Biochip technology for the serological diagnosis of bullous pemphigoid

State-of-the-art diagnosis of autoimmune blistering diseases

Autoimmune blistering disorders (AIBDs) are a heterogeneous group of approximately a dozen entities comprising pemphigus and pemphigoid disorders and dermatitis herpetiformis. The exact diagnosis of AIBDs is critical for both prognosis and treatment and is based on the clinical appearance combined with the detection of tissue-bound and circulating autoantibodies. While blisters and erosions on the skin and/or inspectable mucosal surfaces are typical, lesions may be highly variable with erythematous, urticarial, prurigo-like, or eczematous manifestations. While direct immunofluorescence microscopy (IFM) of a perilesional biopsy is still the diagnostic gold standard, the molecular identification of the major target antigens opened novel therapeutic avenues. At present, most AIBDs can be diagnosed by the detection of autoantigen-specific serum antibodies by enzyme-linked immunosorbent assay (ELISA) or indirect IFM when the clinical picture is known. This is achieved by easily available and highly specific and sensitive assays employing recombinant immunodominant fragments of the major target antigens, i.e., desmoglein 1 (for pemphigus foliaceus), desmoglein 3 (for pemphigus vulgaris), envoplakin (for paraneoplastic pemphigus), BP180/type XVII collagen (for bullous pemphigoid, pemphigoid gestationis, and mucous membrane pemphigoid), laminin 332 (for mucous membrane pemphigoid), laminin β4 (for anti-p200 pemphigoid), type VII collagen (for epidermolysis bullosa acquisita and mucous membrane pemphigoid), and transglutaminase 3 (for dermatitis herpetiformis). Indirect IFM on tissue substrates and in-house ELISA and immunoblot tests are required to detect autoantibodies in some AIBD patients including those with linear IgA disease. Here, a straightforward modern approach to diagnosing AIBDs is presented including diagnostic criteria according to national and international guidelines supplemented by long-term in-house expertise.

Utility of the pattern-based approach using BIOCHIP-indirect immunofluorescence in the evaluation of subepidermal bullous disorders

BACKGROUND

Subepidermal bullous disorders (SEBD) are a heterogeneous group of vesiculobullous diseases because of antibody-mediated destruction of proteins of the dermo-epidermal junction. Direct immunofluorescence (DIF) is the gold standard for diagnosis. BIOCHIP-indirect immunofluorescence (IIF) is a novel serological test that combines multiple target antigens in a single field. The present study aimed to evaluate the utility of the pattern-based approach in BIOCHIP-IIF for the diagnosis of SEBD.

METHODS

Seventy cases of BIOCHIP-IIF that showed clinical, histopathological, and/or DIF features favoring SEBD were included in the study. The interpretation in the BIOCHIP was categorized into one of the following patterns. Pattern I: basement membrane zone (BMZ) staining in monkey esophagus (ME), primate salt-split skin (SSS)-roof staining, BP180+ and/or BP230+; Pattern II: roof staining in SSS, BP180- and BP230- with or without BMZ staining in ME; Pattern III: floor staining in SSS, BP180- and BP230-; and pattern IV: negative in SSS and other substrates. The findings were correlated with histopathology and/or DIF.

RESULTS

Fifty (71.5%) cases showed pattern I or the typical bullous pemphigoid (BP) pattern. Eight (11.4%) cases showed pattern II. Patterns III and IV were observed in seven (10%) and five (7.1%) cases, respectively. BP was the most common diagnosis in patterns I and II, while anti-p200 pemphigoid was most common in pattern III, as confirmed by immunoblotting. The sensitivity of pattern I in the diagnosis of BP was 96%.

CONCLUSION

BIOCHIP-IIF showed a good correlation with DIF and histopathology in the diagnosis of SEBD. This can be used as a first-line investigation in case of bullous disorders.

The significance of preclinical anti-BP180 autoantibodies

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease. Although the pathomechanism of BP onset has yet to be elucidated in detail, BP autoantibodies targeting two hemidesmosomal components, BP180 and BP230, are known to play a pivotal role in BP pathogenesis. Thus, the detection and measurement of BP autoantibodies are necessary for diagnosing BP and monitoring the disease activity. Immune assays such as immunofluorescence microscopy, immunoblotting, and ELISAs using BP180 and BP230 detect BP autoantibodies in most BP cases with high specificity; however, BP autoantibodies are sometimes detected in BP patients before the onset of this disease. BP autoantibodies that are detected in patients without typical tense blisters are defined as “preclinical BP autoantibodies”. These preclinical BP autoantibodies are detected even in a low percentage of normal healthy individuals. Although the importance of preclinical BP autoantibodies remains elusive, these autoantibodies might be a potential risk factor for subsequent BP development. Therefore, previous comparative epidemiological studies have focused on the prevalence of preclinical BP autoantibodies in populations susceptible to BP (e.g., the elderly) or in diseases with a higher risk of comorbid BP. This mini-review summarizes the literature on the prevalence of preclinical BP autoantibodies in patients with various conditions and diseases, and we discuss the significance of preclinical BP autoantibody detection.

Strategies to Improve Outcomes of Bullous Pemphigoid: A Comprehensive Review of Clinical Presentations, Diagnosis, and Patients' Assessment

Bullous pemphigoid (BP) is the most frequent autoimmune bullous disease mainly affecting elderlies. Diagnosis usually results from clinical features, histological examination, and the quantification of circulating typical autoantibodies, due to its higher incidence in elderly patients, bullous pemphigoid treatment and management still represents a challenge due to the higher frequency of several comorbidities in this group of patients, which may also be linked to a reduced tolerance to BP treatments. Hence, an early diagnosis and a prompt correct treatment are mandatory to reach better clinical outcomes and improve as much as possible BP outcomes. Herein, we carried out a comprehensive literature review about the known clinical presentations, diagnosis, assessment and monitoring procedures used in daily clinical practice in patients with BP, to better define strategies to improve as much as possible BP clinical outcomes.

Comparison of the EUROIMMUN Dermatology Profile ELISA to the novel BIOCHIP Mosaic 7 for the diagnosis of immunobullous skin disease

BACKGROUND

The BIOCHIP is an indirect immunofluorescence diagnostic investigation which identifies multiple autoantibodies with a mosaic panel of target antigen-specific substrates in a single incubation field. The EUROIMMUN Dermatology Profile ELISA allows simultaneous investigation of the six most important autoantibodies in bullous autoimmune dermatoses. Evaluation of the BIOCHIP Mosaic 7, compared to that of the EUROIMMUN Dermatology Profile ELISA, when used as a diagnostic investigation in pemphigus and pemphigoid, was undertaken in an Australian cohort.

METHODS

The serum of 27 patients was analysed including patients with pemphigus vulgaris (n = 10), pemphigus foliaceous (n = 4), bullous pemphigoid (n = 8), mucous membrane pemphigoid (n = 3) and negative controls (n = 2). Results of the BIOCHIP were compared with the EUROIMMUN Dermatology Profile ELISA, as well as with histology, direct immunofluorescence and indirect immunofluorescence.

RESULTS

In pemphigus vulgaris, sensitivity & specificity for the BIOCHIP Mosaic 7 were 100% and 94.1%, comparable to that of the EUROIMMUN Dermatology Profile ELISA with 80% sensitivity and 100% specificity. In bullous pemphigoid, sensitivity of the BIOCHIP was 87.5% and sensitivity of the EUROIMMUN Dermatology ELISA profile was 75%, whilst specificities for both diagnostic methods were 100% in our limited cohort. There was substantial or almost perfect concordance between the BIOCHIP Mosaic 7 and EUROIMMUN Dermatology Profile ELISA for pemphigus vulgaris and bullous pemphigoid.

CONCLUSION

The BIOCHIP Mosaic 7 is a rapid, reliable diagnostic investigation in pemphigus and bullous pemphigoid. Results indicate it is comparable to the EUROIMMUN Dermatology Profile ELISA, whilst also providing additional testing with salt split skin, on one field.

Comparative Analysis of BIOCHIP Mosaic-based Indirect Immunofluorescence with Direct Immunofluorescence in Diagnosis of Autoimmune Bullous Diseases: A Cross-Sectional Study

Background

Autoimmune bullous diseases (AIBD) are a heterogeneous group of diseases characterized by autoantibodies against desmosomal proteins in the pemphigus group of disorders and adhesion molecules of the dermal-epidermal junction in pemphigoid group of diseases. Direct immunofluorescence (DIF) establishes the diagnosis of AIBD by demonstrating intercellular deposits of IgG and C3 in case of pemphigus and linear deposits of IgG and C3 along the basement membrane zone (BMZ) in bullous pemphigoid (BP). BIOCHIP mosaic-based indirect immunofluorescence (IIF), a novel diagnostic approach employs detection of characteristic staining pattern and target antigens in a single miniature incubation field.

Aim

To compare the BIOCHIP mosaic-based IIF with DIF in the diagnosis of AIBD.

Materials and Methods

A total of 40 patients of AIBD in the active phase of the disease were included in the study. Skin biopsy was done in these patients for DIF study and serum was subjected to BIOCHIP mosaic-based IIF assay. The results were then compared.

Results

DIF revealed a diagnosis of Pemphigus in 18 patients and BP in 22 patients. BIOCHIP showed a diagnosis of pemphigus in 18 patients, BP in 18 patients and floor pattern staining in four patients, which could be attributed to any of the floor pattern staining subepidermal blistering disease.

Limitations

Small sample size, lack of control group and no comparison made with ELISA.

Conclusion

This study concludes that the result of BIOCHIP shows correlation with the DIF and can be used as a first line-screening tool in the diagnosis of AIBD.

Role of BIOCHIP Indirect Immunofluorescence Test in Cutaneous Vesiculobullous Diseases

BIOCHIP mosaics for indirect immunofluorescence in cutaneous vesiculobullous diseases provide antibody profiles in a single run and can be an alternative to performing multistep assays. There is scanty data regarding their utility. BIOCHIP tests performed over 4 years were compared with biopsy and/or direct immunofluorescence (DIF). Of 209 BIOCHIP tests, 108 were positive. Pemphigus vulgaris and Bullous pemphigoid were the commonest. Dsg3 was the commonest positive substrate in pemphigus group (86%) with 100% sensitivity. Intercellular space pattern on BIOCHIP primate esophagus was seen only in 49%. BP 180 was the commonest positive substrate in pemphigoid (95%) with 78% sensitivity. In 68 cases, corresponding biopsy/DIF was available with concordance of 89% in pemphigus and 93% in pemphigoid groups. In 40 cases where BIOCHIP was positive without biopsy/DIF, 97.5% were concordant with clinical diagnosis. Among the negative results, 13 had biopsy/DIF that were diagnostic. The overall positivity of BIOCHIP was 92% for pemphigus and 84% for pemphigoid groups. Indirect immunofluorescence by BIOCHIP method shows good concordance with histopathology/DIF. However, the sensitivity of some of the substrates varies. It is an effective screening tool to identify cases requiring further ELISA/immunoblots or where biopsy is not feasible.

Comparative Analysis of BIOCHIP Mosaic-Based Indirect Immunofluorescence with Direct Immunofluorescence in Diagnosis of Autoimmune Bullous Diseases: A Cross-Sectional Study

Background:

Autoimmune bullous diseases (AIBD) are a heterogeneous group of diseases characterized by autoantibodies against desmosomal proteins in the pemphigus group of disorders and adhesion molecules of the dermal-epidermal junction in pemphigoid group of diseases. Direct immunofluorescence (DIF) establishes the diagnosis of AIBD by demonstrating intercellular deposits of IgG and C3 in case of pemphigus and linear deposits of IgG and C3 along the basement membrane zone (BMZ) in bullous pemphigoid (BP). BIOCHIP mosaic-based indirect immunofluorescence (IIF), a novel diagnostic approach employs detection of characteristic staining pattern and target antigens in a single miniature incubation field.

Aim:

To compare the BIOCHIP mosaic-based IIF with DIF in the diagnosis of AIBD.

Materials and Methods:

A total of 40 patients of AIBD in the active phase of the disease were included in the study. Skin biopsy was done in these patients for DIF study and serum was subjected to BIOCHIP mosaic-based IIF assay. The results were then compared.

Results:

DIF revealed a diagnosis of Pemphigus in 18 patients and BP in 22 patients. BIOCHIP showed a diagnosis of pemphigus in 18 patients, BP in 18 patients and floor pattern staining in four patients, which could be attributed to any of the floor pattern staining subepidermal blistering disease.

Limitations:

Small sample size, lack of control group and no comparison made with ELISA.

Conclusion:

This study concludes that the result of BIOCHIP showed a significant correlation with the DIF and can be used as a first line-screening tool in the diagnosis of AIBD.

Comparison of C3d immunohistochemical staining to enzyme-linked immunosorbent assay and immunofluorescence for diagnosis of bullous pemphigoid

BACKGROUND

Bullous pemphigoid (BP), the most common autoimmune blistering disease, may be diagnostically challenging. Direct immunofluorescence (DIF), indirect immunofluorescence (IIF), enzyme-linked immunosorbent assay (ELISA), and recently, C3d immunohistochemistry (IHC), are used as adjuncts to diagnosis.

OBJECTIVE

To compare C3d IHC to DIF, IIF, and ELISA testing in BP diagnosis.

METHODS

C3d IHC was performed on skin biopsy specimens from 51 patients (27 with BP and 24 with other blistering diseases) and compared to DIF and IIF, with anti-BP180 or anti-BP230 ELISA results used as the gold standard.

RESULTS

We found C3d IHC, DIF, and IIF had similar sensitivity (74.1%, 63.1%, and 70.4%), specificity (95.8%, 100%, and 100%), positive predictive value (95.2%, 100%, and 100%), and negative predictive value (76.7%, 70.6%, and 75%) for BP. Cases with positive C3d IHC, DIF, and IIF had significantly higher anti-BP180 and anti-BP230 by ELISA than cases with negative testing (P < .0001). False-negative IIF results were associated with lower BP230 compared with true-positive results (P = .03).

LIMITATIONS

This was a single-center, retrospective study.

CONCLUSION

Our study compared C3d IHC to DIF and IIF in BP diagnosis, demonstrating C3d IHC on fixed tissue provides similar diagnostic utility to immunofluorescence and ELISA.

Validation of the BIOCHIP test for the diagnosis of bullous pemphigoid, pemphigus vulgaris and pemphigus foliaceus

BACKGROUND

The BIOCHIP is a novel multiplex indirect immunofluorescence technique used in the serological diagnosis of bullous pemphigoid and pemphigus. The BIOCHIP method combines the screening of autoantibodies and target antigen-specific substrates in a single miniature incubation field.

OBJECTIVE

To evaluate the diagnostic accuracy of the new immunofluorescence BIOCHIP multiplex tool in pemphigus and bullous pemphigoid.

METHODS

For the validation of the BIOCHIP, sera from patients with BP (n = 38), PF (n = 8) and pemphigus vulgaris (PV) (n = 23) were used. In addition, sera from disease control patients (n = 63) and healthy volunteers (n = 39) were used. The multiplex BIOCHIP and direct immunofluorescence (DIF) were performed for all BP, PF and PV patients. Additional indirect immunofluorescence (IIF) was performed on patients with BP, and ELISA was performed on patients with pemphigus.

RESULTS

The BIOCHIP mosaic showed a sensitivity of 86.8% and specificity of 85% for BP180 or BP230 being positive in BP. It demonstrated a sensitivity of 75% and specificity of 97.7% for Dsg1 in PF. The BIOCHIP was found to have a sensitivity of 60.9% and specificity of 73.6% for Dsg3 in PV.

CONCLUSION

The BIOCHIP mosaic-based immunofluorescence test is potentially a simple, time and effort saving test that can aid in the diagnosis and screening of BP, PV and PF. However, there is potential for interpretation bias and a learning curve that needs to be taken into consideration.

Updates on diagnosis and management of autoimmune blistering diseases

Over the last several decades, advances in the understanding of the pathogenesis of autoimmune blistering diseases has resulted in significant improvements in diagnosis and management. These improvements include new diagnostic assays and therapies targeted at specific disease mediators. Furthermore, the abundance of new therapies in clinic trials for autoimmune blistering diseases will translate to an enhanced therapeutic armamentarium for clinicians. The aim of this article is to review new developments in the understanding of autoimmune blistering diseases and to summarize advancements in their diagnosis and management.

Serological Diagnosis of Autoimmune Bullous Skin Diseases

Autoimmune bullous dermatoses (AIBD) encompass a variety of organ-specific autoimmune diseases that manifest with cutaneous and/or mucosal blisters and erosions. They are characterized by autoantibodies targeting structural proteins of the skin, which are responsible for the intercellular contact between epidermal keratinocytes and for adhesion of the basal keratinocytes to the dermis. The autoantibodies disrupt the adhesive functions, leading to splitting and blister formation. In pemphigus diseases, blisters form intraepidermally, whereas in all other disease types they occur subepidermally. Early identification of autoimmune bullous dermatoses is crucial for both treatment and prognosis, particularly as regards tumor-associated disease entities. The diagnosis is based on clinical symptoms, histopathology, direct immunofluorescence to detect antibody/complement deposits, and the determination of circulating autoantibodies. The identification of various target antigens has paved the way for the recent development of numerous specific autoantibody tests. In particular, optimized designer antigens and multiplex test formats for indirect immunofluorescence and ELISA have enhanced and refined the laboratory analysis, enabling highly efficient serodiagnosis and follow-up. This review elaborates on the current standards in the serological diagnostics for autoimmune bullous dermatoses.

Biochip detection of BP180 autoantibodies in blister fluid for the serodiagnosis of bullous pemphigoid: A pilot study

Bullous pemphigoid is an autoimmune subepidermal blistering skin disease immunologically defined by autoantibodies directed against basement membrane zone antigens, the main of which is BP180. Laboratory tests are essential for diagnosis and include direct immunofluorescence and serologic assessments with indirect immunofluorescence and ELISA. Serology may be performed on blister fluid, in alternative to blood serum. This study investigated the use of a Biochip-based indirect immunofluorescence approach for the serum diagnosis of bullous pemphigoid on blister fluid. We compared the results using the Biochip-method with the ELISA detection of bullous pemphigoid-180 autoantibodies in blister fluid and observed a perfect correlation between these 2 methods in our group of 13 patients with clinical and direct immunofluorescence diagnosis of bullous pemphigoid. The Biochip is a simple, standardized and inexpensive diagnostic tool and its use on blister fluid may facilitate the diagnosis of this and other autoimmune bullous disorders. Our results suggest that the Biochip assay on serum of bullae is a non-invasive screening technique for the early diagnosis of bullous pemphigoid that is practical for fragile elderly patients and achievable even in small laboratory settings.

Involvement of Nail Apparatus in Pemphigus Vulgaris in Ethnic Poles Is Infrequent

Pemphigus vulgaris lesions have a tendency to localize around natural body orifices. The aim here was to analyze the involvement of nail apparatus in pemphigus vulgaris. Sixty seven ethnic Poles suffering from pemphigus vulgaris on photographic files archiving initial presentation were retrospectively evaluated. Pemphigus vulgaris was diagnosed using combination of clinical data, H+E histology, direct immunofluorescence of plucked scalp hair and/or perilesional tissue also for IgG1 and IgG4 deposits evaluation, indirect immunofluorescence on mosaic substrate and/or monkey esophagus, mono-analyte ELISA with desmoglein 1/3 or multi-analyte ELISA. The nail apparatus involvement was found in 9 of 67 patients (13.4%; 3 females and 6 males). Periungual fingernail lesions were found in 6 patients (2 females, 4 males), whereas periungual toenail lesions in just 3 patients (1 female, 2 males). Our patients nail apparatus changes included, by order of frequency, paronychia, nail discoloration, onychorrhexis, Beau lines, periungual hemorrhages, onychomadesis, cross-ridging, onycholysis, and trachyonychia. The average time between the onset, as recalled by patients, and the diagnosis of pemphigus vulgaris with direct immunofluorescence was not statistically different in PV patients with and without nail apparatus lesions. In this article the molecular and immunological rationale for of periungual involvement is discussed. Our single-center study suggests that nail apparatus involvement is infrequent in pemphigus vulgaris in ethnic Poles. Due to the fact that nail apparatus lesions in pemphigus vulgaris may clinically resemble onychomycosis, giving the proper diagnosis can be difficult particularly when other lesions are overlooked or misinterpreted.

Accuracy of molecular diagnostics in pemphigus and bullous pemphigoid: comparison of commercial and modified mosaic indirect immunofluorescence tests as well as enzyme-linked immunosorbent assays

Introduction

Pemphigus and bullous pemphigoid (BP) are identified by autoantibodies (abs) against desmoglein 1, 3 (DSG1/3) and BP180/BP230, respectively. A novel mosaic to indirect immunofluorescence (IIF) using purified BP180 recombinant proteins spotted on slide and transfected cells expressing BP230, DSG1, DSG3 is available. The commercial (IgG detection) and modified (IgG4 detection) mosaic for indirect immunofluorescence (IIFc – IIF commercial, IIFm – IIF modified) and IgG ELISAs were evaluated in pemphigus and bullous pemphigoid (BP) molecular diagnostics.

Aim

To compare diagnostic accuracy of commercial (IgG detection) and modified (IgG4 detection) mosaic IIF assay and to examine the diagnostic value of ELISAs in relation to mosaic IIF in routine laboratory diagnostics of pemphigus and BP.

Material and methods

Sera from 37 BP and 19 pemphigus patients were studied. Associations between tests were assessed using Fisher’s exact test.

Results

There are associations between the positive/negative samples detected by IIFc with desmoglein1 (DSG1)/desmoglein3 (DSG3)/BP230 transfected cells and ELISAs and no association between anti-BP180 IgG detection by IIFc and ELISA. IIFm with DSG1 and DSG3 showed both 100% sensitivity and 100% and 78% specificity, respectively, and 100% and 83% positive predictive value in relation to IIFc. IIFm with BP230 had 87% specificity, 55% sensitivity, whereas IIFm with BP180 had a 100% sensitivity and 13% specificity in relation to IIFc.

Conclusions

The IIFc with DSG1/DSG3/BP230 transfected cells, excluding BP180 spots, is an alternative method to ELISA in pemphigus/BP diagnostics. IgG4 antibodies, both pathogenically and diagnostically important, are inconsistently detectable with IIFm.

Clinical features and diagnosis of epidermolysis bullosa acquisita

INTRODUCTION

Epidermolysis bullosa acquisita (EBA) is a rare autoimmune blistering disease of skin and mucous membranes. EBA is caused by autoantibodies against type VII collagen, which is a major component of anchoring fibrils, attaching epidermis to dermis. Binding of autoantibodies to type VII collagen leads to skin fragility and, finally, blister formation. The clinical picture of EBA is polymorphic, with several distinct phenotypes being described. Despite recent progress in understanding the pathophysiology of EBA, its diagnosis is still challenging. Areas covered: This review provides an update on the clinical manifestations and diagnostic methods of EBA. We searched PubMed using the terms 'epidermolysis bullosa acquisita' covering articles in English between 1 January 2005 and 31 May 2016. Relevant older publications were retrieved form cited literature. Expert commentary: While the clinical picture is highly variable, diagnosis relies on direct immunofluorescence (IF) microscopy of a perilesional skin biopsy. Linear deposits of IgG, IgA and/or C3 along the dermal-epidermal junction with an u-serrated pattern are diagnostic for EBA alike the detection of serum autoantibodies against type VII collagen. Several test systems for the serological diagnosis of EBA have recently become widely available. In some patients, sophisticated diagnostic approaches only available in specialized centers are required.

Anti-early endosome antigen 1 autoantibodies were detected in a pemphigus-like patient but not in the majority of pemphigus diseases

Although the major autoantigens in classic pemphigus are desmogleins, sera from various types of pemphigus react with a number of other molecules, including desmocollins and plakin proteins. However, other novel pemphigus-related autoantigens remain to be identified. In this study, immunoblotting for serum from an atypical autoimmune bullous disease patient identified an unknown 175 kDa protein. Subsequent studies using two-dimensional gel electrophoresis, immunoblotting and mass-spectrometry identified the 175 kDa protein as early endosome antigen 1 (EEA1). This finding was confirmed by subsequent immunological studies, including indirect immunofluorescence of skin and cultured keratinocytes, two-dimensional gel electrophoresis and immunoblotting with anti-EEA1 polyclonal antibody, and preabsorption with EEA1 recombinant protein. Finally, we developed a novel BIOCHIP assay using full-length EEA1 recombinant protein to detect anti-EEA1 antibodies. However, none of 35 sera from various types of pemphigus showed anti-EEA1 antibodies in the BIOCHIP assay, with the exception of the serum from the index case. In addition, various findings in the index case did not suggest pathogenic role of anti-EEA1 autoantibodies. Therefore, although we successfully identified the 175 kDa protein reacted by a serum of an atypical pemphigus-like patient as EEA1, novel BIOCHIP study for other pemphigus sera indicated that EEA1 is not a common and pathogenic autoantigen in pemphigus.

The use of Biochip immunofluorescence microscopy for the serological diagnosis of epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita is a rare autoimmune bullous disease characterized by the presence of circulating antibodies directed against the collagen type VII. Diagnosis is generally based on clinical history, clinical features, histology, direct and indirect immunofluorescence, immunoblotting and ELISA. Our study aims to determine the validity of the Biochip immunofluorescence microscopy for the serological diagnosis of epidermolysis bullosa acquisita. Six patients with epidermolysis bullosa acquisita and presence of antibodies against type VII collagen confirmed by ELISA were included in the study. Subsequently, all sera of patients were analyzed using Biochip. Antibodies anti-collagen type VII were detected in all sera by means of the Biochip technology. Thus, Biochip shows a good correlation with ELISA and seems to be an appropriate method for the diagnosis of epidermolysis bullosa acquisita. It is an easy, fast and standardized method which could facilitate the diagnosis of this autoimmune bullous disease. We suggest that it could be used as an initial screening test to identify patients with epidermolysis bullosa acquisita.

Advances in understanding and managing bullous pemphigoid

Bullous pemphigoid (BP) is the commonest subtype of autoimmune blistering disease in most countries of the world. It occurs most frequently in elderly patients and is characterised clinically by large, tense blisters in the skin preceded by urticarial plaques and pruritus. Immunopathologically, it is characterised by autoantibodies directed against the 180 kD antigen (BP180) and the 230 kD antigen (BP230). New knowledge regarding BP is being continually uncovered. This article reviews the recent advances in BP, including newer diagnostic tests, standardised outcome measures and emerging therapeutic options, as well as the evidence supporting their use.

The use of biochip immunofluorescence microscopy for the diagnosis of Pemphigus vulgaris

Pemphigus vulgaris is an autoimmune intraepithelial blistering skin disease characterized by the presence of circulating autoantibodies directed against surfaces of keratinocytes. Diagnosis is generally based on clinical features, histology, direct and indirect immunofluorescence and ELISA. This study describes a new BIOCHIP mosaic-based indirect immunofluorescence technique based on recombinant antigenic substrates and transfected cells. We investigated the diagnostic use of BIOCHIP for the serological diagnosis of Pemphigus vulgaris. Autoantibodies against desmoglein 3 were detected in 97.62% of patients (41/42) with P. vulgaris. There were no positive results in the negative control group. Our study revealed that BIOCHIP has high sensitivity and specificity comparable to that of the ELISA assays. Therefore the BIOCHIP technique seems to be an appropriate method for the diagnosis of P. vulgaris as it has been shown to be a simple, standardized and readily available novel tool, which could facilitate the diagnosis of this autoimmune bullous disease. We suggest that it could be used as an initial screening test to identify patients with P. vulgaris before using the ELISA approach.