Type 2 T-Cell Responses against Distinct Epitopes of the Desmoglein 3 Ectodomain in Pemphigus Vulgaris

Pemphigus vulgaris (PV) is an autoimmune blistering disorder of the skin and/or mucous membranes caused by IgG autoantibodies that predominantly target two transmembrane desmosomal cadherins: desmoglein (DSG)1 and DSG3. DSG-specific T cells play a central role in PV pathogenesis because they provide help to autoreactive B cells for autoantibody production. In this study, we characterized DSG3-specific peripheral T cells in a cohort of 52 patients with PV and 41 healthy controls with regard to cytokine profile and epitope specificity. By ELISpot analysis, type 2 T cells reactive with the DSG3 ectodomain were significantly increased in patients with PV compared with those in healthy controls. By dextramer analysis, CD4+ T cells specific for an epitope within the extracellular domain of DSG3, DSG3(206-220), were found at significantly higher frequencies in patients with PV than in HLA-matched healthy controls. T-cell recognition of two distinct DSG3 epitopes, that is, DSG3(206-220) and DSG3(378-392), correlated significantly, suggesting a synergistic effect in B-cell help. Immunization of HLA-DRB1∗04:02-transgenic mice with PV with the same set of DSG3 peptides induced pathogenic DSG3-specific IgG antibodies, which induced loss of keratinocyte adhesion in vitro. Thus, DSG3 peptide-specific T cells are of particular interest as surrogate markers of disease activity and potential therapeutic targets in PV.

A life for autoimmune blistering diseases: in memoriam Detlef Zillikens

Detlef Zillikens, MD, director and chair of the Department of Dermatology at the University of Lübeck, Lübeck, Germany, died in September 2022, aged only 64. He dedicated his professional life to autoimmune blistering diseases (AIBDs) and built his department into one of the world's leading centers for these diseases. Herein, his professional life and the impact on the field of AIBDs and the research landscape at the University of Lübeck are addressed. With his warm, integrative, open-minded, ever-optimistic attitude, he was a highly reliable colleague, mentor, and friend to many in the field including each of the authors. Combined with his in-depth knowledge of dermatology, interest in many fields of life science, and hard work, Detlef Zillikens initiated the founding of two independent research institutes, the Lübeck Institute of Experimental Dermatology and the Institute and Comprehensive Center for Inflammation Medicine. He was also instrumental in establishing the Center for Research on Inflammation of the Skin, where in a new research building, over 140 scientists pursue research questions related to skin inflammation. By inviting numerous researchers and clinicians to his department and hosting two large international meetings, he brought the field of AIBDs much closer together and inspired multiple national and international research initiatives. His ideas will live on and grow in many of his colleagues and mentees.

Mast cell deficiency prevents BCR::ABL1 induced splenomegaly and cytokine elevation in a CML mouse model

The persistence of leukemic stem cells (LSCs) represents a problem in the therapy of chronic myeloid leukemia (CML). Hence, it is of utmost importance to explore the underlying mechanisms to develop new therapeutic approaches to cure CML. Using the genetically engineered ScltTA/TRE-BCR::ABL1 mouse model for chronic phase CML, we previously demonstrated that the loss of the docking protein GAB2 counteracts the infiltration of mast cells (MCs) in the bone marrow (BM) of BCR::ABL1 positive mice. Here, we show for the first time that BCR::ABL1 drives the cytokine independent expansion of BM derived MCs and sensitizes them for FcεRI triggered degranulation. Importantly, we demonstrate that genetic mast cell deficiency conferred by the Cpa3^Cre allele prevents BCR::ABL1 induced splenomegaly and impairs the production of pro-inflammatory cytokines. Furthermore, we show in CML patients that splenomegaly is associated with high BM MC counts and that upregulation of pro-inflammatory cytokines in patient serum samples correlates with tryptase levels. Finally, MC-associated transcripts were elevated in human CML BM samples. Thus, our study identifies MCs as essential contributors to disease progression and suggests considering them as an additional target in CML therapy. Mast cells play a key role in the pro-inflammatory tumor microenvironment of the bone marrow. Shown is a cartoon summarizing our results from the mouse model. BCR::ABL1 transformed MCs, as part of the malignant clone, are essential for the elevation of pro-inflammatory cytokines, known to be important in disease initiation and progression.

Survival and prognostic factors in bullous pemphigoid: A retrospective cohort study

Background

Bullous pemphigoid is the most common subepidermal autoimmune blistering disease. Till now, the reported prognostic factors in bullous pemphigoid vary considerably.

Aims

The purpose of this study was to determine the overall survival rate and prognostic factors in bullous pemphigoid.

Methods

We conducted a retrospective cohort study on newly diagnosed bullous pemphigoid patients between July 2001 and November 2019 in a referral unit for autoimmune blistering skin diseases in Romania.

Results

One hundred forty-eight patients were included in the study. The Kaplan-Meier overall survival rates at 1, 3, 5 and 10 years were respectively 74.2% (95% confidence interval, 67.5-81.6%), 53.4% (45.7-62.2%), 43.6% (35.9-53%) and 31.3% (23.5-41.7%). The median follow-up among survivors was 48 months (interquartile range: 11-150). Ninety (60.8%) patients died during the follow-up period; of them, 38 (42.2%) had active disease at the time of death. Advanced age, neurological diseases, valvular heart disease, malignancies, use of statins, skin infections and extensive cutaneous involvement were linked to poorer outcomes, while the use of topical corticosteroids was associated with increased overall survival.

Limitations

This study lacks a control cohort to validate the obtained results. It was conducted in a retrospective manner in a single centre. In addition, indirect immunofluorescence microscopy was not performed in all patients.

Conclusion

Beyond ageing and neurological comorbidities, the prognosis of bullous pemphigoid patients was significantly influenced by the presence of skin infections, valvular heart disease, use of statins and extensive cutaneous involvement. Topical corticosteroid treatment was associated with increased survival in these patients.

Anti-FcαRI Monoclonal Antibodies Resolve IgA Autoantibody-Mediated Disease

Immunoglobulin A (IgA) is generally considered as a non-inflammatory regulator of mucosal immunity, and its importance in diversifying the gut microbiota is increasingly appreciated. IgA autoantibodies have been found in several autoimmune or chronic inflammatory diseases, but their role in pathophysiology is ill-understood. IgA can interact with the Fc receptor FcαRI on immune cells. We now established a novel IgA autoimmune blistering model, which closely resembles the human disease linear IgA bullous disease (LABD) by using genetically modified mice that produce human IgA and express human FcαRI. Intravital microscopy demonstrated that presence of IgA anti-collagen XVII, - the auto-antigen in LABD-, resulted in neutrophil activation and extravasation from blood vessels into skin tissue. Continued exposure to anti-collagen XVII IgA led to massive neutrophil accumulation, severe tissue damage and blister formation. Importantly, treatment with anti-FcαRI monoclonal antibodies not only prevented disease, but was also able to resolve existing inflammation and tissue damage. Collectively, our data reveal a novel role of neutrophil FcαRI in IgA autoantibody-mediated disease and identify FcαRI as promising new therapeutic target to resolve chronic inflammation and tissue damage.

Challenges and pitfalls between lichen planus pemphigoides and bullous lichen planus

Lichen planus pemphigoides (LPP) and bullous lichen planus (BLP) are rare dermatoses, which are characterised by blisters and lichenoid lesions. Their clinical presentation is heterogenous, displaying overlapping features or mimicking other dermatological diseases. Therefore, diagnosis can often be challenging, requiring a thorough dermatological examination along with distinctive histological and immunopathological characteristics. Lichenoid degeneration of the basal epidermis exposes various antigens of the dermal-epidermal junction in LPP, resulting in the breakdown of immune tolerance, hence, the production of autoantibodies against type XVII collagen. Conversely, no pathogenic autoantibodies are detected in BLP. However, some cases of mucosal lichen planus might display immunopathological features suggestive of autoimmune blistering diseases. Therefore, a better understanding of the pathophysiology of these two distinct dermatoses is imperative. The aim of this review was to provide a summary of the current knowledge on the clinical hallmarks, diagnosis and available therapeutic options in LPP and BLP.

S2k guidelines (consensus statement) for diagnosis and therapy of dermatitis herpetiformis initiated by the European Academy of Dermatology and Venereology (EADV)

INTRODUCTION

Dermatitis herpetiformis (DH) is a chronic, pruritic, gluten-induced skin disorder characterized by subepidermal granular IgA deposition and a variable degree of enteropathy identical to that seen in coeliac disease. So far, there has been no European consensus about the management of DH.

METHODS

The guidelines were created by small subgroups of a guideline committee consisting of 26 specialists from various medical fields and one patients' representative. The members of the committee then discussed the guidelines and voted for the final version at two consensus meetings. The guidelines were developed under the support of the European Academy of Dermatology and Venereology (EADV) and in collaboration with the European Dermatology Forum (EDF).

RESULTS

The guidelines summarize evidence-based and expert-based recommendations (S2 level) for the management of DH (see Appendix).

CONCLUSION

These guidelines will improve the quality of management of DH and support dermatologists in their diagnostic and therapeutic decisions.

Autoreactive Peripheral Blood T Helper Cell Responses in Bullous Pemphigoid and Elderly Patients With Pruritic Disorders

Bullous pemphigoid (BP) is a prototypic autoimmune disorder of the elderly, characterized by serum IgG autoantibodies, namely anti-BP180 and anti-BP230, directed against components of the basal membrane zone that lead to sub-epidermal loss of adhesion. Pruritus may be indicative of a pre-clinical stage of BP, since a subset of these patients shows serum IgG autoantibodies against BP230 and/or BP180 while chronic pruritus is increasingly common in the elderly population and is associated with a variety of dermatoses. Clinical and experimental evidence further suggests that pruritus of the elderly may be linked to autoimmunity with loss of self-tolerance against cutaneous autoantigens. Thus, the objective of this study was to determine autoreactive T cell responses against BP180 in elderly patients in comparison to patients with BP. A total of 22 elderly patients with pruritic disorders, 34 patients with bullous or non-bullous BP and 34 age-matched healthy controls were included in this study. The level of anti-BP180 and anti-BP230 IgG serum autoantibodies, Bullous Pemphigoid Disease Area Index (BPDAI), and pruritus severity were assessed for all patients and controls. For characterization of the autoreactive T cell response, peripheral blood mononuclear cells were stimulated ex vivo with recombinant BP180 proteins (NH2- and COOH-terminal domains) and the frequencies of BP180-specific T cells producing interferon-γ, interleukin (IL)-5 or IL-17 were subsequently determined by ELISpot assay. Patients with BP showed a mixed Th1/Th2 response against BP180 while autoreactive Th1 cells were identified in a minor subset of elderly patients with pruritic disorders. Furthermore, our T cell characterization revealed that therapeutic application of topical clobetasol propionate ointment in BP patients significantly reduced peripheral blood BP180-specific T cells, along with clinically improved symptoms, strongly suggesting a systemic immunosuppressive effect of this treatment.

Complement-Activating Capacity of Autoantibodies Correlates With Disease Activity in Bullous Pemphigoid Patients

Background: Bullous pemphigoid is a subepidermal blistering skin disease, associated with autoantibodies to hemidesmosomal proteins, complement activation at the dermal-epidermal junction, and dermal granulocyte infiltration. Clinical and experimental laboratory findings support conflicting hypotheses regarding the role of complement activation for the skin blistering induced by pemphigoid autoantibodies. In-depth studies on the pathogenic relevance of autoimmune complement activation in patients are largely lacking. Therefore, the aim of this study was to investigate the pathogenic relevance of complement activation in patients with bullous pemphigoid. Complement activation by autoantibodies in vivo as measured by the intensity of complement C3 deposits in the patients' skin and ex vivo by the complement-fixation assay in serum was correlated with the clinical disease activity, evaluated by Autoimmune Bullous Skin Disorder Intensity Score (ABSIS) and Bullous Pemphigoid Disease Area Index (BPDAI), as well as, with further immunopathological findings in patients with bullous pemphigoid. Results: Complement-activation capacity of autoantibodies ex vivo, but not deposition of complement in the perilesional skin of patients, correlates with the extent of skin disease (measured by ABSIS and BPDAI) and with levels of autoantibodies. Conclusions: Our study provides for the first time evidence in patients for a pathogenic role of complement activation in bullous pemphigoid and should greatly facilitate the development of novel diagnostic tools and of more specific therapies for complement-dependent autoimmune injury.

Molecular diagnosis of anti-laminin 332 (epiligrin) mucous membrane pemphigoid

BACKGROUND

Mucous membrane pemphigoid is a group of chronic subepithelial autoimmune blistering diseases that mainly affect mucous membranes. Laminin 332-specific autoantibodies are present in approximately 1/3 of the patients, being associated with an increased risk of malignancy. Because of the severe complications, an early recognition of the disease allowing a timely therapy is essential. The gold standard methods for detection of laminin 332-specific autoantibodies, including the immunoprecipitation and immunoblotting are non-quantitative, laborious and restricted to a few specialized laboratories worldwide. In addition, the use of radioimmunoassays, although highly sensitive and specific, are laborious, expensive and tightly regulated. Therefore, there is a stringent need for a quantitative immunoassay for the routine detection of laminin 332-specific autoantibodies more broadly available to diagnostic laboratories. The aim of this study was to compare different antigenic substrates, including native, recombinant laminin 332 and laminin 332-rich keratinocyte extracellular matrix, for development of an ELISA to detect autoantibodies in mucous membrane pemphigoid.

RESULTS

Using a relatively large number of sera from MMP patients with well-characterized autoantibody reactivity we show the suitability of ELISA systems using laminin 332 preparations as adjunct diagnostic tools in MMP. While glycosylation of laminin 332 does not appear to influence its recognition by MMP autoantibodies, ELISA systems using both purified, native and recombinant laminin 332 demonstrated a high sensitivity and good correlation with the detection of autoantibodies by immunoblotting. ELISA systems using different laminin 332 preparations represent a feasible and more accessible alternative for a broad range of laboratories.

CONCLUSIONS

Our findings qualify the use of immunoassays with the laminin 332-rich preparations as an ancillary diagnostic tool in mucous membrane pemphigoid.

Monocytes enhance neutrophil-induced blister formation in an ex vivo model of bullous pemphigoid

BACKGROUND

Lesions of bullous pemphigoid (BP), an autoimmune subepidermal blistering disease characterized by the presence of tissue-bound and circulating autoantibodies to hemidesmosomal antigens, harbor a mixed inflammatory cellular infiltrate. In various models, neutrophils, eosinophils, mast cells, monocytes as well as B and T cells have been shown to be involved in the pathogenesis of BP. However, their interactions with and effective role in blister formation remain uncertain. This study was aimed at investigating the effect of monocyte/neutrophil interaction on blister formation in an ex vivo BP model.

METHODS

Skin cryosections were incubated with purified human neutrophils and monocytes, in the presence or absence of BP autoantibodies. Production of reactive oxygen species (ROS), degranulation, mediator release (neutrophil elastase [NE], myeloperoxidase [MPO], matrix metalloproteinase-9 [MMP-9]), binding of Fcγ receptor (CD16, CD32, CD64), and cell adhesion (CD18, ICAM-1) was investigated using appropriate inhibitors. Dermal-epidermal separation (DES) was assessed by light microscopy and quantified by Fiji software.

RESULTS

Monocytes and neutrophils synergistically interact resulting in a significantly higher DES compared to either monocytes or neutrophils separately (P < .0001). Monocyte/neutrophil-induced DES was associated with increased ROS production and was dependent on adhesion and FcγRIII binding. Upon stimulation by the granule-poor fraction of monocyte supernatants, neutrophils increased their release of MMP-9, thereby also DES at the dermal-epidermal junction of skin cryosections.

CONCLUSION

Our observations suggest that the interaction of cells, as shown here for monocytes and neutrophils, enhances mediator release resulting in an increased subepidermal blister formation. Thus, blocking intercellular cross talk promises a new therapeutic approach for blocking tissue damage in BP.

Immunological markers as predictors of developing steroid-induced diabetes mellitus in pemphigus vulgaris patients: An observational study

The aim of this study was to evaluate the clinical importance of autoantibodies in pemphigus vulgaris patients who developed steroid-induced diabetes mellitus (SID) because of the glucocorticoid therapy of pemphigus.A total of 137 patients with pemphigus vulgaris were studied. Patients with SID and pemphigus were compared with those that had only pemphigus. The variables recorded were: age at diagnosis, sex, body mass index, presence of diabetes mellitus (DM), cumulative cortisone dose, treatment duration, value of anti-desmoglein 1 and 3, and anti-glutamic acid decarboxylase autoantibodies.A total of 31 patients (22.62%) that developed steroid-induced DM were identified. Anti-glutamic acid decarboxylase autoantibodies were positive in 20.75% of patients with pemphigus vulgaris and in 25.75% of patients with pemphigus vulgaris and SID.The overall anti-glutamic acid decarboxylase autoantibodies prevalence in pemphigus patients was high, and the risk of developing DM in patients with pemphigus remains a serious problem, being associated with increased risk of mortality.

Serological diagnostics in the detection of IgG autoantibodies against human collagen VII in epidermolysis bullosa acquisita: a multicentre analysis

BACKGROUND

Epidermolysis bullosa acquisita (EBA) is a rare, potentially devastating autoimmune disease of the skin. IgG autoantibodies directed against type VII collagen (Col7), the major component of anchoring fibrils, induce skin fragility leading to cutaneous and mucocutaneous blister formation, which is mostly of a scarring phenotype. Thus, powerful and reproducible diagnostic assays are critical to establish the diagnosis of EBA early to avoid irreversible sequelae.

OBJECTIVES

The present international, retrospective multicentre study included a large cohort of patients with EBA and evaluated the diagnostic power of four different diagnostic assays for the detection of anti-Col7 IgG autoantibodies.

METHODS

Overall, 95 EBA sera and 200 control sera consisting of 100 bullous pemphigoid sera, 50 pemphigus vulgaris sera and 50 sera of healthy controls were tested for anti-Col7 IgG autoantibodies using indirect immunofluorescence (IIF), two commercial enzyme-linked immunosorbent assay (ELISA) systems and Western blot (WB) analysis. EBA sera were taken from patients with positive direct immunofluorescence and IgG reactivity in at least one of the immunoserological assays (IIF, ELISA, WB).

RESULTS

A Col7-NC1/NC2 ELISA (MBL, Nagoya, Japan) showed the highest sensitivity (97·9%), followed by a Col7-NC1 ELISA (Euroimmun, Lübeck, Germany) (89·5%), WB with Col7-NC1 (85·3%), and IIF on saline-split human skin (74·7%). The specificities of both ELISA systems were comparable (NC1 98·7%, NC1/NC2 99·3%). Furthermore, WB was more sensitive than IIF, which was more specific.

CONCLUSIONS

The two commercially available ELISA systems allow for a highly sensitive and specific diagnosis of EBA. The sensitivity of the Col7-NC1/NC2 ELISA is significantly higher compared with the ELISA based on the Col7-NC1 domain only.

Evidence for a role of eosinophils in blister formation in bullous pemphigoid

BACKGROUND

Bullous pemphigoid (BP) is an autoimmune bullous disease of the skin characterized by subepidermal blister formation due to tissue-bound and circulating autoantibodies to the hemidesmosomal antigens BP180 and BP230. Although eosinophils and their toxic mediators are found abundantly in BP lesions, their role in blister formation has remained unclear.

OBJECTIVE

To investigate the role of eosinophils in the pathogenesis of BP with a specific focus on blister formation and to define conditions inducing dermal-epidermal separation (DES).

METHODS

In an ex vivo human model of BP, normal human skin cryosections were incubated with purified human peripheral blood eosinophils with or without activation in the presence or absence of BP autoantibodies, brefeldin A, diphenyleneiodonium, DNase or blocking F(ab')₂ fragments to CD16, CD18, CD32 and CD64. Dermal-epidermal separation was assessed by light microscopy studies and quantified using Fiji software.

RESULTS

Following activation with IL-5 and in the presence of BP autoantibodies, eosinophils induced separation along the dermal-epidermal junction of ex vivo skin. Dermal-epidermal separation was significantly reduced by blocking any of the following: Fcγ receptor binding (P = 0.048), eosinophil adhesion (P = 0.046), reactive oxygen species (ROS) production (P = 0.002), degranulation (P < 0.0001) or eosinophil extracellular trap (EET) formation (P = 0.048).

CONCLUSIONS

Our results provide evidence that IL-5-activated eosinophils directly contribute to BP blister formation in the presence of BP autoantibodies. Dermal-epidermal separation by IL-5-activated eosinophils depends on adhesion and Fcγ receptor activation, requires elevated ROS production and degranulation and involves EET formation. Thus, targeting eosinophils may be a promising therapeutic approach for BP.

The Syk Tyrosine Kinase Is Required for Skin Inflammation in an In Vivo Mouse Model of Epidermolysis Bullosa Acquisita

The inflammatory form of epidermolysis bullosa acquisita is caused by autoantibodies against type VII collagen (C7), a component of the dermal-epidermal junction. We have previously shown that myeloid Src family kinases mediate skin inflammation triggered by anti-C7 antibodies. Here we identify the Syk tyrosine kinase as a critical component of autoantibody-induced skin inflammation downstream of Src family kinases. Immobilized C7–anti-C7 immune complexes triggered neutrophil activation and Syk phosphorylation in a Src family kinase-dependent manner. Bone marrow chimeric mice lacking Syk in their hematopoietic compartment were completely protected from skin inflammation triggered by anti-C7 antibodies despite normal circulating anti-C7 levels. Syk deficiency abrogated the accumulation of CXCL2, IL-1β, and leukotriene B₄ at the site of inflammation and resulted in defective in vivo neutrophil recruitment. Syk^–/– neutrophils had a normal intrinsic migratory capacity but failed to release CXCL2 or leukotriene B₄ upon activation by immobilized C7–anti-C7 immune complexes, indicating a role for Syk in the amplification of the inflammation process. These results identify Syk as a critical component of skin inflammation in a mouse model of epidermolysis bullosa acquisita and as a potential therapeutic target in epidermolysis bullosa acquisita and other mechanistically related inflammatory skin diseases such as bullous pemphigoid.

[Molecular diagnosis of autoimmune dermatoses]

Bullous autoimmune diseases are organ-specific disorders characterized by an autoantibody-mediated blistering of skin and mucous membranes. The detection of tissue-bound and serum autoantibodies is prerequisite for the diagnosis of autoimmune blistering diseases. The individual entities of this group may be difficult to differentiate on clinical grounds alone. An accurate diagnosis is however important for prognosis and therapy. A preliminary diagnostic step includes direct and indirect immunofluorescence microscopy, which provide information about the binding pattern and isotype of autoantibodies and allow the diagnosis of the autoimmune blistering disease. Subsequent characterization of the molecular specificity of autoantibodies is necessary for the exact classification of autoimmune bullous dermatoses. The quantitative measurement of autoantibodies against structural proteins of the skin may be often used to assess disease severity at follow-up.

Granular C3 Dermatosis

There has been no previous systematic study of bullous skin diseases with granular basement membrane zone deposition exclusively of C3. In this study we collected 20 such patients, none of whom showed cutaneous vasculitis histopathologically. Oral dapsone and topical steroids were effective. Various serological tests detected no autoantibodies or autoantigens. Direct immunofluorescence for various complement components revealed deposition only of C3 and C5-C9, indicating that no known complement pathways were involved. Studies of in situ hybridization and micro-dissection with quantitative RT-PCR revealed a slight reduction in expression of C3 in patient epidermis. These patients may represent a new disease entity, for which we propose the term "granular C3 dermatosis". The mechanism for granular C3 deposition in these patients is unknown, but it is possible that the condition is caused by autoantibodies to skin or aberrant C3 expression in epidermal keratinocytes.

Nanocarriers as Tools in Delivering Active Compounds for Immune System Related Pathologies

BACKGROUND

Immune system related pathologies affect an increasing number of patients every year, having potentially lethal consequences and requiring expensive and difficult tolerated treatments. This area of pathologies offers an excellent potential for the development of innovative solutions such as nanoformulations; this review aims to describe the main categories of nanostructured drug delivery platforms that have been developed in order to achieve a more effective, low toxic treatment in autoimmune pathologies.

METHODS

We conducted a systematic search of peer-reviewed original studies focusing on nanoformulations suitable for use against autoimmune disorders. Each study was evaluated by at least two reviewers who applied inclusion and exclusion criteria in order to establish the quality of the research reported in the selected papers. The systematic screening of the literature also identified the most recent patents issued in the field of inflammatory/autoimmune diseases which were included in the current paper.

RESULTS

One hundred ninety-seven bibliographic titles were included in the review of which fifty-three recently published patents. Twenty-one papers were selected to define the interaction between nanoformulations and the immune system triggering either immunosuppression or immunostimulation. Thirty-seven papers outlined the characteristics of liposomal formulations that have been reported as treatment for several autoimmune diseases including multiple sclerosis. Twentythree articles provided data on the main lipid nanoparticles of the first and second generation which may include physiological lipids with low cytotoxicity. Gold nanoparticles were described by thirteen papers which highlighted the advantages of the new hybrid organic-inorganic nanoparticles vs. the classical ionic gold compounds. Polymeric nanoformulations were the subject of fifty-nine papers that described their preparation as well as various advantages in the treatment of inflammatory disorders; dendrimers and polymeric micelles were included in the study. Thirty-three studies were selected to outline the benefits provided by the use of cyclodextrins as carriers for active drugs. The review also identified the possibility of producing combined nanoformulations (e.g. polymer/cyclodextrin, liposome/polymer) thus achieving superior therapeutic results.

CONCLUSION

Nanoformulations offer multiple advantages over the classical pharmaceutical formulations, the main ones being the precise targeted therapy with small doses of active drugs, longer circulating time in the bloodstream, and high loading capacity for diagnostic and therapeutic molecules; moreover, the nanoparticles may be functionalized in order to act as nanotheranostics within the larger frame of personalized medicine.

[Molecular diagnosis of collagen vascular diseases and vasculitides]

Collagen vascular diseases and vasculitides comprise various diseases, which may affect virtually every organ system. Therefore, their diagnosis and management is often an interdisciplinary challenge. Because of the heterogeneous symptoms, these diseases have significant overlap, which interferes with the clinical diagnosis and may require additional investigation. Therefore, a rational and comprehensive diagnostic work-up should be performed at the initial presentation before initiation of therapy. The detection of antinuclear (ANA) or anticell antibodies by indirect immunofluorescence microscopy on Hep2 cells is used to screen for autoantibodies in collagen vascular diseases. The molecular specificity of autoantibodies should be further characterized using immunoassays with recombinant or purified protein. When systemic autoimmune disease is suspected, the function of the frequently affected organs should be evaluated. The immunopathological findings should always be interpreted in the context of clinical, histological, and imaging data. The detection of autoantibodies is helpful for the initial diagnosis, provides prognostic information, may indicate involvement of organs or systems and some parameters may also be used for disease monitoring. The clinical significance of autoantibodies is emphasized by the fact that their detection constitutes diagnostic criteria for most collagen vascular diseases and several vasculitides. The screening for ANCA may be performed using immunoassays with recombinant myeloperoxidase and proteinase 3 or by indirect immunofluorescence microscopy on granulocytes. In this article, the current diagnostic tools and their relevance for the diagnosis and monitoring of systemic autoimmune diseases with primary skin involvement are reviewed.

Role of physical factors in the pathogenesis of bullous pemphigoid: Case report series and a comprehensive review of the published work

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease affecting mainly the elderly. The subtype of the disease induced by physical agents represents a rare and, therefore, insufficiently characterized form. In the present study, we aimed to contribute to a better understanding of the pathogenetic mechanisms involved in the onset of BP induced by different trigger factors. We have retrospectively analyzed nine cases of BP. All patients were characterized based on clinical, epidemiological and immunological parameters. For each case, the trigger factor involved was specified. In addition to our retrospective analysis, a comprehensive review of the 59 published cases was conducted, regarding the involvement of trigger factor in BP, and clinical, epidemiological and immunological data were collected. In the local study, conducted on nine patients diagnosed with BP, various trigger factors were identified: contrast substance injection, surgical procedure, mechanical trauma, insect bite, thermal burn, radiotherapy and ultraviolet exposure associated with pre-existing psoriasis. The autoantibodies from all patients were shown to activate granulocytes and induce dermal-epidermal split. Different hypotheses regarding the pathogenetic mechanism involving the trigger factors have been discussed. In regard of the pathogenetic mechanism, we believe that the most reliable hypothesis is that BP patients already have low titers of anti-basement membrane autoantibodies which activate the granulocytes. However, more studies are needed for a better understanding of the pathogenetic mechanism of the intervention of trigger factors.

Oral mucosal manifestations of autoimmune skin diseases

A group of autoimmune diseases is characterised by autoantibodies against epithelial adhesion structures and/or tissue-tropic lymphocytes driving inflammatory processes resulting in specific pathology at the mucosal surfaces and the skin. The most frequent site of mucosal involvement in autoimmune diseases is the oral cavity. Broadly, these diseases include conditions affecting the cell-cell adhesion causing intra-epithelial blistering and those where autoantibodies or infiltration lymphocytes cause a loss of cell-matrix adhesion or interface inflammation. Clinically, patients present with blistering, erosions and ulcers that may affect the skin as well as further mucosal surfaces of the eyes, nose and genitalia. While the autoimmune disease may be suspected based on clinical manifestations, demonstration of tissue-bound and circulating autoantibodies, or lymphocytic infiltrates, by various methods including histological examination, direct and indirect immunofluorescence microscopy, immunoblotting and quantitative immunoassay is a prerequisite for definitive diagnosis. Given the frequency of oral involvement and the fact that oral mucosa is the initially affected site in many cases, the informed practitioner should be well acquainted with diagnostic and therapeutic aspects of autoimmune dermatosis with oral involvement. This paper reviews the pathogenesis and clinical presentation of these conditions in the oral cavity with a specific emphasis on their differential diagnosis and current management approaches.

Prediction of survival for patients with pemphigus vulgaris and pemphigus foliaceus: a retrospective cohort study

Background

Factors associated with survival in pemphigus have not yet been thoroughly addressed. Therefore, in the present study, risk factors for overall mortality in a large group of patients with pemphigus vulgaris and foliaceus were investigated.

Methods

A retrospective hospital-based cohort study was carried out, between October 1998 and November 2012, in the Department of Dermatology of the University of Medicine and Pharmacy “Iuliu Hatieganu”, Cluj-Napoca, Romania. The investigated prognostic endpoint was the overall survival of the patients.

Results

A total of 130 patients were studied (108 with pemphigus vulgaris and 22 with pemphigus foliaceus). In pemphigus vulgaris group, univariate analysis found a statistically significant association between the age of onset ≥ 65 years (p < 0.001), presence of coronary heart disease (p = 0.006), presence of cardiac arrhythmia (p = 0.004), level of anti-desmoglein1 autoantibodies ≥ 100 U/mL (p = 0.047) at diagnosis and the survival of the patients. An age-adjusted analysis showed significant results for coronary heart disease. Multivariate analysis identified the age of onset ≥ 65 years and the presence of coronary heart disease at diagnosis as independent risk factors associated with overall mortality. In patients with pemphigus foliaceus, age of onset ≥ 65 years (p = 0.021) was associated with poor survival.

Conclusions

In addition to common prognostic factors, including older age and cardiovascular comorbidities, level of autoantibodies was found to be a disease-specific factor associated with overall mortality in pemphigus vulgaris. The newly identified factors have major implications for the stratification of patients and should greatly facilitate further epidemiological studies in pemphigus. In addition, they provide useful information for the design of personalized therapeutic plans in the clinical setting.

Bullous pemphigoid in infants: characteristics, diagnosis and treatment

BACKGROUND

Bullous pemphigoid (BP) in infants is a rare but increasingly reported autoimmune blistering skin disease. Autoantibody reactivity is usually poorly characterized. Current guidelines do not address specific aspects of the infantile form of BP. The objectives of this study are to define clinical and diagnostic characteristics of infantile BP and develop a treatment algorithm.

METHODS

Detailed characterization of a current case series of five infants with BP from our departments. Comprehensive analysis of all reported cases (1-12 months) with respect to clinical and laboratory characteristics, treatment and outcome.

RESULTS

In total 81 cases were identified (including our own). The mean age was 4.5 months. Moderately severe and severe disease was seen in 84% of cases. Involvement of hands and feet was present in all cases. Immunofluorescence microscopy was comparable with BP in adults. Where analyzed, the NC16A domain of bullous pemphigoid 180 kDa antigen/collagen XVII (BP180) was identified as the major target antigen. BP180 NC16A ELISA values in our cohort were significantly higher than in a control cohort of 28 newly diagnosed adult patients. 50% of patients were treated with systemic corticosteroids, 20% with a combination of systemic corticosteroids and dapsone or sulfapyridine and 10% with topical corticosteroids alone. 14% of patients needed a combination of multiple immunosuppressants. All but one patient reached remission. Relapses were rare.

CONCLUSIONS

Presentation of infantile BP is often severe with blistering of hands and feet present in all cases. Pathogenesis and diagnostic criteria are comparable to adult BP, yet BP180 NC16A ELISA levels seem to be significantly higher in infants. The overall disease outcome is favorable. Based on the results of this study we propose a treatment algorithm for infantile BP.

The Src family kinases Hck, Fgr, and Lyn are critical for the generation of the in vivo inflammatory environment without a direct role in leukocyte recruitment

Kovács et al. examine the role of the Src family kinases Hck, Fgr, and Lyn in immune cell–mediated inflammation. Using arthritis and skin inflammation models, the authors show that mice lacking hematopoietic Hck, Fgr, and Lyn are protected from these inflammatory diseases, showing loss of myeloid cell recruitment and lack of inflammatory mediator production. Unexpectedly, the three kinases are dispensable for the intrinsic migratory ability of myeloid cells. These finding may have clinical implications in rheumatic and skin diseases.

Although Src family kinases participate in leukocyte function in vitro, such as integrin signal transduction, their role in inflammation in vivo is poorly understood. We show that Src family kinases play a critical role in myeloid cell–mediated in vivo inflammatory reactions. Mice lacking the Src family kinases Hck, Fgr, and Lyn in the hematopoietic compartment were completely protected from autoantibody-induced arthritis and skin blistering disease, as well as from the reverse passive Arthus reaction, with functional overlap between the three kinases. Though the overall phenotype resembled the leukocyte recruitment defect observed in β₂ integrin–deficient (CD18^−/−) mice, Hck^−/−Fgr^−/−Lyn^−/− neutrophils and monocytes/macrophages had no cell-autonomous in vivo or in vitro migration defect. Instead, Src family kinases were required for the generation of the inflammatory environment in vivo and for the release of proinflammatory mediators from neutrophils and macrophages in vitro, likely due to their role in Fcγ receptor signal transduction. Our results suggest that infiltrating myeloid cells release proinflammatory chemokine, cytokine, and lipid mediators that attract further neutrophils and monocytes from the circulation in a CD18-dependent manner. Src family kinases are required for the generation of the inflammatory environment but not for the intrinsic migratory ability of myeloid cells.

Blister-inducing antibodies target multiple epitopes on collagen VII in mice

Epidermolysis bullosa acquisita (EBA) is an autoimmune subepidermal blistering disease of mucous membranes and the skin caused by autoantibodies against collagen VII. In silico and wet laboratory epitope mapping studies revealed numerous distinct epitopes recognized by EBA patients' autoantibodies within the non-collagenous (NC)1 and NC2 domains of collagen VII. However, the distribution of pathogenic epitopes on collagen VII has not yet been described. In this study, we therefore performed an in vivo functional epitope mapping of pathogenic autoantibodies in experimental EBA. Animals (n = 10/group) immunized against fragments of the NC1 and NC2 domains of collagen VII or injected with antibodies generated against the same fragments developed to different extent experimental EBA. Our results demonstrate that antibodies targeting multiple, distinct epitopes distributed over the entire NC1, but not NC2 domain of collagen VII induce blistering skin disease in vivo. Our present findings have crucial implications for the development of antigen-specific B- and T cell-targeted therapies in EBA.

BP180- and BP230-specific IgG autoantibodies in pruritic disorders of the elderly: a preclinical stage of bullous pemphigoid?

Pruritus increasingly occurs in the elderly population and is associated with a variety of dermatoses of mixed aetiology. Clinical and experimental evidence suggests that senile pruritus may be linked to autoimmune events initiated by loss of self-tolerance against cutaneous autoantigens, which is facilitated by immune ageing processes. T-cell immunity, which underpins the production of pathogenic autoantibodies in autoimmune diseases, is deregulated by immune senescence thereby leading to autoimmune disorders such as bullous pemphigoid (BP). High mortality rates of BP combined with steadily increasing incidence emphasize the need for an effective diagnostic strategy at an early stage. We summarize here the current understanding of immunological alterations during the ageing process, thereby focusing on aberrant T-cell responses against the basement membrane antigens BP180 and BP230, which may eventually lead to the clinical outcome of BP.

IgG antibodies against immunodominant C-terminal epitopes of BP230 do not induce skin blistering in mice

Bullous pemphigoid, the most common autoimmune blistering disease in Western Europe and the USA is characterized by the presence of circulating and tissue-bound autoantibodies against the hemidesmosomal proteins BP230 and BP180/collagen XVII. After binding to their target antigens at the basement membrane of the dermal-epidermal junction these autoantibodies are thought to trigger an inflammatory cascade comprising complement- and granulocyte-dependent reactions that result in tissue damage. Whereas the role of anti-BP180 antibodies has been extensively characterized, few and conflicting data is available on the contribution of anti-BP230 antibodies to bullous pemphigoid pathogenesis. Therefore, we addressed in the present study the role of autoantibodies to BP230 in experimental bullous pemphigoid. Rabbit polyclonal antibodies generated against epitopes of the C-terminal fragment of murine BP230 bound to the basement membrane and activated the complement system ex vivo. Affinity-purified antibodies were subsequently subcutaneously transferred into neonatal and adult BALB/c mice. In vivo, we observed a dose-dependent binding of transferred antibodies in the murine skin; however, there was no complement activation and these mice showed no clinical or histological signs of inflammatory disease, in contrast to mice receiving anti-BP180 antibodies. We further conducted ex vivo experiments and demonstrated that rabbit IgG anti-BP230-specific antibodies, in contrast to antibodies from bullous pemphigoid patients or rabbit IgG anti-BP180 antibodies used as positive controls, did not activate human granulocytes to induce dermal-epidermal separation in skin cryosections. Our present findings demonstrate that antibodies against BP230 are non-pathogenic in experimental models of bullous pemphigoid and suggest that proper activation of the complement and granulocytes represent prerequisites for conferring bullous pemphigoid autoantibodies their tissue destructive potential.

Molecular diagnosis in autoimmune skin blistering conditions

Blister formation in skin and mucous membranes results from a loss of cell-cell or cell-matrix adhesion and is a common outcome of pathological events in a variety of conditions, including autoimmune and genetic diseases, viral and bacterial infections, or injury by physical and chemical factors. Autoantibodies against structural components maintaining cell-cell and cell-matrix adhesion induce tissue damage in autoimmune blistering diseases. Detection of these autoantibodies either tissue-bound or circulating in serum is essential to diagnose the autoimmune nature of disease. Various immunofluorescence methods as well as molecular immunoassays, including enzyme-linked immunosorbent assay and immunoblotting, belong to the modern diagnostic algorithms for these disorders. There is still a considerable need to increase awareness of the rare autoimmune blistering diseases, which often show a severe, chronic-relapsing course, among physicians and the public. This review article describes the immunopathological features of autoimmune bullous diseases and the molecular immunoassays currently available for their diagnosis and monitoring.

Molecular diagnosis of autoimmune skin diseases

A wide range of skin diseases are associated with autoimmune responses against skin-specific or ubiquitous antigens. In many of these diseases, including autoimmune blistering disorders, collagenoses and vasculitides, extensive clinical and experimental evidence shows that autoreactive T-cells and/or autoantibodies play a major pathogenic role, allowing their classification as autoimmune diseases. The presence of tissue-bound and circulating autoantibodies does not only bear relevance for disease pathogenesis, but also allows developing robust diagnostic tools and molecular therapeutic approaches. Thus, various immunofluorescence methods, as well as molecular immunoassays, including enzyme-linked immunosorbent assay and immunoblotting, belong to the modern diagnostic algorithms for these disorders. This review article describes the immunopathological features of autoimmune skin diseases and the molecular assays currently available for their diagnosis and monitoring.

Ex vivo pathogenicity of anti-laminin γ1 autoantibodies

Autoimmunity against laminins has been described in several autoimmune diseases (including mucous membrane pemphigoid, anti-laminin γ1 pemphigoid, and connective tissue diseases), in pregnancy loss, and in infections such as Chagas disease. Except for anti-laminin-332 mucous membrane pemphigoid, adequate evidence has been lacking for the tissue injury potential of laminin-specific antibodies and the pathogenic epitopes. We evaluated the pathogenic potential of antibodies targeting laminin γ1, a major constituent of basement membranes and the main antigen in anti-laminin γ1 pemphigoid. Rabbit antibodies were generated against fragments of the N-terminus and C-terminus of murine laminin γ1, and their ability to disrupt ligand interactions and/or to activate complement and granulocytes was assessed using previously established ex vivo assays. Our findings document a pathogenic potential of antibodies targeting the laminin γ1 N-terminus. These antibodies interfere with the binding of nidogen to laminin and can activate granulocytes and the complement cascade. We detected antibodies with different degrees of reactivity with laminin γ1 N-terminus in patients with anti-laminin γ1 pemphigoid, cutaneous lupus erythematosus, and scleroderma. Our results provide mechanistic insights into the tissue damage associated with laminin autoimmunity and could facilitate development of appropriate diagnostic tools and therapeutic strategies.

Passive transfer of collagen XVII-specific antibodies induces sustained blistering disease in adult mice

BACKGROUND

Bullous pemphigoid is a subepidermal blistering disorder associated with tissue-bound and circulating autoantibodies directed mainly to the hemidesmosomal component collagen XVII. While recapitulating the main immunopathological features of the human disease, frank skin blistering does not develop in the absence of skin rubbing in experimental pemphigoid models that have been established in neonatal mice. Moreover, due to their experimental design they only allow for short-term disease observation. In the present study we aimed to establish a model that reproduces the frank skin blistering seen in patients and allows for longer observation times.

METHODS

Rabbit and sheep antibodies specific to several fragments of collagen XVII were generated and the purified antibodies were passively transferred into adult mice.

RESULTS

Collagen XVII-specific IgG bound to the basal membrane of the skin and mucous membranes activating murine complement in vivo. Mice injected with collagen XVII-specific antibodies, in contrast to mice receiving control antibodies, developed frank skin blistering disease, reproducing human bullous pemphigoid at the clinical, histological and immunopathological levels. Titres of circulating IgG in the serum of mice correlated with the extent of the clinical disease. Mice receiving sheep antibodies specific to murine collagen XVII showed an early onset and a more active disease when compared to litter mates receiving specific rabbit antibodies.

CONCLUSION

This novel animal model for bullous pemphigoid should facilitate further investigations of the pathogenesis of bullous pemphigoid and the development of innovative therapies for this disease.