Autoimmune blistering diseases: an up-date of diagnostic methods and investigations

Bullous Pemphigoid with Atypical Skin Lesions and Acute Interstitial Nephritis: A Case Report and Focused Literature Review

Patient: Male, 76

Final Diagnosis: Drug induced bullous pemphigoid

Symptoms: Skin rash

Medication: Cephalexin

Clinical Procedure: Skin biopsy

Specialty: General and Internal Medicine

Basement membrane zone and dermal extracellular matrix of the vulva, vagina and amnion: An immunohistochemical study with comparison with non-reproductive epithelium

BACKGROUND/OBJECTIVES

The basement membrane zone (BMZ) is an anatomically defined region present in all types of skin and mucosa, linking the epithelium to the mesenchyme with a complex structure to provide adhesion. Altered antigenic expression of the BMZ is implicated in interface dermatoses, and the BMZ is targeted by autoantibodies in subepidermal immunobullous dermatoses. This study aims to compare the antigenic expression of the BMZ and the dermal extracellular matrix in female genital skin and mucosa and amnion, with non-reproductive skin and mucosa.

METHODS

An indirect immunofluorescence technique was used to compare the antigenic expression of hemidesmosome, lamina lucida, anchoring filaments, lamina densa, anchoring fibrils and extracellular matrix in samples of non-reproductive skin (three), oral mucosa (three), vulval skin (two), vagina (three) and amnion (four).

RESULTS

Antigenic expression was similar in the stratified epithelium of reproductive and non-reproductive skin and mucosa, but differed in the simple cuboidal epithelium of amnion, which had reduced expression of dermal-associated antigens.

CONCLUSIONS

The BMZ and dermal extracellular matrix of vagina and vulva are very similar to those of non-reproductive skin and mucosa despite their various functions, but differs from amnion. Their antigenic expression does not fully account for the anatomical distribution of immunobullous and interface dermatoses.

Autoantibodies to basement membrane proteins BP180 and BP230 are commonly detected in normal subjects by immunoblotting

Autoantibodies to basement membrane proteins BP180 and BP230 are characteristic of bullous pemphigoid and other subepidermal immunobullous disorders. These antibodies are, however, reported in other pruritic dermatoses, non-bullous disorders and non-cutaneous disease. Few studies have assessed basement membrane antibodies in normal subjects; antibody prevalence in this population is not clear. This study aims to examine basement membrane zone antibodies in normal middle-aged to elderly subjects. Sera from 61 healthy subjects (majority age 50-70 years) were assessed by immunoblot, indirect immunofluorescence and enzyme-linked immunosorbent assay. Ninety-one bullous pemphigoid patients acted as positive controls. Antigenic target, antibody class and titre were examined; sera binding BP180 were assessed for reactivity to the non-collagenous 16A (NC16A) domain. Thirty-six normal subjects (59%) had antibodies to either BP180 or BP230 on immunoblot analysis. BP180 was the commonest target antigen, detected in 35 subjects; binding to the immunodominant NC16A domain was not detected. Immunofluorescence was positive in three subjects. Of the bullous pemphigoid sera, 88% were positive on immunoblot or immunofluorescence; a higher frequency had antibodies against BP230. In conclusion, significant numbers of normal healthy subjects have circulating autoantibodies to basement membrane proteins, chiefly BP180 detectable by immunoblot, but these do not bind the NC16A domain.

Canadian consensus statement on the use of intravenous immunoglobulin therapy in dermatology

BACKGROUND

As a safe, well-tolerated, and potentially beneficial therapy, intravenous immunoglobulin (IVIG) has been increasingly used by dermatologists to treat immune-mediated skin disease. However, practical and comprehensive guidelines for the use of IVIG have yet to be established.

OBJECTIVE

To develop the first Canadian consensus statement on the use of IVIG therapy in skin disease.

METHODS

A group of Canadian dermatologists convened to discuss current issues in IVIG therapy. The participants reviewed and evaluated the literature and shared clinical experience. Using a modified Delphi process, a consensus statement was developed.

RESULTS

Herein we provide a brief overview of pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, mucous membrane pemphigoid, epidermolysis bullosa acquisita, Stevens-Johnson syndrome, and toxic epidermal necrolysis. Recommendations for the management of these diseases are detailed, and therapeutic algorithms for the treatment of various autoimmune mucocutaneous blistering diseases are presented. The appropriate use of IVIG therapy is placed in context for each disease.

CONCLUSION

Although preliminary data suggest that IVIG is a safe and effective therapy for many skin disorders, uncontrolled clinical trials, case series, and anecdotal case reports dominate the literature. Collaborative randomized controlled trials are required to firmly establish the role of IVIG in dermatology.

Increased Expression of Matrix Metalloproteinase-2, Matrix Metalloproteinase-9 and Matrix Metalloproteinase-13 in Lesional Skin of Bullous Pemphigoid

BACKGROUND

Matrix metalloproteinase (MMP)-2, MMP-9 and MMP-13 can degrade type IV collagen which is the major component of the basement membrane zone (BMZ). In bullous pemphigoid (BP), the separation occurs within the BMZ.

OBJECTIVE

To evaluate the involvement of MMPs in the pathogenesis of BP, we examined the expression of MMP-2, MMP-9 and MMP-13 in the lesional skin of BP patients.

METHODS

The expression of MMP-2, MMP-9, MMP-13, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 was analyzed by immunohistochemistry in the lesional skin of BP patients in comparison with that in normal human skin. Next, the cellular sources of MMP-2, MMP-9 and MMP-13 were analyzed by double immunohistochemistry. Finally, the levels of these MMPs in the serum and blister fluid of BP patients were measured by ELISA.

RESULTS

The number of cells expressing MMP-2, MMP-9 and MMP-13 were significantly increased in the lesional skin of BP patients as compared to that in normal skin. Although the number of cells expressing TIMP-1 and TIMP-2 were also increased in the lesional skin of BP patients as compared to that in normal skin, the ratio of MMPs to TIMPs in the lesional skin of BP patients was high (2.4:1). T cells comprised the major source of MMP-2, MMP-9 and MMP-13, while a proportion of mast cells and eosinophils also expressed these MMPs. Furthermore, marked expression of MMP-2 was detected in the epidermal keratinocytes. The levels of these MMPs in the blister fluid were significantly greater than those in the serum.

CONCLUSION

These results suggest that MMP-2, MMP-9 and MMP-13 may be involved in the mechanism of blister formation in BP and that besides infiltrating inflammatory cells, structural cells like epidermal keratinocytes may also participate in the induction of blister formation in BP.

Bullous Pemphigoid

Bullous pemphigoid (BP) is a chronic, autoimmune, blistering disease observed primarily in the elderly population. Several clinical variants have been described, including classic (bullous), localised, nodular, vegetating, erythrodermic, erosive, childhood and drug-induced forms. Autoantibodies target the BP230 and BP180 antigens, located in the hemidesmosomal complex of the skin basement membrane zone. Subsequent complement activation recruits chemical and cellular immune mediators to the skin, ultimately resulting in blister formation. Both autoantibodies and complement may be detected by various immunofluorescent, immune electron microscopy and molecular biology techniques. Recent trials suggest that potent topical corticosteroids should be considered as first-line therapy. Tetracycline with or without nicotinamide may benefit a subset of patients with mild BP. Oral corticosteroids should rarely exceed 0.75 mg/kg/day and corticosteroid-sparing agents may be useful for recalcitrant disease.

Comparison of immunofluorescence microscopy, immunoblotting and enzyme-linked immunosorbent assay methods in the laboratory diagnosis of bullous pemphigoid

This prospective study investigated patients with a clinical diagnosis of bullous pemphigoid (BP) who presented to a tertiary dermatology referral centre in Singapore. All patients had blood samples and skin biopsies taken for histology, immunofluorescence (IF) and immunoblot analysis prior to initiation of treatment. We analysed 23 new cases of BP during the 1-year study period. Seventeen of 22 biopsy specimens showed subepidermal blister formation, and 12 of the 17 (71%) had a predominance of eosinophils (>50%) in the blister cavity. The dermal inflammatory infiltrate of 22 biopsy specimens was predominantly lymphocytic in nine (41%) and eosinophilic in eight (36%). The histological picture was highly suggestive of BP in 15 of 22 patients (68%), suggestive in two (9%) and poorly suggestive in five (23%). Twenty-one of 23 (91%) patients had linear deposits of IgG and C3 along the dermo-epidermal junction. Serum indirect IF was positive in 22 of 23 (96%) patients, all showing antibody binding to the roof of the induced blister on salt-split skin. All of the 23 serum samples demonstrated positive immunoblot reactivity to BP180 and/or BP230 from epidermal extracts of normal human skin. Immunoblot reactivity with BP180 and BP230 was 78% (n=18) and 52% (n=12), respectively. The BP180 NC16A antibody could be detected in 22 of 23 (96%) sera using the enzyme-linked immunosorbent assay (ELISA) technique. The sensitivity of traditional diagnostic techniques, i.e. direct IF (91%) and indirect IF (96%), was comparable with that of the newer techniques, i.e. immunoblot analysis (100%) and ELISA (96%). ELISA in combination with routine indirect IF may be a useful diagnostic tool in patients with suspected BP who refuse a skin biopsy but consent to give a serum sample.

Anti-epiligrin cicatricial pemphigoid and epidermolysis bullosa acquisita: differentiation by use of indirect immunofluorescence microscopy

Binding of autoantibodies to laminin 5 and type VII collagen causes anti-epiligrin cicatricial pemphigoid and epidermolysis bullosa acquisita, respectively. Differentiation between these two dermal-binding autoimmune bullous dermatoses is not yet possible by indirect immunofluorescence microscopy. In this study we tested whether two recently described immunofluorescence techniques, "knockout" skin substrate and fluorescent overlay antigen mapping, can differentiate between anti-epiligrin cicatricial pemphigoid and epidermolysis bullosa acquisita. A total of 10 sera were tested: 4 with antilaminin 5, and 6 with antitype VII collagen autoantibodies, as characterized by either immunoblot or immunoprecipitation analysis. Differentiation between anti-epiligrin cicatricial pemphigoid and epidermolysis bullosa acquisita was possible in all 10 sera by indirect immunofluorescence using either knockout skin substrate or fluorescent overlay antigen mapping technique.

Stevens-Johnson syndrome: a diagnostic challenge in the absence of skin lesions

We report a 14-year-old boy with Stevens-Johnson syndrome who presented with mucous membrane lesions but without skin lesions and discuss the differential diagnosis of oral mucous membrane lesions in childhood. Stevens-Johnson syndrome in children is most frequently caused by a Mycoplasma pneumoniae infection. The full clinical picture of Stevens-Johnson syndrome can be present before seroconversion of Mycoplasma antibodies is observed. One should keep in mind that one negative titer of Mycoplasma antibodies does not rule out M. pneumoniae infection.

Ultrastructural immunocytochemistry of autoimmune bullous diseases

Advanced immunopathological assays have been developed to elucidate the pathophysiology and provide more precise nosological definitions of the immunobullous diseases. Forty-seven patients suffering from autoimmune bullous diseases (intra- or subepidermal) were studied by immunoelectron microscopy (direct and indirect). Peroxidase staining was revealed by diaminobenzidine (determination of immune deposit location) in the majority of the cases of subepidermal bullous diseases, but in less than half of the cases of intraepidermal bullous diseases. Immunoelectron microscopy features contributed in verifying the diagnosis of rare entities such as cicatricial pemphigoid, paraneoplastic autoimmune bullous disease, linear IgA disease and epidermolysis bullosa acquisita.

New laboratory techniques for the assessment of acquired immunobullous disorders

This review aims to summarize investigations that are used in the assessment of patients with suspected immunobullous disorders. Emphasis is placed upon new adaptations of existing techniques and the advent of recombinant technology, which has enabled the production of synthetic antigens. The use of recombinant antigens has provided the latest generation of diagnostic techniques that are likely to make a major impact on routine diagnosis of immunobullous disorders.

Childhood bullous pemphigoid developed after the first vaccination

Bullous pemphigoid (BP) typically affects the elderly. There are at least 40 reported cases of BP in childhood, 10 reported cases at 1 year of age or younger. The antigen of this autoimmune disease is localized to the hemidesmosome. Neoplasia, recurrent trauma, some systemic diseases, and psoriasis were previously reported as possible triggering factors of bullous pemphigoid in some cases. In the last 5 years, 10 adult and 2 infantile BP cases with a close relation of vaccination have been reported. Anti-influenza vaccine, tetanus toxoid booster, and tetracoq vaccine were the possible causes of these cases. We report herein a 3.5-month-old BP case in whom the lesions developed 24 hours after the first tetracoq vaccine. We suggest that vaccination may be the triggering factor of BP of any age by stimulating the immune system with an unexplained mechanism.

Mixed immunobullous disease: is this linear IgA disease?

We report five patients who demonstrated clinical, histological and direct immunofluorescence (IF) features typical of linear IgA disease (LAD), but who also displayed IgG anti-basement membrane zone (BMZ) antibodies on indirect IF. The presence of circulating IgG anti-BMZ antibodies is often said to exclude the diagnosis of LAD. Unable to confidently classify these patients, we reviewed their clinical progress for unifying features. This revealed an almost universal benefit from dapsone therapy. We therefore propose that when strong linear IgA deposition is observed at the BMZ, a first line trial of dapsone is indicated, irrespective of the presence of circulating IgG. The class of antibody fixed in vivo appears to influence the clinical picture more than the class of circulating antibody.

An extract of cultured A431 cells contains major tissue antigens of autoimmune bullous diseases

BACKGROUND

Autoantibodies that are characteristic of autoimmune bullous diseases (AIBDs) can be detected by immunoblot assay using epidermal or dermal extracts. However, none of the substrates obtained by ordinary methods seems to contain a sufficient amount of all of the autoantigens involved in AIBDs, and diagnosis may require the use of several different substrates.

OBJECTIVES

To examine the potential of A431 cell extracts as a substrate for immunoblotting.

METHODS

Fourteen sera obtained from patients with major AIBDs (pemphigus vulgaris, pemphigus foliaceus, paraneoplastic pemphigus, bullous pemphigoid and epidermolysis bullosa acquisita) were tested using this substrate.

RESULTS

Bands corresponding to desmoglein 1 and 3, desmoplakin 1 and 2, periplakin, BPAG1, BPAG2 and type VII collagen were identified distinctly with these sera.

CONCLUSIONS

This finding suggests that culture extracts of A431 cells provide an effective substrate for the diagnosis and differential diagnosis of major AIBDs.

A subepidermal bullous eruption associated with IgG autoantibodies to a 200 kd dermal antigen: the first case report from the United States

We describe an 81-year-old white man in whom a subepidermal bullous eruption developed that clinically resembled bullous pemphigoid. The eruption promptly responded to oral tetracycline and niacinamide and topical clobetasol. Histologic examination of perilesional skin revealed neutrophilic infiltration with formation of papillary microabscesses and subepidermal cleavage. Direct immunofluorescence showed linear deposition of IgG and C3 along the basement membrane zone. By indirect immunofluorescence, circulating IgG autoantibodies bound exclusively to the dermal side of salt-split normal human skin. Immunoblot analysis demonstrated that the patient's autoantibodies reacted with a 200 kd dermal protein that was different from type VII collagen, the epidermolysis bullosa acquisita autoantigen. This patient represents the first confirmed case from the United States with a recently reported novel autoimmune subepidermal bullous disease associated with IgG autoantibodies to a 200 kd dermal antigen.

Pemphigus and bullous pemphigoid

Pemphigus and bullous pemphigoid are distinct autoimmune blistering diseases that are characterised by the presence of autoantibodies directed against specific adhesion molecules of the skin and mucous membranes. The comparison and contrast of molecular mechanism of blister formation of these two diseases provide a rational diagnostic and therapeutic approach to affected patients.

Special techniques in diagnostic electron microscopy

The power of electron microscopy as a diagnostic tool can be amplified considerably by the application of ancillary preparative and analytic methods. Subcellular chemistry and structure can be examined by various forms of microprobe analysis and by special staining methods, including cytochemical, immunocytochemical, and negative staining. Qualitative ultrastructural examination can be augmented by morphometric analysis. Correlative microscopic survey methods can be used as a means of targeting ultrastructural investigations. This article provides an overview of the use of these special techniques in the diagnosis and classification of tumors and other selected pathologic processes.

Pemphigus with features of both vulgaris and foliaceus variants, associated with antibodies to 160 and 130 kDa antigens

We report an unusual variant of pemphigus in a 44-year-old man. He presented with scaly and crusted erosions associated with pruritic vesicles and erythema mainly on the chest, abdomen, back and face. Histology showed acantholysis with neutrophilic spongiosis in the granular layer and subcorneal region of the epidermis. Intercellular IgG in the epidermis was positive on direct immunofluorescence. Indirect immunofluorescence showed intercellular antibodies at a titre of 1 : 2 in the suprabasal epidermis. Circulating autoantibodies to 130 kDa and 160 kDa antigens were detected in the patient's serum by immunoblot analysis using epidermal extracts. These two antibodies eluted from individual nitrocellulose membranes reacted with the intercellular space in the epidermis on indirect immunofluorescence. This observation suggests that these antibodies correspond to desmogleins 3 and 1, respectively. The clinical symptoms almost completely disappeared after 28 days treatment with oral prednisolone (30 mg/day), leaving brown pigmented flecks on the lesional sites. These findings suggest that this patient's pemphigus has features of both the vulgaris and foliaceus variants, with antibodies against desmogleins 3 and 1.

A subepidermal blistering disease with histopathological features of dermatitis herpetiformis and immunofluorescence characteristics of bullous pemphigoid: a novel subepidermal blistering disease or a variant of bullous pemphigoid?

A 64-year-old man presented with a bullous eruption which clinically and histopathologically resembled dermatitis herpetiformis. However, direct immunofluorescence analysis showed IgG deposits at the basement membrane zone, indicating a relationship with bullous pemphigoid or epidermolysis bullosa acquisita. Indirect immunofluorescence studies on salt-split skin showed binding of IgG mainly on the dermal side of the blister. Immunoblot analysis revealed a novel 200 kDa dermal antigen that could be associated with a major pathogen in this blistering disease. The histopathological similarity to dermatitis herpetiformis and the immunofluorescence findings indicating bullous pemphigoid or epidermolysis bullosa acquisita seem typical of a distinct subepidermal blistering disease characterized by this 200 kDa antigen. However, the pathogenetic role of autoantibodies against this antigen should be further elucidated before confirming whether this case represents a novel subepidermal blistering disease or a special variant of bullous pemphigoid.

Evaluation of an avidin-biotin-peroxidase method with a monoclonal antibody to type IV collagen in the differential diagnosis of bullous pemphigoid and epidermolysis bullosa acquisita

There are reports in which an immunohistochemical technique with a monoclonal antibody to type IV collagen has been employed for differentiating between bullous pemphigoid (BP) and epidermolysis bullosa acquisita (EBA). The aim of this study was to determine whether this method could be used routinely. Biopsies (paraffin-embedded lesional skin containing a blister) from currently diagnosed patients with clinical features suggesting BP or EBA were examined by an avidin-biotin-peroxidase (ABC) technique. Sera were tested by indirect immunofluorescence on salt-split skin (IF) and immunoblotting (IB). In all cases which exhibited clear type IV collagen staining, the results of the ABC technique agreed with results of both IF and IB. In one confirmed EBA case, it was impossible to unequivocally localize type IV collagen, because it stained very faintly. Taking into consideration the results of our study, data indicating that the level of blistering might not coincide with the localization of immunoreactants in EBA cases and the possibility of an enzymatic destruction of lamina densa, we conclude that the ABC method is unsuitable for differentiation between BP and EBA.

Bullous pemphigoid associated with internal malignancies: identification of 180-kDa antigen by western immunoblotting

We report three cases of bullous pemphigoid associated with internal malignancies. Two cases were associated with gastric cancer and one with rectal cancer. Immunoblot analysis, using epidermal extract of normal human skin, revealed that these patients' sera reacted only with bullous pemphigoid antigen with a molecular weight of 180 kDa (BP180). The relationship of BP180 to malignant tumours is discussed.

Childhood bullous pemphigoid--report of a case with dermal fluorescence on salt-split skin

Bullous pemphigoid (BP) is an acquired bullous disorder which predominantly affects the elderly. It is rare in children, and may be clinically indistinguishable from other immunobullous disorders. As routine histology may be non-specific, a definitive diagnosis of childhood BP usually depends on the results of direct and indirect immunofluorescence investigations. We report a 5-year-old girl who developed bullous pemphigoid, associated with atypical immunofluorescence findings. Indirect immunofluorescence on split-skin showed a pure dermal pattern of IgG binding. This is usually suggestive of epidermolysis bullosa acquisita, but Western immunoblotting was positive with epidermal extracts, confirming a diagnosis of BP. Dermal binding on split-skin occurs in about 5% of adult cases of BP, and has not been reported previously in childhood BP.

Demonstration of antibodies to bovine desmocollin isoforms in certain pemphigus sera

We have shown previously that IgG antibodies in certain pemphigus sera, particularly endemic Brazilian pemphigus foliaceus (BPF) sera, react with bovine desmocollins (Dsc), which are transmembranous glycoproteins of desmosome junctions. Desmocollins occur as three different isoforms (Dsc 1, 2 and 3), all of which are represented in the epidermis. In this study, we examined sera of various pemphigus types by immunoblotting purified bovine desmosomes and bovine Dsc 1, 2 and 3 fusion proteins, expressed in pGEX expression vectors. Six of 15 (40.0%) BPF sera, two of 18 (11.1%) non-endemic pemphigus foliaceus sera, eight of 39 (20.5%) pemphigus vulgaris (PV) sera, and two of 11 (18.2%) normal sera, showed reactivity with Dsc from desmosomes. Experiments with fusion proteins showed that no Dsc isoform was specifically recognized by sera of any individual pemphigus type. Our results indicate that the pathogenesis of pemphigus might be more complex than previously believed.

Immunofluorescence study of pemphigus from north India

Both serum studies by indirect immunofluorescence (IIF) tests and skin biopsy examination by direct immunofluorescence (DIF) were performed on 22 cases of pemphigus with clinically active lesions. Twenty cases had pemphigus vulgaris and two, pemphigus foliaceus. The majority of cases (70%) were between 21 and 60 years old; the mean age was 39.5 +/- 12.7 years. There was no sex predilection. DIF showed the positive fluorescence of intercellular cement substance (ICS) of the epidermis in all 22 cases (100%). IgG was positive in 77.2%, followed sequentially by C3C (50%), IgA (45.45%), and IgM (36.36%). Six cases (27.27%) also showed granular immunoglobulin and/or complement deposits at the dermoepidermal junction. IIF detected serum antiepithelial antibodies in 18 cases (81.81%) using human esophagus as substrate. Most of these cases (88.88%) showed IgG type of antibodies; the other 11.11% exhibited IgA and IgM in low concentrations. 1+ titer positivity was observed in 15 cases. This study demonstrates the value of DIF for a definitive diagnosis of pemphigus. However, it is also important to appreciate that immunofluorescence is not a substitute for histopathology, but rather complementary to it.