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.  Mucus membrane pemphigoid affects ocular and/or oral mucosal surfaces primarily; 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 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. 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 antibodies 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 fluorescent antibody [IFA]) testing and enzyme-linked immunosorbent assays (ELISAs), and may include immunoblotting or immunoprecipitation.  Broad serologic screening 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 fluorescent antibody [IFA]) 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) BP 180 and IgG BP 230 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

Immunohistopathology

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 IFA 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.  

IFA tests and ELISAs are both useful serologic tests. IFA 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

BP 180, BP 230a

Mucous membrane pemphigoid

BP 180, p200 (laminin γ1), laminin-332, α6β4 integrinb

Pemphigoid gestationis (formerly called herpes gestationis)

BP 180 (rarely also BP 230)

Anti-p200 pemphigoid

p200 antigen (laminin γ1)

aPatients with nonbullous variants demonstrate lower levels of antibodies against BP 180 and more often have antibodies against BP 230. 

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 BP 180 and BP 230, structural proteins of the BMZ.  Therefore, testing for BMZ antibodies and IgG antibodies to BP 180 and BP 230 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 BP 180 and BP 230 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 BP 180 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 BP 180 and BP 230 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 IFA for BMZ antibodies and BP 180 and BP 230 IgG antibody levels is useful to detect changing antibody patterns, which may have implications for disease expression and activity. IgG BP 180 antibody levels are more closely correlated with disease activity in some patients with pemphigoid than are IgG BP 230 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 BP 180 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 BP 180 and/or IgG BP 230 antibody levels.

ARUP Lab Tests

Immunohistopathologic Test (DIF)

Use with serum antibody testing and formalin-fixed tissue histopathology for assessment of pruritic, urticarial, blistering, and/or erosive disorders (including possible pemphigoid and pemphigoid variants); perilesional specimen recommended for blisters and/or erosions

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

Optimal specimen location varies according to disease type, blistering or nonblistering

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

For initial assessment of suspected epithelial antibody-associated immunobullous diseases; also assists in distinguishing the diseases

Semiquantitative IFA and ELISA; positive limiting-dilution end-point antibody titer (IFA) and antibody level in units (ELISA)

To aid in the diagnosis of pemphigoid and pemphigus variants, EBA, linear IgA disease, bullous lupus erythematosus

Components: IFA for IgG and IgA BMZ antibodies (pemphigoid, EBA, linear IgA disease), includes split-skin substrate, and IgG and IgA cell surface antibodies (IgG and IgA pemphigus subtypes); ELISAs for IgG antibodies to BP 180, BP 230, type VII collagen, desmoglein 1, and desmoglein 3

Preferred antibody panel for initial assessment and disease monitoring in pemphigoid, EBA, and linear IgA bullous dermatosis

Semiquantitative IFA and ELISA; positive limiting-dilution end-point antibody titer (IFA) and antibody level in units (ELISA)

To aid in diagnosis of immunobullous diseases with epithelial BMZ antibodies, alternatively order Immunobullous Disease Panel, Epithelial

Components: IFA for IgG and IgA BMZ antibodies (pemphigoid, EBA, linear IgA disease), includes split-skin substrate; ELISAs for IgG antibodies to BP 180, BP 230, and type VII collagen (all components included in immunobullous disease panel)

Antibody panel for initial assessment and disease monitoring in pemphigoid and linear IgA bullous dermatosis and to discriminate among the immunobullous skin diseases

Semiquantitative IFA and ELISA; positive limiting-dilution end-point antibody titer (IFA) and antibody level in units (ELISA)

To aid in diagnosis of pemphigoid along with other possible immunobullous diseases with epithelial BMZ antibodies; alternatively order Basement Membrane Zone Antibody Panel or Immunobullous Disease Panel, Epithelial

Components: IFA for IgG and IgA BMZ antibodies (pemphigoid, EBA, linear IgA disease); ELISAs for IgG antibodies to BP 180 and BP 230 (all components included in the immunobullous disease panel and in the BMZ antibody panel, but this panel does not include IgG antibodies to type VII collagen ELISA that is included in others)

Preferred antibody panel for initial assessment and disease monitoring in pemphigoid gestationis (herpes gestationis), includes IgG BP 180 antibody level by ELISA; also consider other immunobullous disease testing (eg, IgA epithelial BMZ, IgG collagen type VII, and/or pemphigus antibody panel, IgG)

Semiquantitative IFA and ELISA; positive limiting-dilution end-point antibody titer (IFA) and antibody level in units (ELISA)

Components: IFA for complement-fixing (C3) and IgG BMZ antibodies (herpes gestationis factor in pemphigoid gestationis, pemphigoid, EBA); ELISA for IgG antibodies to BP 180

Other Serologic Tests, Separate Components

Semiquantitative IFA and Semiquantitative ELISA

Assess and monitor patients with positive IgG BMZ antibodies in pemphigoid and EBA, especially in patients with normal IgG BP 180, IgG BP 230, and IgG type VII collagen antibody levels

Semiquantitative IFA; positive limiting-dilution end-point antibody titer(s)

Consider ordering concurrently with IgA epithelial BMZ antibody testing, bullous pemphigoid antigens, BP 180 and BP 230 antibodies, and/or IgG collagen type VII antibody; alternatively order Basement Membrane Zone Antibody Panel or Immunobullous Disease Panel, Epithelial

Components: IFA for IgG BMZ antibodies (included in the immunobullous disease panel, the BMZ antibody panel, the pemphigoid antibody panel, and the epithelial skin antibody panel)

Assess and monitor patients with positive IgA BMZ antibodies in linear IgA disease, including linear IgA bullous dermatosis and chronic bullous disease of childhood, IgA variant EBA, and overlap expression in pemphigoid with IgG BMZ antibodies

Semiquantitative IFA; positive limiting-dilution end-point antibody titer(s)

Consider ordering concurrently with IgG epithelial BMZ antibody testing, bullous pemphigoid antigens, BP 180 and BP 230 antibodies, and/or IgG collagen type VII antibody; alternatively order Basement Membrane Zone Antibody Panel or Immunobullous Disease Panel, Epithelial

Components: IFA for IgA BMZ antibodies (included in the immunobullous disease panel, the BMZ antibody panel, the pemphigoid antibody panel, and the epithelial skin antibody panel)

Monitor disease in patients diagnosed with pemphigoid and increased IgG BP 180 and/or BP 230 antibody levels

Semiquantitative ELISA; antibody level in units

For initial diagnosis and assessment of disease progression/changes and intermittent monitoring, preferred test is Basement Membrane Zone Antibody Panel or Immunobullous Disease Panel, Epithelial

Components: ELISAs for IgG antibodies to bullous pemphigoid antigens, BP 180 and BP 230 (included in the immunobullous disease panel, in the BMZ antibody panel, and in the pemphigoid antibody panel)

Monitor disease in patients diagnosed with EBA or bullous lupus erythematosus and increased IgG type VII collagen antibody levels

Semiquantitative ELISA; antibody level in units

For initial diagnosis and assessment of disease progression/changes and intermittent monitoring, preferred test is Immunobullous Disease Panel, Epithelial, or Basement Membrane Zone Antibody Panel

Components: ELISA for IgG antibodies to type VII collagen (included in the immunobullous disease panel and in the BMZ antibody panel)

Other Serologic Tests for Potential Overlapping or Coexpression

Semiquantitative IFA and Semiquantitative ELISA

General initial test for immunobullous diseases and monitoring EBA and linear IgA disease expression (test does not include ELISAs for specific disease-related antigenic targets)

Semiquantitative IFA; positive limiting-dilution end-point antibody titer(s)

Consider ordering with ELISAs for IgG bullous pemphigoid antigens, BP 180 and BP 230, antibodies for suspected pemphigoid, IgG collagen type VII antibody for suspected EBA, and/or IgG desmoglein 1 and IgG desmoglein 3 antibodies for suspected pemphigus

For more sensitive and specific pemphigoid or pemphigus testing, refer to antibody panels for pemphigus, BMZ, or pemphigoid

Components: IFA for IgG and IgA BMZ antibodies (pemphigoid, EBA, linear IgA disease) and IgG and IgA cell surface antibodies (IgG and IgA pemphigus subtypes) (all components included in immunobullous disease panel, epithelial)

Assess and monitor disease in patients with possible dermatitis herpetiformis

Semiquantitative ELISA; antibody level in units

For initial diagnosis and assessment of disease progression/changes and to distinguish from other possible immunobullous diseases with epithelial antibodies, order with Celiac Disease Reflexive Cascade and Immunobullous Disease Panel, Epithelial, OR with Celiac Disease Reflexive Cascade and Basement Membrane Zone Antibody Panel and/or pemphigus antibody panel, IgG

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 dermatitis herpetiformis and to discriminate among the immunobullous skin diseases

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

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

Preferred antibody panel for initial assessment and disease monitoring in IgG-variant pemphigus

Semiquantitative IFA and ELISA; positive limiting-dilution end-point antibody titer (IFA) and antibody level in units (ELISA)

To aid in diagnosis of pemphigus along with other possible immunobullous diseases with IgG epithelial cell surface antibodies, alternatively order Immunobullous Disease Panel, Epithelial

Components: IFA for IgG epithelial cell surface antibodies; ELISAs for IgG antibodies to desmoglein 1 and IgG desmoglein 3 (all components included in immunobullous disease panel)

Assess and monitor patients with possible IgA pemphigus, a rare disease with certain clinical and histopathologic subtypes

Semiquantitative IFA; positive limiting-dilution end-point antibody titer(s)

If other types of pemphigus are of diagnostic consideration, order Immunobullous Disease Panel, Epithelial, first or this test concurrently with panel test for IgG pemphigus antibodies

Components: IFA for IgA cell surface antibodies (included in the immunobullous disease panel and the epithelial skin antibody panel)

Medical Experts

Contributor

Leiferman

 

Co-Director, Immunodermatology Laboratory, Professor of Dermatology, University of Utah

Consultant, Immunodermatology at ARUP Laboratories

References

Additional Resources