Utility of immunofluorescence in dermatology

Abstract

Immunofluorescence (IF) tests have redefined our understanding of many immune-mediated skin diseases, especially autoimmune blistering diseases (AIBDs). Nomenclature of certain AIBDs (for example, linear IgA diseases and IgA pemphigus) has been done based solely on the finding of tissue-bound immunoreactants as detected by IF tests. Direct and indirect are the two major types of IF tests; they are not only useful in the diagnosis but also guide the clinician in the treatment at least in certain AIBDs, as the titer of circulating antibodies as detected by IF reflects the disease activity. In this review, we describe techniques, various types of IF, and its modification.

Keywords: Autoimmune blistering diseases; diagnosis; immunofluorescence tests.

Figure 1

Schematic diagram of a special type of adhesive slide used in our department (Procured from Henley, UK). Each panel in the slide contains two frozen sections of patient's skin and are stained with different fluorescein isothiocyanate conjugates

Figure 2

Algorithmic approach based on the immunofluorescence findings in AIBDs. (Abbreviations: ICS - Intercellular space, BMZ - basement membrane zone, PV - pemphigus vulgaris, PF - Pemphigus foliaceus, PNP - paraneoplastic pemphigus, PE - pemphigus erythematosus, LAD - linear IgA disease, DH - dermatitis herpetiformis, EBA - epidermolysis bullosa acquisita, b-SLE - bullous systemic lupus erythematosus, Lam 332 MMP - laminin-332 mucous membrane pemphigoid, p-200 - p200 pemphigoid)

Figure 3

Intercellular staining of the epidermis with IgG in pemphigus (fluorescein isothiocyanate, ×200)

Figure 4

Both intercellular and basement membrane zone staining with IgG in a patient with paraneoplastic pemphigus (fluorescein isothiocyanate, ×200)

Figure 5

Linear basement membrane zone staining with C3 in bullous pemphigoid (fluorescein isothiocyanate, ×200)

Figure 6

Linear basement membrane zone staining with IgA in linear IgA disease (fluorescein isothiocyanate, ×200)

Figure 7

Granular staining of dermal papillae with IgA in dermatitis herpetiformis (fluorescein isothiocyanate, ×400)

Figure 8

Granular blood vessel wall staining with IgA Henoch–Schönlein purpura (fluorescein isothiocyanate, ×400)

Figure 9

Salt-spit technique showing IgG staining on the epidermal side of the split skin in bullous pemphigoid (a) and staining with IgG on the dermal side in epidermolysis bullosa acquisita (b) (fluorescein isothiocyanate, ×200)