Immunofluorescence   (prof. MUDr. Zdenek Vlašín, MD)

4.3.1.1  Pemphigus vulgaris and its variants (immunofluorescence)

ICS antibodies are not found in Hailey-Hailey disease.

Cases after therapy (high doses of steroids and cytostatics) may show negative results.

4.3.1.2  Bullous pemphigoid (immunofluorescence)

4.3.1.3  Pemphigoid (herpes) gestationis (immunofluorescence)

4.3.1.4  Dermatitis herpetiformis Duhring (immunofluorescence)

IgA linear dermatitis will show band-like IgA positivity in basement membrane area.

4.3.1.5  Lupus erythematosus (SLE, CDE a SCLE); (immunofluorescence)

In addition to the lupus band the aggregates, oval formations in subepidermal and periadnexal areas are being found. Rarely (in cases with basement membrane destruction in CDE and lichen ruber) such aggregates are intraepidermally located. Usually show IgM positivity, but sometimes react with IgG and c3 as well.

In cases of CDE there is usually fluorescence of the connective tissue in the upper corium. This sign alone is not a diagnostic sign, however.

Lupus band is formed by immune complex aggreages and can be sometimes found in other diseases as well, especially in diseases affecting the face, which are accompanied by angiectasias (rosacea, scleroderma or even tinea faciei).

In addition, in systemic lupus erythematodes cytoplasmatic fluorescence of some keratinocytes is sometimes present.

4.3.1.6  Sharp's syndrome

4.3.1.7  Lichen ruber planus (immunofluorescence)

4.3.1.8  Vasculitis, immunocomplex type (immunofluorescence)

4.3.1.9  Porphyria cutanea tarda (PCT) and hepatopathies (immunofluorescence)

4.3.2.1  Antinuclear antibodies (ANA)

4.3.2.2  Endomysial antibodies

4.3.2.3  Antibodies aganist neutrophilic cytoplasm (ANCA)

Homogenous type fo fluorescecne on the substrate of cell culture HEp-2.

Test with the substrate from Crithidium luciliae. This protozas have their flagella attached to the kinetoplast containing native dsDNA. Positive test therefore indicates presence of anti-dsDNA antibodies. This test is highly specific but less sensitive.

Coarse speckled immunofluorescence indicates antibodies against U1-snRNP antigene (typical of Sharp's syndrome) or against Sm proteins (indicates systemic lupus erythematodes). Similar is large speckled type (antibodies against ribonuclear proteins of nuclear matrix), positive in some cases of Sharp's syndrome and other rheumatic diseases. Fine speckled positivity is found eg. in presence of anti Ro (SS-A) and La (SS-B).

Nucleolar type of fluorescence of the serum, systemic scleroderma. Further subtypes of nucleolar fluorescence are associated with systemic scleroderma.

Antibodies against centromeres are characteristic for about 60% cases of CREST syndrome.

Few nuclear dots type antibodies appear as about 6 discrete dots in one nucleus. These antibodies are present in primary biliary cirrhosis and chronic active hepatitis. The antigen (p80-coilin) belongs to the group of small nuclear ribonucleoproteins and is associated with fibrillarin. Its function is unknown. Similar is multiple nuclear dots fluorescence (about 10 dots/nucleus), associated with Sjögren's syndrome, less common systemic lupus erythematosus and primary biliary cirrhosis.

Antimitochondrial antibodies are characteristic of primary biliary cirrhosis; sometimes is present in people with systemic scleroderma or mixed cases. This antibodies are detected using HEp-2 or rat tissues (liver, kidney, stomach).

Detection of surface antigens of keratinocytes is less sensitive than direct immunofluorescence, nevertheless positive in about 90% of developed cases of pemphigus vulgaris. Antibodies are of IgG4 and IgG1 types. Net-like deposits are characteristic of antidesmosomal antibodies (desmoglein I. in pemphigus vulgaris and desmoglein III. in pemphigus foliaceus).

Bullous pemphigoid is characterized by antibodies against the basement membrane zone. Main antigens were characterized by immunoblotting as BP 230 and BP 180 (herpes gestationis BP 180). Correlation with the disease activity is less tight. In cicatrical pemphigoid (antibodies against laminin) indirect immunofluorescence usually fails.

Antibodies (IgA) against the endomysium are characteristic of dermatitis herpetiformis Duhring and celiac sprue.

Antibodies against cytoplasmic antigens of neutrophils (ANCA) are important in diagnosing vasculitides and monitoring on activity of some vasculitides. In C-ANCA type granular and homogenous positivity of cytoplasm with minimal fluorescence of nuclear lobes is present. Antigene is proteinase 3. Positivity is found in Wegener's granulomatosis, Churg Strauss sydrome and microscopic polyarteritis.

P-ANCA type is characterized by fluorescence of the borders of nuclear lobes. Positivity is found in polyarteritis nodosa, ulcerous colitis, sclerotising cholangitis, Crohn's disease, some forms of uveitis, microscopic polyarteritis, systemic lupus erythematodes and rheumatoid arthritis. The antigen is myeloperoxidase.