CTA Lab Direct Immunofluorescence Information.
What is Direct Immunofluorescence Testing?
Direct Immunofluorescence [dih-rekt im-yuh-noh-floo-res-uh ns]: Staining cells with antibodies directly linked to fluorochromes is known as direct immunofluorescence (DIF). Multiple antibodies may be detected on one sample.
Direct Immunofluorescence testing for difficult cases of autoimmune and inflammatory skin diseases requires specialized equipment both to process and to diagnose. Our full service Direct Immunofluorescence lab can rapidly and accurately process Direct Immunofluorescence biopsy cases and deliver a final report within 24-48 hours. Dr. Curtis Thompson and Dr. Jessica Spies are highly skilled at diagnosing Direct Immunofluorescence cases and look forward to assisting your practice.
How to send specimen for Direct Immunofluorescence Testing
Skin or mucosal specimens for Direct Immunofluorescence testing must be sent in Michel's Transport Medium; a 4mm punch is recommended. This test cannot be performed on specimens fixed in formalin. CTA Lab will provide bottles of Michel's Transport Medium to you.
The specimen can be transported at room temperature. Importantly, the specimen must be received (and frozen) within 5 days of biopsy.
Below are our guidelines for obtaining Direct Immunofluorescence biopsies for different diseases:
- Pemphigus and Pemphigoid Groups (including inear IgA bullous dermatosis and chronic bullous disease of childhood): Biopsy erythematous perilesional skin or mucosa. Avoid erosions, ulcers, and bullae while obtaining tissue adjacent to active lesions. Label as perilesional skin.
- Dermatitis Herpetiformis: Biopsy normal-appearing skin, 0.5-1.0 cm away from lesion. Label as perilesional skin.
- Lupus Erythematosus & Other Collagen Vascular Diseases: Involved areas of skin such as erythematous or active borders are preferred biopsy sites to confirm the diagnosis of lupus erythematosus, either discoid or systemic. Label as involved skin. Avoid ulcers, old lesions, and facial lesions, if possible. Uninvolved, nonexposed skin is the preferred site to detect a lupus band as may be found in systemic lupus erythematosus. Should unexposed skin be desired, buttock or medial thigh is suggested. Label as uninvolved, nonexposed skin.
- Vasculitis versus Urticaria: The erythematous or active border of a new lesion is preferred. Avoid old lesions and ulcers. Label as involved skin. If appropriate skin lesion is not present, diagnosis may sometimes be made from uninvolved skin.
- Porphyria Cutanea Tarda: Biopsy involved skin. Avoid old lesions and ulcers. Label as involved skin.