Category: |
Vesiculo-Bullous Disease |
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Test Code: | 114 |
Disease: | Pemphigus / Pemphigoid / EBA |
Methodology: | ELISA |
Reference Range: | Negative: < 9 ; Positive : ≥ 9 |
Units: | U/ml |
CPT Code: | 83516 (x1) |
Schedule / Turnaround Time: | Assay performed once every two weeks. Report availability is two weeks from the time of specimen receipt. |
Specimen Requirements: |
Specimen need not be refrigerated or frozen. Collect 2-3 ml of blood in a red top or serum separator tube. If possible, separate serum from clot and place into white tube provided with Immco Diagnostics’ collection kits. If separation facilities are not available, the blood can be sent in the tube used for collection. |
Sample Stability: |
Sample is stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8°C) up to five days and frozen (-20°C or lower) up to one year. |
Relevance: |
Bullous pemphigoid (BP) is an autoimmune mediated immunobullous skin disorder found mainly in the elderly population and is characterized by frequent occurring of tense blisters and erythema. Antibodies are directed to the basement membrane zone and are found in the serum of patients as linear IgG or C3 sediments. Target antigens of the autoantibodies in BP patient serum are BP230 and BP180, also called BPAG1 and BPAG2. Molecular weight of these antigens is 230 kD and 180 kD respectively. BP180 is thought to be the direct target of the autoantibody because of its location, and the autoantibodies against BP230 are thought to be secondarily produced. The antibodies against BP180 are thought to be pathogenic, because the rabbit antibody against mouse in the NC16a region of BP180 forms blisters similar to BP when injected into neonatal mice. The main epitope of BP180 is located in the region close to cell membrane called NC16a and most patient serum reacts with the recombinant NC16a protein. Serum levels of BP180 co-relate with the disease activity. |