Laboratory diagnosis of paraneoplastic pemphigus

Absence of Epidermal Antibodies in Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis Patients but Beware of Single Positive Results

Background

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare and potentially life-threatening mucocutaneous blistering diseases that clinically can resemble autoimmune bullous diseases. Moreover, it has been shown that autoantibodies against epidermal proteins are present in SJS/TEN.

Objectives

To establish the presence of antibodies against desmosomal and hemidesmosomal proteins in confirmed SJS/TEN patients.

Methods

Serum of SJS/TEN patients diagnosed based on clinical criteria, e.g., epidermal detachment with erosions and severe mucosal lesions, (suspicion of) a culprit drug, and matching histologic results was evaluated by various techniques, e.g., indirect immunofluorescence on monkey esophagus, salt split skin and rat bladder, immunoblotting (IB) and immunoprecipitation (IP), ELISAs against desmogleins and BP180, keratinocyte footprint assay, and keratinocyte binding assay.

Results

A total of 28 patients were included in this study, 15 men and 13 women with a mean age of 56 years. In most patients, none of the serological tests were positive. In two patients, an elevated DSG3 titer was found suspicious for pemphigus vulgaris. Three patients had elevated NC16a titers, suggesting bullous pemphigoid. However, in all these patients, no other tests were positive and in these patients, the biopsy for direct immunofluorescence showed no evidence for an autoimmune bullous disease. Three patients showed reactivity against rat bladder rat bladder; these were, however, completely negative for A2ML1, envoplakin, and periplakin in the IB as well as the IP.

Conclusions

Serological analysis for desmosomal and hemidesmosomal antibodies is reliable to rule an autoimmune bullous disease in patients with suspected SJS/TEN. However, one should not rely on one single test method since false positive results can occur. Moreover, this study also makes it less plausible that antibodies against desmosomal and/or hemidesmosomal components are involved in the pathogenesis of SJS/TEN.

Diagnostic Techniques in Autoimmune Blistering Diseases

Autoimmune blistering diseases (AIBD) comprise a heterogeneous group of uncommon disorders of the skin and mucous membranes, characterised by antibodies targeting structural proteins within epithelial tissue and the underlying basement membrane. There can be significant overlap in clinical presentation of these diseases and accurate diagnosis relies on the detection and characterisation of relevant autoantibodies. Immunofluorescence provides the gold-standard diagnostic tool for these diseases, identifying both tissue-bound autoantibodies in biopsy material using direct immunofluorescence and circulating antibodies in serum through indirect immunofluorescence. Following advances in the identification and subsequent characterisation of numerous antigenic targets in these diseases, the development of antigen-specific tests, in particular, enzyme-linked immunosorbent assays on serum specimens, has provided a third key tool to not only identify, but also quantify AIBD autoantibodies. This quantification has proven particularly useful in monitoring disease activity and informing clinical management decisions. Accurate diagnosis of these diseases is important since optimal treatment strategies differ between them and, prognostically, some diagnoses are associated with an increased risk of malignancy. This review outlines the molecular pathology underlying the major AIBD and describes how the three principal techniques can be used in combination, to provide best practice for diagnosis and treatment monitoring.

A2ML1 Inhibits Esophageal Squamous Cell Carcinoma Progression and Serves as a Novel Prognostic Biomarker

Studies have established a correlation between α2-macroglobulin-like 1 (A2ML1) and the prognosis of lung, pancreatic, and breast cancers; however, research on its involvement in the pathogenesis of esophageal carcinoma remains limited. Therefore, in this study, we aimed to investigate the role of A2ML1 in the progression of esophageal squamous cell carcinoma (ESCC). Immunohistochemical staining was employed to assess the expression level of A2ML1 protein in both tumor and adjacent normal tissues of patients with ESCC. The Kaplan-Meier method, along with univariate and multivariate Cox risk ratio analyses, was used to determine survival rates and prognostic factors. Furthermore, two human ESCC cell lines, KYSE30 and KYSE150, were used to assess the effect of A2ML1 overexpression on cell proliferation and apoptosis. A human apoptosis antibody kit was also used to analyze the downstream action proteins of A2ML1, and a nude mouse xenotransplantation model was used to evaluate the effect of A2ML1 on ESCC tumorigenesis in vivo. The protein level of A2ML1 in ESCC tissues was significantly lower than that in normal esophageal tissues, and higher A2ML1 protein levels were associated with smaller ESCC tumor sizes and improved tumor-specific survival rates. Multivariate analysis established A2ML1 as a novel independent prognostic factor for ESCC. Moreover, A2ML1 overexpression significantly inhibited ESCC cell proliferation and promoted apoptosis. A2ML1 consistently inhibited tumor growth in mouse models. Furthermore, the human apoptotic antibody kit results showed increased expression of the proliferation-inhibiting protein p21 downstream of KYSE150 cells overexpressing A2ML1. Our findings demonstrate that a correlation exists between A2ML1 and ESCC prognosis and that A2ML1 plays an antitumor role in ESCC progression. This study underscores the potential of A2ML1 as a novel biomarker for predicting the prognosis of ESCC.

Paraneoplastic pemphigus misdiagnosed as juvenile dermatomyositis: A case report

Paraneoplastic pemphigus (PNP) is a rare autoimmune skin disease closely related to tumors, characterized by a maculopapular rash with mucosal pain, bronchiole occlusion, and respiratory failure may occur over time, even resulting in death. We report a rare case of a child with autoimmune PNP misdiagnosed as juvenile dermatomyositis (JDM), and summarize the key points of differentiation of clinical manifestations and auxiliary examinations of PNP and JDM. When the diagnosis is not clear because the patient has features not typical of JDM, then skin biopsy and other diagnostic studies should be considered prior to any immunosuppressive therapy, as this could potentially obscure and delay the diagnosis of malignancy.

S2k guidelines on the management of paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome initiated by the European Academy of Dermatology and Venereology (EADV)

BACKGROUND

Paraneoplastic pemphigus (PNP), also called paraneoplastic autoimmune multiorgan syndrome (PAMS), is a rare autoimmune disease with mucocutaneous and multi-organ involvement. PNP/PAMS is typically associated with lymphoproliferative or haematological malignancies, and less frequently with solid malignancies. The mortality rate of PNP/PAMS is elevated owing to the increased risk of severe infections and disease-associated complications, such as bronchiolitis obliterans.

OBJECTIVES

These guidelines summarize evidence-based and expert-based recommendations (S2k level) for the clinical characterization, diagnosis and management of PNP/PAMS. They have been initiated by the Task Force Autoimmune Blistering Diseases of the European Academy of Dermatology and Venereology with the contribution of physicians from all relevant disciplines. The degree of consent among all task force members was included.

RESULTS

Chronic severe mucositis and polymorphic skin lesions are clue clinical characteristics of PNP/PAMS. A complete assessment of the patient with suspected PNP/PAMS, requiring histopathological study and immunopathological investigations, including direct and indirect immunofluorescence, ELISA and, where available, immunoblotting/immunoprecipitation, is recommended to achieve a diagnosis of PNP/PAMS. Detection of anti-envoplakin antibodies and/or circulating antibodies binding to the rat bladder epithelium at indirect immunofluorescence is the most specific tool for the diagnosis of PNP/PAMS in a patient with compatible clinical and anamnestic features. Treatment of PNP/PAMS is highly challenging. Systemic steroids up to 1.5 mg/kg/day are recommended as first-line option. Rituximab is also recommended in patients with PNP/PAMS secondary to lymphoproliferative conditions but might also be considered in cases of PNP/PAMS associated with solid tumours. A multidisciplinary approach involving pneumologists, ophthalmologists and onco-haematologists is recommended for optimal management of the patients.

CONCLUSIONS

These are the first European guidelines for the diagnosis and management of PNP/PAMS. Diagnostic criteria and therapeutic recommendations will require further validation by prospective studies.

Paraneoplastic pemphigus uncovers distinct clinical and biological phenotypes of western unicentric Castleman disease

Unicentric Castleman disease (UCD) is a lymphoproliferative disease of unknown cause. Paraneoplastic pemphigus (PNP) is a major complication shown to be associated with a poor prognosis, with particular severity in patients with bronchiolitis obliterans (BO). This study describes the clinical and biological characteristics of UCD-PNP patients in a large Western cohort. A total of 148 patients diagnosed with UCD were identified, including 14 patients with a defined PNP. PNP was significantly associated with myasthenia gravis (MG) and FDC sarcoma during follow-up (FDCS). PNP was also significantly associated with reduced survival. These data, together with a multivariate analysis by principal components, led to the identification of UCD-PNP as a group at risk of MG, FDCS and death. PDGFRB sequencing performed on UCD lesions from six patients found the gain-of-function p.N666S variant in two. Interestingly, both patients had hyaline-vascular UCD subtype, were in the UCD-PNP subgroup and had FDCS. Sera from 25 UCD-PNP patients and 6 PNP patients without UCD were tested for PNP-associated autoantibodies. Sera from UCD-PNP patients had a strong reactivity against the N-terminal domain of recombinant periplakin (rPPL, 82%) and showed reactivity against at least two domains of rPPL. These features were not found in patients with UCD alone or in the PNP group without UCD. These data indicate that UCD-PNP patients belong to a subgroup sharing strong clinical and biological identity that might help to decipher the different dynamics of UCD natural history.

Paraneoplastic pemphigus and Castleman's disease: a case report and a revision of the literature

BACKGROUND

In literature, a few reports described an association between paraneoplastic pemphigus (PNP) and Castelman's disease (CD), but no consensus have been proposed for the diagnostic-therapeutical approach. Aim of this study is to present a case report and explore the relationship between PNP and CD in pediatric patients, focusing on clinical manifestations, histopathological findings, treatment and outcome to find elements for an early diagnosis.

CASE PRESENTATION

We present the clinical case of a 13 years old girl with a challenging diagnosis of PNP and CD who underwent therapy at first with Rituximab and then with Siltuximab, for the control of symptoms.

CONCLUSIONS

Reviewing literature, 20 clinical cases have been described in the pediatric age. Diagnosis may be challenging, requiring an average of 3 months (range from 3 weeks to 2 years). In all cases, the initial manifestations were mucocutaneous lesions, especially oral lesions with poor response to conventional treatment. Systemic symptoms may be present as well. Therapeutical approach is still discussed with no consensus. Almost all patients received corticosteroids with poor response. Other drugs including azathioprine, methotrexate, cyclosporine and monoclonal antibodies have been evaluated for the control of the disease. Further studies and experimental trials urge to define the diagnostic criteria and therapy protocol.

Paraneoplastic pemphigus: A detailed case series from the Netherlands revealing atypical cases

BACKGROUND

Paraneoplastic pemphigus (PNP) is an extremely rare life-threatening blistering autoimmune disease that is associated with an underlying neoplasm. There is a set diagnostic criterion for PNP, which is primarily based on a severe stomatitis and the detection of specific antibodies against envoplakin, periplakin and alpha-2-macroglobulin-like protein 1. However, it has become increasingly evident that there are patients with PNP that do not meet all the diagnostic criteria requirements.

OBJECTIVES

The aim of this study was to analyse our cohort of Dutch patients and to define the atypical cases that did not meet the diagnostic criteria.

METHODS

A retrospective case study of all known Dutch PNP patients of the past 25 years. Patients' clinical and immunological variables were thoroughly analysed and described.

RESULTS

Twenty-four patients were included in this study. The results revealed several atypical patient cases that did not completely meet the set diagnostic criteria. Of the 24 patients, two patients presented without stomatitis, in three patients an underlying neoplasm could not be detected, and in two patients the presence of specific autoantibodies could not be demonstrated, although all other criteria for PNP were met. Finally, three of the 24 patients survived the disease.

CONCLUSION

Although our findings showed similarities to previous studies and most of the patients met the criteria, there were a few atypical patient cases; highlighting the importance of not strictly adhering to the set criteria when making a diagnosis, as this can lead to a missed or late diagnosis. Thus, it is of crucial importance to combine clinical and elaborate laboratory results to confirm the diagnosis of PNP in suspected patients. Although PNP harbours an unfavourable prognosis in most cases, it might be resolved by timely treatment of the underlying cause.

Indirect immunofluorescence on rat bladder epithelium in patients with pemphigus vulgaris with an extended follow‐up

Background

Indirect immunofluorescence (IIF) on rat bladder epithelium (RBE) has been widely used to detect anti‐plakin antibodies present in paraneoplastic pemphigus (PNP). However, anti‐plakin antibodies have also been found in a group of patients with pemphigus vulgaris (PV).

Objectives

To assess the reactivity rate of PV sera in IIF using RBE as substrate and the diagnostic usefulness of the aforementioned test.

Methods

Patients diagnosed with PV presenting to Razi Hospital, Tehran, Iran, were recruited. The patients' demographics, disease severity, and response to the initial treatment were recorded. Sera were collected and tested by IIF on RBE and by desmoglein 3/1 (Dsg 3/1) enzyme‐linked immunosorbent assay. Patients were followed up closely for a mean of 53.9 months for any evidence of malignancy.

Results

Forty‐six patients were enroled (mean age of 42.9 years old, 31 females). Nine sera (19.6%) showed reactivity in IIF on RBE. Mean serum anti‐Dsg levels did not differ significantly among the two groups with positive and negative IIF results. Negative anti‐Dsg3 was related to a higher positive rate in IIF on RBE. There was no significant correlation between the reactivity of IIF on RBE and patients' demographic, clinical, or serological characteristics.

Conclusions

IIF on RBE is a sensitive test for detecting antibodies against plakins. However, it has a relatively high false‐positive rate in PV, probably due to the epitope spreading phenomenon. This test should be suggested when there is a clinical or immunohistopathological suspicion of PNP and should be interpreted with caution.

Paraneoplastic pemphigus associated with post-transplant lymphoproliferative disorder after small bowel transplantation

BACKGROUND

PNP is a malignancy-associated autoimmune mucocutaneous syndrome due to autoantibodies against plakins, desmogleins, and other components of the epidermis and basement membrane of epithelial tissues. PNP-causing malignancies comprise mainly lymphoproliferative and hematologic neoplasms. PNP is extremely rare, especially in children.

METHODS

Here, we present the first case of a child who developed PNP on a PTLD after small bowel transplantation because of a severe genetic protein-losing enteropathy.

RESULTS

The patient in this case report had a severe stomatitis, striate palmoplantar keratoderma, and lichenoid skin lesions. In addition, she had marked esophageal involvement. She had lung pathology due to recurrent pulmonary infections and ventilator injury. Although we found no evidence of BO, she died from severe pneumonia and respiratory failure at the age of 12 years.

CONCLUSION

It is exceptional that, despite effective treatment of the PTLD, the girl survived 5 years after her diagnosis of PNP. We hypothesize that the girl survived relatively long after the PNP diagnosis due to strong T-cell suppressive treatments for her small bowel transplantation.

Current status and prospects for the diagnosis of pemphigus vulgaris

Introduction: Pemphigus vulgaris (PV) is an intraepidermal autoimmune bullous disease (AIBD) characterized by autoantibodies against desmosomal adhesion proteins, most commonly desmoglein (Dsg)3, leading to the suprabasal cleft formation and acantholysis.Areas covered: Direct immunofluorescence (DIF) and indirect immunofluorescence (IIF) studies display the intercellular deposition of IgG/C3 throughout the epidermis and presence of circulating autoantibodies respectively, as a net-like pattern. However, the target antigen remains unknown using immunofluorescence techniques. Thanks to the development of Dsg ELISA, using recombinant technology, circulating antibodies against Dsg1 and 3 could be detected sensitively. It is possible to differentiate PV from pemphigus foliaceus (PF) using this assay. BIOCHIP mosaic and multivariant ELISA are two novel serologic methods with the added value of the ability to screen several AIBDs simultaneously.Non-Dsg1/3 antigens are also involved in the pathogenesis of PV and investigated more deeply thanks to the protein microarrays technique. Additionally, patients with high values of anti-Dsg1/3 may be lesion-free, suggesting the presence of nonpathogenic autoantibodies.Expert opinion: Newer diagnostic methods to replace traditional techniques should possess high sensitivity and specificity and be widely available, noninvasive, and relatively cheap. The newly developed methods need to be further evaluated before being recommended for routine use.

Paraneoplastic pemphigus: Revised diagnostic criteria based on literature analysis

BACKGROUND

Paraneoplastic pemphigus (PNP) is a rare autoimmune bullous disease classically associated with an underlying neoplasm. The heterogeneous clinical and histopathologic features of the disease make diagnosis challenging for clinicians. There are no formally accepted diagnostic criteria, and newer techniques for identifying antibodies directed against plakin proteins have largely replaced immunoprecipitation, the historic gold standard.

METHODS

An analysis of 265 published cases of PNP was performed. The clinical, histopathologic, and immunologic features of PNP were assessed.

RESULTS

Based on this review, we modified previous diagnostic criteria to capture 89.4% of PNP cases compared to 71.2% of cases captured by the most commonly referenced criteria devised by Camisa and Helm (p-value < 0.01, z-test; 95% CI [10.2, 33.6]).

CONCLUSION

These revised diagnostic criteria address the variable clinical, histopathologic, and biochemical features of PNP, allowing physicians to have greater confidence in diagnosis of this rare and often fatal disease. The revised criteria include three major criteria and two minor criteria, whereby meeting either all three major criteria or two major and both minor criteria would fulfill a diagnosis of paraneoplastic pemphigus. The major criteria include (a) mucous membrane lesions with or without cutaneous involvement, (b) concomitant internal neoplasm, and (b) serologic evidence of anti-plakin antibodies. The minor criteria include (a) acantholysis and/or lichenoid interface dermatitis on histopathology and (b) direct immunofluorescence staining showing intercellular and/or basement membrane staining.

[Paraneoplastic autoimmune dermatoses]

Paraneoplastic skin manifestations associated with malignancies are extremely polymorphous. Clinicians should be familiar with paraneoplastic dermatoses to establish an early diagnosis of the underlying neoplasm. Lack of familiarity with cutaneous clues for internal malignancies may delay diagnosis and treatment of cancer. In this review, we describe several paraneoplastic autoimmune dermatoses, including paraneoplastic autoimmune multiorgan syndrome, paraneoplastic bullous pemphigoid, and paraneoplastic dermatomyositis.

Immune-Mediated Dermatoses in Patients with Haematological Malignancies: A Comprehensive Review

Haematological malignancies induce important alterations of the immune system, which account for the high frequency of autoimmune complications observed in patients. Cutaneous immune-mediated diseases associated with haematological malignancies encompass a heterogeneous group of dermatoses, including, among others, neutrophilic and eosinophilic dermatoses, autoantibody-mediated skin diseases, vasculitis and granulomatous dermatoses. Some of these diseases, such as paraneoplastic pemphigus, are associated with an increased risk of death; others, such as eosinophilic dermatoses of haematological malignancies, run a benign clinical course but portend a significant negative impairment on a patient’s quality of life. In rare cases, the skin eruption reflects immunological alterations associated with an unfavourable prognosis of the associated haematological disorder. Therapeutic management of immune-mediated skin diseases in patients with haematological malignancies is often challenging. Systemic corticosteroids and immunosuppressive drugs are considered frontline therapies but may considerably augment the risk of serious infections. Indeed, developing a specific targeted therapeutic approach is of crucial importance for this particularly fragile patient population. This review provides an up-to-date overview on the immune-mediated skin diseases most frequently encountered by patients with onco-haematological disorders, discussing new pathogenic advances and therapeutic options on the horizon.

Immune serological diagnosis of pemphigus

Pemphigus is a rare autoimmune blistering disease which manifests with painful erosions and blisters of the skin and mucosa. This disorder is caused by autoantibodies attacking desmosomal proteins, necessary for cell-cell contact stability and epidermal integrity. Desmoglein (Dsg) 1 and Dsg3 are the two major target antigens in pemphigus. Yet, many other target proteins, which have been described over the years, seem to be involved in the loss of epidermal integrity. Clinical examination, combined to serological advances and detection of targeted antigens, permitted to differentiate among several pemphigus subtypes, in which pemphigus vulgaris and pemphigus foliaceus are the most common. Nowadays, serological analysis in pemphigus is a fundamental step of the diagnostic algorithm. This is based on analysis of clinical symptoms, histopathological examination of lesional skin, detection of tissue bound and circulating antibodies by direct and indirect immunofluorescence, and determination of target antigens either by enzyme-linked immunosorbent essay (ELISA) or by western blot analysis. A correct and exhaustive diagnostic algorithm is fundamental to characterize pemphigus subtypes, which lastly permits to adopt a correct treatment approach. Moreover, quality and quantity of circulating antibodies in patient's sera deliver important information regarding clinical course, disease severity and treatment response; thus, relevantly affecting physician's decision. To facilitate this process, "easy-to-perform" diagnostic kits with high sensitivity and specificity are being commercialized. In this review, we focus on available methods and established assays to correctly detect circulating autoantibodies in pemphigus. Moreover, we discuss subtype specific serological peculiarities in the five most relevant subtypes (pemphigus vulgaris, pemphigus foliaceus, pemphigus vegetans, paraneoplastic pemphigus and intercellular IgA dermatosis (also called as IgA pemphigus).

Practical Direct Immunofluorescence

Direct immunofluorescence (DIF) remains a valuable tool that may be underused because of perceived challenges in the interpretation, limitations, and processing of DIF specimens. The aim of this review is to provide a practical guide for appropriately incorporating DIF in a variety of clinical diseases, such as autoimmune blistering disorders. In vasculitis, the role of DIF continues to evolve, particularly in the setting of IgA vasculitis. Although typically not indicated for the workup of connective tissue disease, DIF may be helpful in cases with negative serologies, nondiagnostic histologic findings, or scarring alopecia. Practical pearls for biopsy technique, specimen handling, and storage are also discussed.

Paraneoplastic autoimmune multiorgan syndrome

Originally described by Anhalt as paraneoplastic pemphigus in 1990, paraneoplastic autoimmune multiorgan syndrome (PAMS) is a potentially lethal blistering disease, characterized by polymorphous clinical features, including mucocutaneous erosions, blisters, lichenoid papules, and erythemas. Several autoantibodies have been detected in serum of PAMS patients, including antiplakins, anti-alpha-2-macroglobulin like 1, and antidesmogleins autoantibodies. The mortality rate of PAMS is up to 90%. This is due on the one hand to the poor response to treatments and on the other hand to the delay in the diagnosis and to the prognosis of the underlying neoplasia.

Retrospective analysis of 45 cases of localized retroperitoneal Castleman disease from a single center

Background

Castleman disease (CD) is a rare lymphoproliferative disease characterized by high heterogeneity in clinical manifestation and prognosis. This study aimed to summarize clinical features of localized retroperitoneal CD and our experiences to improve the diagnosis and treatment of this disease.

Methods

Clinical data of 45 patients with localized retroperitoneal CD were retrospectively analyzed. The differences in clinical features between groups with and without paraneoplastic pemphigus (PNP) were compared. Survival was analyzed between groups depending on whether complicating with PNP, bronchiolitis obliterans (BO), gender, age and uni-centric CD (UCD)/multi-centric CD (MCD), respectively.

Results

Significant differences were observed between patient groups in the prevalence of retroperitoneal CD with PNP complicated with BO (P=0.010), the constituent ratios of initial symptoms (P<0.001) and the duration from appearance of the initial symptoms to being diagnosed (P=0.009). Among 45 cases, 43 tumors had clear margins and intact envelops and were completely resected, 40 patients were cured or significantly relieved, 3 patients were not significantly relieved, 2 patients received palliative surgical therapy and eventually relapsed and died after surgery. There were significant differences in the survival rate between groups depending on complication with BO, gender and age (≤40 and >40 years) (all P<0.05).

Conclusions

Prompt and complete removal of the retroperitoneal CD tumor is critical to the management of this disease, as palliative resection tends to cause relapse and lead to a poor prognosis. Retroperitoneal CD patients with PNP may develop complications from BO leading to death. Complication with PNP, complication with BO, male gender and age ≥40 years were identified as prognostic risk factors for patients with localized retroperitoneal CD.

Detection of autoantibodies against alpha-2-macroglobulin-like 1 in paraneoplastic pemphigus sera utilizing novel green fluorescent protein-based immunoassays

BACKGROUND

Paraneoplastic pemphigus (PNP) is a devastating autoimmune multiorgan syndrome associated with autoantibodies against several autoantigens, including the alpha-2-macroglobulin-like-1 (A2ML1). A2ML1 is recognized by up to 70 % of PNP sera. The currently recommended techniques for serological diagnosis of PNP are inadequate to detect anti-A2ML1 antibodies.

OBJECTIVES

To develop novel assays which allow to easily and reliably detect anti-A2ML1 autoantibodies in PNP sera.

METHODS

We produced full-length A2ML1 in fusion with enhanced green fluorescent protein (EGFP-A2ML1) in transfected human embryonic kidney 293 T cells. The recombinant protein was used as fluorescent ligand for immunoprecipitation studies. We further developed an enzyme-linked immunosorbent assay (ELISA) by immobilizing EGFP-A2ML1 on 96-well plates.

RESULTS

A2ML1-positive PNP sera were able to immunoprecipitate EGFP-A2ML1. Direct measurement of fluorescence in immunoprecipitates correlates with the relative levels of anti-A2ML1 antibodies in the PNP sera. By the novel ELISA, based on the determined best cut-off value, 61 % of the tested 36 PNP sera were A2ML1 positive with a specificity of 88.9 % and a sensitivity of 95 %. The 20 tested normal sera (NHS) were negative, while 2 (10 %) of 20 pemphigus vulgaris and 3 (15 %) of 20 bullous pemphigoid sera showed borderline values.

CONCLUSIONS

Our novel immunoassays enable rapid stratification of PNP patients. The novel green fluorescent protein-based ELISA utilizing an active eukaryotic A2ML1 is highly sensitive and reliable and, hence, is useful for a better understanding of the immunological background of PNP. This approach may be easily applied for the rapid detection of antibodies to various other antigens.

Paraneoplastic Dermatoses: A Brief General Review and an Extensive Analysis of Paraneoplastic Pemphigus and Paraneoplastic Dermatomyositis

Skin manifestations of systemic disease and malignancy are extremely polymorphous. Clinicians should be familiarized with paraneoplastic dermatoses in order to perform an early diagnosis of the underlying neoplasm. Lack of familiarity with cutaneous clues of internal malignancy may delay diagnosis and treatment of cancer. In this review, we described several paraneoplastic dermatoses and discussed extensively two paradigmatic ones, namely paraneoplastic pemphigus and paraneoplastic dermatomyositis.

Modern diagnostic methods of paraneoplastic pemphigus

Paraneoplastic pemphigus (PNP) is one of the least investigated and rare forms of bullous dermatoses, which comes from underlying neoplasm. The article presents a literature review of dermatologist`s longstanding international experience about etiology, pathogenesis, diagnostics and treatment of this disease. According to the research results of native and foreign authors systematization of modern diagnostic methods of PNP and detectable antigens was performed.

Conflict of interest: the authors state that there is no potential conflict of interest requiring disclosure in this article.

Oral Lesions in Autoimmune Bullous Diseases: An Overview of Clinical Characteristics and Diagnostic Algorithm

Autoimmune bullous diseases are a group of chronic inflammatory disorders caused by autoantibodies targeted against structural proteins of the desmosomal and hemidesmosomal plaques in the skin and mucosa, leading to intra-epithelial or subepithelial blistering. The oral mucosa is frequently affected in these diseases, in particular, in mucous membrane pemphigoid, pemphigus vulgaris, and paraneoplastic pemphigus. The clinical symptoms are heterogeneous and may present with erythema, blisters, erosions, and ulcers localized anywhere on the oral mucosa, and lead to severe complaints for the patients including pain, dysphagia, and foetor. Therefore, a quick and proper diagnosis with adequate treatment is needed. Clinical presentations of autoimmune bullous diseases often overlap and diagnosis cannot be made based on clinical features alone. Immunodiagnostic tests are of great importance in differentiating between the different diseases. Direct immunofluorescence microscopy shows depositions of autoantibodies along the epithelial basement membrane zone in mucous membrane pemphigoid subtypes, or depositions on the epithelial cell surface in pemphigus variants. Additional immunoserological tests are useful to discriminate between the different subtypes of pemphigoid, and are essential to differentiate between pemphigus and paraneoplastic pemphigus. This review gives an overview of the clinical characteristics of oral lesions and the diagnostic procedures in autoimmune blistering diseases, and provides a diagnostic algorithm for daily practice.

Oral lichen planus: A disease or a spectrum of tissue reactions? Types, causes, diagnostic algorhythms, prognosis, management strategies

Oral lichen planus and lichenoid lesions comprise a group of disorders of the oral mucosa that likely represent a common reaction pattern to 1 or more unknown antigens. The coexistence of hyperkeratotic striation/reticulation, varying degrees of mucosal inflammation from mild erythema to severe widespread ulceration, and a band-like infiltrate of mononuclear inflammatory cells including activated T lymphocytes, macrophages, and dendritic cells, are considered suggestive of oral lichen planus and lichenoid lesions. Several classification systems of oral lichen planus and lichenoid lesions have been attempted, although none seem to be comprehensive. In this paper, we present a classification of oral lichen planus and lichenoid lesions that includes oral lichen planus, oral lichenoid contact lesions, oral lichenoid drug reactions, oral lichenoid lesions of graft vs. host disease, discoid lupus erythematosus, and systemic lupus erythematosus, lichen planus-like variant of paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome, chronic ulcerative stomatitis, lichen planus pemphigoides, solitary fixed drug eruptions, and lichen sclerosus. We present the clinical and diagnostic aspects of oral lichen planus and lichenoid lesions, and discuss related treatment options.

Paraneoplastic Pemphigus Revealed by Anti-programmed Death-1 Pembrolizumab Therapy for Cutaneous Squamous Cell Carcinoma Complicating Hidradenitis Suppurativa

A 64-year-old patient developed a widespread autoimmune mucocutaneous blistering disease 3 weeks after the initiation of the anti-programmed death-1 (anti-PD-1) pembrolizumab therapy administered for a locally advanced cutaneous squamous cell carcinoma (SCC) of the buttocks arising from hidradenitis suppurativa. A diagnosis of paraneoplastic pemphigus (PNP) was made based on the presence of a suprabasal acantholysis associated with intercellular deposits of immunoglobulin G and C3 on basement membrane zone. Analysis of the patient's sera was positive on monkey bladder and detected circulating antibodies against desmoglein 3 and desmoplakin I prior to the initiation of pembrolizumab. At that time, the patient had few localized blisters limited to the peri-tumoral skin of the buttocks with acantholysis but without in vivo immune deposits. Pembrolizumab therapy was discontinued and a complete remission of PNP was obtained using oral steroids. Reintroduction of pembrolizumab resulted in flare of PNP. Given the close temporal relation between pembrolizumab initiation and the subsequent clinical expression of a widespread PNP, the patient was diagnosed with pre-existing subclinical PNP exacerbated by PD-1 inhibitor. The extreme rarity of PNP in the setting of cutaneous SCC and the effects of challenge, dechallenge, and rechallenge of pembrolizumab argue in favor of a checkpoint inhibitor related adverse effect. Our case is the first PNP associated with anti-PD-1 therapy and serological follow-up suggest that one infusion of pembrolizumab is sufficient to allow clinical expression of underlying pemphigus auto-immunity.

Diagnosis of autoimmune bullous diseases

Autoimmune bullous disorders (AIBDs) are a heterogeneous group of rare diseases clinically characterized by erosions and/or blisters on the skin and mucous membranes. AIBDs can be categorized into two groups: pemphigus diseases, characterized by intraepidermal blistering and autoantibodies against desmosomal proteins such as desmoglein (Dsg) 1, Dsg3, members of the plakin family, and subepidermal AIBDs, comprised of pemphigoid diseases and dermatitis herpetiformis. Autoantibodies in dermatitis herpetiformis target transglutaminases 2 and 3, while in pemphigoid disease, autoantibodies are directed against structural proteins of the dermal-epidermal junction. Although analysis of a perilesional biopsy with direct immunofluorescence (IF) microscopy is still the diagnostic gold standard, several assays have become widely available that allow serological diagnosis in the majority of patients. Standard serological diagnosis includes indirect IF on monkey esophagus and salt-split human skin. Assays to further characterize autoantibody specificity include ELISA systems based on recombinant forms of the immunodominant regions of the target antigens as well as multivariant indirect IF microscopy tests with several miniature substrates. These serological assays are complemented by various in-house assays using immunoblotting and ELISA, which are only available in specialized laboratories. Here we review new developments in the diagnosis of AIBDs and describe state-of-the-art diagnostic procedures for this group of diseases.

Paraneoplastic pemphigus: a clinical, laboratorial, and therapeutic overview

Paraneoplastic pemphigus is a rare and severe autoimmune blistering disease characterized by mucocutaneous lesions associated with benign and malignant neoplasms. Diagnostic criteria include the presence of chronic mucositis and polymorphic cutaneous lesions with occult or confirmed neoplasia; histopathological analysis exhibiting intraepidermal acantholysis, necrotic keratinocytes, and vacuolar interface dermatitis; direct immunofluorescence with intercellular deposits (IgG and C3) and at the basement membrane zone (IgG); indirect immunofluorescence with intercellular deposition of IgG (substrates: monkey esophagus and simple, columnar, and transitional epithelium); and, autoreactivity to desmogleins 1 and 3, desmocollins 1, 2, and 3, desmoplakins I and II, envoplakin, periplakin, epiplakin, plectin, BP230, and α-2-macroglobulin-like protein 1. Neoplasias frequently related to paraneoplastic pemphigus include chronic lymphocytic leukemia, non-Hodgkin lymphoma, carcinomas, Castleman disease, thymoma, and others. Currently, there is no standardized treatment for paraneoplastic pemphigus. Systemic corticosteroids, azathioprine, mycophenolate mofetil, cyclosporine, rituximab, cyclophosphamide, plasmapheresis, and intravenous immunoglobulin have been used, with variable outcomes. Reported survival rates in 1, 2, and 5 years are 49%, 41%, and 38%, respectively.

Diagnostik blasenbildender Autoimmundermatosen

Blasenbildende Autoimmundermatosen (BAIDs) sind eine heterogene Gruppe seltener Erkrankungen, die klinisch durch Erosionen und/oder Blasen an Haut und Schleimhäuten charakterisiert sind. BAIDs können in zwei Gruppen eingeteilt werden: Pemphigus-Erkrankungen, die durch intraepidermale Blasenbildung und Autoantikörper gegen desmosomale Proteine wie Desmoglein (Dsg) 1, Dsg3 und Mitglieder der Plakin-Familie charakterisiert sind, sowie subepidermale BAIDs, die Pemphigoid-Erkrankungen und die Dermatitis herpetiformis umfassen. Bei der Dermatitis herpetiformis greifen die Autoantikörper die Transglutaminasen 2 und 3 an, während sie bei Pemphigoid-Erkrankungen gegen Strukturproteine der dermoepidermalen Junktionszone gerichtet sind. Die Analyse einer periläsionalen Biopsie mittels direkter Immunfluoreszenzmikroskopie (IF-Mikroskopie) stellt zwar nach wie vor den diagnostischen Goldstandard dar, mittlerweile sind jedoch verschiedene Tests allgemein verfügbar, die eine serologische Diagnosefindung für den Großteil der Patienten ermöglichen. Zur serologischen Standarddiagnostik gehört die indirekte IF auf Affenösophagus und NaCl-separierter Spalthaut. Die Spezifität der Autoantikörper kann mit ELISA-Systemen, die auf rekombinanten Formen der immundominanten Regionen der Zielantigene basieren, sowie indirekter IF-Mikroskopie anhand multivarianter Tests mit mehreren multivariate näher charakterisiert werden. Diese serologischen Tests werden durch verschiedene hauseigene Immunoblotting- und ELISA-Systeme ergänzt, die nur in spezialisierten Laboratorien verfügbar sind. In diesem Review geben wir einen Überblick über neue Entwicklungen bei der Diagnose von BAIDs und beschreiben moderne Diagnoseverfahren für diese Krankheitsgruppe.

Pemphigus

Pemphigus consists of a group of rare and severe autoimmune blistering diseases mediated by pathogenic autoantibodies mainly directed against two desmosomal adhesion proteins, desmoglein (Dsg)1 and Dsg3 (also known as DG1 and DG3), which are present in the skin and surface-close mucosae. The binding of autoantibodies to Dsg proteins induces a separation of neighbouring keratinocytes, in a process known as acantholysis. The two main pemphigus variants are pemphigus vulgaris, which often originates with painful oral erosions, and pemphigus foliaceus, which is characterised by exclusive skin lesions. Pemphigus is diagnosed on the basis of either IgG or complement component 3 deposits (or both) at the keratinocyte cell membrane, detected by direct immunofluorescence microscopy of a perilesional biopsy, with serum anti-Dsg1 or anti-Dsg3 antibodies (or both) detected by ELISA. Corticosteroids are the therapeutic mainstay, which have recently been complemented by the anti-CD20 antibody rituximab in moderate and severe disease. Rituximab induces complete remission off therapy in 90% of patients, despite rapid tapering of corticosteroids, thus allowing for a major corticosteroid-sparing effect and a halved number of adverse events related to corticosteroids.

Bullous autoimmune dermatoses

Pathophysiologically, bullous autoimmune dermatoses are caused by autoantibodies directed against adhesion molecules or structural proteins of the skin and mucous membranes, clinically resulting in blister formation. Depending on the respective target proteins of the autoimmune response and their location in the skin, a distinction is made between intraepidermal (pemphigus disorders), junctional (pemphigoid disorders), and subepidermal (epidermolysis bullosa acquisita, dermatitis herpetiformis) autoimmune blistering diseases. The most common bullous autoimmune dermatosis, bullous pemphigoid is characterized by marked clinical variability and intense pruritus. Predominantly affecting elderly individuals, there has been a significant increase in its incidence in recent years. While mucosal lesions occur in less than 30 % of bullous pemphigoid patients, the second most common bullous autoimmune dermatosis, pemphigus vulgaris, typically presents with oral erosions as the predominant and - frequently - initial symptom. Its onset is usually in the 4^th to 6^th decade of life. Scarring is typically found in subepidermal blistering disorders such as epidermolysis bullosa acquisita or mucous membrane pemphigoid. Diagnosis is based on clinical and histological findings as well as direct and indirect immunofluorescence and detection of circulating autoantibodies. Although a number of controlled clinical trials have been conducted in recent years, treatment of bullous autoimmune disorders is still primarily based on clinical experience. Therapeutic options include topical and systemic corticosteroids as well as adjuvant immunosuppressants. Recalcitrant cases may require treatment with immunoadsorption, intravenous immunoglobulins, or the monoclonal anti-CD20 antibody rituximab.

Serological Diagnosis of Autoimmune Bullous Skin Diseases

Autoimmune bullous dermatoses (AIBD) encompass a variety of organ-specific autoimmune diseases that manifest with cutaneous and/or mucosal blisters and erosions. They are characterized by autoantibodies targeting structural proteins of the skin, which are responsible for the intercellular contact between epidermal keratinocytes and for adhesion of the basal keratinocytes to the dermis. The autoantibodies disrupt the adhesive functions, leading to splitting and blister formation. In pemphigus diseases, blisters form intraepidermally, whereas in all other disease types they occur subepidermally. Early identification of autoimmune bullous dermatoses is crucial for both treatment and prognosis, particularly as regards tumor-associated disease entities. The diagnosis is based on clinical symptoms, histopathology, direct immunofluorescence to detect antibody/complement deposits, and the determination of circulating autoantibodies. The identification of various target antigens has paved the way for the recent development of numerous specific autoantibody tests. In particular, optimized designer antigens and multiplex test formats for indirect immunofluorescence and ELISA have enhanced and refined the laboratory analysis, enabling highly efficient serodiagnosis and follow-up. This review elaborates on the current standards in the serological diagnostics for autoimmune bullous dermatoses.

Paraneoplastic Pemphigus with Underlying Castleman's Disorder: A Rare Report with Literature Review

Paraneoplastic pemphigus (PNP), also known as paraneoplastic autoimmune multisystem syndrome (PAMS), is an autoimmune blistering disorder of the skin associated with various hematological and nonhematological malignancies. In most of the cases, it can be a harbinger of a concealed benign or malignant neoplasm. We report the case of a 23-year-old female patient who presented to the dermatology consult service with a previously known diagnosis of refractory pemphigus vulgaris but she failed to reach remission for her oral and skin lesions on steroid and intravenous immunoglobulin (IVIG). She was later investigated for underlying malignancy as the concern of PNP was raised. She was found to be diagnosed with a pelvic mass which was found to be Castleman's disease. Our patient responded well to surgery and postoperative course of pulsed methylprednisolone and IVIG. Here, we discuss the diagnosis and clinical course of this unique case and strive to create awareness about PNP that can present as a refractory polymorphous blistering dermatological disorder and can hinder the diagnosis and management of patients.

Paraneoplastic Pemphigus: Paraneoplastic Autoimmune Disease of the Skin and Mucosa

Paraneoplastic pemphigus (PNP) is a rare but life-threatening mucocutaneous disease mediated by paraneoplastic autoimmunity. Various neoplasms are associated with PNP. Intractable stomatitis and polymorphous cutaneous eruptions, including blisters and lichenoid dermatitis, are characteristic clinical features caused by humoral and cell-mediated autoimmune reactions. Autoreactive T cells and IgG autoantibodies against heterogeneous antigens, including plakin family proteins and desmosomal cadherins, contribute to the pathogenesis of PNP. Several mechanisms of autoimmunity may be at play in this disease on the type of neoplasm present. Diagnosis can be made based on clinical and histopathological features, the presence of anti-plakin autoantibodies, and underlying neoplasms. Immunosuppressive agents and biologics including rituximab have been used for the treatment of PNP; however, the prognosis is poor due to underlying malignancies, severe infections during immunosuppressive treatment, and bronchiolitis obliterans mediated by autoimmunity. In this review, we overview the characteristics of PNP and focus on the immunopathology and the potential pathomechanisms of this disease.

Immunological methods for the diagnosis of oral mucosal diseases

Immunological methods, which have been widely used in autoimmune blistering diseases (AIBDs) of the oral mucosa, can also be adopted as auxiliary diagnostic tools in oral lichen planus (OLP) and discoid lupus erythematosus (DLE). AIBDs, characterized by autoantibodies against structural proteins of keratinocytes or the basement membrane zone, clinically present as blisters and erosions of the oral mucosa. When atypical lesions occur, OLP or DLE may be confused with AIBDs. The improvement of diagnostic accuracy is necessary due to the significant differences in treatment and prognosis among these diseases. A variety of immunological methods are used for qualitative and quantitative detection of target antigens and autoantibodies. These methods can evaluate efficacy of treatment, monitor diseases and guide treatment decisions. In this review, we discuss the application of immunofluorescence, biochemical tests, and protein microarrays for AIBDs, OLP and DLE, as well as the differential diagnostic methods using immunological tests.

Suprabasal acantholytic dermatologic toxicities associated checkpoint inhibitor therapy: A spectrum of immune reactions from paraneoplastic pemphigus-like to Grover-like lesions

Checkpoint inhibitors (CPIs) restore the function of effector immunocytes to target and destroy cancer cells. Immune-related adverse events (irAEs) are a consequence of immune reactivation, with unpredictable inflammatory response, loss of self-tolerance, and development of autoimmunity. Adverse events from CPIs that present as dermatologic toxicities have diverse clinical and histopathologic features. CPI-associated dermatologic toxicities may exhibit histopathologic features of lichenoid dermatitis, bullous pemphigoid, and granulomatous/sarcoid-like reactions. Suprabasal acantholytic dermatologic toxicities associated with CPIs are particularly rare but represent an emerging histopathologic pattern and include lichenoid dermatitis with suprabasal acantholysis/vesicle formation to Grover disease (transient acantholytic dermatosis). Here, we report two patients who developed suprabasal acantholytic dermatologic toxicities during CPI therapy. One patient exhibited a CPI-associated autoimmune blistering disease with paraneoplastic pemphigus (PNP)-like features restricted to histopathology and immunofluorescence, while the other patient had Grover-like lesions. A review of the literature revealed a spectrum of suprabasal acantholytic dermatologic toxicities associated CPIs that may present as lichenoid dermatitis with acantholysis/vesicle formation, Grover-like eruptions, and lesions with PNP-like features restricted to histopathology and immunofluorescence. It is important for clinicians and pathologists to recognize the types of dermatologic toxicities associated with CPIs to direct appropriate therapeutic strategies.

Paraneoplastic pemphigus associated with chronic lymphocytic leukemia: a case report

Background

Paraneoplastic pemphigus is a rare multiorgan disease of autoimmune causes, usually triggered by neoplasias, mainly of lymphoproliferative origin, such as leukemia and lymphoma. This disorder is categorized by the presence of autoantibodies that react against proteins, such as desmoplakins, desmogleins, desmocollins, and others that exist in cellular junctions. Paraneoplastic pemphigus can manifest clinically in a variety of ways, ranging from mucositis to lesions involving the skin and pulmonary changes. The diagnosis depends on the correlation between the clinical and histopathologic evaluations. Currently, the treatment of this disease is still very difficult and ineffective. The prognosis is poor, and the mortality rate is very high.

Case presentation

We report a case of a Caucasian patient who had chronic lymphocytic leukemia and developed paraneoplastic pemphigus with severe impairment of skin and mucosa. The initial diagnostic hypothesis was Stevens-Johnson syndrome. The histopathological examination of the skin biopsy was compatible with paraneoplastic pemphigus, and the definitive diagnosis was made on the basis of clinical-pathological correlation.

Conclusions

With the presence of multiorgan lesions in patients with lymphoproliferative neoplasia, paraneoplastic pemphigus should always be considered among the possible diagnostic hypotheses, because diagnosis and early treatment may allow a better prognosis for the patient.

Unicentric castleman disease complicated by paraneoplastic bronchiolitis obliterans and pemphigus

Bronchiolitis obliterans (BO) and paraneoplastic pemphigus are rare and ominous complications of Castleman disease. Collectively, these processes have been reported as part of paraneoplastic autoimmune multiorgan syndrome (PAMS), and they can occur in the setting of various hematologic malignant tumors, carcinoid tumors, and melanoma. Irrespective of the underlying malignancy driving PAMS, the clinical outcomes are uniformly poor, and there are no standard treatment regimens, given the clinical rarity of the syndrome. We describe 2 patients with unicentric Castleman disease complicated by paraneoplastic pemphigus and bronchiolitis obliterans. In addition to primary surgical resection for Castleman disease, we also used therapy from a treatment protocol used for bronchiolitis obliterans resulting from hematopoietic stem cell transplant (HSCT). We were able to treat the patients using intravenous immunoglobulin; rituximab; fluticasone, azithromycin, and montelukast (FAM); and rosuvastatin therapy. One patient demonstrated a favorable response, while the other demonstrated minimal response to this therapy.

Buccal paraneoplastic pemphigus multi-resistant: Case report and review of diagnostic and therapeutic strategies

Paraneoplastic pemphigus is a rare autoimmune blistering disease generally associated with malignancy. The clinical presentation consists typically of painful and diffuse erosive stomatitis that may be accompanied by polymorphic skin lesions and systemic involvement. Diagnosis is based on clinical manifestations and confirmed by histology and immunological testing. The current first-line treatment is systemic corticosteroids and adjuvant therapies, including immunosuppressive agents. We report a case of buccal paraneoplastic pemphigus resistant to ibrutinib and rituximab successfully treated with azathioprine and polyclonal immunoglobulins.

Immunofluorescence of Autoimmune Bullous Diseases

Autoimmmune bullous diseases of skin and mucosa are uncommon, disabling, and potentially lethal diseases. For a quick and reliable diagnosis immunofluorescence is essential. This article describes two variants of immunofluorescence. The direct method uses a skin or mucosal biopsy of the patient to detect in vivo bound antibodies. Indirect immunofluorescence uses patient's serum and a substrate to visualize circulating autoantibodies. These two methods supplemented with advanced techniques allow reliable classification of autoimmune bullous diseases; not only the main entities pemphigus and pemphigoid, but also subclasses within these groups. This is important because prognosis and therapy vary among different variants of autoimmune bullous diseases.

Pediatric 8p11 eosinophilic myeloproliferative syndrome (EMS): A case report and review of the literature

The 8p11 eosinophilic myeloproliferative syndrome (EMS) is an aggressive neoplasm driven by translocation of the fibroblast growth factor receptor 1 and often transforms to leukemias and lymphomas that are refractory to treatment. The first case was identified in 1983, and to date over 70 cases have been reported in the literature. Despite those reports, no consensus exists on management of this condition, and inconsistency in treatment regimens is even more pronounced in the pediatric literature. We report a case of a male infant with the 8p11 EMS, review the published pediatric experience with EMS, and discuss treatment strategies for this enigmatic hematological disorder.

Paraneoplastic pemphigus associated with chronic lymphocytic leukemia: A case report

RATIONALE

Paraneoplastic pemphigus (PNP) is an autoimmune syndrome associated with neoplasms. The treatment approach principally includes suppressing the immunity, but its therapeutic effect is not satisfying.

PATIENT CONCERNS

We report a case of paraneoplastic pemphigus linked to chronic lymphocytic leukemia in a 63-year-old man.

DIAGNOSES

At first, the patient was diagnosed with pityriasis rose caused by a viral infection. Biopsies for histology and immunofluorescence showed PNP, was treated with immunosuppressive and antiinfective therapy.

INTERVENTIONS

Immunosuppressive and antiinfective therapy were performed.

OUTCOMES

The skin lesions of PNP were alleviated. However, the infections were aggravated and the disease progressed. The patient died of respiratory failure.

LESSONS

Treatment for PNP should be adapted to disease severity as early as possible. Antiinfection treatment should be timely and effective because infections are the most common complication that can lead to death.

Paraneoplastic Pemphigus and Autoimmune Blistering Diseases Associated with Neoplasm: Characteristics, Diagnosis, Associated Neoplasms, Proposed Pathogenesis, Treatment

Autoimmune paraneoplastic and neoplasm-associated skin syndromes are characterized by autoimmune-mediated cutaneous lesions in the presence of a neoplasm. The identification of these syndromes provides information about the underlying tumor, systemic symptoms, and debilitating complications. The recognition of these syndromes is particularly helpful in cases of skin lesions presenting as the first sign of the malignancy, and the underlying malignancy can be treated in a timely manner. Autoimmune paraneoplastic and neoplasm-associated bullous skin syndromes are characterized by blister formation due to an autoimmune response to components of the epidermis or basement membrane in the context of a neoplasm. The clinical manifestations, histopathology and immunopathology findings, target antigens, associated neoplasm, current diagnostic criteria, current understanding of pathogenesis, and treatment options for a selection of four diseases are reviewed. Paraneoplastic pemphigus manifests with clinically distinct painful mucosal erosions and polymorphic cutaneous lesions, and is often associated with lymphoproliferative neoplasm. In contrast, bullous pemphigoid associated with neoplasm presents with large tense subepidermal bullae of the skin, and mild mucosal involvement, but without unique clinical features. Mucous membrane pemphigoid associated with neoplasm is a disorder of chronic subepithelial blisters that evolve into erosions and ulcerations that heal with scarring, and involves stratified squamous mucosal surfaces. Linear IgA dermatosis associated with neoplasm is characterized by annularly grouped pruritic papules, vesicles, and bullae along the extensor surfaces of elbows, knees, and buttocks. Physicians should be aware that these autoimmune paraneoplastic and neoplasm-associated syndromes can manifest distinct or similar clinical features as compared with the non-neoplastic counterparts.