Pemphigoid

Pemphigoid diseases typically manifest with blistering of the skin and mucous membranes and are associated with autoantibodies that target structural proteins of the hemidesmosome.  Specific disorders are described within the pemphigoid spectrum, and it is important to distinguish the variants because medical implications and treatments differ for the various types.   Bullous pemphigoid, the most common of the pemphigoid disorders, primarily affects the elderly and may be associated with neurologic disease and other chronic illnesses.   A nonbullous variant occurs in up to 20% of patients with pemphigoid  and is associated with delayed diagnosis because it resembles pruritic dermatoses.  Mucous membrane pemphigoid affects ocular and/or oral mucosal surfaces primarily, with debilitating scarring sequelae especially in the eye; skin can be affected as well.  Pemphigoid gestationis occurs during pregnancy, generally in the second trimester, and often resolves within 6 months postpartum ; an association with celiac disease (CD) serum antibodies has been described.  Two other subtypes of pemphigoid are defined by basement membrane zone (BMZ) antigens targeted by the autoantibodies anti-p200 (laminin gamma-1) and anti-laminin-332, and up to 30% of patients with antilaminin-332 pemphigoid have an associated malignancy. IIF testing is in development for autoantibodies against laminin-332. (This testing is not currently performed at ARUP Laboratories.) See the Pemphigoid Indications and Clinical Features table below for additional characteristics of the disorders.

The diseases described using the term “pemphigoid” and the various disorders with BMZ autoantibodies have overlapping clinical manifestations. Certain clinical features can help distinguish the diseases, and they can be further differentiated by specific patterns of antibody binding and specific antigens targeted; therefore, evaluation of tissue-bound and serum autoantibodies is generally required for diagnosis.   Testing involves direct immunofluorescence (DIF) microscopy, serologic assays such as indirect immunofluorescence (also known as indirect immunofluorescence [IIF]) testing and enzyme-linked immunosorbent assays (ELISAs), and may include immunoblotting or immunoprecipitation.  Broad serologic testing for epithelial antibodies is recommended unless a specific immunobullous skin disease type is suspected.

Quick Answers for Clinicians

What causes pemphigoid diseases?

A predisposing factor for pemphigoid diseases is the presence of HLA gene variants such as HLA-DQB1*0301.  In most patients, the factors that have induced the disease cannot be identified, but onset of the disease has been recognized in association with various drugs and other exposures. Some implicated drugs include antibiotics, angiotensin-converting enzyme (ACE) inhibitors, sulfasalazine, phenacetin, dipeptidyl peptidase 4 inhibitors (DPP4is) or gliptins,  and checkpoint inhibitors (PD-1/PD-L1 monoclonal antibodies used in treatment of lung cancer and melanoma). Discontinuation of implicated drugs may improve control of pemphigoid disease activity. Inducing factors other than drugs include viral infections and physical agents such as radiation therapy, although cases induced by such factors are rare. 

How is pemphigoid diagnosed?

Recently proposed criteria require that two of the following three conditions be met for a diagnosis of pemphigoid: pruritus and/or predominant cutaneous blisters; linear deposition of immunoglobulin G (IgG) or complement 3 (C3) along the basement membrane zone (BMZ), as determined by direct immunofluorescence (DIF); and/or IgG on epidermal side staining of split-skin substrate, as ascertained by indirect immunofluorescence (also known as indirect immunofluorescence [IIF]) testing.  

How are the different pemphigoid disorders differentiated?

Disorders associated with basement membrane zone (BMZ) antibodies have overlapping clinical features and, likely, some common pathophysiology. Differentiation of the various pemphigoid disorders requires clinical examination and testing to identify the patterns and profiles of specific tissue-bound and serum antibodies present. Immunoglobulin G (IgG) BP180 and IgG BP230 antibodies are most strongly associated with pemphigoid, although laminin-332 and alpha 6 beta 4 (α6β4) integrin IgG antibodies are associated with some types.  See the Pemphigoid Types and Associated Antibodies table.

Where can I find information on testing for other epithelial-antibody associated immunobullous diseases?

ARUP Consult has an overview of Epithelial-Antibody Associated Immunobullous Diseases, as well as specific information on pemphiguspemphigoid gestationis, epidermolysis bullosa acquisita (EBA), linear IgA disease, and dermatitis herpetiformis. Visit our algorithms for testing steps for the various diseases.

Indications for Testing

Laboratory testing for pemphigoid diseases is appropriate to:

  • Aid in establishing the diagnosis in patients with indications or clinical characteristics of a pemphigoid disease (see table below)
  • Aid in monitoring of disease activity, severity, and treatment response in patients with an established diagnosis of pemphigoid
Pemphigoid Indications and Clinical Features

Cutaneous pemphigoid variants (bullous pemphigoid, nonbullous pemphigoid, urticarial, localized, drug induced)

Tense bullae and erosions, prominent pruritus (variant forms may not have bullae)

Possible erythematous or urticarial lesions, eczematous dermatitis, pruritus without blisters

Association with neurologic disease (eg, Parkinson disease and multiple sclerosis)

Mucosal involvement (in 15-20% of patients)

Mucous membrane pemphigoid (cicatricial, ocular, antiepiligrin, antilaminin-332,a Brunsting-Perry)

Recurrent bullae that affect mucous membranes, with erosions, scarring sequelae

Primarily ocular and oral involvement; ocular cicatricial pemphigoid variant with disabling scarring

Other mucosal involvement rarer, but includes genital and esophageal involvement

Skin involvement is found; Brunsting-Perry variant with head and neck blistering without mucosal lesions

Pemphigoid gestationis (previously called herpes gestationis)
Pruritic urticarial papules and bullae on abdomen and trunk that occur during pregnancy or postpartum period; may flare with menses and/or hormonal treatment

aAntilaminin-332 (current name for antiepiligrin pemphigoid) is associated with malignancy in more than 30% of patients.

Sources: Schmidt, 2013 ; Otten, 2014 ; Lo Schiavo, 2013 ; Witte, 2018 

Laboratory Testing

Diagnosis

Immunopathology

DIF testing of a perilesional biopsy is highly sensitive and useful to detect tissue-bound autoantibody and/or complement 3 (C3) deposition.    The nature and pattern of autoantibody deposition helps distinguish pemphigoid from other immunobullous skin diseases; however, pemphigoid and epidermolysis bullosa acquisita (EBA) may not be distinguishable by DIF.  In both pemphigoid and EBA, immunoglobulin G (IgG) and C3 are deposited in a linear pattern along the BMZ.  In some specimens, it may be possible to recognize the n-serrated pattern of basement membrane staining associated with pemphigoid, compared to the u-serrated pattern associated with EBA, along with a true linear pattern observed in both diseases. Other antibodies, such as IgA and IgM, also may be detected in a linear BMZ pattern.  

Perilesional skin has demonstrated the most sensitivity in DIF testing, compared with healthy or lesional skin.  However, sensitivity of DIF may be lower in patients with a nonbullous presentation.  In addition, C3 may be detected less often in patients with a nonbullous variant. 

Performing both DIF on a perilesional biopsy and IIF serum testing on human split-skin substrate provides the greatest sensitivity and specificity for pemphigoid diagnosis. 

The mucous membrane pemphigoid variant has antibodies to other BMZ components, including laminin-332 (previously known as laminin-5 and epiligrin), laminin-311 (previously known as laminin-6), and beta 4 integrin subunit. Pemphigoid with laminin-332 antibodies is associated with internal malignancy. DIF testing on more than one biopsy may be helpful in patients with mucous membrane pemphigoid who have negative findings on initial testing but persistent suspicion for the disease.

Histopathology

Histopathologic examination typically reveals the most characteristic findings in an intact bullous pemphigoid lesion, which include eosinophilic spongiosis and/or subepidermal separation with numerous eosinophils in blister cleft and/or superficial dermal inflammation of variable intensity and composition of lymphocytes, eosinophils, and neutrophils. Histopathology of nonbullous lesions are commonly nonspecific. Mucous membrane pemphigoid lesions may show epithelial-subepithelial separation and mixed inflammatory cell infiltration of lymphocytes, histiocytes, eosinophils, neutrophils, and plasma cells and, in scarred lesional areas, subepithelial fibrosis.

Serum Testing

Recommended initial serum testing for pemphigoid involves panel testing for epithelial skin antibodies. Serum antibody profiles and titers correlate with pemphigoid disease manifestations and activity. 

In serologic testing for pemphigoid diseases, the patient serum is overlaid on epithelial tissue substrates to determine if there are antibodies in the circulation that target particular surfaces in the substrates being tested. Either or both human split skin or monkey esophagus substrates can be used, but human split skin is considered preferable for pemphigoid, although monkey esophagus provides broader identification of epithelial antibody staining patterns that may indicate other immunobullous diseases.  

IIF tests and ELISAs are both useful serologic tests. IIF testing enables detection of circulating antibodies and deposition patterns, whereas ELISAs both identify and semiquantify antibodies to antigens that are common in bullous pemphigoid and pemphigoid variants.  However, ELISA is considered less useful for diagnosis than for monitoring disease after a pemphigoid diagnosis has been established.  Immunoblotting and immunoprecipitation are other sensitive and specific testing methods that can provide serologic confirmation of immunobullous skin diseases but are mainly used in research applications and are not available in most clinical diagnostic laboratories.  

Pemphigoid-Specific Antibodies
Pemphigoid Types and Associated Antibodies

Bullous pemphigoid

BP180, BP230a

Mucous membrane pemphigoid

BP180, p200 (laminin γ1), laminin-332, α6β4 integrinb

Pemphigoid gestationis (formerly called herpes gestationis)

BP180 (rarely also BP230)

Anti-p200 pemphigoid

p200 antigen (laminin γ1)

aPatients with nonbullous variants demonstrate lower levels of antibodies against BP180 and more often have antibodies against BP230. 

bThe Brunsting-Perry variant of mucus membrane pemphigoid may also demonstrate antibodies against LAD-1. 

α6β4, alpha 6 beta 4

Source: Lamberts, 2019 ; Meijer, 2019 ; Otten, 2014 ; Lau, 2019 

A characteristic feature of pemphigoid is the presence of IgG antibodies against BP180 and BP230, structural proteins of the BMZ.  Therefore, testing for BMZ antibodies and IgG antibodies to BP180 and BP230 antigens is sensitive and specific for pemphigoid, and can help to differentiate between pemphigoid, linear IgA disease, and EBA.  Circulating BMZ IgG antibodies are present in serum in 80-85% of patients with bullous pemphigoid  and approximately 50% of patients with mucous membrane pemphigoid; up to 60% of patients with mucous membrane pemphigoid demonstrate IgA antibodies.  Detection of IgG antibodies to both BP180 and BP230 antigens increases the sensitivity and specificity for diagnosis of pemphigoid. The presence of both IgG and IgA BMZ antibodies may have implications for greater disease severity and treatment considerations for dapsone therapy. Other antibodies may also be detected; for instance, IgE antibodies against BP180 are present in 30-95% of patients with bullous pemphigoid and correlate with more severe disease. 

Unless pemphigoid is specifically suspected, broad screening is recommended because of the overlap in clinical presentations of immunobullous diseases.

Monitoring

A pathophysiologic relationship of the diagnostic markers for pemphigoid has not been established; therefore, monitoring recommendations are linked to clinical disease and to therapeutic decision-making. ELISAs to detect antibodies against BP180 and BP230 may be appropriate for monitoring disease activity after a diagnosis of pemphigoid with increased levels has been established. Intermittent testing with a pemphigoid antibody panel that includes IIF for BMZ antibodies and BP180 and BP230 IgG antibody levels is useful to detect changing antibody patterns, which may have implications for disease expression and activity. IgG BP180 antibody levels are more closely correlated with disease activity in some patients with pemphigoid than are IgG BP230 antibody levels and BMZ antibody titers.  Comparisons of serial testing results in individual patients may give guidance in assessing disease expression, particularly in cases of persistent or progressive activity and therapeutic responsiveness.

Guidelines for monitoring frequency have not been established. Monitoring intervals should take into consideration disease severity, antibody levels, and treatment types. Pemphigoid-associated antibodies may not demonstrate changes for weeks to months with glucocorticoid therapy and demonstrate differing temporal relationships with other treatments. In patients with pemphigoid gestationis, IgG BP180 antibody levels may remain increased even in disease remission. Up to 7% of individuals who are not affected by pemphigoid, including patients with other immunobullous diseases, have increased IgG BP180 and/or IgG BP230 antibody levels.

ARUP Laboratory Tests

Additional detail about the tests below can be found in the ARUP Immunobullous Disease Testing Comparison table

Immunopathologic Test (DIF)

Use with serum immunobullous disease/epithelial antibody testing and formalin-fixed tissue histopathology for assessment of pruritic, urticarial, blistering, and/or erosive disorders

Use with formalin-fixed tissue histopathology for assessment of inflammatory, immune-mediated cutaneous disease

Optimal specimen location and complementary serum testing and/or histopathology examination vary according to disease type; note that specimen location and transport medium/fixative are different for direct immunofluorescence testing and fixed-tissue histopathology

Components: cutaneous DIF, biopsy; EER cutaneous DIF, biopsy; DIF includes IgG, IgG4, IgM, IgA, C3, and fibrinogen with diagnostic interpretation of staining patterns

Recommended Serologic Tests

Semiquantitative IIF and Semiquantitative ELISA (With Biopsy DIF in Initial Assessment)

Use as initial comprehensive testing panel to aid in the diagnosis of and distinguishing among skin and mucous membrane disorders that present with blistering, erosions, eczema, pruritus, and/or urticaria

Use for assessment of suspected epithelial antibody-associated immunobullous diseases, pemphigoid and pemphigus and their variants, that are not clinically distinguishable, have nonspecific features, potentially express overlapping epithelial antibodies, and/or are indicated by concurrent DIF biopsy

Components: BMZ antibodies, IgG by IIF; BMZ antibodies, IgA by IIF; BP180 and BP230 antibodies, IgG by ELISA; collagen type VII antibodies, IgG by ELISA; cell surface antibodies, IgG by IIF; desmoglein 1 and 3 antibodies, IgG by ELISA; cell surface antibodies, IgA by IIF

Use as the preferred initial diagnostic panel for suspected BMZ antibody-associated skin and mucous membrane disorders that present with blistering, erosions, eczema, urticaria, pruritus, and/or mucositis

May be indicated by concurrent DIF biopsy

Alternatively, order the comprehensive Immunobullous Disease Antibody Panel for initial serum diagnostic assessment of epithelial antibody-associated diseases, pemphigoid, pemphigus, and their variants

Components: BMZ antibodies, IgG by IIF; BMZ antibodies, IgA by IIF; BP180 and BP230 antibodies, IgG by ELISA; collagen type VII antibodies, IgG by ELISA 

Use to assess and monitor pemphigoid, pemphigoid variants, and linear IgA disease and to discriminate among the immunobullous diseases with epithelial BMZ antibodies

May be indicated by concurrent DIF biopsy; preferred initial diagnostic serum panel is Basement Membrane Zone Antibody Panel

Components: BMZ antibodies, IgG by IIF; BMZ antibodies, IgA by IIF; BP180 and BP230 antibodies, IgG by ELISA

Use as the preferred panel to assess and monitor pemphigoid gestationis (herpes gestationis) or other immunobullous disease with complement-fixing BMZ antibodies

Testing should be correlated initially with concurrent DIF biopsy 

Consider other types of immunobullous disease serum testing concurrently 

Components: complement-fixing BMZ antibodies; BP180 antibody, IgG by ELISA; BMZ antibodies, IgG by IIF

Other Serologic Tests, Separate Components

Semiquantitative IIF and Semiquantitative ELISA

Use to assess and monitor IgG basement membrane zone antibodies in patients with pemphigoid, pemphigoid variants/subtypes, and epidermolysis bullosa acquisita (EBA), especially those with normal relevant IgG BP180, IgG BP230, and IgG type VII collagen antibody levels by ELISAs

Testing should be initially correlated with concurrent DIF biopsy

For initial pemphigoid or EBA diagnosis, a more comprehensive serum panel is preferred; refer to Immunobullous Disease Antibody Panel

Use to assess and monitor IgA BMZ antibodies in patients with linear IgA disease, including linear IgA bullous dermatosis and chronic bullous disease of childhood, and IgA variant EBA

Testing should be correlated with concurrent DIF biopsy 

For initial linear IgA disease diagnosis, serum Basement Membrane Zone Antibody Panel or Immunobullous Disease Antibody Panel is preferred 

Use to monitor disease in patients diagnosed with pemphigoid and increased IgG BP180 and/or BP230 antibody levels

For initial pemphigoid diagnosis that discriminates among immunobullous diseases and for assessment of disease progression/changes and intermittent monitoring, the Basement Membrane Zone Antibody Panel or Immunobullous Disease Antibody Panel is preferred

Use to monitor disease in patients diagnosed with EBA or bullous lupus erythematosus with increased IgG type VII collagen antibody levels

For initial diagnosis, including discrimination among various immunobullous diseases, and assessment of disease progression/changes and intermittent monitoring, the Immunobullous Disease Antibody Panel or Basement Membrane Zone Antibody Panel is preferred

Other Serologic Tests for Potential Overlapping or Coexpression

Semiquantitative IIF and Semiquantitative ELISA

Use to monitor linear IgG and IgA BMZ antibody-associated diseases and IgG and IgA cell surface antibody-associated diseases in which antibody levels by ELISAs may not be increased and/or to assess for changing patterns of epithelial antibody expression

May be used as general initial serum test for immunobullous diseases; however, for more sensitive and specific serum testing with ELISAs for pemphigoid and EBA or for IgG variant pemphigus, refer to Basement Membrane Zone Antibody Panel or Pemphigus Antibody Panel, IgG

Components: BMZ antibodies, IgG by IIF; BMZ antibodies, IgA by IIF; cell surface antibodies, IgG by IIF; cell surface antibodies, IgA by IIF

Use to assess and monitor DH. Testing should be correlated with concurrent DIF biopsy

Because most patients with DH have associated celiac disease (CD), testing should be performed in conjunction with testing for CD

For initial diagnosis and assessment of disease progression/changes and to distinguish from other immunobullous diseases with epithelial antibodies, order concurrently with serum Immunobullous Disease Antibody Panel 

Component: ELISA for IgA antibodies to epidermal transglutaminase (eTG), also known as transglutaminase type 3 or TG3

Antibody test for initial assessment and disease monitoring of DH and to discriminate among the immunobullous skin diseases

Use with BMZ and pemphigus panel tests and epidermal transglutaminase antibody, IgA, or with Immunobullous Disease Antibody Panel, and epidermal transglutaminase antibody, IgA testing 

Components: Quantitative nephelometry for Immunoglobulin A with one or more reflexive tests that may include IIF for IgA endomysial antibodies; ELISAs for IgA and IgG antibodies to tissue transglutaminase and deamidated gliadin peptide (DGP)

Use as the preferred serum antibody panel to assess and monitor IgG pemphigus variants (includes pemphigus foliaceus and pemphigus vulgaris), which present with blistering and erosive disease affecting skin and mucous membranes

Testing should be correlated initially with concurrent DIF biopsy

Components: cell surface antibodies, IgG by IIF; desmoglein 1 and desmoglein 3 antibodies, IgG by ELISA

Use to assess and monitor IgA pemphigus or other nonclassical pemphigus subtypes with both IgA and IgG cell surface antibodies

Testing should be initially correlated with concurrent DIF biopsy

Consider ordering concurrently with serum Pemphigus Antibody Panel, IgG if other types of pemphigus are diagnostic considerations

References

Additional Resources

Medical Experts

Contributor

Leiferman

Picture of Kristin M. Leiferman, MD

 

Co-Director, Immunodermatology Laboratory, Professor of Dermatology, and Adjunct Professor of Pathology, University of Utah
Medical Director, Immunodermatology, ARUP Laboratories