title: Immunohistochemical localization of basement membrane laminin 5 and collagen IV in adult linear IgA disease.
abstract: BACKGROUND
  Linear immunoglobulin A disease (LAD), also known as linear IgA bullous dermatosis, is an autoimmune disorder characterized by subepidermal bullae caused by IgA autoantibodies directed against several antigens located in the basement membrane zone of the skin. Laminin 5 (laminin-332) is considered a key component of the lamina lucida/lamina densa interface, which provides stable attachment of the epidermis to the dermis. Meanwhile, collagen IV is a major component of the lamina densa. Laminin 5 and collagen IV bind to the cell membrane and induce cytoskeletal rearrangements, which contribute to the basement membrane's final mat-like structure. The study aimed to evaluate the immunohistochemical staining of laminin 5 and collagen IV and to identify the site of blister formation in formalin-fixed, paraffin-embedded skin biopsies from adults with LAD.
  
  
  METHODS
  Skin biopsies from 20 adult patients with LAD were subjected to routine hematoxylin-eosin as well as immunohistochemical staining of collagen IV and laminin 5.
  
  
  RESULTS
  Linear staining was positive on the floor of the blister for laminin 5 in 65% and collagen IV in 90% of biopsies denoting that the site of separation in most cases of LAD is above the lamina densa.
  
  
  CONCLUSIONS
  The use of laminin 5 and collagen IV immunohistochemistry can be considered as an adjuvant diagnostic tool and may aid in the identification of the site of blister formation in routine skin biopsies in adults with LAD.
authors.affiliation: Department of Dermatology, Faculty of Medicine, Al-Minya University, Al-Minya, Egypt.
authors.forename: Moetaz
authors.initials: M
authors.lastname: El-Domyati
authors.affiliation: Department of Dermatology, Faculty of Medicine, Al-Minya University, Al-Minya, Egypt.
authors.forename: Hossam
authors.initials: H
authors.lastname: Abdel-Wahab
authors.affiliation: Department of Dermatology, Faculty of Medicine, Al-Minya University, Al-Minya, Egypt.
authors.forename: Hesham
authors.initials: H
authors.lastname: Ahmad
mesh_terms: D000328:Adult; D000368:Aged; D001485:Basement Membrane / Q000737:chemistry*; D001768:Blister / Q000378:metabolism* / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000032:analysis*; D024141:Collagen Type IV / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D062027:Linear IgA Bullous Dermatosis / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D000097794:Kalinin
chemical_list: D015815:Cell Adhesion Molecules; D024141:Collagen Type IV; D000097794:Kalinin