What does direct immunofluorescence test for?

Direct immunofluorescence (DIF) test for tissue-bound autoantibodies, has been found to be of value in the diagnosis of several dermatological disorders. The location and pattern of deposition of immunoreactants helps in classifying various immune-mediated diseases.

What is direct immunofluorescence staining?

Direct immunofluorescence (DIF) is a one-step histological staining procedure in which tissue antigens (fixed in a solid phase, mostly slides) can be recognized directly by adding fluorochrome-labeled antibodies.

When do you use dif?

DIF is useful in the diagnosis of suspected autoimmune disease, connective tissue diseases and vasculitis. The staining patterns seen in tissue samples may be specific to a disease entity or they may need to be interpreted with the clinical and histological findings.

Where is a bullous pemphigoid biopsy done?

Direct immunofluorescence in bullous pemphigoid: effects of extent and location of lesions. The specimen should be taken from above the waist if possible, and some experts advise trunk skin over extremity skin. It should be noted that most data regarding biopsy site choice are from patients with BP.

How do you test for bullous pemphigoid?

To confirm the diagnosis, your doctor may order blood tests and take a small sample of the affected skin (skin biopsy) for laboratory testing.

What is the difference between direct and indirect immunofluorescence?

The key difference between direct and indirect immunofluorescence is that the direct immunofluorescence uses a single antibody that works against the target of interest while the indirect immunofluorescence uses two antibodies to label the target of interest.

Does direct immunofluorescence use monoclonal antibodies?

In direct immunofluorescence, the fluorescent dye is conjugated directly to the specific, detecting antibody. The latter technique is advantageous because the number of steps are reduced, but some sensitivity may be lost, particularly when monoclonal antibodies are used (Salinas et al., 1994).

What is the difference between pemphigus and pemphigoid?

Pemphigus is characterized by shallow ulcers or fragile blisters that break open quickly. Pemphigoid presents with stronger or “tense” blisters that don’t open easily. Those with pemphigoid are also more likely to have hot, red and itchy hive spots.

Is there a blood test for pemphigoid?

Serum Testing. Recommended initial serum testing for pemphigoid involves panel testing for epithelial skin antibodies. Serum antibody profiles and titers correlate with pemphigoid disease manifestations and activity.

What is bullous pemphigoid caused by?

Bullous pemphigoid occurs when your immune system attacks a thin layer of tissue below your outer layer of skin. The reason for this abnormal immune response is unknown, although it sometimes can be triggered by taking certain medications.

What is included in the differential diagnoses of bullous pemphigoid (BP)?

The differential diagnosis includes bullous pemphigoid, cicatricial pemphigoid, linear IgA disease, a bullous drug eruption and a severe arthropod bite reaction. Additional material for immunofluorescence studies is recommended.

What is bullbullous pemphigoid (BP)?

Bullous pemphigoid is the most common autoimmune dermatosis presenting with crops of tense pruritic blisters, often in older adults. Mucosal involvement may occur and a number of clinical subtypes exist.

What is the sensitivity of DIF in pemphigus?

The sensitivity for DIF approaches 100% for the pemphigus group of diseases, and sensitivity has been reported to be 55–96% for bullous pemphigoid. A study of ten patients with Henoch–Schönlein purpura and nine with lupus erythematosus demonstrated positive DIF testing in all of the patients.

How is salt-split skin immunofluorescence used in the workup of epidermolysis bullosa?

A salt-split skin immunofluorescence study may be done where the patient serum is applied on the salt-split skin, which splits the skin at the level of the lamina lucida. Bullous pemphigoid immunoreactants will localize to the epidermal side of the preparation, versus epidermolysis bullosa acquisita which localizes to the dermal side.