophagus (ME), and/or enzyme-linked immunosorbent assay (ELISA) testing on recombinantly produced fragments of BP180 and BP230 (BP180-NC16A, BP230-C/N)., Objectives: To determine if NC16A epitopes are well represented on ME substrate., Methods: Sera from different BP cohorts were tested by IIF on ME and normal human skin (NHS). To confirm findings, affinity-purified anti-BP180-NC16A/BP230 polyclonal Abs and recombinant anti-BP180-NC16A/BP230 monoclonal antibodies (mAbs) were used., Results: For sensitive detection of BP180-NC16A-specific IgG Abs, sections of NHS are superior to the widely used ME. Confirmation comes from polyclonal affinity-purified anti-BP180-NC16A/BP230 Abs, and by mAbs cloned from a patient with active BP., Conclusions: Use of NHS is preferable over ME in routine IIF testing for BP. These results are of clinical relevance because anti-BP180-NC16A IgG titres are correlated to disease activity and detecting them reliably is important for screening, diagnosis and follow-up of patients with BP., (© 2018 British Association of Dermatologists.)

Anti-p200 pemphigoid is a rare autoimmune blistering disease. It belongs to the group of pemphigoid diseases and was first described in 1996. The diagnostic gold standard is the combination of (1) linear deposits of immunoreactants at the dermal epidermal junction by direct immunofluorescence microscopy of a perilesional skin biopsy, (2) detection of circulating autoantibodies binding to the dermal side (blister floor) of human salt split skin by indirect immunofluorescence microscopy, and reactivity with a 200 kDa protein (p200) in extract of human dermis by immunoblotting. In 2009, laminin γ1 was described as an additional target antigen in 90% of anti-p200 pemphigoid patients. Since ex vivo and in vivo studies have shown no direct pathogenic relevance for laminin γ1 antibodies and the preadsorption of patient sera against laminin γ1 does not reduce their reactivity with p200, the molecular identity of p200 still remains to be elucidated. The clinical phenotype of the disease is heterogeneous; in most cases, however, it resembles bullous pemphigoid. Anti-p200 patients are younger and skin lesions more often appear on palms of the hands and soles of the feet than in bullous pemphigoid. Therapy consists of topical and systemic corticosteroids. In addition, the use of daspone and immunosuppressants has been reported.

Bullous pemphigoid (BP) following dementia diagnosis has been reported in the elderly. Skin and brain tissues express BP180 and BP230 isoforms. Dementia has been associated with rs6265 (Val66Met) polymorphism of the brain-derived neurotrophic factor (BDNF) gene and low serum BDNF. Here we investigated a possible cross-antigenicity between BP180/BP230 brain and skin isoforms. We assessed antibodies against BP180/BP230 and BDNF levels by ELISA and BDNF Val66Met SNP by PCR in three groups: 50 BP patients, 50 patients with dementia, and 50 elderly controls. Heatmap hierarchical clustering and data mining decision tree were used to analyze the patients' demographic and laboratorial data as predictors of dementia-BP association. Sixteen percent of BP patients with the lowest serological BDNF presented dementia-BP clinical association. Anti-BP180/230 positivity was unexpected observed among dementia patients (10%, 10%) and controls (14%, 1%). Indirect immunofluorescence using healthy human skin showed a BP pattern in two of 10 samples containing antibodies against BP180/BP230 obtained from dementia group but not in the control samples. Neither allelic nor genotypic BDNF Val66Met SNP was associated with dementia or with BP (associated or not with clinical manifestation of dementia). Heatmap analysis was able to differentiate the three studied groups and confirmed the ELISA results. The comprehensive data mining analysis revealed that BP patients and dementia patients shared biological predictors that justified the dementia-BP association. Autoantibodies against the BP180/BP230 brain isoforms produced by dementia patients could cross-react with the BP180/BP230 skin isoforms, which could justify cases of dementia preceding the BP disease.

Importance: Enzyme-linked immunosorbent assay (ELISA) and/or chemiluminescent enzyme immunoassay (CLEIA) for BP180 noncollagenous 16A (NC16A) extracellular domain is a sensitive diagnostic tool for bullous pemphigoid (BP). However, some patients with BP have negative results for these assays., Objective: To elucidate the clinical and immunological features of patients with BP without antibodies that react to BP180 NC16A., Design, Setting, and Participants: This retrospective case series study included 152 patients who were diagnosed with BP and followed up at the Kurume University Hospital in Japan from 2007 to 2016. The diagnosis was made using clinical, histological, and immunological findings., Main Outcomes and Measures: Clinical and immunological features of patients with BP who had negative results for BP180 NC16A using ELISA and/or CLEIA., Results: Of the 152 patients, 69 (45.4%) were men and 83 (54.6%) were women. The mean (SD) age of participants was 75.2 (14.4) years. Of the 152 patients with BP, 14 (9.2%) had negative results for BP180 NC16A on ELISA and/or CLEIA; most of these patients exhibited no erythema and had relatively mild phenotypes. Two (14%) of the 14 patients had positive results for intact BP180 in epidermal extracts, 10 (71%) had positive results for a 120-kD fragment of BP180 (LAD-1) and 3 (21%) had positive results for BP180 C-terminal domain. Seven (50%) patients tested positive in BP230 ELISA. Five (36%) patients did not require oral prednisolone treatment, whereas the others required a dose of prednisolone at less than 30 mg per day. Three (21%) patients were administered a dipeptidyl peptidase-4 inhibitor (DPP4i) before disease onset. This ratio was not significantly higher than that in patients with BP who tested positive for BP180 NC16A ELISA and/or CLEIA (19 [14%] of 138 patients). Our follow-up study (mean [SD], 31.9 [33.2] weeks; range, 0-108 weeks) revealed that patients with BP tested negative for BP180 NC16A ELISA and/or CLEIA during the later stages of the disease., Conclusions and Relevance: This study indicates that patients with BP negative for BP180 NC16A ELISA and/or CLEIA had milder phenotypes, fewer erythemas, and required less extensive treatments.

Background: Bullous pemphigoid (BP) is the most common autoimmune blistering disease of the skin requiring skin and serum tests for a precise diagnosis., Objectives: We analysed the sensitivity and specificity of BP-relevant parameters and the value of autoantibody titres during follow-up of BP patients., Materials & Methods: In a retrospective single-centre study, we included 200 consecutive patients with BP and 400 non-BP patients, and evaluated the test results of patients' serum and skin. In addition, we followed patients' autoantibody titres and clinical characteristics., Results: BP180-ELISA revealed the highest sensitivity (85.0%; specificity: 93.9%), while BP230-ELISA demonstrated the lowest sensitivity (55.5%; specificity: 92.9%). Direct and indirect immunofluorescence showed comparable results for sensitivity (77.2%/72.7%) and specificity (94.9%/93.7%). The sensitivity for skin histology was 76.3% (specificity: 81.3%). Longitudinal analysis showed significant changes in autoantibody titres., Conclusions: BP diagnostics should include serum tests for BP autoantibodies and skin immunofluorescence. Skin histology is supportive for diagnosis. Autoantibody titres are markers for disease activity.

Linear IgG deposits along the basement membrane of adnexa has been proposed to be useful in the diagnosis of bullous pemphigoid (BP), but no controlled studies have been performed. This study evaluated linear IgG fluorescence of the basement membrane of sweat gland ducts (SGD) and other adnexa in perilesional biopsies from patients with BP (n = 64) and controls (n = 82), using direct immunofluorescence microscopy. Fluorescence intensity was graded semi-quantitatively. Positive SGDs were found in 58 (90.6%) patients with BP and 44 (53.7%) controls, a statistically significant difference (p < 0.0001). The sensitivity of positive SGDs for BP was high (90.6%), but the specificity was low (46.3%). Only strong fluorescence intensity was associated with high specificity. In conclusion, positive SGDs in direct immunofluorescence microscopy are highly sensitive for BP; however, only strong fluorescence has acceptable specificity. Weak positivity of SGDs without linear fluorescence of the epidermal basement membrane may not be sufficiently specific for BP.

Importance: Bullous pemphigoid (BP) is by far the most frequent autoimmune blistering disease. The presence of IgE autoantibodies against the transmembrane protein BP antigen 2 (BP180, type XVII collagen) has previously been reported in 22% to 100% of BP serum samples, and the pathogenic relevance of anti-BP180 IgE has been suggested in various experimental models and by the successful use of omalizumab in individual patients with BP., Objectives: To determine the rate of anti-BP180-reactive IgE in BP, to evaluate the diagnostic relevance of anti-BP180 IgE in BP, and to correlate anti-BP180 IgE with disease activity and the clinical phenotype of patients with BP., Design, Setting, and Participants: This case-control cohort study examined 3 groups of patients with BP. Sixty-five patients with BP underwent an enzyme-linked immunosorbent assay for IgE antibodies against the 16th noncollagenous domain of BP180 (NC16A); 52 consecutive patients with BP underwent clinical evaluation with the Bullous Pemphigoid Disease Activity Index (BPDAI); and 36 patients with BP without anti-BP180 NC16A IgG reactivity underwent evaluation of the diagnostic importance of serum anti-BP180 IgE. In addition, 49 age-matched control individuals with noninflammatory dermatoses, 127 controls undergoing allergy testing for IgE levels, and 30 controls with pemphigus vulgaris or pemphigus foliaceus were included for comparison. Patients were seen at a university clinic from January 1, 2008, to July 31, 2014., Main Outcomes and Measures: Serum anti-BP180 NC16A IgE and IgG levels and BPDAI scores., Results: Of 117 patients with BP (69 women and 48 men), anti-BP180 NC16A serum IgE was detected in 47 (40.2%) and correlated with disease activity as measured by total BPDAI (r = 0.918; P = .06). An intraindividual correlation of anti-BP180 NC16A serum levels with the total BPDAI was observed during the course of the disease in 10 randomly selected patients with BP (r = 0.983; P = .003). Although no association of circulating BP180 NC16A IgE antibodies with urticarial or erythematous lesions was observed (r = 0.481; P = .31), the presence of IgG anti-BP180 NC16A antibodies was associated with the occurrence of erosions and blisters (r = 0.985; P = .006) but not urticarial and erythematous lesions (r = 0.632; P = .23). Assaying for anti-BP180 IgE increased the diagnostic sensitivity by only 2.2% (1 of 46 serum samples) when combined with the IgG anti-BP180 enzyme-linked immunosorbent assay., Conclusions and Relevance: Although detection of serum anti-BP180 IgE is not of diagnostic importance, it may be relevant for therapeutic decisions (eg, the use of anti-IgE treatment). The correlation of serum anti-BP180 NC16A IgE levels with disease activity in patients with BP supports the notion that anti-BP180 IgE is of pathogenic relevance. Our observation that IgG anti-BP180 antibodies are related to the occurrence of blisters and erosions may encourage further studies on the association of fine autoantibody reactivities with clinical features of BP.

Anti-p200 pemphigoid is a rare autoimmune subepidermal blistering disease characterized by the presence of circulating immunoglobulin G antibodies directed against laminin gamma-1, a 200-kDa protein located in the lamina lucida of the basement membrane. We review the clinical, histopathological and immunological characteristics of the first 2 cases described in Spain. Anti-p200 pemphigoid shares histopathological and immunopathological findings with epidermolysis bullosa acquisita, the main entity in the differential diagnosis. However, its management follows the same guidelines as those used for bullous pemphigoid. The diagnosis is confirmed by immunoblotting, which is a complex technique available in few centers. We propose the immunohistochemical detection of collagen type IV on the floor of the blister, combined with standard immunofluorescence techniques, as a simple, accessible alternative to differentiate anti-p200 pemphigoid from epidermolysis bullosa acquisita., (Copyright © 2016 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.)

Topical steroids are effective in treating bullous pemphigoid (BP). Autoantibodies against BP180 are related to disease activity, but correlation of these autoantibodies with response to topical steroid therapy has not yet been clearly evaluated. We investigate the usefulness of close and early monitoring of autoantibodies against BP180 and BP230 for assessment of response to therapy and early detection of therapeutic failure in BP patients treated topically. In eight BP patients under treatment with topical or systemic steroid therapy we retrospectively evaluated clinical course and autoantibodies against BP180 and BP230 as well as indirect immunofluorescence titres (IIF). Data were included at diagnosis, during hospitalization and follow-ups. Autoantibodies against BP180 parallel disease activity in all topically and as well as systemically treated patients. Autoantibodies against BP230 correlated in five out of eight patients. Autoantibodies directed against BP180 and, to a lesser degree, against BP230 correlate with the clinical course of topically treated BP patients. Monitoring autoantibodies against BP180 is a useful tool to evaluate the efficacy of topical therapy in BP., (© 2016 Wiley Periodicals, Inc.)

Importance: Anti-p200 pemphigoid is a rare subepidermal autoimmune blistering disease characterized by autoantibodies against a 200-kDa protein in the basement membrane zone. Anti-p200 pemphigoid is probably often misdiagnosed because of low availability of diagnostic assays and expertise and classified as bullous pemphigoid or epidermolysis bullosa acquisita., Objective: To clinically characterize patients with anti-p200 pemphigoid, identified by using indirect immunofluorescence microscopy on skin substrates deficient in type VII collagen and laminin-332 (knockout analysis), to validate this technique by immunoblot with dermal extract, and to incorporate direct immunofluorescence serration pattern analysis in the diagnostic algorithm., Design, Setting, and Participants: This was a retrospective study performed from January 2014 to June 2015 with biobank patient materials and clinical data for the period 1998 to 2015 from the single national referral center on autoimmune bullous diseases. Patients were selected based on a dermal side binding on 1-mol/L salt (sodium chloride)-split human skin substrate by indirect immunofluorescence microscopy, not diagnosed epidermolysis bullosa acquisita or anti-laminin-332 mucous membrane pemphigoid., Main Outcomes and Measures: Indirect immunofluorescence microscopy knockout analysis was performed and diagnosis of anti-p200 confirmed by immunoblot with dermal extract. Clinical, histological, and immunological findings were registered. Autoantibodies against laminin γ1 were determined by immunoblot., Results: Twelve patients with anti-p200 pemphigoid (7 male and 5 female; mean age, 66.6 years) were identified using the indirect immunofluorescence microscopy knockout analysis. Direct immunofluorescence microscopy showed a linear n-serrated IgG deposition pattern along the basement membrane zone in 9 of 11 patients. The diagnosis was confirmed by immunoblot showing autoantibodies against 200-kDa protein in dermal extract in 12 of 12 patients. Autoantibodies against recombinant laminin γ1 were detected by immunoblot in 8 of 12 patients. Remarkable similarities were seen in clinical features with predominantly tense blisters on hands and feet, resembling dyshidrosiform pemphigoid. Mucosal involvement was seen in 6 (50%) of the patients., Conclusions and Relevance: Predominance of blisters on hands and feet may be a clinical clue to the diagnosis of anti-p200 pemphigoid. Direct immunofluorescence microscopy serration pattern analysis and indirect immunofluorescence microscopy knockout analysis are valuable additional techniques to facilitate the diagnosis of anti-p200 pemphigoid.

Bullous pemphigoid (BP) is a common autoimmune blistering disorder of the elderly. Several diagnostic modalities are available, including clinical impression, histopathology, direct and indirect immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) detection of pathogenic antibodies. In this study, we aim to examine the utility of the newest test, ELISA, in comparison to the constellation of other tests. We describe our clinical experience in which 170 patients diagnosed with bullous pemphigoid had multiple tests performed. BP180 alone showed a sensitivity of 54 % and specificity of 94 %. The positive predictive value (PPV) is 95 % while the negative predictive value (NPV) is 52 %. BP230 alone yielded a sensitivity of 48 % and specificity of 94 %. The PPV is 94 % and the NPV is 49 %. Using both tests in combination yielded a sensitivity of 66 % and specificity of 89 %. The PPV of at least one of two tests returning positive is 92 % while the NPV of dual negative tests is 58 %. Use of ELISAs for suspected cases of BP are an inadequate standalone test, and are only helpful in making the diagnosis should they return positive. However, they would appear to miss about one-third of cases.

A 61-year-old Japanese man developed bullous skin lesions during topical therapy for psoriasis vulgaris. Physical examination demonstrated numerous tense bullae and scaly erythemas on the trunk and extremities. Histopathology of the skin biopsy demonstrated subepidermal bullae and lymphocytic infiltration with eosinophils in the dermis. Direct immunofluorescence revealed linear deposits of immunoglobulin (Ig)G, IgA and C3 along the basement membrane zone. Indirect immunofluorescence of 1 mol/L NaCl-split skin showed IgG reactivity with both epidermal and the dermal sides. IgM reactivity with both the epidermal and dermal sides was also detected. Enzyme-linked immunosorbent assays showed negative results for both BP180 and BP230. Immunoelectrophoresis of serum and bone marrow aspiration revealed underlying primary macroglobulinemia with M-proteinemia of IgM-κ type. Immunoblot analysis revealed IgG, but not IgM, antibodies to recombinant protein of BP180 C-terminal domain. We diagnosed the present case as bullous pemphigoid with IgG anti-BP180 C-terminal domain autoantibodies associated with primary macroglobulinemia and psoriasis vulgaris. Systemic administration of prednisolone 30 mg/day resulted in dramatic improvement of both bullous and psoriatic skin lesions. When the bullous and psoriatic lesions relapsed, DRC chemotherapy (dexamethasone, rituximab and cyclophosphamide) for macroglobulinemia was performed. Then, the psoriatic lesions improved and the bullous lesions disappeared. We suggested that the present case may be paraneoplastic syndrome of bullous pemphigoid associated with primary macroglobulinemia and psoriasis vulgaris., (© 2015 Japanese Dermatological Association.)

Bullous pemphigoid (BP) is characterized by IgG and IgE autoantibodies to the NC16a domain of BP180. This study evaluated the correlation between body surface area (BSA), total serum IgE and enzyme-linked immunoassay (ELISA) for IgG and IgE anti-NC16a in 77 patients with BP in the active stage, and the degree of conversion to negative of the studied parameters in clinical remission. Statistically positive correlations were observed between BSA and examined parameters (correlation index 0.2548, 0.2491, 0.311, respectively). Originally, patients with BP with positive ELISAs for both IgG and IgE autoantibodies presented twice as extensive skin lesions as those with positive IgG and negative IgE ELISAs. Conversion of ELISAs for IgG and IgE to negative in clinical remission occurred in 9.3% and 81% of patients with BP, respectively. This confirmed that ELISA for IgE anti-NC16a is a helpful parameter in the modification of current treatment and the assessment of risk of relapse in BP.

Autoimmune bullous diseases (AIBDs) are characterized by autoantibodies against structural proteins of the dermal-epidermal junction (in pemphigoid diseases) and the epidermal/ epithelial desmosomes (in pemphigus diseases). By far, the most common AIBD is bullous pemphigoid, which is immunopathologically characterized by autoantibodies against BP180 (type XVII collagen) and BP230. IgG and, to a lesser extent, IgA autoantibodies are the major autoantibody isotypes in these disorders. IgE autoantibodies are increasingly reported in particular in bullous pemphigoid. The development of specific and sensitive anti-BP180 IgE ELISA systems, the report of two experimental murine models employing IgE autoantibodies against BP180, and the successful treatment of bullous pemphigoid with the anti-IgE antibody omalizumab have raised interest in the role of IgE autoantibodies and the modulation of their production in AIBDs. Here, the relevance of IgE autoantibodies in the diagnosis, pathophysiology, and treatment decisions of AIBDs, with a focus on bullous pemphigoid, is reviewed.

Background: Bullous pemphigoid (BP) is a subepidermal blistering disease, characterized by autoantibodies directed against BP180 and BP230. Collecting saliva is an easy and painless way of obtaining biological samples, and can be used for diagnosis of autoimmune diseases., Aim: To compare the diagnostic accuracy of serum and salivary BP180-NC16a and BP230-C3 in the initial diagnosis of BP., Methods: We assessed 50 patients newly diagnosed with BP and 50 healthy controls. The diagnosis of BP was confirmed based on clinical, histopathological and immunofluorescence findings. Serum and saliva samples were collected from both groups, and BP180 and BP230 titres were assessed using commercially available ELISA kits., Results: Using serum, the sensitivity of the serum BP180 and BP230 ELISA assays was 88% and 48%, respectively, and the specificity of both was 96%. Using saliva with the cutoff value proposed by the manufacturer, sensitivity was 56.2% and 14.6%, and specificity was 98% and 100%, respectively. Using the best calculated cutoff for saliva, sensitivity increased to 87.5% and 77.1%, and specificity to 96% and 62%, respectively. There was a significant correlation between serum and saliva BP180 levels and the severity of skin disease. Both serum and saliva BP230 levels were significantly higher in patients with mucosal involvement., Conclusion: Serum BP180 NC16a ELISA is a sensitive and specific test for the initial diagnosis of BP, whereas serum BP230-C3 ELISA is highly specific, but less sensitive. Saliva may be a noninvasive and convenient alternative for use in the BP180 NC16a ELISA to diagnose BP., (© 2014 British Association of Dermatologists.)

Introduction: Anti-BP180 IgG titres were observed to parallel disease activity in case series of bullous pemphigoid (BP). This study aimed to examine whether anti-BP180 titres are an indicator of disease severity, clinical course and outcome in Asian patients with BP., Materials and Methods: This was a prospective observational study conducted between March 2005 and March 2008 in the Immunodermatology Clinic at the National Skin Centre, Singapore. Disease activity and anti-BP180 IgG titres were measured 4-weekly for 12 weeks and during disease flares and clinical remission. Associations between anti-BP180 titres and disease activity, disease flare, clinical remission and cumulative prednisolone dose were examined., Results: Thirty-four patients with newly diagnosed BP were recruited. Median follow-up duration was 3 years. Notable correlations between disease activity and anti-BP180 titres were at baseline (r = 0.51, P = 0.002), and disease flare (r = 0.85, P <0.001). Lower titres at Week 12 were associated with greater likelihood of clinical remission (P = 0.036). Post hoc, patients with anti-BP180 titres above 87.5 U/mL at time of diagnosis who reached remission within 2 years of diagnosis received significantly higher cumulative doses (mg/kg) of prednisolone (median, 72.8; range, 56.5 to 127.1) than those with titres <87.5 U/mL (median, 44.6; range, 32.5 to 80.8); P = 0.025)., Conclusion: Anti-BP180 titres may be a useful indicator of disease activity at time of diagnosis and at disease flare. Lower titres at Week 12 may predict greater likelihood of clinical remission. Titres above 87.5 U/mL at time of diagnosis may suggest the need for higher cumulative doses of prednisolone to achieve remission within 2 years.

Bullous pemphigoid (BP) is a common autoimmune blistering skin disease in which two hemidesmosomal components--the transmembrane collagen XVII (BP180 or BPAG2) and the plakin family protein BP230 (BPAG1)--are targeted by autoimmunity. Of these, collagen XVII (COL17) is thought to be a major autoantigen, and vital roles of IgG autoantibodies in blister formation have been elucidated. However, BP shows distinct features, including pruritic urticarial erythema and eosinophilic infiltration, which may be independent of IgG-mediated autoimmunity. Recently, it has been revealed that sera from certain patients with BP contain IgE autoantibodies to COL17 and that IgE autoantibodies bind to peri-lesional dermal-epidermal junctions. Mouse models have demonstrated that IgE antibodies to COL17 induce erythema and eosinophilic infiltration in skin. In addition, the successful treatment of severe BP with omalizumab, a humanized monoclonal antibody targeting IgE, has been reported. These findings suggest that both IgG and IgE autoantibodies to COL17 may be involved in the BP pathogenesis. This article summarizes IgE-mediated autoimmunity to COL17 in BP., (Copyright © 2015 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.)

Background: Direct immunofluorescence (DIF), indirect immunofluorescence (IIF), and enzyme-linked immunosorbent assay (ELISA) are used for the laboratory diagnosis of bullous pemphigoid (BP)., Objective: The diagnostic value of DIF and IIF on rabbit and monkey esophagus or human salt-split skin and commercial ELISAs was assessed., Methods: This was a single-center retrospective study where 313 patients with BP were compared with 488 control subjects., Results: DIF was the most sensitive test (90.8%) whereas sensitivities for IIF on rabbit esophagus, IIF on monkey esophagus, IIF on salt-split skin, BP180 ELISA, and BP230 ELISA were 76.0%, 73.2%, 73.3%, 72.0%, and 59.0%, respectively. The sensitivity of the serologic tests was 88.8% altogether. The specificities for DIF, IIF on rabbit esophagus, IIF on monkey esophagus, IIF on salt-split skin, BP180 ELISA, and BP230 ELISA were 98%, 96.5%, 97.1%, 100%, 94.1%, and 99.2%, respectively., Limitations: The retrospective nature of study was a limitation. Correlation of diagnostic data with clinical manifestations or disease course was not possible., Conclusions: In suspected BP, both serologic tests and DIF have to be performed because of a sensitivity issue. Although the ELISAs had a relatively low sensitivity, the serologic tests altogether almost reached the level of sensitivity of DIF. The specificities of all assays were excellent., (Copyright © 2013 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.)

Background: Bullous pemphigoid (BP) is an acquired autoimmune subepidermal blistering disease characterized by circulating IgG autoantibodies directed against BP180 and BP230 hemidesmosomal proteins. Previous studies have demonstrated that antibodies against the NC16a domain of BP180 mediate BP pathogenesis, while antibodies against BP230 enhance the inflammatory response. Recently, commercial BP180-NC16a enzyme-linked immunosorbent assay (ELISA) and BP230 ELISA kits were developed to detect anti-BP180 and anti-BP230 autoantibodies in human BP sera., Aims: To evaluate the efficacy of BP180-NC16a ELISA and BP230 ELISA in the initial diagnosis of BP., Methods: Sera from 62 BP patients and 62 control subjects were tested by BP180-NC16a ELISA and BP230 ELISA and compared with findings from indirect immunofluorescence (IIF) and immunoblotting (IB) to determine the sensitivity and specificity of these assays., Results: The sensitivities of BP180-NC16a ELISA and BP230 ELISA were 87.1% (54/62) and 56.5% (35/62), respectively, and the specificities of both were 100% (62/62). Using both ELISAs for diagnosis increased the sensitivity to 95.2% (59/62) and was statistically comparable with IB sensitivity., Conclusions: ELISA is a convenient, effective, and reliable method for serodiagnosis of BP, and combined use of BP180-NC16a ELISA and BP230 ELISA can increase the sensitivity of this diagnostic approach.

Bullous pemphigoid (BP) represents the most common autoimmune subepidermal blistering disease. BP typically affects the elderly and is associated with significant morbidity. It has usually a chronic course with spontaneous exacerbations. The cutaneous manifestations of BP can be extremely protean. While diagnosis of BP in the bullous stage is straightforward, in the non-bullous stage or in atypical variants of BP signs and symptoms are frequently non-specific with eg, only itchy excoriated, eczematous, papular and/or urticarial lesions that may persist for several weeks or months. Diagnosis of BP critically relies on immunopathologic examinations including direct immunofluorescence microscopy and detection of serum autoantibodies by indirect immunofluorescence microscopy or BP180-ELISA., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Autoimmune blistering skin diseases are a heterogeneous group of diseases characterized by autoantibodies against structural components of the skin. In pemphigus vulgaris (PV) autoantibodies react mainly with desmoglein 3 (Dsg3) alone and/or in combination with desmoglein 1 (Dsg1). In bullous pemphigoid (BP) autoantibodies target two hemidesmosomal proteins, BP180 and BP230., Objective: To evaluate the diagnostic accuracy of a new indirect immunofluorescence (IIF) multiplex biochip method for the detection of anti-skin specific autoantibodies., Methods: Sera from 36 patients with PV and from 40 patients with BP were collected. The control group included 54 patients with other skin diseases and 40 healthy subjects. The detection of circulating autoantibodies to Dsg1, Dsg3, BP230 and BP180 was performed with a new IIF multiplex biochip method and with two currently commercially available ELISA methods., Results: The multiplex IIF method showed a high diagnostic sensitivity (100%) for PV on cells transfected with Dsg3. In patients with BP, the positivity to the BP180 antigen was higher (90%) than that on monkey esophagus (50%) and on cells transfected with BP230 (40%). A good rate of agreement was observed among methods (IIF vs. ELISA) and among ELISA systems., Conclusions: The new multiplex biochip IIF method has a high diagnostic accuracy for the diagnosis of PV and BP, comparable to ELISA methods, and is able to screen autoimmune bullous diseases., (Copyright © 2012 S. Karger AG, Basel.)

Background: Types of subepidermal autoimmune bullous dermatosis (AIBD) are classified by anatomoclinical picture and target antigen. A new entity has recently been identified: anti-p200 pemphigoid., Patients and Methods: An 82-year-old man consulted for a profuse pruritic bullous eruption refractory to the standard treatments for bullous pemphigoid (BP). Direct immunofluorescence examination of a skin biopsy revealed linear deposits of IgG and of C3 at the dermal-epidermal junction, but Elisa screening for circulating anti-BP180 and anti-BP230 antibodies was negative. Indirect immunofluorescence (IIF) testing of cleaved skin revealed a deposit of IgG4 antibodies on the dermal side. Immunoblotting was negative for a dermal extract but showed an antibody directed against a 200-kD epidermal antigen. A diagnosis of anti-p200 pemphigoid was eventually made and the patient was successfully treated with dapsone., Discussion: The diagnosis of anti-p200 pemphigoid was made in this case in spite of discrepancy between the IIF and immunoblotting results, and despite the fact that the target antigen in this disease is considered as being restricted to dermal sites. Anti-p200 pemphigoid usually begins in the second part of life and differs from standard bullous pemphigoid in terms of more frequent mucous membrane and cephalic involvement, as well as a greater degree of miliary scarring. This disease appears more prominent in males and is associated with psoriasis in around one third of cases. Autoantibodies recognize laminin gamma-1, an extra-desmosomal protein that contributes to dermal-epidermal adhesion., Conclusion: This recently described disease as probably under-diagnosed in France. It should be considered in atypical presentations of bullous disease. Diagnosis is confirmed by immunoblotting detection of autoantibodies directed against a 200-kD antigen normally present in the extract. Dapsone appears to be the most effective treatment., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

Background: Pemphigoids are rare diseases associated with IgG, IgE and IgA autoantibodies against collagen XVII/BP180. An entity of the pemphigoid group is the lamina lucida-type of linear IgA disease (IgA pemphigoid) characterized by IgA autoantibodies against BP180. While for the detection of IgG and IgE autoantibodies specific to collagen XVII several ELISA systems have been established, no quantitative immunoassay has been yet developed for IgA autoantibodies. Therefore, the aim of the present study was to develop an ELISA to detect IgA autoantibodies against collagen XVII in the sera of patients with pemphigoids., Methods: We expressed a soluble recombinant form of the collagen XVII ectodomain in mammalian cells. Reactivity of IgA autoantibodies from patients with IgA pemphigoid was assessed by immunofluorescence microscopy and immunoblot analysis. ELISA test conditions were determined by chessboard titration experiments. The sensitivity, specificity and the cut-off were determined by receiver-operating characteristics analysis., Results: The optimized assay was carried out using sera from patients with IgA pemphigoid (n = 30) and healthy donors (n=105). By receiver operating characteristics (ROC) analysis, an area under the curve of 0.993 was calculated, indicating an excellent discriminatory capacity. Thus, a sensitivity and specificity of 83.3% and 100%, respectively, was determined for a cut-off point of 0.48. As additional control groups, sera from patients with bullous pemphigoid (n=31) and dermatitis herpetiformis (n = 50), a disease associated with IgA autoantibodies against epidermal transglutaminase, were tested. In 26% of bullous pemphigoid patients, IgA autoantibodies recognized the ectodomain of collagen XVII. One of 50 (2%) of dermatitis herpetiformis patients sera slightly topped the cut-off value., Conclusions: We developed the first ELISA for the specific and sensitive detection of serum IgA autoantibodies specific to collagen XVII in patients with pemphigoids. This immunoassay should prove a useful tool for clinical and translational research and should essentially improve the diagnosis and disease monitoring of patients with IgA pemphigoid. Moreover, our findings strongly suggest that IgA pemphigoid and IgG bullous pemphigoid represent two ends of the clinical spectrum of an immunological loss of tolerance against components of hemidesmosomes, which is mediated by both IgG and IgA autoantibodies., (© 2011 Csorba et al; licensee BioMed Central Ltd.)

Objective: To assess the usefulness of enzyme-linked immunosorbent assay (ELISA) assessment of the combination of bullous pemphigoid antigen 1 (BPAG1) and BPAG2 in the diagnosis of bullous pemphigoid (BP)., Design: Retrospective study of serum samples from patients with BP., Setting: Tertiary care center., Patients: A total of 190 patients with newly diagnosed BP and 78 controls with other autoimmune bullous diseases., Intervention: Serum samples were tested using commercialized BPAG1 and BPAG2 ELISA and indirect immunofluorescence (IIF)., Main Outcome Measures: The sensitivity and specificity of ELISA for the combination of BPAG1 and BPAG2 in the diagnosis of BP were contrasted with ELISA for each of the antigens alone and with IIF., Results: The sensitivity and specificity of ELISA for the combination of BPAG1 and BPAG2 were 87% and 88%, respectively, compared with 79% and 90% for BPAG2 ELISA, 61% and 96% for BPAG1 ELISA, and 81% and 63% for IIF. The combination of BPAG1 ELISA and BPAG2 ELISA permitted 8% and 16% gains in sensitivity compared with each of BPAG2 ELISA and BPAG1 ELISA alone, respectively. Anti-BPAG1 antibodies were detected in 15 of 40 BP serum samples with no anti-BPAG2 antibodies (38%) and in 8 of 13 serum samples from patients with BP and mucosal involvement (62%) compared with 2 of 22 samples of cicatricial pemphigoid (P = .002) and 0 of 16 epidermolysis bullosa acquisita serum samples (P < .001). The BPAG2 ELISA values were more closely correlated with initial extent of BP lesions (r = 0.44, P < .001) than BPAG1 ELISA values (r = 0.16, P = .03)., Conclusion: Since the combination of BPAG1 and BPAG2 ELISA only slightly increases the sensitivity of BP diagnosis over BPAG2 ELISA alone, BPAG1 ELISA could be adequately proposed in a minority of BP cases with mucosal involvement and in those with no circulating anti-BPAG2 antibodies.

Objective: To investigate the diagnostic value of commercially available BP230 and BP180-NC16a enzyme-linked immunosorbent assays (ELISAs) in routine practice in patients with bullous pemphigoid (BP)., Design: Single-center retrospective study., Setting: French academic dermatology department., Patients: The study population comprised 138 patients, who were admitted from January 1998 through December 2008., Interventions: Sera samples were analyzed by ELISA; clinical and immunopathological data were recorded from the patients' medical charts., Main Outcome Measures: BP230 and BP180-NC16a ELISA scores were evaluated with respect to clinical characteristics (number of blisters, mucosal involvement, localized or generalized disease, and outcome) and routine indirect immunofluorescence (IF)., Results: Of the 138 study patients, 81 (59%) had a positive BP230 ELISA result and 119 (86%) had a positive BP180 ELISA result. There was no relationship between a positive ELISA BP230 result and the disease extent at diagnosis or the presence of mucosal involvement. Serum anti-basement membrane zone autoantibodies (indirect IF) were more frequently detected when the BP230 ELISA result was positive (P < .001). The median anti-basement membrane autoantibody titer as detected by indirect IF was higher in patients with a positive BP230 result (P < .001). The BP180 ELISA result was associated with disease extent at diagnosis as estimated by both the percentage of patients with extensive BP (P = .01) and the mean number of blisters (P = .03) but was not associated with mucosal involvement., Conclusions: The currently available BP230 ELISA is a reliable although less-sensitive test than BP180 ELISA in BP, and its diagnostic added value compared with BP180 ELISA alone is approximately 5%. Our results support the predominant contribution of the BP230-specific autoantibodies to anti-basement membrane zone antibody titer as detected by indirect IF.

Bullous pemphigoid (BP) is a humoral autoimmune disease directed predominantly against the non-collagenous NC16A domain of the BP180 hemidesmosomal protein. Our laboratory has recently shown, using a mouse xenograft model, that passive transfer of IgE autoantibodies from BP sera induces a skin phenotype that recapitulates the early phases of the disease. Herein, we describe the development of a highly specific and sensitive ELISA to detect circulating IgE autoantibodies that recognize BP180-NC16A. Using this assay, we detected NC16A-specific IgE-class autoantibodies in 77% of BP sera. This frequency, which is significantly higher than reported previously, is comparable to that of anti-NC16A IgG autoantibody production. In 3 BP patients monitored over time, the circulating NC16A-specific levels of both IgE and IgG were associated with clinical disease activity; however, patient sera did not always contain high levels of both isotypes. In conclusion, our ELISA provides a highly sensitive and specific tool for the detection of BP180-specific IgE in patient sera. Furthermore, we report that the majority of BP sera contain both IgE and IgG class autoantibodies specific for NC16A and suggest that screening for both isotypes of autoantibodies may provide a better diagnostic value than IgG alone.

Background: The 180-kDa transmembrane hemidesmosomal protein (BPAG2) has been identified as an important autoantigen in bullous pemphigoid (BP). Using the NC16A domain as the antigenic target, a highly sensitive and specific enzyme-linked immunosorbent assay (ELISA) for the detection of autoantibodies to BP180 was developed., Aim: To investigate the correlation of clinical severity and ELISA indices in BP., Methods: Antibody titers in the sera from 20 patients were measured using BP180NC16a-ELISA, and an analysis of the correlation of ELISA indices with disease activity was performed. Serum was obtained from each patient with BP at least three times: before the initiation of treatment, during complete disease control just before the decrease in corticosteroid, and when the dosage of corticosteroid was successfully decreased to half the initial dose. Of the 20 patients, three showed recurrence at a later stage, caused by their decision to stop treatment; serum was obtained at the early stage of recurrence., Results: ELISA indices were significantly decreased after successful therapy, although indirect immunofluorescence titers did not always show apparent correlations. Indices measured using BP180NC16a-ELISA were well correlated with disease activity. Three patients decided to stop taking their medication; subsequently (within 1-2 weeks), blisters recurred, and the levels of antibodies to BP180 increased to close to those before the initiation of treatment., Conclusion: BP180 antibody titers showed a closer correlation than indirect immunofluorescence titers to disease activity. The titer of BP180 antibody may be a useful tool for the evaluation of disease activity and for the assessment of the effectiveness of treatments in BP.