Pemphigus and bullous pemphigoid

Erythema multiforme-like lip presentation in pemphigus vulgaris patients: a multicenter case series

Pemphigus vulgaris (PV) is a chronic autoimmune mucocutaneous blistering disease. Autoantibodies are directed against desmogleins, leading to the formation of intraepithelial bullae. PV, as with other autoimmune mucocutaneous disorders of the oral cavity, presents diagnostic and therapeutic challenges. Approximately 50-70% of cases present first with oral lesions. The lesions commonly start as vesicles or bullae that rapidly rupture, leading to erosions and ulcerations. The palatal, gingival, buccal, and labial mucosa are the most commonly affected sites. Oral PV can mimic several other diseases that cause mucosal erosions and/or ulcerations, including erythema multiforme (EM). EM is an acute, immune-mediated, self-limited hypersensitivity condition primarily associated with herpes simplex infection. Oral lesions can be variable, but a very characteristic presentation with labial hemorrhagic erosions, ulcerations and crusting is commonly seen. In this case series, we present six cases of PV: one male patient and five female patients whose ages ranged from 34 to 65 years old. All patients presented with hemorrhage and crusting of the lips in addition to multiple intraoral erosions and ulcerations. Three patients presented with oral and skin lesions. All patients underwent biopsies, and a diagnosis of PV was confirmed. All patients were treated with steroids (topical and systemic) and variable steroid-sparing agents. This case series emphasizes that oral PV may be misdiagnosed as EM in a subgroup of patients who present with persistent lip hemorrhage and crusting. Therefore, a comprehensive history, clinical examination and incisional biopsies should be considered in such patients.

Imputation of the major histocompatibility complex region identifies major independent variants associated with bullous pemphigoid and dermatomyositis in Han Chinese

As autoimmune skin diseases, both bullous pemphigoid (BP) and dermatomyositis (DM) show significant associations with the major histocompatibility complex (MHC) region. In fact, the coexistence of BP and DM has been previously reported. Therefore, we hypothesized that there may be a potential genetic correlation between BP and DM. Based on data for 312 BP patients, 128 DM patients, and 6793 healthy control subjects, in the MHC region, we imputed single-nucleotide polymorphisms (SNP), insertions and deletions (INDEL), and copy number variations (CNV) using the 1KGP phase 3 dataset and amino acids (AA) and SNP using a Han-MHC reference database. An association study revealed the most significant SNP associated with BP, namely, rs580921 (p = 1.06E-08, odds ratio [OR] = 1.61, 95% confidence interval [CI] = 1.37-1.90), which is located in the C6orf10 gene, and the most significant classic human leukocyte antigen (HLA) allele associated with DM, namely, HLA-DPB1*1701 (p = 6.56E-10, OR = 3.61, 95% CI = 2.40-5.42). Further stepwise regression analyses with rs580921 identified a threonine at position 163 of the HLA-B gene as a new independent disease-associated AA, and HLA-DPB1*1701 indicated that no loci were significant. Three-dimensional ribbon models revealed that the HLA-B AA position 163 (p = 3.93E-07, OR = 1.64, 95% CI = 1.35-1.98) located in the α2 domain of the HLA-B molecule was involved in the process of specific antigen presentation. The calculations showed that there was no significant genetic correlation between BP and DM. Our study identified three significant loci in the MHC region, proving that the HLA region was significantly correlated with BP and DM separately. Our research highlights the key role of the MHC region in disease susceptibility.

Molecular Basis for Global Incidence of Pemphigoid Diseases and Differences in Phenotypes

Pemphigoid (Pg) diseases are a group of potentially fatal autoimmune mucocutaneous diseases. They have different clinical phenotypes, involving only the skin or multiple mucous membranes. They occur globally and frequently affect the elderly. The common marker among all variants is the presence of autoantibodies targeting the dermal-epidermal or mucosal-submucosal junctions, or basement membrane zone (BMZ). Four target antigens in the BMZ were studied. These included BPAG1, BPAG2 and subunits of α6 and β4 human integrins. Our objective was to find a molecular basis for the global incidence of Pg diseases and a mechanism that will explain the vast differences in clinical phenotypes and outcomes. All the variants of Pg that were analyzed had a statistically significant association with HLA-DQβ1*03:01 in ten countries on four continents. This explains the reason for global incidence. Prediction models discovered multiple peptides in each of the four antigens that serve as T cell epitopes. These T cell epitopes were shown to bind to HLA-DQβ1*03:01. In addition, structure modelling demonstrated the peptide-HLA complex bound to the T cell receptor. These autoreactive T cells would stimulate B cells to produce specific anti-BMZ autoantibodies. Anti-BMZ autoantibodies with different specificities will produce different phenotypes, which will account for involvement of different tissues and organs in different molecules. The contribution this study makes is that it provides a molecular basis of why a similar disease occurs in different racial groups. Furthermore, it provides the basis for the production of autoantibodies with different specificities, which resultantly produces different phenotypes.

The impact of diabetes mellitus on medical complication and mortality rates among inpatients with bullous pemphigoid

BACKGROUND

There is currently limited population-based data on the effect of type 2 diabetes mellitus (T2DM) on bullous pemphigoid (BP) inpatients.

AIMS

To evaluate the relative comorbidities, medical complications, and mortality rates between BP inpatients with and without T2DM.

METHODS

All inpatients with a primary BP diagnosis in the National Inpatient Sample from 2003 to 2012 were queried. BP inpatients with or without T2DM were compared to identify disparities in relative comorbidities and medical complications. Comorbidities were established using the Agency for Healthcare Research and Quality standardized values. Medical complications were classified using ICD-9 codes.

RESULTS

Of the 1978 BP patients identified, 660 (33.4%) had a concurrent diagnosis of T2DM. These patients had significantly higher rates of concurrent comorbidities, including chronic renal failure, congestive heart failure, iron deficiency anemia, hypertension, obesity, and peripheral vascular disease. On bivariate analysis, T2DM patients also had significantly higher rates of medical complications including acute kidney injury (14.5% vs. 10.1%, p = 0.004) and venous thromboembolism (1.8% vs. 0.5%, p = 0.012). On multivariable-adjusted analysis, the odds of venous thromboembolism (OR = 3.01, p = 0.027) remained increased. Inpatient mortality did not differ between the groups.

CONCLUSIONS

Our findings suggest that BP inpatients with T2DM have a greater medical comorbidity and complication burden. However, inpatient mortality was not increased.

Simultaneous immunofluorescence and histology in pemphigus vulgaris using ex vivo confocal laser scanning microscopy

Ex vivo confocal laser scanning microscopy (ex vivo CLSM) provides rapid, high-resolution imaging and immunofluorescence examinations of the excised tissues. We aimed to evaluate the applicability of ex vivo CLSM in histomorphological and direct immunofluorescence (DIF) examination of pemphigus vulgaris (PV). 20 PV sections were stained with fluorescent-labeled anti-IgG and anti-C3 using various dilutions and incubation periods. Subsequently, the determined ideal staining protocol was applied on 20 additional PV and 20 control sections. Ex vivo CLSM identified intraepidermal blisters and acantholytic cells in 80% and 60% of PV patients, respectively. The sensitivity of ex vivo CLSM in detecting intraepidermal fluorescence was 90% both with IgG and C3. The specificity of staining for IgG and C3 was 70% and 90%, respectively. Histomorphological and immunofluorescence features of PV could be detected within the same ex vivo CSLM session showing a comparable performance to conventional histopathology and DIF microscopy.

Non-Cell-Autonomous Activity of the Hemidesmosomal Protein BP180/Collagen XVII in Granulopoiesis in Humanized NC16A Mice

BP180 (also termed type XVII collagen) is a hemidesmosomal protein and plays a critical role in cell-cell matrix adhesion in the skin; however, its other biological functions are largely unclear. In this study, we generated a BP180 functional-deficient mouse strain by deleting its extracellular domain of humanized NC16A (termed ΔNC16A mice). We found that BP180 is expressed by bone marrow mesenchymal stem cells (BM-MSC), and its functional deficiency leads to myeloid hyperplasia. Altered granulopoiesis in ΔNC16A mice is through bone marrow stromal cells evidenced by bone marrow transplantation. Furthermore, the level of G-CSF in bone marrow and circulation were significantly increased in ΔNC16A mice as compared with wild-type mice. The increased G-CSF was accompanied by an increased activation of the NF-κB signaling pathway in bone marrow and BM-MSC of ΔNC16A mice. Blockade of G-CSF restored normal granulopoiesis in ΔNC16A mice. Inhibition of NF-κB signaling pathway significantly reduces the release of G-CSF from ΔNC16A BM-MSC in vitro and the level of serum G-CSF in ΔNC16A mice. To our knowledge, these findings provide the first direct evidence that BP180 plays an important role in granulopoiesis through regulating NF-κB signaling pathway in BM-MSC.

False-Negative Rate of Direct Immunofluorescence on Lower Extremities in Bullous Pemphigoid

ABSTRACT

Bullous pemphigoid (BP) is the most common autoimmune blistering disorder of the skin. It is typified by tense blisters with a subepidermal split and mixed dermal inflammatory infiltrate on histology. Biopsy of the perilesional skin for direct immunofluorescence (DIF) has become the gold standard in the diagnosis of BP. Currently there is a pervasive clinical opinion that the lower extremity is a site with a high false-negative rate (FNR) for DIF in the diagnosis of BP. This notion is primarily based on 2 early studies from the 1980s without more recent confirmatory studies. To readdress this question regarding the lower extremities, a retrospective study from 2012 to 2018 was performed in our institution that evaluated the FNR of DIF by an anatomical site in the diagnosis of BP. Cases of BP were identified using standard criteria (clinical and histological data reviewed in cases with negative DIF), and overall, 79 patients were included in the study. A total of 4 false-negative DIF biopsies were verified. Two negative DIF were from the lower extremity yielding a FNR of 10% compared with 4% on the trunk and 3% from the upper extremity, with no statistically significant difference by anatomical sites. Our study fails to demonstrate a high FNR of DIF from the lower extremity in the diagnosis of BP.

Association of pemphigus and pemphigoid with osteoporosis and pathological fractures

Patients with pemphigus and bullous pemphigoid (BP) have potential risk factors for osteoporosis and/or fractures. To determine whether pemphigus and BP are associated with osteoporosis and fractures in the US, a cross-sectional study of 198,102,435 adults was performed, including 4506 with pemphigus and 8864 with BP from the 2006-2012 National Emergency Department Sample, a 20% sample of emergency care visits throughout the US. Pemphigus was associated with higher odds (multivariate logistic regression; adjusted odds ratio [95% confidence intervals]) of osteopenia (2.20 [1.59-3.05]), osteoporosis (2.54 [2.16-2.98]), osteomalacia (29.70 [4.05-217.83]), and pathological fractures (2.04 [1.42-2.91]). BP was associated with osteoporosis (1.55 [1.39-1.73]) and pathological fractures (1.52 [1.22-1.88]). When compared to BP, pemphigus was associated with higher odds of osteopenia (1.59 [1.06-2.41]), osteoporosis (1.38 [1.18-1.63]), and fractures (1.26 [1.04-1.53]), particularly of the ulna and radius (3.17 [1.23-8.17]). Patients with pemphigus or BP as well as long-term systemic corticosteroid use had highest odds of osteoporosis and fractures. No data were available on treatments for pemphigus or BP. Pemphigus and BP were associated with osteopenia, osteoporosis, and pathologic fractures. Patients with PEM and BP may benefit from increased screening for osteoporosis and interventions to prevent fractures.

Alopecia in Autoimmune Blistering Diseases: A Systematic Review of Pathogenesis and Clinical Features of Disease

Background

Autoimmune blistering diseases (AIBD) are characterised by the body's production of autoantibodies against structural proteins in the epidermis and/or the basement membrane on cutaneous and mucosal surfaces. Alopecia is a complication of AIBD that has generally been overlooked in patients with severe blistering diseases because it is regarded as a cosmetic issue. Yet recent research into quality of life tools has found that stigmatisation by appearance plays a significant role in blistering diseases.

Aim

To review the current literature detailing the pathogenesis and clinical presentations of alopecia in AIBD patients.

Method

We searched Medline, PubMed and EMBASE electronic databases up to September 2018, for empirical human and animal studies.

Results

Only 36 human studies including 223 patients (190 pemphigus, 25 pemphigoid, 5 epidermolysis bullosa acquisita, 2 dermatitis herpetiformis and 1 linear IgA disease) detailed demographic and clinical manifestations of alopecia. A range of hair evaluation methods was demonstrated to reach alopecia diagnosis. Furthermore, with no universal validated scoring system for alopecia severity, alopecia patterns have been summarised.

Conclusion

Previous randomised trials have not highlighted alopecia as an important outcome of AIBD, so epidemiological evaluation of the available literature has been helpful in summarising trends between existing studies and demonstrating inconsistencies.

Protein-Based Salivary Profiles as Novel Biomarkers for Oral Diseases

The Global Burden of Oral Diseases affects 3.5 billion people worldwide, representing the number of people affected by the burden of untreated dental caries, severe periodontal disease, and edentulism. Thus, much more efforts in terms of diagnostics and treatments must be provided in the fight of these outcomes. In this sense, recently, the study of saliva as biological matrix has been identified as a new landmark initiative in the search of novel and useful biomarkers to prevent and diagnose these conditions. Specifically, saliva is a rich reservoir of different proteins and peptides and accessible due to recent advances in molecular biology and specially in targeted and unbiased proteomics technologies. Nonetheless, emerging barriers are an obstacle to the study of the salivary proteome in an effective way. This review aims at giving an overall perspective of salivary biomarkers identified in several oral diseases by means of molecular biology approaches.

Investigation of the predisposing factor of pemphigus and its clinical subtype through a genome-wide association and next generation sequence analysis

BACKGROUND

Pemphigus is an autoimmune blistering disease with pemphigus vulgaris (PV) and foliaceus (PF) as the two major histological subtypes. Associations with HLA molecules have been suggested, but specific HLA risk variants as well as non-HLA risk variants remain to be discovered.

METHODS

We performed a two-stage genome-wide association study in the Chinese Han population through a genome-wide discovery analysis and follow-up validation analysis in a total number of 210 PV, 159 PF and 2493 healthy controls. HLA imputation as well as high coverage next generation sequencing based HLA genotyping was employed to investigate the association of classical HLA alleles and amino acid change.

RESULTS

We have discovered independent novel associations with PF at rs2178077 on 12q24.33, located next to RAN (P_PF = 1.57 × 10^-9 ) and rs3888722 within the MHC region (P = 6.73 × 10^-9 ). For the HLA variants, we confirmed independent genome-wide level risk associations in HLA-DQB1 and HLA-DRB1, with DQB1*05:03 to be the strongest association with PV (P = 8.59 × 10^-68 , OR = 31.16) and PF (P = 4.84 × 10^-17 , OR = 5.64). In addition, DRB1*14 was demonstrated to be a second independent variants (P = 4.2 × 10^-63 , OR = 35.47) for PV, while DRB1*04:06 was demonstrated to be the second independent signal (P = 7.44 × 10^-13 , OR = 5.58) for PF.

CONCLUSIONS

These findings advance our understanding of the genetic basis of pemphigus susceptibility and may offer opportunities for risk prediction and preventive treatment for pemphigus, in particular for PV.

Immune response patterns in non-communicable inflammatory skin diseases

Non-communicable inflammatory skin diseases (ncISD) such as psoriasis or atopic eczema are a major cause of global disease burden. Due to their impact and complexity, ncISD represent a major challenge of modern medicine. Dermatology textbooks describe more than 100 different ncISD based on clinical phenotype and histological architecture. In the last decades, this historical description was complemented by increasing molecular knowledge - and this knowledge is now being translated into specific therapeutics. Combining the enormous advances made in lymphocyte immunology and molecular genetics with clinical and histological phenotyping reveals six immune response patterns of the skin - type I immune cells cause the lichenoid pattern characterized by immune-mediated cell death of keratinocytes; type II immune cells underlie the eczematous pattern with impaired epidermal barrier, infection and eosinophils as well as the bullous pattern with loss of epithelial integrity; Th17 cells and ILC3 mediate the psoriatic pattern characterized by acanthosis, high metabolic activity and neutrophils; dysbalance of regulatory T cells causes either the fibrogenic pattern with rarefication of cells and dermal thickening or the granulomatous pattern defined by formation of granulomas. With more and more specific therapeutic agents approved, classifying ncISD also according to their immune response pattern will become highly relevant. This review defines the six immune response patterns of ncISD and highlights therapeutic strategies targeting key lymphocyte mediators.

The value of ultrahigh resolution OCT in dermatology - delineating the dermo-epidermal junction, capillaries in the dermal papillae and vellus hairs

Optical coherence tomography (OCT) imaging of the skin is gaining recognition and is increasingly applied to dermatological research. A key dermatological parameter inferred from an OCT image is the epidermal (Ep) thickness as a thickened Ep can be an indicator of a skin disease. Agreement in the literature on the signal characters of Ep and the subjacent skin layer, the dermis (D), is evident. Ambiguities of the OCT signal interpretation in the literature is however seen for the transition region between the Ep and D, which from histology is known as the dermo-epidermal junction (DEJ); a distinct junction comprised of the lower surface of a single cell layer in epidermis (the stratum basale) connected to an even thinner membrane (the basement membrane). The basement membrane is attached to the underlying dermis. In this work we investigate the impact of an improved axial and lateral resolution on the applicability of OCT for imaging of the skin. To this goal, OCT images are compared produced by a commercial OCT system (Vivosight from Michaelson Diagnostics) and by an in-house built ultrahigh resolution (UHR-) OCT system for dermatology. In 11 healthy volunteers, we investigate the DEJ signal characteristics. We perform a detailed analysis of the dark (low) signal band clearly seen for UHR-OCT in the DEJ region where we, by using a transition function, find the signal transition of axial sub-resolution character, which can be directly attributed to the exact location of DEJ, both in normal (thin/hairy) and glabrous (thick) skin. To our knowledge no detailed delineating of the DEJ in the UHR-OCT image has previously been reported, despite many publications within this field. For selected healthy volunteers, we investigate the dermal papillae and the vellus hairs and identify distinct features that only UHR-OCT can resolve. Differences are seen in tracing hairs of diameter below 20 μm, and in imaging the dermal papillae where, when utilising the UHR-OCT, capillary structures are identified in the hand palm, not previously reported in OCT studies and specifically for glabrous skin not reported in any other in vivo optical imaging studies.

New diagnosis of bullous pemphigoid after withdrawal of immunosuppressive therapy in a failed renal transplant recipient on hemodialysis

The occurrence of the autoimmune blistering disease, bullous pemphigoid (BP), in patients with failed renal allograft is rare and the few reported cases suggest various provocative factors without reaching a consensus. Here we report the case of a patient presenting with bullous lesions soon after the complete discontinuation of immunosuppressant therapy following renal allograft failure. Skin biopsy confirmed the diagnosis of BP. Administration of systemic corticosteroid controlled the occurrence of BP lesions in our patient. Increased clinical suspicion is warranted in cases of patients with renal transplant failure, since withdrawal of the immunosuppressant therapy could lead to unmasking the underlying autoimmune skin disease.

Ethnic variations in the epidemiology of bullous pemphigoid in Israel

BACKGROUND

No ethnic or geographic predisposition to bullous pemphigoid (BP) was reported so far.

OBJECTIVE

To evaluate trends in the incidence of BP in northern Israel, shedding light on differences between two distinct ethnic populations who inhabit the same region, namely Jews and Arabs.

METHODS

Bullous pemphigoid incidence was retrospectively estimated from January 2000-December 2015 in two Israeli regions with a total population of 1.56 million inhabitants.

RESULTS

A total of 287 new-onset BP patients (mean age: 77.6 ± 12.1) were identified. The incidence rate was 11.4 per million inhabitants per year (95% CI, 10.2-12.9). The crude incidence rate in Jews was 4.8-fold higher than that in Arabs (16.4 vs. 3.4 cases per million per year, respectively [P < 0.0001]). After adjusting for age, the discrepancy between the two populations diminished (11.7 vs. 8.9 cases per million per year, respectively) but remained statistically significant (P = 0.032). The incidence increased consistently from 7.6 cases per million per year in the calendar period 2000-2005 to 12.6 and 14.3 cases in 2006-2010 and 2011-2015, respectively (P < 0.0001). Bullous pemphigoid patients of Arab ancestry presented with the disease significantly earlier than Jews (69.5 ± 15.3 vs. 78.7 ± 11.1 years, respectively, P = 0.002).

CONCLUSIONS

The incidence of BP in northern Israel has increased in the last 16 years and is significantly higher among Jews compared to Arabs. The age of presentation is remarkably different between patients belonging to the two populations.

Decreased expression levels of complement regulator CD55 contribute to the development of bullous pemphigoid

Bullous pemphigoid is a common autoimmune blistering disease of the elderly associated with autoantibody-mediated complement activation, and complement dysregulation is critical for its pathogenesis. As a crucial regulator of the complement system, CD55 has been widely studied in autoimmune diseases. Here, we investigated the involvement of CD55 in bullous pemphigoid, as little is known regarding its role in this disease. We found that CD55 levels were significantly lower in the lesions of patients with bullous pemphigoid (n = 8) compared to those in skin samples from healthy controls (n = 6). Interestingly, CD55 depletion in HaCaT human keratinocytes enhanced autoantibody-mediated complement activation. Moreover, complement activation was blocked by exogenous recombinant CD55 protein in both skin sections and keratinocytes exposed to pathogenic antibodies from patients with bullous pemphigoid. Notably, a significant increase in the expression of TNF-α and IFN-γ, administration of which downregulated CD55 levels in HaCaT cells, was observed in the sera of patients with bullous pemphigoid (n = 38) compared to that in healthy controls (n = 19). We found that ERK1/2 is involved in both TNF-α- and IFN-γ-induced CD55 downregulation. Thus, CD55 deficiency is a crucial factor in bullous pemphigoid pathogenesis, suggesting that increasing CD55 levels may exert a therapeutic effect.

Dysregulation of mCD46 and sCD46 contribute to the pathogenesis of bullous pemphigoid

Bullous pemphigoid (BP) is an autoimmune bullous disease caused by autoantibodies against BP180 in the epidermal basement membrane. Autoantibody-mediated complement activation is an important process in BP pathogenesis. CD46, a crucial complement regulatory protein in the complement activation, has been reported to be involved in several autoimmune diseases. In the present study, we investigated whether CD46 plays a role in BP development. We found that sCD46 expression was significantly increased in the serum and blister fluids of BP patients and correlated with the levels of anti-BP180 NC16A antibody and C3a. Otherwise, the level of mCD46 was decreased in lesions of BP patients, whereas the complement activation was enhanced. We also found that CD46 knockdown in HaCaT human keratinocytes enhanced autoantibody-mediated complement activation. Importantly, exogenous CD46 blocked complement activation in both healthy skin sections and keratinocytes induced by exposure to pathogenic antibodies from BP patients. These data suggest that CD46 deficiency is an important factor in BP pathogenesis and that increasing CD46 levels might be an effective treatment for BP.

Recurrent corneal melting in the paraneoplastic pemphigus associated with Castleman's disease

Background

The ocular presentation of Castleman’s disease (CD)-associated paraneoplastic pemphigus (PNP) has rarely been reported. In this report, we describe a young patient with CD-associated PNP who had recurrent corneal ulceration in addition to cicatrizing conjunctivitis.

Case presentation

We describe a case of 23-year-old male with mucocutaneous erosion and conjunctival injection and erosion who was found to have PNP. Pelvic hyaline-vascular CD was detected and completely excised. The mucocutaneous lesions improved postoperatively. Two years after pelvic surgery, the patient gradually developed conjunctival symblepharon in both eyes and pterygium in the right eye. The patient then underwent a successful exclusion of the symblepharon, an excision of the pterygium and an amniotic membrane transplantation in the right eye. However, after 6 months, he experienced an aseptic corneal ulcer and recurrent pterygiumin the right eye. After treatment with systemic and local immunosuppressive medications, the corneal ulcer gradually healed and remained stable.

Conclusion

Corneal ulceration and melting, in addition to conjunctivitis, as a complication of CD-associated PNP, can be successfully managed with systemic and local immunosuppressants.

Bullous pemphigoid after bilateral forefoot surgery

The case of a 76-year-old woman who developed blisters on both forefeet within 2 weeks of bilateral forefoot surgery is reported; the diagnosis of bullous pemphigoid was made by histological and immunofluorescence studies. The pathogenesis and management of this autoimmune condition, which occurs mainly in patients older than 70 years and may occasionally be associated with surgical wounds, are reviewed. It is important for foot and ankle specialists to be aware of and consider the diagnosis when a bullous contact dermatitis-like eruption persists at a surgical site.

LEVEL OF EVIDENCE

Therapeutic Level IV: Case report.

Castleman's Disease with Paraneoplastic Pemphigus

Castleman's disease is a rare autoimmune disorder with varied clinical presentations. Castleman's commonly involves mediastinum and hence it is thoracic in most of the reported cases. Paraneoplastic pemphigus (PNP) and myasthenia gravis can be associated with multicentric Castleman's disease. Its association with HIV, Kaposi sarcoma, and lymphoma is also well known. We report a rare combination of unicentric, extrathoracic Castleman's disease with PNP and myasthenia gravis.

Refractory pemphigus foliaceus and Behçet's disease successfully treated with tocilizumab

Pemphigus foliaceus (PF) and Behçet's disease (BD) are immune-mediated conditions which are usually treated with corticosteroids, immunosuppressants, and, when refractory, with biologic agents. In both diseases, interleukin (IL)-6 serum levels are increased driving the immune-mediated inflammatory process. Tocilizumab is a humanized monoclonal antibody, targeting IL6-receptor, used in the treatment of rheumatoid arthritis. Besides the current indication, it has been recently administered to patients with refractory immune inflammatory diseases as an off-label treatment. Here, we report the case of a woman affected with PF and BD, who did not respond to corticosteroids, immunosuppressants, and biologic agents including adalimumab, anakinra, and infliximab. A complete, long-lasting, clinical, and serological remission was achieved only with tocilizumab. To the best of our knowledge, the association between PF and BD has never been reported. Moreover, only two cases of BD and no cases of PF treated with tocilizumab have been described to date. A literature review on the use of biologic agents on patients with PF and BD was also carried out.

Diagnosis and classification of pemphigus and bullous pemphigoid

Pemphigus and bullous pemphigoid represent the two major groups of autoimmune blistering diseases. Pemphigus has three major variants: pemphigus vulgaris, pemphigus foliaceus and paraneoplastic pemphigus and is characterized by autoantibodies directed against the cell surface of keratinocytes, producing acantholysis that in turn leads to intraepithelial blisters in the skin and/or mucous membranes. In bullous pemphigoid, the autoantibodies are present at the dermo-epidermal junction and attack the hemidesmosomes, causing subepidermal blister formation. The classification of the major variants of both the pemphigus group and bullous pemphigoid can be based on the combination of clinical, histopathological and immunopathological criteria. Many tools are available for the diagnosis of these entities including biopsy, direct and indirect immunofluorescence, immunoprecipitation, immunoblotting and ELISA. However, currently there are no generally accepted criteria for the diagnosis of these disorders. The present review provides a proposal for diagnostic criteria.

Clinical and histological characterization of oral pemphigus lesions in patients with skin diseases: a cross sectional study from Sudan

Background

Pemphigus is a rare group of life-threatening mucocutaneous autoimmune blistering diseases. Frequently, oral lesions precede the cutaneous ones. This study aimed to describe clinical and histological features of oral pemphigus lesions in patients with skin disease has been canceled aged 18 years and above, attending outpatient’s facility of Khartoum Teaching Hospital - Dermatology Clinic, Sudan. In addition, the study aimed to assess the diagnostic significance of routine histolopathology along with immunohistochemical (IHC) examination of formalin-fixed, paraffin-embedded biopsy specimens in patients with oral pemphigus.

Methods

A cross-sectional hospital-based study was conducted from October 2008 to January 2009. A total of 588 patients with confirmed skin has been canceled disease diagnosis completed an oral examination and a personal interview. Clinical evaluations supported with histopathology were the methods of diagnosis. IHC was used to confirm the diagnosis. Location, size, and pain of oral lesions were used to measure the oral disease activity.

Results

Twenty-one patients were diagnosed with pemphigus vulgaris (PV), 19 of them (mean age: 43.0; range: 20–72 yrs) presented with oral manifestations. Pemphigus foliaceus was diagnosed in one patient. In PV, female: male ratio was 1.1:1.0. Buccal mucosa was the most commonly affected site. Exclusive oral lesions were detected in 14.2% (3/21). In patients who experienced both skin and oral lesion during their life time, 50.0% (9/18) had oral mucosa as the initial site of involvement, 33.3% (6/18) had skin as the primary site, and simultaneous involvement of both skin and oral mucosa was reported by 5.5% (1/18). Two patients did not provide information regarding the initial site of involvement. Oral lesion activity score was higher in those who reported to live outside Khartoum state, were outdoor workers, had lower education and belonged to Central and Western tribes compared with their counterparts. Histologically, all tissues except one had suprabasal cleft and acantholytic cells. IHC revealed IgG and C3 intercellularly in the epithelium.

Conclusions

PV was the predominating subtype of pemphigus in this study. The majority of patients with PV presented with oral lesions. Clinical and histological pictures of oral PV are in good agreement with the literature. IHC confirmed all diagnoses of PV.

Pemphigus

Pemphigus vulgaris and paraneoplastic pemphigus are 2 subtypes of pemphigus that involve the oral mucosa. These autoimmune blistering disorders have antibodies targeted against proteins of keratinocyte adhesion, thereby causing acantholysis. Clinical findings include oral erosions and flaccid cutaneous bullae and erosions. Further malignancy workup in patients with suspected paraneoplastic pemphigus is warranted. Retrospective uncontrolled studies suggest that immunosuppressive agents reduce mortality in pemphigus vulgaris and cohort uncontrolled studies of rituximab, a monoclonal antibody against CD20, suggest it is an effective treatment for refractory patients. Ongoing studies will define its role in early disease.

Absence of some common organ-specific and non-organ-specific autoimmunity in autoimmune polyendocrinopathy candidiasis ectodermal dystrophy

BACKGROUND

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is a rare autosomal recessive disorder caused by mutations of the autoimmune regulator (AIRE) gene, whose loss of function leads to the escape of self-reactive T cells from the thymus and autoimmunity. APECED patients typically develop tissue-specific autoantibodies and anti-cytokine antibodies. Consequently, various endocrine and non-endocrine autoimmune disorders appear. However, only a certain number of autoimmune diseases develop, while some common autoimmune conditions have not been reported or are seen only anecdotally.

OBJECTIVE

We investigated the clinical manifestations and occurrence of antinuclear antibodies (AN-Abs) and antibodies against extractable nuclear antigens, citrullinated peptide, and transglutaminase in 24 patients and against bullous pemphigoid antigen 180 and desmogleins 1 (Dsg1) and Dsg3 in 30 patients of a Finnish cohort of APECED patients.

RESULTS

Despite the loss of central tolerance, the autoantibodies investigated were not overrepresented among the APECED patients. None of the patients had a history of autoimmune connective tissue disease, rheumatoid arthritis, celiac disease, or autoimmune cutaneous bullous disorders. Altogether, 25% (6/24) had low-titer (1:80) AN-Abs. Two patients had anti-BP180 antibodies and two others had anti-Dsg3 antibodies without any cutaneous or mucosal symptoms. No anti-citrullinated peptide and anti-transglutaminase reactivity was found.

CONCLUSIONS

The mechanisms that drives tolerance to tissue autoantigens is not fully understood as even APECED patients, who are genetically prone to develop autoantibodies, are tolerant against some common autoantigens. The hypothesis that some of the anti-cytokine antibodies commonly found in APECED patients may be protective should be investigated in larger series.

Rituximab in the treatment of pemphigus vulgaris

INTRODUCTION

Rituximab is increasingly used in patients with pemphigus vulgaris (PV) who are nonresponders to conventional therapy.

METHODS

A PubMed search was conducted using the words pemphigus vulgaris and rituximab therapy from papers published between 2000 and 2012. Two protocols were used. In the lymphoma protocol, patients received four weekly infusions of rituximab (dose 375 mg/m(2)). The rheumatoid arthritis (RA) protocol consisted of two infusions of 1,000 mg each 15 days apart. The variables recorded from each study included clinical remission off or on therapy, relapse rate, incidence of serious adverse events, concomitant therapies, duration of follow-up, and when available, levels of B cells and autoantibodies.

RESULTS

Forty-two studies were found, which reported 272 patients; 180 were treated by the lymphoma protocol and 92 by the RA protocol. Both protocols were effective in treating recalcitrant PV. The lymphoma protocol had a lower response rate, relapse rate and serious infections, but higher mortality, and there were nonresponders. The RA protocol produced a higher response rate, relapse rate, number of infections, but lower mortality rate, and lacked nonresponders. The cumulative follow-up for patients treated with the lymphoma protocol was 15.44 months (range 1-41) and 21.04 months (range 8.35-29) for the RA protocol. A major concern in both protocols was the high infection rates, some of which were fatal. A different protocol using a combination of rituximab with intravenous immunoglobulin in a defined manner with a definitive endpoint, used in a limited cohort of patients, showed promising results.

CONCLUSION

Neither protocol produced a sustained clinical remission and both required continued systemic therapy. Before initiation of treatment, physicians should have a specific goal and endpoint and be aware of its potential side effects and lack of information on its long-term effects. Patients should be carefully monitored during and after therapy.

The molecular composition and function of desmosomes

Desmosomes are intercellular adhesive junctions that are particularly prominent in tissues experiencing mechanical stress, such as the heart and epidermis. Whereas the related adherens junction links actin to calcium-dependent adhesion molecules known as classical cadherins, desmosomes link intermediate filaments (IF) to the related subfamily of desmosomal cadherins. By tethering these stress-bearing cytoskeletal filaments to the plasma membrane, desmosomes serve as integrators of the IF cytoskeleton throughout a tissue. Recent evidence suggests that IF attachment in turn strengthens desmosomal adhesion. This collaborative arrangement results in formation of a supracellular network, which is critical for imparting mechanical integrity to tissues. Diseases and animal models targeting desmosomal components highlight the importance of desmosomes in development and tissue integrity, while the downregulation of individual protein components in cancer metastasis and wound healing suggests their importance in cell homeostasis. This chapter will provide an update on desmosome composition, function, and regulation, and will also discuss recent work which raises the possibility that desmosome proteins do more than play a structural role in tissues where they reside.

The use of intravenous immunoglobulin in autoimmune bullous diseases

Intravenous immunoglobulin (IVIG) has been shown to be effective in the treatment of autoimmune blistering diseases and may be an option if disease is refractory to conventional treatment. IVIG effectiveness appears to increase when administered concurrently with a cytotoxic drug and used in multiple treatment cycles (though a single cycle may give benefit). Tapering administration may improve the duration of remission and subcutaneous injections may be an option. This article provides an introduction to the make-up and use of IVIG, and reviews previous studies.

The molecular basis for the presence of two autoimmune diseases occurring simultaneously--preliminary observations based on computer analysis

Specific Human Leukocyte Antigen Class II (HLA II) molecules associated with pemphigus vulgaris (PV), mucous membraine pemphigoid (MMP), and mixed connective tissue disease (MCTD) may react with multiple T cell epitopes within desmoglein 3 (Dsg 3), bullous pemphigoid antigen 2 (BPAG 2), and 70 kDa polypeptide small nuclear ribonucleoproteins (snRNP70) in autoantibody production. We report a group of patients with simultaneous occurrences of PV with MCTD, and MMP with MCTD. In one patient group, we performed serological studies to show presence of antibodies to Dsg 3, Dsg 1, and snRNP70 simultaneously. In the second group, we performed serological studies to show presence of antibodies to BPAG 1, BPAG 2, β4 integrin, and snRNP70 simultaneously. In both groups, HLA II genes were analyzed and the observations were consistent with previously described associations with PV, MMP, and MCTD. It is possible that HLA-DQβ1*0301 allele, present in 10 of 17 patients and DRβ1*04 in some of the others, may have the ability to bind to several relevant T cell epitopes in the snRNP70 molecule. We have utilized a computer model to demonstrate that HLA II-restricted T cell epitopes present within the known autoantigens may be capable of eliciting an immune response. While other explanations and mechanisms exist, the authors suggest that epitope spreading may be one possible mechanism, amongst others, that may result in the simultaneous presence of two separate pathogenic autoantibodies.

Detection of linear IgE deposits in bullous pemphigoid and mucous membrane pemphigoid: a useful clue for diagnosis

BACKGROUND

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease of the skin associated with IgG autoantibodies to BP180 and BP230, while mucous membrane pemphigoid (MMP) comprises a heterogeneous group of autoimmune blistering diseases characterized by a predominant mucous membrane involvement and scarring tendency associated with an autoantibody response to various autoantigens, including BP180. While the pathogenicity of IgG autoantibodies to BP180 has been demonstrated in BP, the role of IgE autoantibodies in mediating tissue damage in BP and MMP is unclear.

OBJECTIVES

To assess the presence of tissue-bound IgE in patients with BP and MMP, and their correlation with distinct clinical features.

METHODS

In this retrospective study, we assessed the presence of IgE deposits as detected by direct immunofluorescence microscopy of skin biopsy specimens obtained from 44 and 13 patients with a new diagnosis of BP and MMP, respectively. Distinct clinical features at time of diagnosis, such as itch, urticarial papules and plaques and eczematous lesions, were noted.

RESULTS

In 18 of 44 (41%) patients with BP linear deposits of IgE of variable intensity were detectable along the dermoepidermal junction. In 14 (32%) of the cases, IgE deposits were found concomitantly with IgG and C3. In two (5%) patients, diagnosis of BP was based on the isolated detection of IgE together with consistent clinicopathological features. Nine of 13 (69%) patients with MMP also exhibited linear IgE deposits, including one case with isolated linear IgE deposits. Patients with BP with tissue-bound IgE deposits had clinically significant urticarial papules and plaques when compared with patients with BP without IgE deposits.

CONCLUSIONS

Our findings indicate that demonstration of tissue-bound IgE deposits provides an additional useful criterion for diagnosis of BP and MMP in some patients. Prospective studies are needed to better correlate the presence of tissue-bound and circulating IgE autoantibodies and their specificity with distinct clinical features and course of BP and MMP.

Ocular mucous membrane pemphigoid after Lyell syndrome: occasional finding or predisposing event?

PURPOSE

Ocular mucous membrane pemphigoid (OMMP) is an autoimmune disease involving the eye and characterized by subepithelial detachment resulting from an immunologic reaction against conjunctival basal membrane zone (BMZ) antigens. Lyell syndrome (LS) is a drug-induced, T cell-mediated, cytotoxic reaction involving the mucocutaneous areas. Two patients with LS are presented in whom OMMP developed.

DESIGN

Report of 2 cases.

PARTICIPANTS

Two male patients, 80 and 60 years old, with persistent corneal ulcerations, corneal melting, and inflammation some months after an LS episode.

METHODS

Conjunctival biopsy samples were obtained to perform direct immunofluorescence (DIF) and histologic analyses. Indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) also were performed.

MAIN OUTCOME MEASURES

Immunodeposit findings on the conjunctival BMZ obtained by DIF and IIF, inflammatory infiltration of the corneoconjunctival samples studied by histologic analysis, and autoantibodies of patient sera directed against BMZ antigens tested by ELISA.

RESULTS

Direct immunofluorescence analyses showed immunoglobulin G and complement 3 component deposits along the BMZ in a linear pattern. Histologic analysis revealed the presence of eosinophils, neutrophils, and mast cells with fibrin deposition in the substantia propria of both patients; the data confirmed the clinical suspicion of OMMP. The IIF and ELISA results were negative.

CONCLUSIONS

Chronic eye surface injury associated with LS may promote autoimmunization against ocular epithelial BMZ antigens, playing a strategic role in the subsequent onset of OMMP. The occurrence of OMMP after LS could be an occasional finding, or conversely, LS could be an underestimated predisposing factor in the development of OMMP.

Relevance of rituximab therapy in pemphigus vulgaris: analysis of current data and the immunologic basis for its observed responses

Treatment of pemphigus vulgaris (PV) patients with rituximab therapy has not been critically evaluated. This article will provide in significant detail the available data to date, in order to provide a clinical and immunologic basis for clinicians to decide how best to treat recalcitrant PV patients with rituximab. PV is an autoimmune blistering disorder that affects the skin and mucous membranes. The immunopathology is well characterized, including the target antigens. PV patients have traditionally been treated with systemic corticosteroids and adjuvant immunosuppressive therapies. Clinical remission has been achieved in roughly 30% of patients. However, many patients experience severe side effects from this immunosuppression, including death. B-cell depletion therapy with rituximab therapy has been used to treat several autoimmune diseases including PV. In this article, we examined the data on 153 patients with PV who have been treated with rituximab. Our focus is on the clinical response of the patients with emphasis on adjuvant therapies, dosing regimens, potential adverse events and mechanism of action related to B-cell modulation during therapy. Importantly, the use of rituximab has increased clinical remission rates to 65% including many patients who were able to discontinue all systemic medications. Finally, an expert commentary is provided, which includes suggestions for optimizing current therapy and recommends the future direction of the field. The authors strongly endorse the use of rituximab in treatment of PV patients, particularly those nonresponsive to or who develop serious side effects to conventional therapy. Proper monitoring of patients including peripheral B-cell counts and overt signs of infection are warranted, given the potential for prolonged B-cell depletion.

Role of MHC Class II genes in the pathogenesis of pemphigoid

Pemphigoid (Pg) is an autoimmune subepidermal blistering disease that affects the elderly population. The phenotype can be Bullous Pemphigoid (BP), which primarily involves the skin, or Mucous Membrane Pemphigoid (MMP), which primarily involves mucus membranes. Ocular Cicatricial Pemphigoid (OCP) and Oral Pemphigoid (OP) are subsets of MMP. The known antigens in BP are Bullous Pemphigoid Antigen 1 (BPAG1, also known as BP230), Bullous Pemphigoid Antigen 2 (BPAG2, also known as BP180), and subunits of human integrins α6 and β4. The Human Leukocyte Antigen (HLA) allele HLA-DQβ1*0301 has been reported to be associated with enhanced susceptibility to all of these subsets. Sera of patients with the four subsets are characterized by the presence of anti-Basement Membrane Zone (anti-BMZ) antibodies. In this manuscript, we present a model in which relevant portions of the four different antigens involved in pemphigoid have potential sites that could be presented by an antigen presenting cell (APC) in conjunction with DQβ1*0301 to a T cell receptor to initiate the process that results in anti-BMZ antibody production. Thus, this model provides a hypothetical computer-based mechanism to explain how a single HLA allele can be associated with the production of antibodies to four different antigens that result in four different subsets of a disease with four different clinical profiles and prognoses.

The role of natural killer cells in autoimmune blistering diseases

The major focus of this paper is to describe and evaluate current information on the role of natural killer cells (NK cells) in the pathogenesis of blistering diseases. Until now, only pemphigus vulgaris (PV) has been studied. One co-culture study demonstrated that CD4+ T cells from the peripheral blood or perilesional skin of patients with active disease proliferate and secrete cytokines in the presence of major histocompatibility class II-expressing NK cells loaded with antigenic desmoglein self-peptides. Another study showed that NK cells can contribute to a T helper type 2-biased immune response through impaired interleukins (IL)-12 signaling and upregulation of IL, IL-10 and IL-5. Although significant data on other blistering diseases are unavailable at present, some studies implicate NK cells in disease progression. For instance, information on the role of NK cells in psoriasis and their production of tumor necrosis factor-α (TNF-α) will be provided since several TNF-α-inhibitors are used in its treatment. Studies on alopecia areata are also included in this paper because NK cells seem to play a key role in its pathogenesis. This review highlights the potential importance of NK cells and NKT cells as members of the large repertoire of cells and soluble mediators that play a critical role in pathogenesis of blistering diseases and other autoimmune diseases involving the skin. Therefore, the authors advocate a greater focus and interest on the study of the interaction of NK cells and the skin.

The use of intravenous immunoglobulin in autoimmune bullous diseases

Intravenous immunoglobulin (IVIG) has been shown to be effective in the treatment of autoimmune blistering diseases and may be an option if disease is refractory to conventional treatment. IVIG effectiveness appears to increase when administered concurrently with a cytotoxic drug and used in multiple treatment cycles (though a single cycle may give benefit). Tapering administration may improve the duration of remission and subcutaneous injections may be an option. This article provides an introduction to the make-up and use of IVIG, and reviews previous studies.

Repetitive immunization breaks tolerance to type XVII collagen and leads to bullous pemphigoid in mice

Bullous pemphigoid (BP) is a subepidermal autoimmune blistering disease of the elderly associated with considerable morbidity and mortality. As unspecific immunosuppressants are still the mainstay of BP therapy, several animal models, based on the passive transfer of autoantibodies or immune cells, have been developed to obtain a better understanding of the pathogenesis of BP and evaluate novel therapeutic interventions. We describe in this study an experimental model inducing BP by immunization of immunocompetent mice with a recombinant form of the immunodominant 15th noncollagenous domain of murine BP180 (type XVII collagen). The homologous noncollagenous 16A domain of human BP180 has previously been identified as an immunodominant region in human BP. Immunization of female SJL/J mice with the murine peptide led to clinical disease within 14 wk in 56% of mice. In contrast, none of the other strains developed blisters despite the presence of autoantibodies. The clinical disease manifested for at least 8 wk without further manipulation. This novel immunization-induced model reflects key immunopathological characteristics of human BP, including binding of complement-fixing autoantibodies along the dermal-epidermal junction, elevated total IgE serum levels, and infiltration of skin lesions with eosinophilic granulocytes. The use of immunocompetent mice and the induction of sustained clinical disease not requiring additional interventions make this immunization-induced mouse model most suitable to further explore the pathogenesis of BP and novel therapeutic interventions for this and other autoantibody-mediated diseases.

Approach to the patient with autoimmune mucocutaneous blistering diseases

Autoimmune mucocutaneous blistering diseases (AMBD) are a rare group of dermatoses that can be potentially fatal. There are many subtypes and their clinical presentation can vary from being localized to general involvement. It is crucial that a diagnosis be made as early as possible and appropriate treatments are implemented. This article will discuss the diagnosis and available treatments of the major AMBDs. There are very few case-controlled studies regarding the treatments of these diseases. Most of the treatments used for these diseases are based on anecdotal reports. Hence, a synopsis of the conventional treatments and some brief recommendations will also be discussed. A brief discussion regarding "rescue" therapies that have been used for those patients with more recalcitrant cases of AMBD will also be presented.

Functional and clinical aspects of the B-cell-activating factor (BAFF): a narrative review

B-cell-activating factor (BAFF) influences peripheral B-cell survival, maturation and immunoglobulin class-switch recombination and has a range of potential clinical implications. Biological functions of BAFF and its relevance in various clinical disorders including currently investigated BAFF-targeting therapies are reviewed and discussed based on PubMed search of relevant articles. Serum levels of BAFF are increased in autoimmune diseases including autoimmune hepatitis and primary biliary cirrhosis where BAFF concentrations are related to titres of autoantibodies and disease progression. Increased BAFF levels are found in synovial, bronchoalveolar and gut lavage fluids, suggesting local class switching and immunoglobulin production. Clinical relevance and diagnostic potential of BAFF are also noted in patients with allergic diseases, malignancies and infections including hepatitis C virus. BAFF antagonists are promising new therapeutic agents, currently being tried in B-cell-related autoimmune diseases. Serum level of BAFF may indicate disease mechanisms and the degree of activity. Determination of BAFF in different body compartments like synovium, airways and gut may also have clinical implications. Results of ongoing clinical trials with BAFF antagonists are eagerly awaited.