Evaluation of Recombinant Antigen-Based Assays for Diagnosis of Bullous Autoimmune Diseases

Abstract

The diagnosis of autoimmune bullous diseases is based on clinical observation and on the presence of autoantibodies directed to molecules involved in the adhesion systems of the skin. Immunofluorescence assays are the currently accepted method for detection of autoantibodies; such assays depend greatly on the skill of operators and are difficult to standardize. Recombinant desmoglein-1 (Dsg1), Dsg3, and BP180 peptides, the main autoantigens in pemphigus or bullous pemphigoid, have been used to develop new quantitative enzyme immunoassays (EIA) for the detection of specific antibodies. The present study was undertaken to evaluate the sensitivity and specificity of these immunoassays and to determine the correlation between the results and the clinical aspects of diseases. Serum samples from patients with pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, or mucous membrane pemphigoid, from healthy individuals, and from patients with unrelated autoimmune conditions were tested. Anti-desmoglein reactivity was detected in all the patients with pemphigus and in none of the controls. Patients with the more benign form of cutaneous disease had anti-Dsg1 antibodies, while patients with deeper cutaneous lesions or with mucosal involvement had anti-Dsg3 reactivity also, or exclusively. The BP180-based assay was positive for 66.6% of patients with bullous pemphigoid and for none of the patients with mucous membrane pemphigoid, and no reactivity was detected in the control sera. In conclusion, the anti-Dsg1 and anti-Dsg3 assays are useful in the diagnosis of pemphigus and provide information on the clinical phenotype of the disease. However, the sensitivity of EIA for detection of autoantibodies in bullous pemphigoid should be improved by the use of additional antigens or epitopes.Bullous autoimmune diseases are mediated by autoantibodies directed to the main adhesion systems of the skin (17). These diseases are classified into two major groups according to the level at which the skin blister occurs: pemphigus, characterized by epidermal blistering which is caused by loss of epidermal cell adhesion, and pemphigoid, characterized by subepidermal blistering which is caused by loss of adhesion between the basal keratinocytes and dermis (18). The detection of circulating or tissue-bound autoantibodies by immunofluorescence assay (IFA) is an important criterion for diagnosis in both clinical conditions (14). Recently, enzyme immunoassays (EIAs) based on recombinant desmoglein-1 (Dsg1) or Dsg3, the main autoantigens in pemphigus (1), and on recombinant BP180, the hemidesmosomal autoantigen involved in the pathogenesis of bullous pemphigoid (BP) (12, 19), have been commercialized. In the present study we have analyzed retrospectively the levels of anti-Dsg1 and anti-Dsg3 in the sera of patients with diagnoses of pemphigus and the levels of anti-BP180 in the sera of patients with pemphigoid in order to establish the correlation between the serum reactivity and clinical features of the patients. In fact, EIAs, compared to ...

The Interaction of Pemphigus Autoimmunoglobulins with Epidermal Cells: Activation of the Fas Apoptotic Pathway and the Use of Caspase Activity for Pathogenicity Tests of Pemphigus Patients

“…The ELISA technique, which was developed for specific detection of anti‐Dsg3 and 1, appears to be a sensitive and highly specific assay mainly for the diagnosis of pemphigus vulgaris and pemphigus foliaceus 19. There are only a few publications that show a high correlation of titer with the acantholytic activity of the disease 19,20…”

A systematic review with pooled analysis of clinical presentation and immunodiagnostic testing in mucous membrane pemphigoid: association of anti‐laminin‐332 IgG with oropharyngeal involvement and the usefulness of ELISA

“…13,18,20 This likely explains why older studies failed to identify anti-BP180 IgG by ELISA with MMP sera which were positive by IIF. 24 Therefore, ELISA utilizing both N-and C-terminal regions of BP180 has an increased sensitivity compared to BP180-NC16a alone, with a sensitivity consistently above 90%. 13,18,25 Still, assays that only include NC16a have been noted to be of use in half of patients with oral MMP.…”

“…IgG reactivity with both the N‐ and C‐terminal domains is associated with mucosal lesions in BP patients . This likely explains why older studies failed to identify anti‐BP180 IgG by ELISA with MMP sera which were positive by IIF . Therefore, ELISA utilizing both N‐ and C‐terminal regions of BP180 has an increased sensitivity compared to BP180‐NC16a alone, with a sensitivity consistently above 90% .…”

Evaluation of Serum Desmoglein 1 and Desmoglein 3 in Oral Erosive Lichen Planus before and after Topical Application of Tacrolimus

“…13 At present, commercial ELISA tests for antibodies against Dsg1 and Dsg3 are available and have been used as a routine indicative method for diagnosis of autoimmune blistering diseases. 14 Till now, there is no definitive cure for OLP, although that there is a variety of medications they are palliative as opposed to therapeutic. The primary role of the treatment is to reduce the duration and severity of symptomatic exacerbation episodes.…”