Direct immunofluorescence for immunobullous and other skin diseases

Abstract

A swift glance at ample evidence currently available about the assay clearly illustrates that the development of direct immunofluorescence (DIF), in which direct fluorescent antibodies are utilized to identify the target antigen, has been of immense importance. The immunoreactant deposits have been delineated by the DIF assay in three main locations, including throughout the epidermis, at the dermoepidermal junction (also known as the basement membrane zone) and in and/or around blood vessel walls. DIF testing can be conducted on several specimen sources, which are categorized according to feasibility of collection into invasive (e.g., skin) and non-invasive (e.g., hair). This review was intended to indicate that inspection of immunoreactant deposits via DIF is highly instrumental in diagnosing and monitoring the immunobullous and other diseases of the skin.

Keywords:

• autoimmune diseases
• direct immunofluorescence
• immunobullous skin diseases
• immunopathology

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

Key issues

• Direct immunofluorescence (DIF) contributes enormously to the clinical aspects of immunobullous and other skin diseases by detection of immunoreactants, for example, IgA, IgG and IgM, and complement C3, in the epithelium, at the basement membrane zone (BMZ) area, or in and/or around blood vessels.

• The intraepithelial IgG deposition corroborated by DIF represents conditions that bear the name ‘pemphigus’, including pemphigus vulgaris, pemphigus vegetans, pemphigus foliaceus, pemphigus erythematosus and paraneoplastic pemphigus.

• DIF at the BMZ area is acknowledged as the most important pattern of the three major ones detected by the assay and may be finely linear, thick and glassy linear or granular.

• Deposition of immunoreactants – particularly complement C3 – at the BMZ determined by DIF is of utmost importance to the diagnostic work-up of pemphigoid diseases, although it has shown a great strategic potential not only for the differential diagnosis but also for the prognosis of other skin diseases.

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