AUTOIMMUNE SKIN DISEASE

Instructions for use

The MESACUP Desmoglein TEST “Dsg1” is a semi-quantitative enzyme-linked immunosorbent assay (ELISA) for the detection of anti-Desmoglein1 antibodies in human serum.

Background:

Desmoglein 1 (Dsg1) is a desmosomal cadherin expressed in stratified squamous epithelia and the target antigen in pemphigus foliaceus (PF). PF is an autoimmune blistering disease of skin and characterized clinically by small flaccid blisters and scaly, crusted erosions, and histologically by intraepidermal blister formation due to loss of cell adhesion of keratinocytes. Anti-Dsg1 IgG autoantibodies are detected in sera from patients with PF and play a pathogenic role in blister formation in PF. Anti-Dsg1 IgG is also detected in about 60% of patients with pemphigus vulgaris (PV) ; another type of pemphigus. Amagai et al. have produced a recombinant human Dsg1 (rDsg1) using a baculovirus expression system. rDsg1 is designed as a secreted protein consisting of the entire extracellular domain of Dsg1. rDsg1 is capable of immunoadsorbing pathogenic autoantibodies in PF patients' sera, preventing blister formation in a neonatal mouse model of pemphigus. These findings indicate that rDsg1 expresses most, if not all, conformational epitopes of the native antigens critical in the pathogenesis of pemphigus. Currently, diagnosis of pemphigus largely relies on immunofluorescence testing (IF) utilizing sectioned normal human skin or monkey esophagus. However, there are several disadvantages in the current immunofluorescence. (a) IF requires an experienced technician and a subjective determination of antibody titer. (b) Antibody against any cell surface protein makes false positive. (c) Similar staining pattern in IF makes it difficult to distinguish between PV and PF. To overcome the problems of IF, ELISA has been developed using rDsg1 as a sensitive and specific assay for the diagnosis of pemphigus.

The MESACUP Desmoglein TEST “Dsg1” is for measuring anti-Desmoglein1 IgG autoantibodies with high sensitivity.

Principle:

The MESACUP Desmoglein TEST “Dsg1” measures anti-Dsg1 antibodies present in the serum by ELISA. Calibrators and patient sera are added to microwell coated with Dsg1, allowing anti-Dsg1 antibodies to react with the immobilized antigen (Sample incubation). Afte washing to remove any unbound serum proteins, horseradish peroxidase conjugated anti-human IgG monoclonal antibody is added and incubated (Conjugate incubation). Following another washing step, the peroxidase substrate is added and incubated for an additional period of time (Substrate incubation). Acid solution is then added to each well to terminate the enzyme reaction and to stabilize the color development. The assay can be quantified by measuring the reaction photometrically.

Size: 48 wells

Method: ELISA

Antigen: recombinant