Test Code RSBV Rare Subepithelial Autoimmune Blistering Disease Variants, Serum
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Useful For
Aiding in the diagnosis of rare subepithelial autoimmune blistering diseases, including anti-laminin 332 pemphigoid, anti-p200 pemphigoid, epidermolysis bullosa acquisita, and systemic bullous lupus erythematosus
Method Name
Indirect Immunofluorescence
Reporting Name
Rare Subepi Blistering Variants, SSpecimen Type
SerumSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 14 days | |
Frozen | 30 days | ||
Ambient | 14 days |
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Clinical Information
Laminin 332 (LM332) pemphigoid is a rare subepithelial autoimmune blistering disease that can affect the conjunctival, esophageal, oral, and genital mucosa and skin. With LM332 pemphigoid, there is a risk of blindness and esophageal stricture, among other serious complications. In addition, approximately 20% to 30% of patients with LM332 pemphigoid have an underlying malignancy driving their mucocutaneous disease. Therefore, it is generally accepted that patients found to have circulating LM332 antibodies should be screened for an occult malignancy.
P200 pemphigoid, a rare subepithelial autoimmune blistering disease affecting the skin, shares some clinical characteristics with psoriasis, a much more common inflammatory dermatosis of the skin. However, identification of circulating p200 autoantibodies predicts the development of blisters and portends a worse clinical therapeutic response.
Collagen VII autoantibodies are pathogenic in two rare subepithelial autoimmune blistering diseases: epidermolysis bullosa acquisita (EBA) and bullous systemic lupus erythematosus (BSLE). A diagnosis of EBA is confirmed upon identification of circulating autoantibodies to collagen VII and predicts a refractory treatment course. In addition, patients with EBA have a high rate of associated inflammatory bowel disease (IBD), so identification of collagen VII autoantibodies may prompt clinicians to increase surveillance for IBD. In the appropriate clinical context, circulating autoantibodies to collagen VII may support a diagnosis of BSLE. Accurate identification of BSLE is important, as most patients with this condition have severe manifestations of lupus in other organs, such as lupus nephritis. While our immunodermatology laboratory offers another test to detect collagen VII autoantibodies (COL7 / Anti-Collagen type VII, IgG antibodies, Serum), collagen VII is a large protein, rendering autoantibodies against this target immunologically heterogeneous.
Reference Values
Normal patients: Negative
Interpretation
This test panel is comprised of cell-based assays to detect antibodies directed against laminin-332, p200, or collagen VII. This panel's intended in vitro use is as an aid in the diagnosis of rare subepithelial autoimmune blistering diseases, including anti-laminin 332 pemphigoid, anti-p200 pemphigoid, epidermolysis bullosa acquisita, and systemic bullous lupus erythematosus.
A positive test result for laminin-332 antibodies may correlate with a diagnosis of laminin-332 pemphigoid in the appropriate clinical setting. Laminin-332 pemphigoid is associated with a higher rate of associated malignancy and ocular mucosal disease than conventional pemphigoid.
A positive test result for p200 antibodies may correlate with a diagnosis of p200 pemphigoid in the appropriate clinical setting. P200 pemphigoid can be associated with a more recalcitrant disease course than conventional pemphigoid and may be associated with psoriasis.
A positive test result for collagen VII antibodies may correlate with a diagnosis of epidermolysis bullosa acquisita (EBA) or bullous systemic lupus erythematosus (BSLE) in the appropriate clinical setting. EBA can be associated with inflammatory bowel disease and a more recalcitrant disease course in some patients. BSLE is usually associated with systemic lupus erythematosus.
Recommend correlation with clinical presentation, histopathologic findings from standard biopsy, direct immunofluorescence from a perilesional biopsy (CIB / Cutaneous Direct Immunofluorescence Assay, Varies), indirect immunofluorescence with IgG (CIFS / Cutaneous Immunofluorescence Antibodies, IgG, Serum), and other testing as clinically indicated.
Cautions
Results should be interpreted in conjunction with clinical information, histopathologic pattern observed on skin biopsy, results of direct immunofluorescence from a perilesional biopsy, results of indirect immunofluorescence with salt-split skin and esophageal substrates, and other testing as clinically indicated.
Method Description
Biochip slides with transfected cells are overlaid with dilutions of patient’s serum, incubated, covered with fluorescein-conjugated IgG+IgG4 antiserum, and interpreted with a fluorescence microscope.(Unpublished Mayo method)
Day(s) Performed
Varies
Report Available
1 to 7 daysSpecimen Retention Time
30 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
86255
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
RSBV | Rare Subepi Blistering Variants, S | In Process |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
621392 | Laminin 332 | In Process |
621393 | p200 | In Process |
621394 | Collagen VII | In Process |
621404 | Other | 77202-0 |