A case of bullous pemphigoid with antidesmoplakin autoantibodies

Desmoplakin I/II immunohistochemical staining may be a helpful tool in differentiating cutaneous graft versus host disease from the erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis spectrum disorders

Cutaneous graft versus host disease (cGVHD) has substantial clinical and histopathologic overlap with erythema multiforme (EM), Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN). This overlap can make it difficult to distinguish these disorders in patients who have received hematopoietic transplants. We sought to evaluate the utility of Dp I/II immunohistochemical stain in differentiating EM/SJS/TEN and cGVHD in a large cohort. Skin biopsy specimens from patients with cGVHD (n = 58) and EM/SJS/TEN (n = 60) were evaluated for Dp I/II expression by immunohistochemistry. We found a statistically significant difference in Dp I/II staining between cGVHD (all grades) and EM/SJS/TEN (mean scores 1.62 and 2.14, respectively; p < 0.005), as well as between Grades 2 + 3 cGVHD and EM/SJS/TEN (mean scores 2.26 and 1.62, respectively; p < 0.005), while we did not find a significant difference between Grade 4 cGVHD and EM/SJS/TEN (mean scores 1.69 and 1.62, respectively; p = 0.71). Dp I/II immunostain may be useful for differentiating EM/SJS/TEN from Grade 2 and Grade 3 cGVHD, especially in clinically ambiguous cases without extracutaneous GVHD.

Case of bullous pemphigoid coexisting with anti-desmoglein autoantibodies

A 79-year-old Japanese woman had clinical and histopathological features of bullous pemphigoid, while direct immunofluorescence test revealed C3 and immunoglobulin G depositions in the lower cell surfaces of the epidermis in addition to those in the dermoepidermal junction. Chemiluminescent enzyme immunoassays were positive for desmoglein-1 and -3 antibodies in addition to anti-BP180 antibodies. In an immunoblotting study, antibodies against both 180-kDa bullous pemphigoid antigen and 130-kDa pemphigus vulgaris antigen were detected. Based on these results, bullous pemphigoid coexisting with anti-desmoglein autoantibodies was diagnosed in this case.

Analysis of the reactivity of indirect immunofluorescence in patients with pemphigus foliaceus and pemphigus vulgaris using rat bladder epithelium as a substrate

OBJECTIVES

To evaluate the reactivity of indirect immunofluorescence using rat bladder epithelium as a substrate in patients with pemphigus foliaceus and pemphigus vulgaris from the Department of Dermatology, University of São Paulo Medical School, Brazil.

METHODS

Thirty-two patients (8 male and 24 female) from the Department of Dermatology, University of São Paulo Medical School, were selected. Three had mucosal pemphigus vulgaris, 20 had mucocutaneous pemphigus vulgaris, and 9 had pemphigus foliaceus. Patients' sera were tested by indirect immunofluorescence performed on human foreskin and rat bladder epithelium and by ELISA assays utilizing baculovirus-expressed recombinant desmoglein 3 and desmoglein 1.

RESULTS

No patients with mucosal pemphigus vulgaris, 5 of 20 patients with mucocutaneous pemphigus vulgaris (25%) and 4 of 9 patients with pemphigus foliaceus (44%) had positive indirect immunofluorescence using rat bladder epithelium as a substrate.

CONCLUSION

Indirect immunofluorescence using rat bladder epithelium as a substrate is recommended whenever a diagnosis of paraneoplastic pemphigus is considered. The identification of a subset of pemphigus foliaceus and pemphigus vulgaris patients that recognizes desmoplakins by this laboratory tool is critical to avoid the misdiagnosis of paraneoplastic pemphigus.

Paraneoplastic pemphigus

Paraneoplastic pemphigus (PNP) is a life-threatening autoimmune blistering skin disease. Clinically, it is characterized by severe mucosal erosions and various cutaneous lesions associated with lymphoproliferative neoplasmas. Suprabasal acantholysis and clefts with scattered necrotic keratinocytes are the unique histopathological features. PNP patient sera recognize multiple antigens, which have been identified as the plakin protein family that includes desmoplakin, bullous pemphigoid antigen I (BPAG1), envoplakin and periplakin, and desmogleins 1 and 3. Castleman's tumor, non-Hodgkin's lymphoma, thymoma, follicular dendritic cell sarcoma and chronic lymphocytic leukemia are the commonly associated neoplasmas in PNP. We have also demonstrated that the autoantibodies reacting to epidermal proteins are directly produced by the cells in the associated tumors. Bronchiolitis obliterans is frequently found in PNP and may cause respiratory failure and death. In our experience, the early detection and removal of the tumor and i.v. administration of immunoglobulin are critical for the treatment of PNP.

Vesicular pemphigoid with circulating autoantibodies against 230-kDa and 180-kDa proteins, and additional autoantibodies against 97-kDa and 45-kDa proteins

The vesicular variant of bullous pemphigoid is a clinical entity in which the principal type of lesions are multiple small tense vesicles in a symmetric distribution, instead of the classical large, more randomly distributed large bullae. We describe a 62-year-old female who developed a vesicular variant of bullous pemphigoid, with intensely pruritic vesiculopapular eruptions and erythematous irregularly outlined patches confluent on the face, neck, trunk, extremities and oral mucosa. Direct immunofluorescence revealed a linear deposition of IgG and C3 at the basement membrane zone of the skin, and indirect immunofluorescence detected circulating IgG autoantibodies reacting with antigens located on the epidermal side of skin split with 1 M NaCl. Indirect immunogold electron microscopy revealed IgG deposition at the underneath membrane of the basal cells and in the lamina lucida. In addition to the 230-kDa and 180-kDa bullous pemphigoid antigen, immunoblot analysis also demonstrated the presence of IgG antibodies reactive with 97-kDa and 45-kDa protein. Treatment with systemic corticosteroid, minocycline and antihistamines plus topical steroid resulted in moderate improvement. A few vesicles, however, continued to appear intermittently during the past year of treatment.

Métodos diagnósticos en las enfermedades ampollosas subepidérmicas autoinmunes

There is considerable clinical and histological overlap among the subepidermal autoimmune bullous diseases. The knowledge at the molecular level of the dermo-epidermal junction is essential to understand this group of diseases. The immune-based techniques have contributed to increase the knowledge of these entities and have been progressively incorporated into clinical practice. In this review of the diagnostic methods of subepidermal autoimmune bullous diseases we summarize the most recent advances on the molecular biology of the dermo-epidermal junction, focusing on the immune-based diagnostic techniques. We distinguish two main groups of diagnostic methods: those that detect autoimmune deposits in the skin (direct immunofluorescence and its variants including confocal microscopy) and those that detect antibodies in serum or in other fluids (indirect immunofluorescence and its variants, ELISA, immunoblot and immunoprecipitation). We explain the methodology and diagnostic keys of the techniques most widely applied in our milieu.

Antidesmoplakin antibodies in pemphigus vulgaris

BACKGROUND

Besides being present in paraneoplastic pemphigus (PNP), circulating antidesmoplakin (DP) antibodies have been found anecdotally in other bullous diseases, including pemphigus foliaceus and pemphigus vulgaris.

OBJECTIVES

To verify how frequent anti-DP antibodies are in pemphigus vulgaris.

METHODS

We studied 48 sera from patients with proven pemphigus vulgaris (29 mucosal dominant pemphigus and 19 mucocutaneous pemphigus) by indirect immunofluorescence (IIF) with rat bladder epithelium (RBE) as a substrate and by immunoblotting (IB) on human keratinocyte cultures enriched in DP.

RESULTS

Ten sera (21%) were positive in IIF on RBE. By IB, eight sera proved to have antibodies to both DP I (250 kDa) and DP II (210 kDa), one serum had antibodies directed to DP I only, and two sera to DP II only.

CONCLUSIONS

Our data confirm that RBE is not a specific IIF substrate for the serological diagnosis of PNP. It remains a sensitive and specific substrate for the detection of anti-DP antibodies, which, in patients with pemphigus vulgaris, are probably caused by an epitope-spreading phenomenon.

Molecular abnormalities of the desmosomal protein desmoplakin in human disease

Desmoplakin is the principal plaque protein of desmosomes, specialized adhesion junctions found in various tissues including skin, heart and meninges. It is an entirely intracellular protein and in keratinocytes desmoplakin binds to other structural components of desmosomes such as cadherins and armadillo proteins, as well as to keratin filaments. Clues to the biological significance of desmoplakin have recently emerged from a number of naturally occurring human desmoplakin gene mutations. Both autosomal dominant and autosomal recessive disorders have been reported. The spectrum of clinical features includes varying degrees of keratoderma, blisters, nail dystrophy, woolly hair and, in some cases, cardiomyopathy. This review provides an update on genotype-phenotype correlation for human desmoplakin mutations as well as an overview of desmoplakin abnormalities in other conditions, including autoimmune blistering diseases, epithelial malignancies and blood vessel morphogenesis.

Parallel fluctuation of anti-desmoglein 3 and anti-BP180 autoantibody titres in a patient with bullous pemphigoid

We report a 73-year-old Japanese female who developed IgG autoantibodies against BP180 as well as desmoglein 3 (Dsg3). She showed tense blisters on the extremities without apparent mucosal involvement and a skin biopsy indicated subepidermal blisters with eosinophilic spongiosis. Her clinical and histologic features indicated the diagnosis of bullous pemphigoid while anti-Dsg3 IgG might not show an apparent pathogenic effect. Interestingly, titres of anti-Dsg3 IgG fluctuated in parallel with those of anti-BP180 IgG throughout the course with two flares. Although the exact mechanism for autoantibody production is still unknown, the close link in the production of IgG autoantibodies against two independent skin antigens suggests a shared immunoregulatory mechanism against cutaneous autoantigens.

Mucosal dominant pemphigus vulgaris with anti-desmoplakin autoantibodies

BACKGROUND

Anti-desmoplakin (DP) antibodies are present in paraneoplastic pemphigus (PNP) as a component of a complex humoral autoimmune reaction characterized by antibodies against proteins of the plakin family, desmogleins, and an unidentified 170 kd protein. Anti-DP antibodies have also been rarely identified in other blistering diseases. The significance of anti-DP antibodies in the pathogenesis of bullous diseases is unclear.

OBSERVATION

We studied 3 patients with severe and chronic mucosal dominant pemphigus vulgaris (PV). In addition to anti-desmoglein 3 antibodies, these patients had anti-DP autoantibodies, demonstrable by immunofluorescence (IF), immunoprecipitation (IP), and indirect immunoelectromicroscopy (IIEM). This finding suggested these patients may have had PNP and not PV. However, antibodies against periplakin, envoplakin, bullous pemphigoid antigen 1 (BPAG 1), plectin, and 170 kd PNP antigen could not be detected using IP and immunoblotting. Extensive and repeated investigations for an underlying neoplasm throughout the follow-up period were consistently negative for all patients.

CONCLUSION

This study demonstrates that anti-DP antibodies without the presence of any other anti-plakin antibodies are not specific for PNP, and are present in some cases of PV. Cellular disadhesion induced by anti-desmoglein antibodies can trigger an epitope-spreading phenomenon with a secondary formation of autoantibodies against desmoplakins, intracellular desmosomal antigens. The role of anti-DP antibodies in the pathogenesis of these PV patients is still unclear. The presence of anti-DP antibodies will produce a false positive serologic interpretation for the diagnosis of PNP especially if one uses only indirect IF on murine bladder, the most commonly employed screening test to identify PNP. More specific immunologic tests are required in this subset of patients with PV.

Oral and genital lichenoid reactions associated with circulating autoantibodies to desmoplakins I and II: a novel target antigen or example of epitope spreading?

We describe the first reported case of persistent oral and genital lichenoid reactions associated with circulating antibodies to 250- and 215-kd proteins, compatible with desmoplakin I and II, respectively. We discuss the potential role of epitope spreading, leading to the novel development of specific autoantibodies to desmoplakin.

Sensitivity and specificity of clinical, histologic, and immunologic features in the diagnosis of paraneoplastic pemphigus

BACKGROUND

Paraneoplastic pemphigus (PNP) is an autoimmune blistering disease characterized by the production of autoantibodies mainly directed against proteins of the plakin family. An overlapping distribution of autoantibody specificities has been recently reported between PNP, pemphigus vulgaris (PV), and pemphigus foliaceus (PF), which suggests a relationship between the different types of pemphigus.

OBJECTIVE

Our purpose was to evaluate the sensitivity and the specificity of clinical, histologic, and immunologic features in the diagnosis of PNP.

METHODS

The clinical, histologic, and immunologic features of 22 PNP patients were retrospectively reviewed and compared with those of 81 PV and PF patients without neoplasia and of 8 PV and 4 PF patients with various neoplasms.

RESULTS

One clinical and 2 biologic features had both high sensitivity (82%-86%) and high specificity (83%-100%) whatever the control group considered: (1) association with a lymphoproliferative disorder, (2) indirect immunofluorescence (IIF) labeling of rat bladder, and (3) recognition of the envoplakin and/or periplakin bands in immunoblotting. Two clinicopathologic and two biologic features had high specificity (87%-100%) but poor sensitivity (27%-59%): (1) clinical presentation associating erosive oral lesions with erythema multiforme-like, bullous pemphigoid-like, or lichen planus-like cutaneous lesions; (2) histologic picture of suprabasal acantholysis with keratinocyte necrosis, interface changes, or lichenoid infiltrate; (3) presence of both anti-epithelial cell surface and anti-basement membrane zone antibodies by IIF; and (4) recognition of the desmoplakin I and/or BPAG1 bands in immunoblotting. Interestingly, 45% of patients with PNP presented initially with isolated oral erosions that were undistinguishable from those seen in PV patients, and 27% had histologic findings of only suprabasal acantholysis, which was in accordance with the frequent detection of anti-desmoglein 3 antibodies in PNP sera.

CONCLUSION

The association with a lymphoproliferative disorder, the IIF labeling of rat bladder, and the immunoblotting recognition of envoplakin and/or periplakin are both sensitive and specific features in the diagnosis of PNP.

Unique immunobullous disease in a child with a predominantly IgA response to three desmosomal proteins

We report the case of a 15-year-old girl who presented at 11 years of age with an interesting, acquired and, to our knowledge, unique blistering disease. It involved both skin and mucous membranes with extensive oral and periungual lesions, clinically resembling paraneoplastic pemphigus. Skin biopsy showed an inflammatory cell infiltrate in the upper dermis with numerous leucocytoclastic nuclear fragments, neutrophilic papillary microabscesses and a small subepidermal bulla. Direct and indirect immunofluorescence studies showed marked intercellular staining with IgA and less prominent staining with IgG. Granular deposition of IgA and, to a lesser extent IgG and C3, was also seen along the basement membrane zone. Immunoblotting and enzyme-linked immunosorbent assay studies showed both IgG and IgA antibodies to desmocollin, desmoglein 3 and desmoplakin. However, despite extensive investigation, no underlying neoplasm was found. Treatment with dapsone and sulphapyridine proved ineffective but methylprednisolone and azathioprine have reduced the blistering. We believe that this patient is unique for her combination of IgA and IgG antibodies to desmoplakin, desmocollin and desmoglein 3, although further studies may provide further clarification.

Specific detection of anti-cell surface antibodies in herpes gestationis sera

We examined 42 herpes gestationis sera with immunofluorescence of normal human skin sections, and found that anti-keratinocyte cell surface antibodies were detected specifically in 10 herpes gestationis sera. The diagnosis of these herpes gestationis cases was confirmed by detecting antibodies against the 180 kD bullous pemphigoid antigen with immunoblotting of its fusion protein. The results of immunoadsorption assay using baculoproteins of both pemphigus vulgaris and pemphigus foliaceus antigens indicated that the herpes gestationis sera did not recognize common pemphigus antigens. Immunoblotting of human epidermal extracts and immunofluorescence of various tissues also suggested that the sera did not recognize any other desmosomal components or paraneoplastic pemphigus antigens. The significance of this reactivity is unclear. However, because no control bullous pemphigoid sera showed this reactivity, it may suggest a different pathophysiology between herpes gestationis and bullous pemphigoid.