023
Test #
Collagen VII Antibodies - IgG (ELISA)
CPT Code(s) #
83520
If Profile, Includes Tests:
N/A
Disease Name:
Epidermolysis Bullosa Acquisita (EBA), Bullous LE
Type of Study:
Serum
Methodology:
ELISA
Substrate:
N/A
Reference Range:
Negative: < 6 U/mL
Positive: ≥ 6 U/mL
Units:
Units/mL
Schedule:
Assay performed once weekly. Report availability is within 7 days from time of specimen receipt.
Specimen Requirements:
Serum: Serum Separator Tube or red top tube, 2-5 mL preferred, 0.5 mL minimum sample volume. Separate serum from cells ASAP or within 2 hours of collection.
Sample Stability:
Storage & Stability:
Room temperature = 3 days
2-8ºC = 7 days
-15ºC to -25ºC = samples in long-term storage
Clinical Relevance:
Type VII Collagen is found in the lamina densa and the sublamina densa fibrillar area of the dermal-epidermal junction. The pathogenicity of autoantibodies targeting collagen VII has been independently demonstrated both in vitro, ex vivo and in vivo. Collagen VII autoantibodies specific to COL7 is the current standard for EBA diagnosis(Hashimoto, 2012). Type VII collagen (COL7)-specific autoantibodies were primarily of the IgG isotype and were seen in over 75% of the EBA patients (Iwata, 2018). The immunodominant domains of type VII collagen can also be recognized by IgG autoantibodies from patients with bullous lupus erythematosus (BSLE). Antitype VII collagen autoantibodies can be detected 3 months before the inception of BSLE in patients with SLE. In a study by Grabell (2015) of BSLE, 100% of the patient had circulating Collagen VII antibodies before and during the skin eruption. The healthy and LSE controls did not show any circulating collagen VII antibodies (Grabell, 2015, Ishikawa,1997).
