Dermatology Services

Diagnostic Tests

Tissue Tests - skin and mucosal biopsy specimens

Serum Tests - peripheral blood serum specimens

Test Descriptions

  • Direct Immunofluorescence (DIF) of cutaneous tissue (skin and mucosa)
    The DIF test is performed on skin or mucosal biopsy specimens. All biopsy specimens are examined for the presence and staining pattern of immunoglobulins (IgG, IgM, IgA), third component of complement (C3), and fibrinogen. An optimal analysis is obtained when the specimen is procured from an appropriate site (biopsy site information) using the proper technique (see specimen collection instructions) and accompanied by a separate fixed tissue specimen for histological examination (see below). Accompanying serum for indirect immunofluorescence and/or enzyme-linked immunosorbent assays is diagnostically helpful for immunobullous diseases. [top]

  • Histological examination of fixed tissue (H&E and other stains as indicated)
    Histological examination is performed on skin or mucosal biopsy specimens submitted in formalin. If accompanying tissue for direct immunofluorescence, separate reports are issued incorporating the direct immunofluorescence results along with the histological findings. All fixed specimens are examined following hematoxylin and eosin (H&E) staining; other stains are performed and examined as indicated. [top]

  • Eosinophil major basic protein (eMBP) of tissue
    This is an indirect immunofluorescence test on tissue to detect eosinophil involvement in disease and is performed on formalin-fixed tissue. Eosinophils often disrupt in tissue, losing morphologic identity. This test, which detects an eosinophil granule protein, released upon eosinophil activation, is particularly useful for detecting eosinophil activity in inflammatory diseases including allergic diseases in a variety of epithelial tissues (skin, conjunctiva, upper and lower respiratory tract, gastrointestinal tract) and connective tissue (fibrotic processes). [top]

  • Basement membrane zone antibodies by Indirect Immunofluorescence (IIF) of serum
    This IIF test is performed on serum to detect the presence and amount of circulating IgG and/or IgA antibodies to epidermal/epithelial antigens. Semiquantitative levels of antibodies are reported as titers. Basement membrane zone antibodies are helpful in diagnosing and distinguishing subepidermal immunobullous diseases such as pemphigoid, epidermolysis bullosa acquisita and linear IgA bullous disease. [top]

  • Cell surface (also known as intercellular substance and pemphigus) antibodies by Indirect Immunofluorescence (IIF) of serum
    This IIF test is performed on serum to detect the presence and amount of circulating IgG and/or IgA antibodies to epidermal/epithelial antigens. Semiquantitative levels of antibodies are reported as titers. Cell surface antibodies are helpful in diagnosing pemphigus, including pemphigus vulgaris, pemphigus foliaceus, pemphigus vegetans and pemphigus erythematosus for IgG cell surface antibodies and IgA pemphigus for IgA cell surface antibodies. Levels of antibodies correlate with disease activity in pemphigus. [top]

  • Endomysial Antibodies (EMA) by IIF of serum
    This IIF test is performed to detect the presence and levels of circulating IgA and/or IgG endomysial antibodies (EMA). IgA EMA are present in essentially all patients with celiac disease and in 70-80% of patients with dermatitis herpetiformis who are not adhering to a gluten-free diet. The test is highly specific and sensitive for both celiac disease and dermatitis herpetiformis. EMA levels can be used to monitor adherence to a gluten-free diet.  IgG EMA antibodies may be found in patients with celiac disease and dermatitis herpetiformis who also have IgA antibodies and may be helpful in a diagnostic testing panel. IgG EMA may occur earlier than IgA antibodies in celiac disease, and they may useful in aiding the diagnosis of these diseases in patients who are IgA deficient. [top]

  • Pemphigoid (Herpes) gestationis factor by complement fixing IIF of serum
    This test is a complement-fixing indirect immunofluorescence test of serum that is useful in the diagnosis of pemphigoid (herpes) gestationis, an immunobullous disease of pregnancy. [top]
  • Paraneoplastic pemphigus screen by IIF of serum on rodent substrates
    This test is performed on rodent bladder, liver, and heart substrates with patient's serum suspected of having paraneoplastic pemphigus. Patients with paraneoplastic pemphigus develop autoantibodies to epithelium that can be detected on rodent substrates. This test aids in the diagnosis of paraneoplastic pemphigus and should be used in combination with both cell surface and basement membrane zone indirect immunofluorescence. [top]
  • Desmoglein 1 and desmoglein 3 IgG antibodies for pemphigus by enzyme linked immunosorbent assays (ELISAs)
    The cell surface antigens in pemphigus to which patients develop circulating autoantibodies are desmoglein 1 for pemphigus foliaceus (and pemphigus erythematosus) and desmoglein 3 for pemphigus vulgaris (and pemphigus vegetens). Overlap occurs among the types of pemphigus. Detection of the antibodies aids in the diagnosis of and subtyping of pemphigus, and antibody levels correlate with disease activity. [top]
  • Bullous pemphigoid antigens, BP 180 and BP 230, IgG antibodies by ELISAs
    The primary basement membrane zone antigens in pemphigoid to which patients develop circulating autoantibodies are bullous pemphigoid antigen 1, BP230, and bullous pemphigoid antigen 2 (BP180). Antibody levels to either or both antigen correlates with disease activity in bullous pemphigoid. [top]
  • Tissue Transglutaminase (tTg) IgA and/or IgG Antibodies in serum by ELISA
    The presence of these antibodies aids the diagnosis of gluten sensitive enteropathy-associated diseases including celiac disease and dermatitis herpetiformis; IgA tTG antibody levels are useful for monitoring patient's adherence to a gluten-free diet. Tissue transglutaminase is an autoantigen in the endomysium to which autoantibodies in gluten-sensitive enteropathies react. IgG tTG antibodies may be present along with or in the absence of IgA tTG antibodies and may be present in patients with IgA deficiency. [top]
  • Total Serum IgA
    This test is useful for determining levels of IgA in serum. IgA deficiency is common and, if present, may affect the diagnostic value of testing for IgA antibodies. [top]