Clinical and immunological findings in 104 cases of paraneoplastic pemphigus

Lymphoma With a Skin Rash

A 62-year-old female had a generalized vesiculobullous rash on her face for 4 months. It started over the lips and gradually progressed to involve the oral mucosa and skin of the whole body. What is your diagnosis?

Paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome: Part II. Diagnosis and management

In the second part of this Continuing Medical Education article on paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome (PNP/PAMS), its diagnostic criteria, investigative work-up, and management are reviewed. PNP/PAMS is a rare autoimmune blistering disorder associated with high morbidity and mortality. Recognizing PNP/PAMS's key features and its diagnostic criteria is critical in initiating appropriate work-up. Evaluating PNP/PAMS requires knowledge of its findings on histopathology, direct immunofluorescence, indirect immunofluorescence, and enzyme-linked immunosorbent assay. Lastly, treatments for PNP/PAMS are reviewed with suggestions based on case reports and expert opinions in the literature.

Paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome: Part I. Clinical overview and pathophysiology

Paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome (PNP/PAMS) is a highly fatal autoimmune blistering disease. The condition occurs in patients with underlying benign or malignant neoplasms, most commonly lymphoproliferative disorders. Both humoral and cell-mediated immunities contribute to the pathogenesis, and autoantibodies against plakin family proteins are characteristic. Patients typically present with severe stomatitis and polymorphous skin lesions, which are often resistant to treatment. Bronchiolitis obliterans (BO) is a frequent complication which contributes to the high mortality rate of PNP/PAMS. Given the rarity of this disorder and heterogeneity of clinical presentation, clinicians should maintain a high index of suspicion for PNP/PAMS to avoid delayed diagnosis. In this first part of a two-part continuing medical education (CME) series, risk factors, pathogenesis, and clinical features of PNP/PAMS are discussed.

State-of-the-art diagnosis of autoimmune blistering diseases

Autoimmune blistering disorders (AIBDs) are a heterogeneous group of approximately a dozen entities comprising pemphigus and pemphigoid disorders and dermatitis herpetiformis. The exact diagnosis of AIBDs is critical for both prognosis and treatment and is based on the clinical appearance combined with the detection of tissue-bound and circulating autoantibodies. While blisters and erosions on the skin and/or inspectable mucosal surfaces are typical, lesions may be highly variable with erythematous, urticarial, prurigo-like, or eczematous manifestations. While direct immunofluorescence microscopy (IFM) of a perilesional biopsy is still the diagnostic gold standard, the molecular identification of the major target antigens opened novel therapeutic avenues. At present, most AIBDs can be diagnosed by the detection of autoantigen-specific serum antibodies by enzyme-linked immunosorbent assay (ELISA) or indirect IFM when the clinical picture is known. This is achieved by easily available and highly specific and sensitive assays employing recombinant immunodominant fragments of the major target antigens, i.e., desmoglein 1 (for pemphigus foliaceus), desmoglein 3 (for pemphigus vulgaris), envoplakin (for paraneoplastic pemphigus), BP180/type XVII collagen (for bullous pemphigoid, pemphigoid gestationis, and mucous membrane pemphigoid), laminin 332 (for mucous membrane pemphigoid), laminin β4 (for anti-p200 pemphigoid), type VII collagen (for epidermolysis bullosa acquisita and mucous membrane pemphigoid), and transglutaminase 3 (for dermatitis herpetiformis). Indirect IFM on tissue substrates and in-house ELISA and immunoblot tests are required to detect autoantibodies in some AIBD patients including those with linear IgA disease. Here, a straightforward modern approach to diagnosing AIBDs is presented including diagnostic criteria according to national and international guidelines supplemented by long-term in-house expertise.

Paraneoplastic pemphigus presenting as a prodrome to aggressive T cell lymphoma

Paraneoplastic pemphigus (PNP) is a rare disease with an unclear mechanism of pathogenesis. We present a case of a male patient who presented with wound management after being diagnosed with Castleman disease-associated paraneoplastic pemphigus (PNP). The patient's condition was not improving; as a result, extensive workup was repeated, which confirmed the diagnosis of aggressive T cell lymphoblastic lymphoma. Our case signifies the importance of keeping a high index of suspicion for PNP-associated malignancies. This case report also adds emphasis to the diagnostic challenges faced by clinicians, making clinical correlation with multidisciplinary approach essential. Therefore, if clinically indicated, we need to revisit the diagnosis and seek alternative explanations to prevent delays in management.

Whole-Exome Sequencing Reveals the Genomic Profile and IL6ST Variants as a Prognostic Biomarker of Paraneoplastic Pemphigus-Associated Unicentric Castleman Disease

Unicentric Castleman disease (UCD) is a rare lymphoproliferative disorder. Paraneoplastic pemphigus (PNP) is a major complication associated with poor UCD prognosis. However, the genomic profiles and prognostic biomarkers of PNP-associated UCD remain unclear. In this study, we performed whole-exome sequencing analysis for 28 matched tumor-normal pairs and 9 tumor-only samples to define the genomic landscape of Chinese patients with PNP-associated UCD. An integrative analysis was performed to identify somatic variants, the mutational signatures, and key pathways in tumors. Besides, we analyzed the relationship among mutated genes, clinical characteristics, and prognosis. Sixty-one somatic mutant genes were identified in >1 patient with PNP-associated UCD. Specifically, IL6ST and PDGFRB were the most frequently mutated genes (32%), followed by DPP6 (18%) and MUC4 (18%). Signaling molecules and interactions, cellular processes, and signal transduction pathways were enriched. Furthermore, we found that poor overall survival was related to IL6ST variants (P = .02). Finally, we classified PNP-associated UCD into 4 genomic subgroups: IL6ST, PDGFRB, IL6ST-PDGFRB, and an unknown subgroup. In summary, we defined the molecular profile of PNP-associated UCD and identified a potential molecular biomarker for predicting prognosis, which may provide therapeutic targets for treating this severe disorder.

Variations of oral anatomy and common oral lesions

Several topics related to the oral cavity are briefly addressed in this article, from anatomical variations that, when recognized, avoid unnecessary investigations, to diseases that affect exclusively the mouth, mucocutaneous diseases, as well as oral manifestations of systemic diseases. A complete clinical examination comprises the examination of the mouth, and this approach facilitates clinical practice, shortening the path to diagnosis in the outpatient clinic as well as with in-hospital patients. The objective of this article is to encourage the examination of the oral cavity as a useful tool in medical practice, helping to recognize diseases in this location.

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.

Ocular involvement in autoimmune bullous diseases

Autoimmune bullous diseases represent a heterogenous group of disorders caused by autoantibodies against adhesion molecules; the location of the target protein determines the level of cleft formation. The spectrum of ocular lesions in autoimmune bullous diseases can range from mild symptoms to severe involvement with sight impairment and even, in some cases, blindness. In pemphigus vulgaris, the prevalence of ocular involvement has been reported to be between 7% and 26%. The most common clinical sign of ocular pemphigus vulgaris is bilateral conjunctivitis with hyperemia. Ocular involvement also occurs in 41% to 70% of patients with paraneoplastic pemphigus. The main ocular manifestations are bilateral cicatrizing conjunctivitis with symblepharon formation, and shortening of the fornices. In mucous membrane pemphigoid, ocular involvement is seen in 61% to 70% of patients; the most frequent ocular finding is cicatricial conjunctivitis. Patients with autoimmune bullous diseases having common ocular involvement should be assessed by an ophthalmologist to avoid serious complications. Diagnostic procedures and treatment require multidisciplinary care based on the close cooperation between dermatologists and ophthalmologists.

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: Diagnostic mimics, confounders and management challenges in a series of five long-term survivors from a single centre

We present a series of five cases who presented to our institution with treatment-refractory mucosal ulceration, all of whom were subsequently diagnosed with paraneoplastic pemphigus (PNP). This case series highlights the diagnostic and treatment considerations for PNP - in particular, the steroid-dependent, recalcitrant, polymorphic manifestations; the combination of histopathological and clinical findings that may overlap with clinically similar diseases, for example, pemphigus vulgaris and lichen planus; the importance of immunopathological findings for its diagnosis, and the need for surveillance and management of life-threatening bronchiolitis obliterans.

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.

Classification and Antigen Molecules of Autoimmune Bullous Diseases

Autoimmune bullous diseases (AIBDs), which are a group of tissue-specific autoimmune diseases of the skin, present with various blistering lesions on the skin and mucous membranes, and show autoantibodies of IgG, IgA and IgM against epidermal cell surfaces and basement membrane zone. To date, AIBDs have been classified into a number of distinct subtypes by clinical and histopathological findings, and immunological characteristics. In addition, various biochemical and molecular biological studies have identified various novel autoantigens in AIBDs, which has resulted in proposals of new subtypes of AIBDs. In this article, we summarized various distinct AIBDs, and proposed the latest and most comprehensive classification of AIBDs with their autoantigen molecules.

T cell autoimmunity and immune regulation to desmoglein 3, a pemphigus autoantigen

Pemphigus is a life-threatening autoimmune bullous disease mediated by anti-desmoglein IgG autoantibodies. Pemphigus is mainly classified into three subtypes: pemphigus vulgaris, pemphigus foliaceus, and paraneoplastic pemphigus. The pathogenicity of autoantibodies has been extensively studied. Anti-human CD20 antibody therapy targeting B cells emerged as a more effective treatment option compared to conventional therapy for patients with an intractable disease. On the other hand, autoreactive T cells are considered to be involved in the pathogenesis based on the test results of human leukocyte antigen association, autoreactive T cell detection, and cytokine profile analysis. Research on the role of T cells in pemphigus has continued to progress, including that on T follicular helper cells, which initiate molecular mechanisms involved in antibody production in B cells. Autoreactive T cell research in mice has highlighted the crucial roles of cellular autoimmunity and improved the understanding of its pathogenesis, especially in paraneoplastic pemphigus. The mouse research has helped elucidate novel regulatory mechanisms of autoreactive T cells, such as thymic tolerance to desmoglein 3 and the essential roles of regulatory T cells, Langerhans cells, and other molecules in peripheral tissues. This review focuses on the immunological aspects of autoreactive T cells in pemphigus by providing detailed information on various related topics.

Paraneoplastic pemphigus associated with Castleman disease: A multicenter case series

INTRODUCTION

Paraneoplastic pemphigus (PNP) is a rare, often fatal, autoimmune blistering disease of the skin and mucous membranes. In children, PNP is frequently associated with Castleman disease (CD). This series describes five cases of PNP associated with CD.

METHODS

Data were collected retrospectively from the medical records of patients with a diagnosis of PNP and CD from January 2013 to June 2022. Patients ≤22 years old with clinical and immunopathologic evidence of PNP were included; CD was diagnosed histopathologically.

RESULTS

Two children, two adolescents, and one young adult (two males, three females) were included. The average age at disease presentation was 11.8 years (range: 7-22 years). Oral (n = 5) and anogenital (n = 3) mucositis were common. Four patients had "unicentric" CD (UCD); one patient had "multicentric" CD (MCD). Castleman tumors were in the retroperitoneum (n = 4) or axilla (n = 1). One patient had myasthenia gravis without thymoma. Three patients had bronchiolitis obliterans (BO). Three patients had complete resection of their CD; two had partial resection. Three patients remain alive with a median follow-up of 13 months (range: 12 months to 13 years); two are clinically stable with resolution of mucocutaneous lesions; one has persistent BO requiring ongoing ventilatory support. Patients who remain alive had UCD with complete resection; all deceased patients had partial resection and BO.

CONCLUSION

Most patients had UCD, and the retroperitoneum was the most common location. Patients with MCD, incomplete resection, and BO died; patients with UCD and complete resection remain alive, even in the setting of BO. Consideration of PNP is critical when pediatric patients present with mucositis as PNP may be clinically indistinguishable from more common causes of mucositis.

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.

Idiopathic multicentric Castleman disease and associated autoimmune and autoinflammatory conditions: practical guidance for diagnosis

Idiopathic multicentric Castleman disease (iMCD) is an infrequent and life-threatening disorder characterised by systemic inflammatory symptoms, generalised lymphadenopathy, polyclonal lymphocyte proliferation, and organ dysfunction caused by a hyperinflammatory state. It accounts for one third to one half of all multicentric Castleman disease (MCD) cases. iMCD is often associated with autoimmune manifestations that may precede the iMCD diagnosis, be identified at the same time or follow it. In addition, iMCD may also coincide with a number of autoimmune diseases (such as psoriasis or myasthenia gravis) or autoinflammatory diseases (such as familial Mediterranean fever). Moreover, diverse inflammatory disorders, such as rheumatoid arthritis, systemic lupus erythematosus, adult-onset Still disease, systemic juvenile idiopathic arthritis, immunoglobulin (IgG4) related disease, or the recently described VEXAS syndrome, can present clinical features or lymphadenopathy with histopathological "Castleman-like" findings compatible with those of iMCD. Given the iMCD clinical heterogeneity and the overlap with other autoimmune or autoinflammatory disorders, iMCD diagnosis can be challenging. In this review, we explore the overlap between iMCD and inflammatory diseases and provide practical guidance on iMCD diagnosis in order to avoid misdiagnosis and confusion with other autoimmune or autoinflammatory conditions.

Mycoplasma pneumoniae-Induced Rash and Mucositis (MIRM) Mimicking Behçet’s Disease and Paraneoplastic Pemphigus (PNP)

MIRM is an uncommon entity characterized by prominent mucositis, usually with sparse cutaneous involvement. The diagnosis of MIRM can be challenging due to the lack of awareness amongst clinicians. Patients with Behçet's disease usually present with recurrent and painful mucocutaneous ulcers, while other clinical manifestations of the disease are more variable. Here, we describe an interesting case of MIRM mimicking Behçet's disease and PNP highlighting the overlapping manifestations and diagnostic challenges.

A Case of IgG and IgA Anti-Laminin-332 Antibody-Positive Mucous Membrane Pemphigoid with IgG and IgA Anti-Envoplakin and Anti-Periplakin Antibodies

A 76-year-old Japanese man presented with a 6-year history of a sore throat. He was treated at several clinics without any improvement before being referred to us. Physical examination revealed widespread erosions and ulcers from the palate to the larynx. Approximately 25 × 15 mm in size, erosive lesions were present on the retroauricular regions, forearms, and glans penis. Pseudomembranous conjunctivitis was also observed. The skin biopsy revealed a partial cleft formation below the epidermis, suggesting subepidermal bullous disease. Immuno-serological tests were negative for anti-desmoglein 1 (Dsg1), anti-Dsg3, anti-BP180, and anti-BP230 antibodies by ELISAs. A whole-body examination revealed gastric cancer. The possibility of mucous membrane pemphigoid (MMP) or paraneoplastic pemphigus (PNP) was considered. Indirect immunofluorescence using rat bladders showed positive IgG reactivity with cell surfaces on the transitional epithelia. Immunoblotting using recombinant proteins of laminin-332 showed both IgG and IgA reactivities with laminin-α3, and immunoblotting using normal human epidermal extract showed double-positive reactivities with envoplakin and periplakin for both IgG and IgA antibodies. Based on the clinical and histopathological features and results of various immuno-serological tests, our case was diagnosed as anti-laminin-332-type MMP with serological findings of PNP. Twenty days after laparoscopic gastrectomy, treatment with oral methylprednisolone 32 mg/day was initiated, and mucosal and skin lesions improved.

Clinical Patterns, Survival, Comorbidities, and Treatment Regimens in 149 Patients With Pemphigus in Tuscany (Italy): A 12-Year Hospital-Based Study

Introduction

Pemphigus encompasses a group of muco-cutaneous autoimmune bullous diseases characterized by the loss of adhesion between keratinocytes. The disease is associated with increased morbidity and mortality.

Materials and Methods

We characterized clinical patterns, survival, comorbidities, and drug prescriptions in patients with pemphigus referred to the Section of Dermatology of the University of Florence from January 2010 to December 2021.

Results

A total of 149 patients were identified (female/male sex ratio = 2.0). Median age at diagnosis was 57.7 ± 17.2 years; 108 patients were diagnosed with pemphigus vulgaris (PV) (72.5%) and 35 (23.5%) with pemphigus foliaceus (PF). Paraneoplastic pemphigus (PNP) and IgA-pemphigus accounted for three patients each. The overall survival rate was 86.9%. Accordingly, 14 (9%) patients died during the study period. The average age at death was 77.8 ± 9.3. Age at diagnosis was a risk factor for death in patients with pemphigus. Average concentration of Dsg3-IgG and Dsg1-IgG was 85.6 ± 68.8 and 75.9 ± 68.4, respectively. The most serious comorbid diseases included cerebro- and cardiovascular accidents and malignancies. Regarding the treatment regimen, we found a substantially stable use of systemic steroids in the 2010–2018 period; the prevalence of use of mycophenolic acid increased, whereas that of azathioprine decreased. The use of rituximab showed the highest increase in the 2013–2018 period. Proton-pump inhibitors and antibiotics were the most frequently prescribed non-immunomodulating drugs.

Conclusions

In this large series of the patients, patients with pemphigus showed a high incidence of serious comorbid diseases, highlighting the importance of a multidisciplinary approach for a proper management of the patients. Rituximab was the immunomodulating drug showing the highest increase in use over time, reflecting the growing evidence of its efficacy as a first-line treatment in pemphigus.

Anaemia, thrombocytopenia and skin lesions

A 73-year-old man affected by hyperuricemia, dyslipidaemia and hypothyroidism presented to the emergency room with a 3-month history of fever, exertional dyspnea, progressive asthenia, and painless not itchy skin lesions. Physical exam showed purplish papules and plaques affecting any area of his body, and a slight bilateral oedema of his legs. Laboratory studies revealed a severe macrocytic anaemia (haemoglobin 4.8 g/dL, mean cell volume 119 fL) and thrombocytopenia (34,000/mm3) with hyperferritinemia (1894 ng/mL, normal value <400) and increased serum B12 (1412 pg/mL, normal value 197-771), associated with ESR 71 mm/h (normal value 1-15), CRP 139 mg/L (normal value <6), and procalcitonin 1.05 ng/mL (normal value <0.5).

Current and Innovated Managements for Autoimmune Bullous Skin Disorders: An Overview

Autoimmune bullous skin disorders are a group of disorders characterized by the formation of numerous blisters and erosions on the skin and/or the mucosal membrane, arising from autoantibodies against the intercellular adhesion molecules and the structural proteins. They can be classified into intraepithelial or subepithelial autoimmune bullous dermatoses based on the location of the targeted antigens. These dermatoses are extremely debilitating and fatal in certain cases, depending on the degree of cutaneous and mucosal involvement. Effective treatments should be implemented promptly. Glucocorticoids serve as the first-line approach due to their rapid onset of therapeutic effects and remission of the acute phase. Nonetheless, long-term applications may lead to major adverse effects that outweigh the benefits. Hence, other adjuvant therapies are mandatory to minimize the potential harm and ameliorate the quality of life. Herein, we summarize the current therapeutic strategies and introduce promising therapies for intractable autoimmune bullous diseases.

Myocardial Damage in a Highly Suspected Case With Paraneoplastic Pemphigus: A Case Report and Literature Review

Paraneoplastic pemphigus (PNP) is a rare mucocutaneous autoimmune disease. It has multiple clinical accompanied symptoms by affecting various types of epithelia, including the gastrointestinal and respiratory tract. However, an extensive review of the literature found no cases of PNP associated with myocardial damage. Here, we present a 56-year-old male patient with clinically and histopathologically typical paraneoplastic pemphigus (PNP), who had sustained myocardial injury due to non-cardiac disease involvement. Therefore, we suppose that, when persistent cardiac necrosis markers are elevated in patients with paraneoplastic pemphigus (PNP), the possibility of concomitant myocardial damage should get more attention from clinicians to obtain quick diagnosis and treatment.

Mechanisms Causing Acantholysis in Pemphigus-Lessons from Human Skin

Pemphigus vulgaris (PV) is an autoimmune bullous skin disease caused primarily by autoantibodies (PV-IgG) against the desmosomal adhesion proteins desmoglein (Dsg)1 and Dsg3. PV patient lesions are characterized by flaccid blisters and ultrastructurally by defined hallmarks including a reduction in desmosome number and size, formation of split desmosomes, as well as uncoupling of keratin filaments from desmosomes. The pathophysiology underlying the disease is known to involve several intracellular signaling pathways downstream of PV-IgG binding. Here, we summarize our studies in which we used transmission electron microscopy to characterize the roles of signaling pathways in the pathogenic effects of PV-IgG on desmosome ultrastructure in a human ex vivo skin model. Blister scores revealed inhibition of p38MAPK, ERK and PLC/Ca2+ to be protective in human epidermis. In contrast, inhibition of Src and PKC, which were shown to be protective in cell cultures and murine models, was not effective for human skin explants. The ultrastructural analysis revealed that for preventing skin blistering at least desmosome number (as modulated by ERK) or keratin filament insertion (as modulated by PLC/Ca2+) need to be ameliorated. Other pathways such as p38MAPK regulate desmosome number, size, and keratin insertion indicating that they control desmosome assembly and disassembly on different levels. Taken together, studies in human skin delineate target mechanisms for the treatment of pemphigus patients. In addition, ultrastructural analysis supports defining the specific role of a given signaling molecule in desmosome turnover at ultrastructural level.

Bronchiolitis Obliterans With Anti-Epiplakin Antibodies in a Boy With Paraneoplastic Pemphigus

Paraneoplastic pemphigus is a rare and severe autoimmune blistering disease characterized by a recalcitrant and severe mucositis, and polymorphic cutaneous lesions, associated with benign and malignant neoplasms. Paraneoplastic pemphigus is caused by production of autoantibodies against various epidermal proteins involved in cell adhesion. Bronchiolitis obliterans (BO) is one of the leading causes of mortality in these patients. Recent advances have associated the presence of anti-epiplakin antibodies with the development of BO in adult patients. Here we describe the first pediatric patient in whom the association of anti-epiplakin antibodies and BO have been reported so far.

Autoimmune Pemphigus: Latest Advances and Emerging Therapies

Pemphigus represents a group of rare and severe autoimmune intra-epidermal blistering diseases affecting the skin and mucous membranes. These painful and debilitating diseases are driven by the production of autoantibodies that are mainly directed against the desmosomal adhesion proteins, desmoglein 3 (Dsg3) and desmoglein 1 (Dsg1). The search to define underlying triggers for anti-Dsg-antibody production has revealed genetic, environmental, and possible vaccine-driven factors, but our knowledge of the processes underlying disease initiation and pathology remains incomplete. Recent studies point to an important role of T cells in supporting auto-antibody production; yet the involvement of the myeloid compartment remains unexplored. Clinical management of pemphigus is beginning to move away from broad-spectrum immunosuppression and towards B-cell-targeted therapies, which reduce many patients’ symptoms but can have significant side effects. Here, we review the latest developments in our understanding of the predisposing factors/conditions of pemphigus, the underlying pathogenic mechanisms, and new and emerging therapies to treat these devastating diseases.

Immune-Mediated Cutaneous Paraneoplastic Syndromes Associated With Hematologic Malignancies: Skin as a Mirror of Hematologic Neoplasms

Malignant neoplasms may present as paraneoplastic syndromes with mucocutaneous manifestations, which may or may not be chronologically associated. The pathophysiological mechanism is complex and not completely understood; therefore, definitive diagnosis may be achieved with a precise differential diagnosis based on the morphology of skin lesions, clinical picture, and histological pattern. The complexities, and low frequency, make the therapeutic approach quite challenging; consequently, the cornerstone of therapy is the eradication of the underlying neoplasms. Corticosteroids are the therapy of choice for most of these immune-mediated manifestations, but for the most part, the successful resolution requires the eradication of the underlying malignancy.

A gene-centric approach to biomarker discovery identifies transglutaminase 1 as an epidermal autoantigen

The nine-member transglutaminase protein family includes five known autoantigens. Because of the frequent roles of transglutaminases in autoimmunity, we decided to explore whether the remaining members might also constitute autoantigens, but in as-yet-unexplained disorders. We turned to TGM1, and since this member is primarily expressed in squamous epithelia, we focused on skin disorders. By screening a broad range of acquired skin disorders, we identified TGM1 to be a major autoantigen in the severe blistering disease paraneoplastic pemphigus. This study illustrates a gene-centric approach to biomarker discovery—starting from a putative autoantigen to search for its corresponding disease—that may prove generally applicable for studies of autoimmunity.

Autoantigen discovery is a critical challenge for the understanding and diagnosis of autoimmune diseases. While autoantibody markers in current clinical use have been identified through studies focused on individual disorders, we postulated that a reverse approach starting with a putative autoantigen to explore multiple disorders might hold promise. We here targeted the epidermal protein transglutaminase 1 (TGM1) as a member of a protein family prone to autoimmune attack. By screening sera from patients with various acquired skin disorders, we identified seropositive subjects with the blistering mucocutaneous disease paraneoplastic pemphigus. Validation in further subjects confirmed TGM1 autoantibodies as a 55% sensitive and 100% specific marker for paraneoplastic pemphigus. This gene-centric approach leverages the wealth of data available for human genes and may prove generally applicable for biomarker discovery in autoimmune diseases.

Castleman disease

Castleman disease (CD), a heterogeneous group of disorders that share morphological features, is divided into unicentric CD and multicentric CD (MCD) according to the clinical presentation and disease course. Unicentric CD involves a solitary enlarged lymph node and mild symptoms and excision surgery is often curative. MCD includes a form associated with Kaposi sarcoma herpesvirus (KSHV) (also known as human herpesvirus 8) and a KSHV-negative idiopathic form (iMCD). iMCD can present in association with severe syndromes such as TAFRO (thrombocytopenia, ascites, fever, reticulin fibrosis and organomegaly) or POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder and skin changes). KSHV-MCD often occurs in the setting of HIV infection or another cause of immune deficiency. The interplay between KSHV and HIV elevates the risk for the development of KSHV-induced disorders, including KSHV-MCD, KSHV-lymphoproliferation, KSHV inflammatory cytokine syndrome, primary effusion lymphoma and Kaposi sarcoma. A CD diagnosis requires a multidimensional approach, including clinical presentation and imaging, pathological features, and molecular virology. B cell-directed monoclonal antibody therapy is the standard of care in KSHV-MCD, and anti-IL-6 therapy is the recommended first-line therapy and only treatment of iMCD approved by the US FDA and EMA.

Plectin in Skin Fragility Disorders

Plectin is a multi-faceted, 500 kDa-large protein, which due to its expression in different isoforms and distinct organs acts diversely as a cytoskeletal crosslinker and signaling scaffold. It functions as a mediator of keratinocyte mechanical stability in the skin, primarily through linking intermediate filaments to hemidesmosomes. Skin fragility may occur through the presence of mutations in the gene encoding for plectin, PLEC, or through the presence of autoantibodies against the molecule. Below, we review the cutaneous manifestations of plectinopathies as well as their systemic involvement in specific disease subtypes. We summarize the known roles of plectin in keratinocytes and fibroblasts and provide an outlook on future perspectives for plectin-associated skin disorders.

An Updated Review of Pemphigus Diseases

Clinicians may encounter a variety of skin conditions that present with vesiculobullous lesions in their everyday practice. Pemphigus vulgaris, pemphigus foliaceus, IgA pemphigus, and paraneoplastic pemphigus represent the spectrum of autoimmune bullous dermatoses of the pemphigus family. The pemphigus family of diseases is characterized by significant morbidity and mortality. Considering the risks associated with a delayed diagnosis or misdiagnosis and the potential for overlap in clinical features and treatment, evaluation for suspected pemphigus disease often requires thorough clinical assessment and laboratory testing. Diagnosis is focused on individual biopsies for histopathology and direct immunofluorescence. Additional laboratory methods used for diagnosis include indirect immunofluorescence and enzyme-linked immunosorbent assay. Recent advancements, including anti-CD20 therapy, have improved the efficacy and reduced the morbidity of pemphigus treatment. This contribution presents updates on the pathophysiology, clinical features, diagnostic work-up, and medical management of pemphigus. Improved strategies for diagnosis and clinical assessment are reviewed, and newer treatment options are discussed.

Anti-Desmocollin Autoantibodies in Autoimmune Blistering Diseases

The presence of anti-desmocollin (Dsc) antibodies is rarely described in autoimmune blistering diseases patients. Moreover, several clinical phenotypes of pemphigus may be associated with these antibodies. In this review we analyze clinicopathological, immunologic and outcome features of anti-Dsc autoimmune blistering diseases patients, to improve their diagnosis and management. We conducted a systematic search of PubMed and Embase (1990-present) for studies reporting cases of autoimmune blistering diseases with anti-Dsc antibodies. We classified the selected patients as patients with exclusively anti-Dsc autoantibodies, and patients with anti-Dsc and other autoantibodies. Of 93 cases with anti-Dsc autoantibodies included, 38 (41%) had exclusively these antibodies. Only 18% of patients presented with the typical clinicopathological phenotype of pemphigus vulgaris or pemphigus foliaceous. Mucosal involvement was seen in approximately half of the patients. Up to 18% of cases were associated with neoplasms. Acantholysis was described in 54% of cases with histopathological information. Treatments and outcomes vary in the different clinical phenotypes. The presence of anti-Dsc antibodies must be suspected mainly in those patients with either atypical pemphigus, in special with clinical pustules, or in cases showing intraepithelial or dermal neutrophilic/eosinophilic infiltrate on histological examination and dual pattern by direct immunofluorescence examination.

Constrictive (Obliterative) Bronchiolitis as Presenting Manifestation of Connective Tissue Diseases

BACKGROUND

Constrictive (obliterative) bronchiolitis (CB) is an uncommon form of obstructive lung disease that can occur in patients with identifiable causes including connective tissue diseases (CTDs) as a form of lung involvement. We explored whether CB can be the presenting manifestation of CTD.

METHODS

We identified 44 patients with cryptogenic CB and examined the presenting clinical, laboratory, and radiologic features, as well as their clinical course.

RESULTS

The mean age at presentation was 60.5 (SD, 13.8) years and included 38 women (86%); 32 (73%) were never smokers. All patients presented for evaluation of dyspnea, commonly associated with cough. An obstructive pattern on pulmonary function testing was demonstrated in 86% of patients. On chest high-resolution computed tomography, nearly all patients manifested a mosaic attenuation pattern with air trapping on expiratory views, characteristic of CB. Bronchoscopic lung biopsy (n = 10) was usually nondiagnostic (90%), whereas all 5 surgical lung biopsies yielded evidence of CB. Serologic testing for CTD was positive in 19 patients (43%) and most commonly included antinuclear antibody, rheumatoid factor, and anti-cyclic citrullinated antibodies. Seven of these patients with positive serologic results were eventually diagnosed to have CTD. Connective tissue diseases included rheumatoid arthritis in 4 patients, Sjögren syndrome in 2, and undifferentiated CTD in 1 patient.

CONCLUSIONS

Nearly one-half of patients with cryptogenic CB manifest positive CTD serology, and some of these patients have CTD not previously diagnosed. These results suggest that CB can be the presenting manifestation of a CTD.

International evidence-based consensus diagnostic and treatment guidelines for unicentric Castleman disease

Castleman disease (CD) includes a group of rare and heterogeneous disorders with characteristic lymph node histopathological abnormalities. CD can occur in a single lymph node station, which is referred to as unicentric CD (UCD). CD can also involve multicentric lymphadenopathy and inflammatory symptoms (multicentric CD [MCD]). MCD includes human herpesvirus-8 (HHV-8)-associated MCD, POEMS-associated MCD, and HHV-8-/idiopathic MCD (iMCD). The first-ever diagnostic and treatment guidelines were recently developed for iMCD by an international expert consortium convened by the Castleman Disease Collaborative Network (CDCN). The focus of this report is to establish similar guidelines for the management of UCD. To this purpose, an international working group of 42 experts from 10 countries was convened to establish consensus recommendations based on review of treatment in published cases of UCD, the CDCN ACCELERATE registry, and expert opinion. Complete surgical resection is often curative and is therefore the preferred first-line therapy, if possible. The management of unresectable UCD is more challenging. Existing evidence supports that asymptomatic unresectable UCD may be observed. The anti-interleukin-6 monoclonal antibody siltuximab should be considered for unresectable UCD patients with an inflammatory syndrome. Unresectable UCD that is symptomatic as a result of compression of vital neighboring structures may be rendered amenable to resection by medical therapy (eg, rituximab, steroids), radiotherapy, or embolization. Further research is needed in UCD patients with persisting constitutional symptoms despite complete excision and normal laboratory markers. We hope that these guidelines will improve outcomes in UCD and help treating physicians decide the best therapeutic approach for their patients.

Paraneoplastic pemphigus caused by pre-existing stroma-rich variant of Castleman disease: from a pathologist's point of view

A young woman presented with mucocutaneous blisters and ulcerating lesions, and was diagnosed with erythrodermic pemphigus complicated by bronchiolitis obliterans. Her clinical condition did not improve on immunosuppressive therapy. She had a history of an asymptomatic retroperitoneal mass, presumed to be a dermoid cyst, followed up clinically. Due to the pre-existing nature of the retroperitoneal mass, the paraneoplastic nature of the pemphigus was initially not recognised, but after a multidisciplinary team meeting a biopsy was performed. Histology revealed a rare stroma-rich variant of Castleman disease with a prominent stroma demonstrating a myoid phenotype. Resection of the retroperitoneal tumour resulted in resolution of the cutaneous blisters. This emphasises the importance to consider paraneoplastic disease in treatment-resistant pemphigus as surgical removal of the tumour forms the mainstay of therapy. The differential diagnosis should include Castleman disease and careful evaluation of histology is essential with the awareness of this rare stroma-rich variant.

Clinicians' pearls and myths in pemphigus

Pemphigus comprises a heterogeneous group of autoimmune blistering diseases, which can affect both skin and mucous membranes, especially oral mucosa. This group of diseases shows usually a chronic-relapsing course. Since pemphigus is a rare disease, the diagnosis is often delayed, because it is based upon the recognition of consistent clinical, histologic, and direct immunofluorescence findings, as well as indirect immunofluorescence, and/or enzyme-linked immunosorbent assay. Usually the patients are treated for multiple other conditions before starting the correct therapy, leading to a critical reduction of the patients' quality of life. This review is a succinct compilation of pearls gathered from clinical experience in pemphigus and the myths that may have influenced everyday practice but have been proven false. This review provided a selection of such dilemmas and controversies, focusing on myths and pearls that can help young dermatologist in the clinic, while also dispelling them.

Current approaches to the diagnosis of autoimmune bullous dermatoses

A modern review of highly effective methods for the diagnosis of autoimmune bullous dermatoses are presented. The specificity of the production of autoantibodies underlying bullous dermatoses are described. Considering the severity of the disease and a significant deterioration in the quality of life of patients suffering from bullous dermatoses; the systematization of diagnostic criteria will help improve the prognosis and management of patients; and it will also help optimize work on the development of targeted drugs for the treatment of patients with this pathology.

Intraepithelial autoimmune blistering dermatoses: Clinical features and diagnosis

Intraepithelial autoimmune blistering dermatoses are a rare group of skin disorders characterized by the intraepithelial disruption of intercellular connections through the action of autoantibodies. The first article in this continuing medical education series explores the background, epidemiology, clinical features, and diagnostic criteria of each of the major intraepithelial autoimmune blistering dermatoses, including pemphigus foliaceus, pemphigus erythematosus, pemphigus herpetiformis, fogo selvagem, pemphigus vulgaris, pemphigus vegetans, drug-induced pemphigus, IgA pemphigus, IgG/IgA pemphigus, and paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome.