Mechanisms of blister induction by autoantibodies

Oral mucosal lesions in the mouth as first sign of dermatological diseases and disorders

Oral mucosal lesions manifest as a first sign of immune-mediated disorders. Lichen planus, pemphigus and pemphigoid are the most frequent immunologically mediated mucocutaneous diseases with oral involvement. Oral lesions are initially detected by dental health practitioners. Early detection can help in appropriate treatment and better quality of life. Based on an analysis of 6,300 medical records from the period 1997 to 2018, 105 (1.66%) were attributable to these immunologically mediated diseases, of which 86 (1.36%) were due to lichen planus, 4 (0.06%) to pemphigus and 15 (0.23%) to pemphigoid.

Perinatal Outcome of Pemphigoid Gestationis: A Report of Three Cases and Review of the Literature

Pemphigoid gestationis (PG) is a rare autoimmune blistering disorder that typically manifests during the second or third trimester of pregnancy. It is characterized by intensely pruritic urticarial plaques and blister formation, driven by an autoimmune response against the BP180 protein in the basement membrane. In this report, three cases of PG are presented, each illustrating distinct clinical courses and management strategies. The first case involves a 32-year-old primigravida at 31 weeks of gestation who presented with abdominal blisters that were unresponsive to topical steroids. Oral prednisone at a dosage of 15 mg was initiated at 33 weeks, leading to the resolution of the rash by 37 weeks. She subsequently delivered vaginally at 40 weeks. The second case concerns a 37-year-old multigravida who developed blisters on her limbs and abdomen at 27 weeks, which improved with the application of topical steroids. Due to a history of a previous cesarean section, she delivered via elective cesarean section at 38 weeks. The third case involves a 35-year-old multigravida who experienced fetal growth restriction starting from 29 weeks. She developed a mild erythematous, pruritic rash, and blisters at 33 weeks and required an emergency cesarean section at 33 weeks due to non-reassuring fetal status. The diagnosis of PG was confirmed postpartum. These cases underscore the clinical variability and potential complications associated with PG. They also suggest that the severity of PG's cutaneous manifestations may not directly correlate with pregnancy outcomes. Early detection and individualized management are crucial to optimizing both maternal and neonatal outcomes.

Analysis of IL-10 and IL-35 in dipeptidyl peptidase-4 inhibitor-related bullous pemphigoid

The association between immunoregulatory cytokines, such as interleukin (IL)-10 or IL-35, and dipeptidyl peptidase-4 inhibitor (DPP4i)-related bullous pemphigoid (BP) has not been evaluated. Serum IL-10 and IL-35 levels were measured in 39 patients with BP (24 males and 15 females; 6 DPP4i-related and 33 DPP4i-unrelated BP patients) and 10 healthy controls. The number of CD26+ cells in the dermis around bulla on sections was counted immunohistochemically for 12 patients (six patients with DPP4i-related BP and six randomly sampled patients with DPP4i-unrelated BP). Patients with DPP4i-related BP had lower levels of serum eosinophils (DPP4i-related vs. DPP4i-unrelated BP: 476.1 ± 234.0 vs. 911.3 ± 948.8/μL; p = 0.537) and a higher rate of infiltrating CD26+ cells (32.9 ± 7.1% vs. 15.7 ± 4.4%; p = 0.01). There were no significant differences in serum IL-10 (6.77 ± 0.24 vs. 6.84 ± 0.20 pg/mL), serum IL-35 (2.63 ± 0.17 vs. 2.63 ± 0.21 pg/mL), serum anti-BP180NC16a antibodies (67.31 ± 37.4 vs. 76.18 ± 54.59 U/mL) and Bullous Pemphigoid Disease Area Index before treatment in this study. Serum IL-10 and IL-35 levels do not increase in patients with BP and may not be a candidate for a therapeutic target for BP. An increase in CD26+ cells might be associated with DPP4i-related BP.

Utility of C3d and C4d immunohistochemical staining in formalin-fixed skin or mucosal biopsy specimens in diagnosis of bullous pemphigoid and mucous membrane pemphigoid

Bullous pemphigoid (BP) and mucous membrane pemphigoid (MMP) sometimes have overlapping clinical, histopathological, and direct immunofluorescence (DIF) features in the early stages. Complement deposition is an intrinsic component of the patho-mechanism of BP in contrast to MMP. Hence immunohistochemistry (IHC) for C3d and C4d may be helpful in differentiating the two disorders. Seventy-four patients of BP and 18 patients of MMP along with 10 negative controls were enrolled in this study. C3d and C4d IHC was performed in formalin-fixed skin biopsy specimens. C3d IHC staining in BP/MMP had a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 59.2%/41.2%, 100%/100%, 100%/100%, 25.6%/50.0%, respectively. C4d IHC staining in BP/MMP had a sensitivity, specificity, PPV and NPV of 26.8%/17.6%, 100%/100%, 100%/100% and 16.1%/41.7%, respectively. Receiver operator analysis showed utility of C3d in diagnosing both BP [Area under curve (AUC) = 0.8, p = 0.0001] and MMP (AUC = 0.71; p = 0.001). C4d was useful in diagnosis of BP (AUC = 0.5; p = 0.0001), but not MMP (AUC = 0.6; p = 0.064). Hence, C3d is a better diagnostic modality for BP as compared to C4d, whereas C3d and C4d have lower diagnostic importance in MMP. C3d IHC can be employed in diagnosing BP when a second biopsy for direct immunofluorescence (DIF) is not possible or where a facility for IF microscopy does not exist.

Antagonizing FcαR1 (CD89) as treatment in IgA-mediated chronic inflammation and autoimmunity

Introduction

Immunoglobulin A (IgA) is mostly considered as a non-inflammatory regulator at mucosal areas. However, previous work of our group showed that IgA can also be involved in disease pathology, because it provides a potent stimulus to activate neutrophils after crosslinking of surface CD89 (FcaRI), resulting in chronic inflammation and tissue damage. IgA (auto)antibodies and neutrophils are key players in various diseases, including blistering skin diseases and rheumatoid arthritis. Therefore, we generated an array of anti-CD89 monoclonal antibodies (mAbs) for therapeutic targeting of CD89. The biological activity of newly developed anti-human CD89 mAbs and their potential therapeutic capacity were investigated.

Methods

Human neutrophils were isolated from heparinized healthy donor blood. The ability of anti-CD89 mAbs to bind human neutrophils was investigated by flow cytometry. Furthermore, the capacity of these anti-CD89 mAbs to inhibit IgA-mediated phagocytosis, neutrophil extracellular trap (NET) release and migration was studied. To this end, neutrophils were pre-incubated with/without anti-CD89 mAbs after which they were stimulated with IgA-coated beads. The amount of phagocytosed beads, NET release and migrated neutrophils were subsequently analysed. In parallel, chemoattractant leukotriene B4 and lactoferrin (as a measure for degranulation) release were determined. Finally, the therapeutic potential of our prototypic anti-CD89 mAb clone 10E7 was in vivo tested in anti-mouse collagen XVII human IgA-treated transgenic CD89 mice, a preclinical model for autoimmune linear IgA bullous disease (LABD).

Results

Our results show that all generated anti-CD89 mAbs bound surface CD89 on neutrophils. Although these anti-CD89 mAbs bind to different epitopes on EC1 of CD89, they all have the capacity to inhibit IgA-mediated phagocytosis, neutrophil extracellular trap (NET) release and neutrophil migration. Moreover, IgA mediated leukotriene B4 and lactoferrin release are decreased in supernatant from anti-CD89 mAbs-treated neutrophils. Finally, anti-CD89 mAb clone 10E7, that was selected based on its selective binding profile on tissue micro arrays, reduced anti-mouse collagen XVII hIgA-induced neutrophil influx in an in vivo linear IgA bullous disease (LABD) mice model.

Conclusion

This study clearly indicates that our newly developed anti-CD89 mAbs inhibited IgA-induced neutrophil activation and reduced anti-autoantigen IgA-induced neutrophil influx in vivo, supporting further clinical development for the treatment of LABD.

The relevance of complement in pemphigoid diseases: A critical appraisal

Pemphigoid diseases are autoimmune chronic inflammatory skin diseases, which are characterized by blistering of the skin and/or mucous membranes, and circulating and tissue-bound autoantibodies. The well-established pathomechanisms comprise autoantibodies targeting various structural proteins located at the dermal-epidermal junction, leading to complement factor binding and activation. Several effector cells are thus attracted and activated, which in turn inflict characteristic tissue damage and subepidermal blistering. Moreover, the detection of linear complement deposits in the skin is a diagnostic hallmark of all pemphigoid diseases. However, recent studies showed that blistering might also occur independently of complement. This review reassesses the importance of complement in pemphigoid diseases based on current research by contrasting and contextualizing data from in vitro, murine and human studies.

Component Identification and Analysis of Vesicular Fluid From Swine Infected by Foot-and-Mouth Disease Virus

Foot-and-mouth disease (FMD) is induced by FMD virus (FMDV) and characterized by fever and vesicular (blister-like) lesions. However, the exact composition of the vesicular fluid in pigs infected with FMDV remains unclear. To identify and analyze the components of the vesicular fluid in FMDV-infected domestic pigs, the fluid was collected and subjected to mass spectrometry. Further analyses were conducted using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genome (KEGG), and protein–protein interaction (PPI). Quantitative ELISA kit for TNF-α, and IFN-α, IFN-β, IL-6, IL-10, IL-1β, and IFN-γ were used to verify the mass spectrometry results. Results showed that 937 proteins were identified in the vesicular fluid from swine after FMDV infection, and bioinformatics analysis indicated that these proteins are related to the innate immune and inflammation pathways. The levels of cytokines involved in the disease-related pathways, tumor necrosis factors, and IL-6 in the fluid samples were significantly increased. This study identified and analyzed the composition of vesicular fluid in pigs after FMD infection for the first time and provided interesting information that help understand the infection and pathogenesis mechanism of FMD. These information will eventually contribute to the prevention and control of FMD.

The epidemiology of autoimmune bullous diseases in Sudan between 2000 and 2016

Objectives

Autoimmune bullous diseases vary in their clinico-epidemiological features and burden across populations. Data about these diseases was lacking in Sudan. We aimed to describe the epidemiological profile and to estimate the burden of autoimmune bullous diseases in Sudan.

Methods

This was a retrospective cross-sectional study conducted at Khartoum Dermatological and Venereal Diseases Teaching Hospital. We used routinely collected health care data, and included all patients with an autoimmune bullous disease who presented to the hospital between 2001 and 2016.

Results

Out of the 4736 patients who were admitted to the hospital during the study period, 923 (19.5%) had an autoimmune bullous disease. The average rate of patients at the hospital was 57.7 per year representing 1.3 per 100,000 population per year. After exclusion of patients where the final diagnosis was missing, 585 were included in the further analysis. Pemphigus vulgaris was the most common disease (50.9%), followed by bullous pemphigoid (28.2%), linear IgA disease/chronic bullous disease of childhood (8.4%), and pemphigus foliaceous (8.2%). Pemphigoid gestationis and IgA pemphigus constituted 1.4% and 1.2% of the cohort, respectively. Paraneoplastic pemphigus, mucous membrane pemphigoid, lichen planus pemphigoidis, bullous systemic lupus erythematosus, and dermatitis herpetiformis were rare. None of the patients had epidermolysis bullosa acquisita.

Conclusions

The clinico-epidemiological characteristics vary among the types of autoimmune bullous diseases. Females were more predominant in most of them. Sudanese patients tended in general to present at a younger age than other populations. The pool of Sudanese patients with autoimmune bullous diseases is large which requires investigation for the local risk factors and presents a field for future trials.

Current status and prospects for the diagnosis of pemphigus vulgaris

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

Beyond the skin: disease parameters in pemphigus

Pemphigus represents a group of rare autoimmune bullous diseases that affect the skin and mucous membranes. This group has a chronic course leading to high morbidity and mortality. Because of the painful chronic-recurring blisters and/or erosions on skin and mucosa, pemphigus can impair quality of life (QOL). Therapeutic modalities, anxiety and depression can also have an additional negative impact in the QOL of the pemphigus patients. Since the nature and course of the pathology and the fact that pemphigus worsens the quality of life of affected patients, scoring systems to objectively evaluate the clinical activity of the disease and to correlate that with the QOL are needed. Nowadays the most used global scales to assess the clinical activity of pemphigus are the Autoimmune Bullous Skin Disorder Intensity Score (ABSIS), the Pemphigus Disease Area Index (PDAI) and the Pemphigus Visual Activity Scale (PVAS). To evaluate the patient's generic QOL the most used score is the Dermatology Life Quality Index (DLQI), but all the sponsered clinical trials in pemphigus are using ABQOL this rather than DLQI.

Pemphigus Vulgaris-Associated Anterior Scleritis: A Case Study

Ocular involvement in pemphigus vulgaris (PV) is relatively rare. The conjunctiva and eyelids are considered the most common affected sites in ocular pemphigus. Scleritis is rarely reported as a manifestation of PV. We present a case report of anterior scleritis as a manifestation of PV and its response to rituximab therapy.

IgA and FcαRI: Versatile Players in Homeostasis, Infection, and Autoimmunity

Mucosal surfaces constitute the frontiers of the body and are the biggest barriers of our body for the outside world. Immunoglobulin A (IgA) is the most abundant antibody class present at these sites. It passively contributes to mucosal homeostasis via immune exclusion maintaining a tight balance between tolerating commensals and providing protection against pathogens. Once pathogens have succeeded in invading the epithelial barriers, IgA has an active role in host-pathogen defense by activating myeloid cells through divers receptors, including its Fc receptor, FcαRI (CD89). To evade elimination, several pathogens secrete proteins that interfere with either IgA neutralization or FcαRI-mediated immune responses, emphasizing the importance of IgA-FcαRI interactions in preventing infection. Depending on the IgA form, either anti- or pro-inflammatory responses can be induced. Moreover, the presence of excessive IgA immune complexes can result in continuous FcαRI-mediated activation of myeloid cells, potentially leading to severe tissue damage. On the one hand, enhancing pathogen-specific mucosal and systemic IgA by vaccination may increase protective immunity against infectious diseases. On the other hand, interfering with the IgA-FcαRI axis by monovalent targeting or blocking FcαRI may resolve IgA-induced inflammation and tissue damage. This review describes the multifaceted role of FcαRI as immune regulator between anti- and pro-inflammatory responses of IgA, and addresses potential novel therapeutic strategies that target FcαRI in disease.

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Evaluation of desmoglein 1 and 3 autoantibodies in pemphigus vulgaris: correlation with disease severity

Background

Pemphigus is an autoimmune blistering disease of the skin and mucous membranes caused by autoantibodies against desmoglein 1 (Dsg1) and desmoglein 3 (Dsg3). Pemphigus vulgaris (PV) is the most common form of pemphigus. The aim of this study was to assess the correlation between the levels of anti-desmoglein 1 and 3 autoantibodies and the severity of PV disease.

Material and Methods

Nineteen newly diagnosed patients with pemphigus vulgaris were enrolled in this study. The titers of Dsg in subjects by using enzyme-linked immunosorbent assay (ELISA) were done at diagnosis time-point, 4th and 8th weeks after the initiation of treatment, and the correlation of antibodies with the oral and skin disease severity was evaluated.

Results

The severity of cutaneous lesions was significantly correlated with anti-Dsg1 titer in all visits and the severity of mucosal lesions was correlated with the titer of Dsg3 in the third visit (<0.001, 0.001, 0.016 and 0.015 P value, respectively).

Conclusions

Anti-Dsg-1 autoantibodies titers seem to be more useful in showing the extent of the disease and activity in pemphigus with mucocutaneous lesions.

Key words:Pemphigus vulgaris, Desmoglein (Dsg), Enzyme-linked immunosorbent assay (ELISA).

On the blistering of thermo-sensitive hydrogel: the volume phase transition and mechanical instability

This paper explores the physical mechanisms responsible for the appearance of small blisters on the surface of temperature sensitive hydrogels as they deswell rapidly during their volume phase transition. For this, we develop a numerical model that couples the processes of hydrogel deswelling and blister growth due to the existence of a thin quasi-impermeable layer on its surface. The model points out that blister inflation originates at defects point under the gel's surface, under the effect of the increasing osmotic pressure in the gel as it undergoes its phase transition. Due to their large deformation, these blisters often experience a mechanical instability that triggers a sudden increase in their growth rate at the expense of their closest neighbors. Using a simple computational model, we then show that blisters are able to communicate via internal pressure and that these interactions are mediated by two characteristic time scales related to solvent transport within and between adjacent blisters. Our study finally indicates that these mechanisms can be controlled by temperature and the gel's cross-link density to achieve diversity of blister patterns on the gel's surface. The proposed analysis provides predictions that agree well with experimental observations of NiPAm gels which deswell in various conditions.

Consensus on the treatment of autoimmune bullous dermatoses: pemphigus vulgaris and pemphigus foliaceus - Brazilian Society of Dermatology

Pemphigus are intraepidermal autoimmune bullous dermatoses that occur with lesions on the skin and / or mucous membranes. The most frequent types are pemphigus vulgaris and pemphigus foliaceus (classic and endemic). This consensus aims to present a complete and updated review of the treatment of these two more frequent forms of pemphigus, based on the literature and the personal experience of the authors. In moderate and severe cases of pemphigus vulgaris and foliaceus, systemic corticosteroid therapy (prednisone or prednisolone) is the treatment of choice. Adjuvant drugs, usually immunosuppressive drugs (azathioprine, mycophenolate mofetil, methotrexate, cyclophosphamide) may be prescribed as corticosteroid sparers in refractory cases or with contraindications to corticosteroids to minimize side effects. In severe and nonresponsive cases, corticosteroids in the form of intravenous pulse therapy, immunoglobulin and plasmapheresis / immunoadsorption can be administered. Immunobiological drugs, particularly rituximab, appear as a promising alternative. For milder cases, smaller doses of oral corticosteroid, dapsone and topical corticosteroids are options. At the end flowcharts are presented as suggestions for a therapeutic approach for patients with pemphigus vulgaris and pemphigus foliaceus.

Association Between Pemphigus and Neurologic Diseases

Importance

The association between pemphigus and neurologic diseases was not evaluated systematically in the past. In a recent uncontrolled cross-sectional study, Parkinson disease was found to be significantly associated with pemphigus; in the same study, epilepsy had a nonsignificant association with pemphigus. Several case reports have suggested that pemphigus coexists with multiple sclerosis and dementia.

Objective

To estimate the association between pemphigus and 4 neurologic conditions (dementia, epilepsy, Parkinson disease, and multiple sclerosis), using one of the largest cohorts of patients with pemphigus.

Design, Setting, and Participants

A retrospective population-based cross-sectional study was performed between January 1, 2004, and December 31, 2014, using the database of Clalit Health Services, the largest public health care organization in Israel, in the setting of general community clinics, primary care and referral centers, and ambulatory and hospitalized care. A total of 1985 patients with a new diagnosis of pemphigus and 9874 controls were included in the study.

Main Outcomes and Measures

The proportion of dementia, epilepsy, Parkinson disease, and multiple sclerosis was compared between patients diagnosed with pemphigus and age-, sex-, and ethnicity-matched control participants. Logistic regression was used to calculate odds ratios (ORs) for dementia, epilepsy, Parkinson disease, and multiple sclerosis. The association was examined after a sensitivity analysis that included only patients treated with long-term, pemphigus-specific medications (corticosteroids, immunosuppressants, or rituximab) and after adjustment for several confounding factors.

Results

When comparing the 1985 cases (1188 women and 797 men; mean [SD] age, 72.1 [18.5] years) with the 9874 controls (5912 women and 3962 men; mean [SD] age, 72.1 [18.5] years), dementia was seen in 622 cases (31.3%) vs 1856 controls (18.8%), with an OR of 1.97 (95% CI, 1.77-2.20). Epilepsy was present in 74 cases (3.7%) vs 210 controls (2.1%), with an OR of 1.78 (95% CI, 1.36-2.33). Parkinson disease was seen in 175 cases (8.8%) vs 437 controls (4.4%), with an OR of 2.09 (95% CI, 1.74-2.51). Multiple sclerosis was present in 2 cases (0.1%) vs 6 controls (0.01%), with an OR of 1.65 (95% CI, 0.34-8.22). Study findings were robust to sensitivity analysis that included patients receiving pemphigus-specific treatments. Estimates were not altered significantly after controlling for comorbidities and overuse of health care.

Conclusions and Relevance

An association was observed between pemphigus and specific neurologic diseases, including dementia, Parkinson disease, and epilepsy. Physicians treating patients with pemphigus should be aware of this possible association. Patients with pemphigus should be carefully assessed for comorbid neurologic disorders and receive appropriate treatment.

Coexistent Solid Malignancies in Pemphigus: A Population-Based Study

Importance

The association of pemphigus vulgaris and pemphigus foliaceus with comorbid malignancies is yet to be firmly established.

Objective

To estimate the association between pemphigus and a wide range of nonhematologic malignancies using one of the largest cohorts of patients with pemphigus to date.

Design, Setting, and Participants

For this cross-sectional study, we used the computerized database of Clalit Health Services, the largest public health care provider organization in Israel insuring 4.4 million individuals in the settings of general community clinics, primary care and referral centers, and ambulatory and hospitalized health care. The study included 1985 patients with pemphigus and 9874 control patients and was conducted from January 2004 to December 2014.

Main Outcomes and Measures

The prevalence of 17 different solid malignancies was compared between patients diagnosed with pemphigus and age-, sex-, and ethnicity-matched control patients; χ2 and t tests were used for univariate analysis, and a logistic regression model was used for multivariate analysis. The association was examined following a sensitivity analysis that included only cases treated with long-term pemphigus-specific medications (corticosteroids, immunosuppressants, or rituximab), and following the adjustment for several confounding factors.

Results

Overall, the total sample included 11 859 eligible patients, of whom 1985 were patients with pemphigus (mean [SD] age at presentation, 72.1 [18.5] years; 1188 women [59.8%]). In patients with pemphigus compared with control patients, there was a greater prevalence of esophageal cancers (0.4% vs 0.1%; odds ratio [OR], 2.9; 95% CI, 1.1-7.4) and laryngeal cancers (0.6% vs 0.3%; OR, 2.0; 95% CI, 1.0-4.1). No significant associations between pemphigus and other solid malignancies were observed. Estimates were not altered significantly after controlling for comorbidities, health care overutilization, immunosuppressive therapy, and other malignancy-specific risk factors (ie, smoking and alcohol abuse in laryngeal cancer, gastroesophageal reflux disease in esophageal cancer).

Conclusions and Relevance

Significant associations were observed between pemphigus and solid malignancies of the larynx and the esophagus. Physicians treating patients with pemphigus should be aware of these findings. Further observational studies are warranted to establish this association in other cohorts.

Ocular Manifestations and Management of Autoimmune Bullous Diseases

Autoimmune bullous diseases with ocular involvement consist of a group of systemic entities that are characterized by formation of autoantibodies against the proteins of the epithelial basement membrane zone of the conjunctiva. Mostly, the elderly are affected by these diseases. The characteristic patterns of mucocutaneous involvement and the specific tissue components targeted by these autoantibodies are differentiating features of these diseases. Ocular pemphigus vulgaris exhibits intraepithelial activity, whereas the autoimmune activity in linear immunoglobulin A disease, mucous membrane pemphigoid, and epidermolysis bullosa acquisita occurs at a subepithelial location. Given the increased risk for blindness with delays in diagnosis and management, early detection of ocular manifestations in these diseases is vital. The precise diagnosis of these autoimmune blistering diseases, which is essential for proper treatment, is based on clinical, histological, and immunological evaluation. Management usually includes anti-inflammatory and immunosuppressive medications. Inappropriate treatment results in high morbidity and even potential mortality.

IgA and FcαRI: Pathological Roles and Therapeutic Opportunities

Immunoglobulin A (IgA) is the most abundant antibody class present at mucosal surfaces. The production of IgA exceeds the production of all other antibodies combined, supporting its prominent role in host-pathogen defense. IgA closely interacts with the intestinal microbiota to enhance its diversity, and IgA has a passive protective role via immune exclusion. Additionally, inhibitory ITAMi signaling via the IgA Fc receptor (FcαRI; CD89) by monomeric IgA may play a role in maintaining homeostatic conditions. By contrast, IgA immune complexes (e.g., opsonized pathogens) potently activate immune cells via cross-linking FcαRI, thereby inducing pro-inflammatory responses resulting in elimination of pathogens. The importance of IgA in removal of pathogens is emphasized by the fact that several pathogens developed mechanisms to break down IgA or evade FcαRI-mediated activation of immune cells. Augmented or aberrant presence of IgA immune complexes can result in excessive neutrophil activation, potentially leading to severe tissue damage in multiple inflammatory, or autoimmune diseases. Influencing IgA or FcαRI-mediated functions therefore provides several therapeutic possibilities. On the one hand (passive) IgA vaccination strategies can be developed for protection against infections. Furthermore, IgA monoclonal antibodies that are directed against tumor antigens may be effective as cancer treatment. On the other hand, induction of ITAMi signaling via FcαRI may reduce allergy or inflammation, whereas blocking FcαRI with monoclonal antibodies, or peptides may resolve IgA-induced tissue damage. In this review both (patho)physiological roles as well as therapeutic possibilities of the IgA-FcαRI axis are addressed.

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.

New insights into immune cells cross-talk during IgG4-related disease

Immunoglobulin G4-related disease (IgG4-RD) is a newly acknowledged entity, characterized by an immune-mediated fibro-inflammatory process affecting virtually all organs, with infiltration of IgG4⁺ bearing plasma cells. Until today the pathogenesis of IgG4-RD remains unknown. Treatment with anti-CD20 monoclonal antibodies efficiently induced remission and attenuated the secretory phenotype of myofibroblasts responsible of uncontrolled collagen deposition. This supports the pathogenic role of the adaptive immunity, particularly B cell compartment and B cell/T cell interaction. Latest studies have also highlighted the importance of innate immune system that has been underestimated before and the key role of a specific T cell subset, T follicular helper cells that are involved in IgG4-class-switching and plasmablast differentiation. In this review, we aim to review the most recent knowledge of innate immunity, T and B cells involvement in IgG4-RD, and introduce tertiary lymphoid organs (TLO) as a potential marker of relapse in this condition.

Fogo selvagem: endemic pemphigus foliaceus

Fogo selvagem or endemic pemphigus foliaceus is an autoimmune acantholytic anti-cadherin bullous disease that primarily affects seborrheic areas, which might disseminate. Brazil has the world's largest number of patients, mainly in the Central-West region, but the disease has also been reported in other South American countries. It affects young people and adults who have been exposed to rural areas, with occurrence of familial cases. Anti-desmoglein-1 autoantibodies are directed against desmosomal structures, with loss of adhesion of the upper layers of the epidermis, causing superficial blisters. The etiology is multifactorial and includes genetic, immune, and environmental factors, highlighting hematophagous insect bites; drug-related factors are occasionally involved. Flaccid blisters readily rupture to yield erosive-crusty lesions that sometimes resemble seborrheic dermatitis, actinic keratosis, and chronic cutaneous lupus erythematosus. The clinical presentation varies from localized to disseminated lesions. Clinical suspicion should be confirmed with histopathological and immunofluorescence tests, among others. The progression is usually chronic, and therapy varies according to clinical presentation, but generally requires systemic corticosteroid therapy associated with adjuvant immunosuppressive treatment to decrease the adverse effects of corticosteroids. Once the disease is under control, many patients remain stable on low-dose medication, and a significant proportion achieve remission.

Granzyme B is elevated in autoimmune blistering diseases and cleaves key anchoring proteins of the dermal-epidermal junction

In healthy skin, epidermis and dermis are anchored together at the dermal-epidermal junction (DEJ), a specialized basement membrane pivotal for skin integrity and function. However, increased inflammation in the DEJ is associated with the disruption and separation of this junction and sub-epidermal blistering. Granzyme B (GzmB) is a serine protease secreted by immune cells. Dysregulated inflammation may lead to increased GzmB accumulation and proteolysis in the extracellular milieu. Although elevated GzmB is observed at the level of the DEJ in inflammatory and blistering skin conditions, the present study is the first to explore GzmB in the context of DEJ degradation in autoimmune sub-epidermal blistering. In the present study, GzmB induced separation of the DEJ in healthy human skin. Subsequently, α6/β4 integrin, collagen VII, and collagen XVII were identified as extracellular substrates for GzmB through western blot, and specific cleavage sites were identified by mass spectrometry. In human bullous pemphigoid, dermatitis herpetiformis, and epidermolysis bullosa acquisita, GzmB was elevated at the DEJ when compared to healthy samples, while α6/β4 integrin, collagen VII, and collagen XVII were reduced or absent in the area of blistering. In summary, our results suggest that regardless of the initial causation of sub-epidermal blistering, GzmB activity is a common final pathway that could be amenable to a single targeted treatment approach.

Evaluation of anti-desmoglein-1 and anti-desmoglein-3 autoantibody titers in pemphigus patients at the time of the initial diagnosis and after clinical remission

It has been suggested that anti-desmoglein autoantibody titers could be helpful in follow-up and therapeutic management of pemphigus patients. However, there is no consensus regarding the relationship between anti-desmoglein autoantibody titers and clinical activity of pemphigus.The aim of our study was to evaluate if clinical remission of pemphigus relates to the presence of anti-desmoglein autoantibodies.Thirty patients with pemphigus vulgaris and 7 patients with pemphigus foliaceous were included in the study. Assessment of autoantibody titers was carried out at the time of the initial diagnosis and after the clinical remission using an enzyme-linked immunosorbent assay-based assay.Our results indicate that pemphigus clinical remission did not necessarily imply a serological remission, and consequently it is necessary to establish if withdrawal of the immunosuppressive regimen in pemphigus should be based exclusively on the achievement of clinical remission or also on the serological findings.

Salivary Samples for the Diagnosis of Pemphigus vulgaris Using the BIOCHIP Approach: a Pilot Study

Pemphigus vulgaris (PV) is a rare autoimmune intraepithelial blistering skin disease characterized by the presence of circulating autoantibodies against desmoglein 3 (DSG3) and desmoglein 1 (DSG1), resulting in loss of the normal epithelial cell-to-cell adhesion, through a process called acantholysis. In recent years, a BIOCHIP-based indirect immunofluorescence technique for the determination of anti-DSG3 and anti-DSG1 autoantibodies has been described. Even though, the use of saliva anti-DSG3 and anti-DSG1 ELISA for the diagnosis of PV has been already reported, there are no studies concerning the utilization of saliva by the BIOCHIP approach. In the present pilot study, ELISA and BIOCHIP were performed, using salivary and serum samples from the same patients to investigate if the detection of anti-desmoglein autoantibodies in salivary samples by BIOCHIP could be used as a test for the diagnosis of PV. There was a strong correlation between ELISA and BIOCHIP results both for anti-DSG3 and anti-DSG1 serum autoantibodies. Autoantibodies to DSG3 were detected in 8 out of 8 salivary samples by ELISA and in 6 out of 8 salivary samples by the BIOCHIP approach. Autoantibodies to DSG1 were negative in all salivary samples using both ELISA and BIOCHIP. There were no positive results in the negative control group. In conclusion, the results of this pilot study indicate lack of correlation between serum and salivary results using both ELISA and BIOCHIP, indicating that saliva may not be the ideal substrate for the laboratory diagnosis of PV using these approaches.

The Prevalence of S. aureus Skin and Soft Tissue Infections in Patients with Pemphigus

Pemphigus vulgaris are autoimmune blistering diseases that may result in significant morbidity and death. Immunosuppressive therapy of pemphigus vulgaris would predispose the patients to infections. The aim of this study was to assess the prevalence of S. aureus infection and PVL gene in patients with pemphigus admitted to dermatology clinic. Materials and Methods. This descriptive study was conducted on 196 pemphigus vulgaris patients (119 males, 77 females) admitted to dermatology clinic between 2014 and 2015. In this study, the diagnosis of pemphigus vulgaris was made by histology, immunofluorescence pattern of perilesional skin, and indirect immunofluorescence testing of serum. Data were collected through a questionnaire. Results. 59.1% of pemphigus vulgaris patients had S. aureus infection. 49 out of 116 were methicillin-resistant. PVL gene was detected in 25 out of 116 S. aureus positive patients. Conclusion. This is the first report of S. aureus infection in pemphigus patients in Iran. More than forty percent of isolates were methicillin-resistant S. aureus. PVL gene carried by methicillin-resistant S. aureus was high in this study.

[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.

Bullous pemphigoid outcome is associated with CXCL10-induced matrix metalloproteinase 9 secretion from monocytes and neutrophils but not lymphocytes

BACKGROUND

The outcome of bullous pemphigoid (BP), the most frequent autoimmune skin-blistering disease, involves matrix metalloproteinase 9 (MMP-9), IL-17, and IL-23 release from infiltrated inflammatory cells. The chemokine CXCL10 has been associated with several autoimmune diseases, but its participation in BP pathophysiology still needs to be clarified.

OBJECTIVE

We sought to assess whether BP outcome was associated with different CXCL10 levels and to evaluate the contribution of CXCL10 to the described cytokine/protease inflammatory loop associated with disease outcome.

METHODS

Skin biopsy specimens (n = 16), serum (n = 114), blister fluid (n = 23), and primary inflammatory cells from patients with BP were used to investigate CXCL10 expression and function.

RESULTS

At baseline, both resident cells, such as keratinocytes and fibroblasts, and infiltrating immune cells expressed CXCL10 at lesional sites in skin of patients with BP. CXCL10 levels were higher in blister fluid (P < .0001) and serum (P < .005) from patients with BP than in serum from age- and sex-matched control subjects (n = 34). Furthermore, CXCL10 serum levels increased at day 60 only in patients who relapsed within the first year of treatment (n = 33, P < .005). Interestingly, CXCL10 expression could be upregulated by itself and IL-17 in inflammatory cells. Notably, neutrophils and monocytes from patients with BP, but not lymphocytes, responded to CXCL10 by increasing MMP-9 secretion through the activation of extracellular signal-regulated kinase 1/2, p38, phosphoinositide-3 kinase signaling pathways. Finally, CXCL10-increased MMP-9 secretion was inhibited by methylprednisolone and also by compound A, a novel nonsteroidal glucocorticoid receptor ligand.

CONCLUSION

We showed that increased levels of inflammatory biomarkers in patients with BP, such as CXCL10, favor neutrophil- and monocyte-associated MMP-9 release and disease relapse and opened new therapeutic horizons in patients with this autoimmune disease.

Immune recruitment or suppression by glycan engineering of endogenous and therapeutic antibodies

Human serum IgG contains multiple glycoforms which exhibit a range of binding properties to effector molecules such as cellular Fc receptors. Emerging knowledge of how the Fc glycans contribute to the antibody structure and effector functions has opened new avenues for the exploitation of defined antibody glycoforms in the treatment of diseases. Here, we review the structure and activity of antibody glycoforms and highlight developments in antibody glycoengineering by both the manipulation of the cellular glycosylation machinery and by chemoenzymatic synthesis. We discuss wide ranging applications of antibody glycoengineering in the treatment of cancer, autoimmunity and inflammation. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc.

Pathogenicity of IgG in patients with IgG4-related disease

OBJECTIVE

IgG4-related disease (IgG4-RD) is a systemic disease characterised by elevated serum IgG4 and IgG4-positive lymphoplasmacytic infiltration in the affected tissues. The pathogenic role of IgGs, including IgG4, in patients with IgG4-RD, however, is unknown.

DESIGN

We examined the pathogenic activity of circulating IgGs in patients with IgG4-RD by injecting their IgGs into neonatal male Balb/c mice. Binding of patient IgGs to pancreatic tissue was also analysed in an ex vivo mouse organ culture model and in tissue samples from patients with autoimmune pancreatitis (AIP).

RESULTS

Subcutaneous injection of patient IgG, but not control IgG, resulted in pancreatic and salivary gland injuries. Pancreatic injury was also induced by injecting patient IgG1 or IgG4, with more destructive changes induced by IgG1 than by IgG4. The potent pathogenic activity of patient IgG1 was significantly inhibited by simultaneous injection of patient IgG4. Binding of patient IgG, especially IgG1 and IgG4, to pancreatic tissue was confirmed in both the mouse model and AIP tissue samples.

CONCLUSIONS

IgG1 and IgG4 from patients with IgG4-RD have pathogenic activities through binding affected tissues in neonatal mice.

Autoimmunity against laminins

Laminins are ubiquitous constituents of the basement membranes with major architectural and functional role as supported by the fact that absence or mutations of laminins lead to either lethal or severely impairing phenotypes. Besides genetic defects, laminins are involved in a wide range of human diseases including cancer, infections, and inflammatory diseases, as well as autoimmune disorders. A growing body of evidence implicates several laminin chains as autoantigens in blistering skin diseases, collagenoses, vasculitis, or post-infectious autoimmunity. The current paper reviews the existing knowledge on autoimmunity against laminins referring to both experimental and clinical data, and on therapeutic implications of anti-laminin antibodies. Further investigation of relevant laminin epitopes in pathogenic autoimmunity would facilitate the development of appropriate diagnostic tools for thorough characterization of patients' antibody specificities and should decisively contribute to designing more specific therapeutic interventions.

Quality of Life Assessment in Korean Patients with Pemphigus

Background

Measuring the quality of life (QOL) is important in the evaluation of nonclinical aspects of diseases, for the discovery of functional and psychological limitations, and in choosing treatment in the initial phase of the disease. Pemphigus is a potentially fatal autoimmune bullous disease caused by autoantibodies against desmogleins (cadherin family proteins in desmosomes). Thus far, there has been no published study on QOL in Korean patients with pemphigus.

Objective

To study the impact of pemphigus on the QOL in a large number of Korean patients.

Methods

Sixty-six patients enrolled at the Gangnam Severance Hospital from March 2012 to March 2013 were assessed for QOL by using the Dermatology Life Quality Index (DLQI), and for anxiety and depression by using the General Health Questionnaire (GHQ). Spearman's rank-order correlation, t-test, and ANOVA were used to identify the relations between the DLQI score and other clinical variables.

Results

Pemphigus vulgaris and pemphigus foliaceus significantly reduced the QOL of patients. The average DLQI score for all patients was 10.18. The mean DLQI score was 13.45 in patients in the active state and 5.15 in the patients in the remission state. The DLQI score highly correlated with disease severity, titer of anti-desmoglein 1 in enzyme-linked immunosorbent assay, and the corticosteroid dose. However, the QOL was not affected by sex, age, subtype of pemphigus, duration of disease, or comorbidities. Forty-two percent of the patients showed a positive result in the GHQ, reflecting probable minor psychiatric nonpsychotic conditions, and the GHQ score positively correlated to the DLQI score.

Conclusion

Pemphigus significantly impairs the QOL of patients. The QOL of Korean pemphigus patients significantly correlates with clinical severity. Therefore, considerable attention should be paid to the patients' QOL and psychological states as well as clinical status.

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.

Prevalence of pemphigus and pemphigoid autoantibodies in the general population

BACKGROUND

Mucocutaneous blistering is characteristic of autoimmune bullous dermatoses (AIBD). Blisters are caused by autoantibodies directed against structural components of the skin. Hence, detection of specific autoantibodies has become a hallmark for AIBD diagnosis. Studies on prevalence of AIBD autoantibodies in healthy individuals yielded contradictory results.

METHODS

To clarify this, samples from 7063 blood donors were tested for presence of anti-BP180-NC16A, anti-BP230 and anti-Dsg1/3 IgG by indirect immunofluorescence (IF) microscopy using a biochip.

RESULTS

Cumulative prevalence of these autoantibodies was 0.9 % (CI: 0.7-1.1 %), with anti-BP180-NC16A IgG being most prevalent. Validation of IF findings using ELISA confirmed presence of autoantibodies in 7/15 (anti-Dsg1), 6/7 (anti-Dsg3), 35/37 (anti-BP180-NC16A) and 2/3 (anti-BP230) cases. Moreover, in 16 samples, anti-BP180-NC16A autoantibody concentrations exceeded the cut-off for the diagnosis of bullous pemphigoid. Interestingly, these anti-BP180-NC16A autoantibodies from healthy individuals formed immune complexes with recombinant antigen and dose-dependently activated neutrophils in vitro. However, fine-epitope mapping within NC16A showed a different binding pattern of anti-BP180-NC16A autoantibodies from healthy individuals compared to bullous pemphigoid patients, while IgG subclasses were identical.

CONCLUSIONS

Collectively, we here report a low prevalence of AIBD autoantibodies in a large cohort of healthy individuals. Furthermore, functional analysis shows differences between autoantibodies from healthy donors and AIBD patients.

Burden of disease during quiescent periods in patients with pemphigus

BACKGROUND

Studies conducted using different tools have invariably observed that physical and mental components of health status are seriously compromised in patients with pemphigus. An improvement in quality of life (QoL) has been commonly observed over the treatment period.

OBJECTIVES

The aim of the study is to verify whether the patients' wellbeing is affected by pemphigus also in absence of cutaneous and mucosal lesions.

MATERIALS AND METHODS

The clinical records of 203 patients were analysed. A total of 47 patients were without bullae/erosions and reported a score = 0 for both the Patient Global Assessment and the Ikeda index. In order to assess the QoL we used the Skindex-17 and the 12-item General Health Questionnaire (GHQ-12).

RESULTS

Patients without bullae/erosions had a better QoL when compared with patients with active lesions. This difference, with a reduction of approximately 30% of the Skindex-17 scores in the patients without lesions, was statistically significant, for both the symptoms and the psychosocial scales. The proportion of patients at risk of anxiety/depression (GHQ-positive cases) was 44% lower in patients without lesions compared with patients with lesions. In a multiple linear regression model the presence of bullae/erosions negatively influences QoL with an average increase of Skindex-17 symptoms and psychosocial scale scores of 11·7 and 10·6 points, respectively. Female patients had a statistically significantly worse QoL than males on the symptoms but not on the psychosocial Skindex-17 scales.

CONCLUSIONS

While patients without lesions reported a better QoL than patients with bullae/erosions, their Skindex-17 scores remained elevated. Dermatologists should be aware that a clearing of the skin manifestations does not mean 'perfect health' for the patient.

A case of lichen planus pemphigoides with autoantibodies to the NC16a and C-terminal domains of BP180 and to desmoglein-1

Lichen planus pemphigoides (LPP) is a rare autoimmune blistering disease that occurs in association with lichen planus (LP). This report describes a 59-year-old Japanese female patient with LPP. The patient first showed LP lesions on her hands, and subsequently developed bullae on her extremities and erosions of the oral mucosa. The patient's serum was positive for IgG autoantibodies against the BP180 NC16a domain, the BP180 C-terminal domain and desmoglein-1. However, a serum sampled one and a half years before the diagnosis of LPP was negative for autoantibodies against BP180 NC16a and BP180 C-terminal domains. These findings strongly suggest that the damage to the basal cells in the LP lesions exposed a sequestered antigen or formed neoantigens, leading to the production of pathogenic autoantibodies for LPP. Most of the previous cases of LPP have produced autoantibodies to the NC16a domain of BP180. This is the first case in which autoantibodies to the C-terminal domain of BP180 were detected. The oral mucosal symptoms in this case may have been caused by autoantibodies to the BP180 C-terminal domain.

IgG4 antibodies in autoimmune polyglandular disease and IgG4-related endocrinopathies: pathophysiology and clinical characteristics

PURPOSE OF REVIEW

This review discusses the IgG4-related disease spectrum (IgG4-RD), the autoimmune polyglandular syndromes (APS), the association of IgG4 with APS, and possible pathobiology.

RECENT FINDINGS

IgG4-RD is a multiorgan autoimmune disorder characterized by fibrous inflammation, IgG4-positive plasma cell infiltration in affected tissues, and elevated serum concentrations of IgG4. IgG4-RD can affect any organ and has a heterogeneous presentation. Consensus criteria for diagnosis in specific organs have been established. The recognition and diagnosis of IgG4-RD are crucial because the disease responds favorably to immunosuppression (e.g., glucocorticoids, rituximab). The precise mechanisms leading to disease are unknown, but IgG4 antibodies may undergo a half antibody exchange, which renders them incapable of activating the complement pathway.

SUMMARY

Despite significant advances in disease recognition and treatment strategies, the disorder remains poorly understood. The precise role of IgG4, whether it is protective or pathogenic, is still being debated.

Immobilized immune complexes induce neutrophil extracellular trap release by human neutrophil granulocytes via FcγRIIIB and Mac-1

Canonical neutrophil antimicrobial effector mechanisms, such as degranulation, production of reactive oxygen species, and release of neutrophil extracellular traps (NETs), can result in severe pathology. Activation of neutrophils through immune complexes (ICs) plays a central role in the pathogenesis of many autoimmune inflammatory diseases. In this study, we report that immobilized ICs (iICs), which are hallmarks of several autoimmune diseases, induce the release of NETs from primary human neutrophils. The iIC-induced NET formation was found to require production of reactive oxygen species by NADPH oxidase and myeloperoxidase and to be mediated by FcγRIIIb. Blocking of the β2 integrin macrophage-1 Ag but not lymphocyte function-associated Ag-1 abolished iIC-induced NET formation. This suggests that FcγRIIIb signals in association with macrophage-1 Ag. As intracellular signaling pathways involved in iIC-induced NET formation we identified the tyrosine kinase Src/Syk pathway, which downstream regulates the PI3K/Akt, p38 MAPK, and ERK1/2 pathways. To our knowledge, the present study shows for the first time that iICs induce NET formation. Thus, we conclude that NETs contribute to pathology in autoimmune inflammatory disorders associated with surface-bound ICs.

The use of biochip immunofluorescence microscopy for the diagnosis of Pemphigus vulgaris

Pemphigus vulgaris is an autoimmune intraepithelial blistering skin disease characterized by the presence of circulating autoantibodies directed against surfaces of keratinocytes. Diagnosis is generally based on clinical features, histology, direct and indirect immunofluorescence and ELISA. This study describes a new BIOCHIP mosaic-based indirect immunofluorescence technique based on recombinant antigenic substrates and transfected cells. We investigated the diagnostic use of BIOCHIP for the serological diagnosis of Pemphigus vulgaris. Autoantibodies against desmoglein 3 were detected in 97.62% of patients (41/42) with P. vulgaris. There were no positive results in the negative control group. Our study revealed that BIOCHIP has high sensitivity and specificity comparable to that of the ELISA assays. Therefore the BIOCHIP technique seems to be an appropriate method for the diagnosis of P. vulgaris as it has been shown to be a simple, standardized and readily available novel tool, which could facilitate the diagnosis of this autoimmune bullous disease. We suggest that it could be used as an initial screening test to identify patients with P. vulgaris before using the ELISA approach.

Review: dermatitis herpetiformis

Dermatitis herpetiformis (DH) or Duhring-Brocq disease is a chronic bullous disease characterized by intense itching and burning sensation in the erythematous papules and urticarial plaques, grouped vesicles with centrifuge growth, and tense blisters. There is an association with the genotypes HLA DR3, HLA DQw2, found in 80-90% of cases. It is an IgA-mediated cutaneous disease, with immunoglobulin A deposits appearing in a granular pattern at the top of the dermal papilla in the sublamina densa area of the basement membrane, which is present both in affected skin and healthy skin. The same protein IgA1 with J chain is found in the small intestinal mucosa in patients with adult celiac disease, suggesting a strong association with DH. Specific antibodies such as antiendomysium, antireticulina, antigliadin and, recently identified, the epidermal and tissue transglutaminase subtypes, as well as increased zonulin production, are common to both conditions, along with gluten-sensitive enteropathy and DH. Autoimmune diseases present higher levels of prevalence, such as thyroid (5-11%), pernicious anemia (1-3%), type 1 diabetes (1-2%) and collagen tissue disease. The chosen treatment is dapsone and a gluten-free diet.

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.