Skin antibodies
- Description
- The identification of autoantibodies in the bullous disorders of the skin, pemphigus and pemphigoid by indirect immunofluorescence (IIF) plays a major part in the diagnosis and treatment of these disorders. Inter-epithelial (chicken-wire appearance on IF) autoantibodies are detected in the different clinical forms of pemphigus (pemphigus vulgaris, pemphigus foliaceus and paraneoplastic pemphigus). The autoantibodies target antigenic cadherin proteins are in the desosomes. In pemphigus vulgaris the autoantibody reacts with desmoglein 3 while in pemhigus foliaceus the antigen is desmoglein 1. These autoantibodies are present in 70-90% of affected individuals. Paraneoplastic pemphigus antibodies react with desmoplakins in the epidermal desmosomes and hemidesmosomes in the suprabasal layers of the epidermis. The immunofluorescent pattern seen in IIF using primate lip does not differentiate between desmogleins 1 and 3. Antigen specific assays are required for such differentiation. Some 70% of bullous pemphigoid patients have circulating autoantibodies to a hemidesmosomal component, BP 230 (BPAG1) and a collagen XVII domain known as BP180 (BPAG2). In IIF pemphigoid antibodies produce linear staining of the dermo-epidermal junction, (basement membrane zone). Other immunobullous disorders can be usefully investigated with IIF. Please contact the laboratory for further advice. It is strongly advised that biopsy of the affected skin and examination by direct immunofluorescence and light microscopy be undertaken as part of the investigation of the above disorders, in addition to serum autoantibodies.
- Reference range
- Negative
- Units
- Negative / Positive
- Testing site
- Synnovis : Reference Services : Blackfriars Hub
- Laboratory
- Diagnostic Immunology
- Sample type and volume required
- Clotted (Gold top vacutainer)
- Special sample instructions
All tests are compromised by prolonged transit times. For this reason, date of bleed and date of postage must be provided with each request.
- Storage and transport
- Serum stored at 4°C should be sent by first class post
- Turnaround time
- 28 working days
- Time limit for extra tests
- 10 days