Salivary Samples for the Diagnosis of Pemphigus vulgaris Using the BIOCHIP Approach: a Pilot Study

Saliva Proteomics as Fluid Signature of Inflammatory and Immune-Mediated Skin Diseases

Saliva is easy to access, non-invasive and a useful source of information useful for the diagnosis of serval inflammatory and immune-mediated diseases. Following the advent of genomic technologies and -omic research, studies based on saliva testing have rapidly increased and human salivary proteome has been partially characterized. As a proteomic protocol to analyze the whole saliva proteome is not currently available, the most common aim of the proteomic analysis is to discriminate between physiological and pathological conditions. The salivary proteome has been initially investigated in several diseases: oral squamous cell carcinoma and oral leukoplakia, chronic graft-versus-host disease, and Sjögren's syndrome. Otherwise, salivary proteomics studies in the dermatological field are still in the initial phase, thus the aim of this review is to collect the best research evidence on the role of saliva proteomics analysis in immune-mediated skin diseases to understand the direction of research in this field. The results of PRISMA analysis reported herein suggest that human saliva analysis could provide significant data for the diagnosis and prognosis of several immune-mediated and inflammatory skin diseases in the next future.

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.

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.

Saliva and Oral Diseases

Saliva is a fascinating biological fluid which has all the features of a perfect diagnostic tool. In fact, its collection is rapid, simple, and noninvasive. Thanks to several transport mechanisms and its intimate contact with crevicular fluid, saliva contains hundreds of proteins deriving from plasma. Advances in analytical techniques have opened a new era-called "salivaomics"-that investigates the salivary proteome, transcriptome, microRNAs, metabolome, and microbiome. In recent years, researchers have tried to find salivary biomarkers for oral and systemic diseases with various protocols and technologies. The review aspires to provide an overall perspective of salivary biomarkers concerning oral diseases such as lichen planus, oral cancer, blistering diseases, and psoriasis. Saliva has proved to be a promising substrate for the early detection of oral diseases and the evaluation of therapeutic response. However, the wide variation in sampling, processing, and measuring of salivary elements still represents a limit for the application in clinical practice.

New biochip immunofluorescence test for the serological diagnosis of pemphigus vulgaris and foliaceus: A review of the literature

The immunoassays that are available for the serological diagnosis of the more common subtypes of autoimmune blistering diseases such as pemphigus vulgaris (PV) and pemphigus foliaceus (PF) include enzyme-linked immunosorbent assay (ELISA) testing to specific antigens desmoglein (Dsg)1 and Dsg3, direct immunofluorescence (DIF), indirect immunofluorescence (IIF), and immunoblotting. A review of the literature on the biochip assay was conducted. Six studies investigated the validity of a new biochip, mosaic-based, IIF test in patients with pemphigus and demonstrated its relatively high sensitivity and specificity (Dsg3: 97.62-100%, 99.6-100%; Dsg1: 90%, 100%) in comparison with ELISA (Dsg3: 81-100%, 94-100%; Dsg1: 69-100%, 61.1-100%), and/or IIF (PV: 75-100%, 91.8-100%; PF: 67-100%) using suitable substrates. So far, validation studies of the biochip have been conducted in four countries (Germany, Italy, Turkey, and Poland) but none in the southern hemisphere. Caucasian patients were recruited as normal controls for these studies; thus, the diagnostic value of the biochip remains uncertain in population groups of other ethnicities. A range of disease control patients were recruited including patients with linear immunoglobulin A dermatosis, psoriasis, discoid lupus erythematosus, lichen planus, and noninflammatory skin diseases (e.g., squamous cell carcinoma, basal cell carcinoma, and vascular leg ulcers). Prospective studies with control patients from a diverse range of ethnicities are needed to better validate the biochip.