062
Test #
Laminin 332 Autoimmunity (includes primate esophagus and split skin for IgG and IgG4, Laminin 332)
CPT Code(s) #
See individual tests
If Profile, Includes Tests:
N/A
Disease Name:
Laminin 332 Pemphigoid
Type of Study:
Serum Studies
Methodology:
Indirect Immunofluorescence
Substrate:
Transfected Human Epithelial Cells, Primate Esophagus, Split Skin
Reference Range:
Monkey Esophagus (IgG/IgG4)
• Negative <10
Split Skin (IgG/IgG4)
• Negative <5
Laminin 332
• Negative <10
Units:
Titer
Schedule:
Assay performed daily Monday-Friday. Report availability is within 48-72 hours from the time of specimen receipt. The turnaround time may be more than 72 hours if there is a need to run this test in batches.
Specimen Requirements:
Specimen need not be refrigerated or frozen. Collect 2-5 ml of blood in a red top or serum separator tube. Minimum volume requested is 2ml. If possible, separate serum from clot and place into red top tube provided with Beutner Laboratories collection kits. If separation facilities are not available, the blood can be sent in the tube used for collection.
Sample Stability:
Stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8ºC) up to five days and frozen (-20ºC or lower) up to one year.
Clinical Relevance:
Mucous membrane pemphigoid (MMP) is a mucosal autoimmune subepithelial blistering disease mediated autoantibodies against various autoantigens in the basement membrane zone (BMZ). The predominant autoantigens are BP180, BP230, laminin 332 , integrin alpha 6 beta 4, and collagen VII (COL7) (Egan, 2001). MMP mediated by antibodies to laminin 332 presents with a different clinical presentation and risk. Anti-laminin 332 MMP lesions tend to scar and can result in serious complications depending on the mucosal surface affected. Scarring of ocular mucosa can result in symblepharon, disruption of the tear film, entropion, and/or corneal opacities, all of which may lead to blindness. Other irreversible, severe complications are esophageal, anal stenosis, and urethral strictures. An additional complication of anti-laminin 332 MMP increased relative risk of solid epithelial malignancies, mainly adenocarcinoma affecting the gastrointestinal, genital mucosa, and lungs (Balestri, 2016). Clinically, patients with anti-laminin 332 MMP cannot be differentiated from patients with MMP with autoantibodies against the other main target antigen, BP180, although pharyngeal involvement was reported to occur less frequently in the latter patients. Patients with anti-laminin 332 MMP cannot be differentiated from other variants of MMP based on clinical appearance and can only be distinguished by serological testing. Identification of MMP patients with laminin 332-specific antibodies are essential since 25%-30% of these patients might have a malignancy. The introduction of the laminin 332-specific biochip mosaic developed in 2019 by Goletz et al., provided a widely available standardized test system for the detection of anti-laminin 332 serum autoantibodies. External and internal studies showed that the test showed a sensitivity of 84% and a specificity of 99.8%.
References:
Balestri R, Magnano M, La Placa M, Patrizi A, Angileri L, Tengattini V, Bardazzi F. Malignancies in bullous pemphigoid: a controversial association. J Dermatol 2016; 43: 125-133.
Egan CA, Lazarova Z, Darling TN, Yee C, Cote T, Yancey KB. Anti-epiligrin cicatricial pemphigoid and relative risk for cancer. Lancet 2001; 9: 1850-1851.
Goletz S, Probst C, Komorowski L, Schlumberger W, Fechner K, van Beek N, et al. A Sensitive and Specific Assay for the Serological Diagnosis of Antilaminin 332 Mucous Membrane Pemphigoid. Br J Dermatol (2019) 180(1):149-56. doi: 10.1111/bjd.17202
