86148 – ASA IFA

The ASA IFA is an immunofluorescence assay (IFA) for the qualitative and semi-quantitative determination of IgG antibodies in human serum against skin antigens on tissue sections of monkey esophagus. The ASA IFA is intended as an aid in the diagnosis of autoimmune skin diseases in conjunction with other clinical and laboratory findings.

Blistering skin disease, a group of chronic disorders, is often caused by immunological phenomena, which may be used to clinically differentiate them. Histological findings and the presence of characteristic autoantibodies further aid the differentiation. Indirect immunofluorescence tests on epithelial tissue sections (basement membrane (BM)), as well as immunohistological determination of skin biopsies are used for the detection of circulating antibodies, especially autoantibodies of IgG class, which are directed against intercellular epithelial antigens such as desmoglein III and I, and hemidesmosomes of basal keratinocytes. Highly specific BM antibodies are found in about 70% of patients suffering from pemphigoid but not in healthy individuals. The clinical symptoms correlate with pathogenic antibody reaction.

The IFA (indirect immunofluorescence assay) is an immunoassay for the determination of specific antibodies. Tissue sections or cells containing the antigen of interest are immobilized on slides. If specific antibodies are present in the patient´s sample, they bind to the antigen in the tissue. A secondary antibody conjugated with fluorescein-isothiocyanat (FITC) detects the generated immune complex. The slides are examined using a fluorescence microscope. A specific fluorescent staining pattern demonstrates the presence of specific antibodies in the patient´s sample.

The immunoassay is designed for manual professional in vitro diagnostic use only.