The burden of neurological comorbidities in six autoimmune bullous diseases: a population-based study

Epidemiological Insights into Autoimmune Bullous Diseases in China: A Comprehensive Analysis

OBJECTIVE

This study aims to conduct an extensive analysis of autoimmune bullous diseases, particularly pemphigus vulgaris and bullous pemphigoid, in Shanghai, China, from 2016 to 2023. It seeks to understand the demographic profiles, comorbidities, mortality rates, risk factors, and socioeconomic impacts associated with autoimmune bullous disease.

METHODS

A cross-sectional study design was employed, enrolling 1,072 patients. Diagnostic measures included clinical manifestations, histopathology, direct immunofluorescence, and serologic tests. The study also involved a detailed socioeconomic analysis and evaluation of occupational risks.

RESULTS

The findings highlight a significant occupational risk in industries requiring enhanced safety measures, with a notable prevalence of autoimmune bullous disease among workers in these sectors. A considerable portion of the patients were from low-income backgrounds with limited literacy, indicating the economic burden of autoimmune bullous disease. A key discovery of the study is the potential pathological link between autoimmune bullous disease and interstitial lung disease.

CONCLUSION

This research, one of the first comprehensive studies on autoimmune bullous disease in China, underscores the need for targeted healthcare strategies and further investigation into autoimmune bullous disease, particularly its relationship with interstitial lung disease.

Reactivity against the BP180 ectodomain in patients with bullous pemphigoid, mucous membrane pemphigoid, multiple sclerosis and Parkinson disease

The 16th non-collagenous domain (NC16A) of BP180 is the main antigenic target of autoantibodies in bullous pemphigoid (BP) and mucous membrane pemphigoid (MMP). Commercially available assays detect serum autoantibodies against NC16A in the majority of BP (80%-90%) and in approximately 50% of MMP patients. However, a standardized test system for detecting antibodies against other regions of BP180 is still lacking. Moreover, anti-BP180 autoantibodies have been found in neurological conditions such as multiple sclerosis and Parkinson disease. This study aimed at identifying primary epitopes recognized by BP autoantibodies on the BP180 ectodomain. Serum samples of 51 BP and 30 MMP patients both without anti-NC16A reactivity were included along with 44 multiple sclerosis and 75 Parkinson disease sera. Four overlapping His-tagged proteins covering the entire BP180 ectodomain (BP180(ec)1-4) were cloned, expressed, purified and tested for reactivity by immunoblot. IgG antibodies to BP180(ec)3 were detected in 98% of BP, 77% of MMP and 2% of normal human sera. Only weak reactivity was detected for neurological diseases against BP180(ec)1, BP180(ec)2 and BP180(ec)4, in 3%, 11% and 7% of tested multiple sclerosis sera, respectively. 8% of Parkinson disease sera reacted with BP180(ec)2 and 9% with BP180(ec)4. In conclusion, this study successfully identified epitopes recognized by BP autoantibodies outside the NC16A domain in pemphigoid diseases. These findings contribute to a better understanding of the immune response in BP and MMP with potential implications for a future diagnostic assay for NC16A-negative pemphigoid patients.

Hospitalization and mortality in Asian autoimmune bullous dermatosis patients: A 17-year retrospective study

Limited data exist on the factors associated with hospitalization and mortality in Asian inpatients with autoimmune bullous dermatoses (AIBDs). This study aimed to elucidate the risk factors affecting hospitalization and mortality rates in Asian patients with AIBDs. A retrospective analysis of patients with AIBDs treated at Siriraj Hospital during a 17-year period was performed using the International Classification of Diseases 10th revision codes. The characteristics of inpatients and outpatients were compared, and mortality rates and associated factors were identified. The study included 360 AIBD patients (180 inpatients, 180 outpatients). Inpatients were significantly younger than outpatients. The identified risk factors for hospitalization were malignancy (odds ratio [OR] 2.83, 95% confidence interval [CI] 1.13-8.04; p = 0.034), moderate to severe disease (OR 2.52, 95% CI 1.49-4.34; p < 0.001), systemic corticosteroid use ≥15 mg/day (OR 2.27, 95% CI 1.21-4.41; p = 0.013) and oral cyclophosphamide treatment (OR 9.88, 95% CI 3.82-33.7; p < 0.001). Kaplan-Meier analysis revealed mortality rates of 26%, 36% and 39% for inpatients with pemphigus at 1, 3 and 5 years, respectively. For inpatients with pemphigoid, the corresponding rates were 28%, 38% and 47%. Infections, particularly pneumonia, were the predominant cause of death in both conditions. This study confirmed that both Asian ethnicity and healthcare disparities may be correlated with adverse outcomes in patients with AIBDs. Pemphigus mortality rates were substantially greater in Asian patients than in Caucasian patients. Continuous monitoring of factors contributing to hospitalization and mortality is imperative to improve treatment outcomes.

Accurate diagnosis of bullous pemphigoid requires multiple health care visits

Introduction

Accurate use of diagnostic codes is crucial for epidemiological and genetic research based on electronic health record (EHR) data.

Methods

This retrospective study validated the International Classification of Diseases (ICD)-10 diagnostic code L12.0 for bullous pemphigoid (BP) using EHR data from two Finnish university hospitals. We found 1225 subjects with at least one EHR entry of L12.0 between 2009 and 2019. BP diagnosis was based on clinical findings characteristic of BP and positive findings on direct immunofluorescence (DIF), BP180-NC16A enzyme-linked immunosorbent assay (ELISA) or indirect immunofluorescence (IIF) assay.

Results

True BP was found in 901 patients; the positive predictive value (PPV) for L12.0 was 73.6% (95% CI 71.0-76.0). L12.0 was more accurately registered in dermatology units than any specialized health care units (p<0.001). Including patients with multiple L12.0 registrations (≥3), increased the accuracy of the L12.0 code in both dermatology units and other settings.

Discussion

One diagnostic code of L12.0 is not enough to recognize BP in a large epidemiological data set; including only L12.0 registered in dermatology units and excluding cases with <3 L12.0 record entries markedly increases the PPV of BP diagnosis.

Autoimmune blistering diseases: promising agents in clinical trials

INTRODUCTION

Treatment options for autoimmune bullous diseases (AIBD) are currently limited to corticosteroids and traditional immunomodulants and immunosuppressants that are associated with unfavorable adverse effect profiles. The most frequent AIBDs, i.e. bullous pemphigoid, pemphigus vulgaris, and mucous membrane pemphigoid, impose a high disease burden onto affected patients and can be detrimental due to infections, exsiccosis, and impaired food intake. Significant progress has been made in elucidating disease mechanisms and key mediators by in vivo and in vitro models, thus identifying a multifaceted range of possible drug targets. However, except for rituximab for pemphigus vulgaris, no new drugs have been approved for the treatment of AIBDs in the last decades.

AREAS COVERED

This review covers new drug developments and includes ongoing or completed phase 2 and 3 clinical trials. Studies were identified by querying the registries of ClinicalTrials.gov and Cochrane Library.

EXPERT OPINION

Promising results were shown for a variety of new agents including nomacopan, efgartigimod, omalizumab, dupilumab, as well as chimeric autoantibody receptor T cells. Clinical translation in the field of AIBDs is highly active, and we anticipate significant advances in the treatment landscape.

Comorbidity in bullous pemphigoid: up-date and clinical implications

Bullous pemphigoid is the most common autoimmune blistering disease in industrialized countries and particularly affects the elderly. In this patient population, comorbid diseases are frequent and may complicate management and treatment of bullous pemphigoid. A better understanding why distinct diseases are more frequent in bullous pemphigoid patients may lead to new pathophysiological insights and - as a consequence - result in better patient care. The association of bullous pemphigoid with neurological and psychiatric diseases is well known and confirmed by several case-control studies. Association with further diseases such as malignancy and metabolic diseases are still discussed controversially. In recent years new relationships between bullous pemphigoid and autoimmune as well as inflammatory skin diseases have been reported. This review provides a systematic overview on studies addressing comorbidity in bullous pemphigoid patients. Increasing the awareness of both, common and rare comorbid diseases, may enable clinicians to optimize patient support and individualized treatment of bullous pemphigoid.

A systematic review on efficacy, safety and treatment durability of intravenous immunoglobulin in autoimmune bullous dermatoses: Special focus on indication and combination therapy

Autoimmune bullous diseases (AIBDs) are a group of rare blistering dermatoses of the mucous membrane and/or skin. The efficacy, safety and treatment durability of intravenous immunoglobulin (IVIg) as an alternative treatment should be explored to systematically review the available literature regarding treatment outcomes with IVIg in AIBD patients. The predefined search strategy was incorporated into the following database, MEDLINE/PubMed, Embase, Scopus and Web of Science on 18 July 2022. Sixty studies were enrolled using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The use of IVIg alone or combined with rituximab was reported in 500 patients with pemphigus, 82 patients with bullous pemphigoid, 146 patients with mucous membranes pemphigoid and 19 patients with epidermolysis bullosa acquisita. Disease remission with IVIg therapy and RTX + IVIg combination therapy were recorded as 82.8% and 86.7% in pemphigus, 88.0% and 100% in bullous pemphigoid and 91.3% and 75.0% in mucous membrane pemphigoid, respectively. In epidermolysis bullosa acquisita, treatment with IVIg led to 78.6% disease remission; no data were available regarding the treatment with RTX + IVIg in this group of patients. Among all the included patients, 37.5% experienced at least one IVIg-related side effect; the most common ones were headaches, fever/chills and nausea/vomiting. The use of IVIg with or without rituximab had a favourable clinical response in patients with AIBDs. IVIg has no major influence on the normal immune system, which makes its utilization for patients with AIBDs reasonable.

[Immunopathogenesis of mucous membrane pemphigoid]

A detailed understanding of the immunopathogenesis of mucous membrane pemphigoid (MMP) is of particular importance in view of the mostly difficult diagnostics and treatment of this blistering autoimmune dermatosis. A still unknown disturbance of the body's own immune tolerance leads to the formation of autoreactive cells. As the disease progresses these produce autoantibodies which are directed against structural proteins in the basement membrane zone (BMZ). After they bind to the target antigen, complement factors are deposited along the BMZ and inflammatory cells invade the underlying tissue and produce the characteristic subepithelial blistering. This inflammatory response is associated with fibrosis and scarring in many affected tissues. Most phases of MMP pathogenesis are poorly understood; however, the last few years have shed more light on this processes. These advances are mostly the result of animal and cell culture models. Typical clinical and immunopathological characteristics of MMP, such as oral, conjunctival and skin lesions, are reflected, for example, in an antibody transfer-induced mouse model for anti-laminin 332 MMP in adult mice. Dapsone, as first-line treatment for MMP patients, significantly reduced the severity of these symptoms, and fibrosis in the skin and mucous membranes was also found histologically, which makes the model well-suited for testing new therapeutic approaches for MMP patients and might be of help for further elucidation of the immunopathogenesis of MMP.

The association between Parkinson's disease and autoimmune diseases: A systematic review and meta-analysis

Parkinson's disease (PD) is a neurodegenerative disorder that frequently occurs in the older population. Previous epidemiological studies have suggested an association between PD and autoimmune diseases (AIDs). However, some studies have shown conflicting results. This study aimed to summarize existing epidemiological studies on the association between PD with AIDs and to conduct a meta-analysis of combinable results. Four electronic databases (PubMed, Embase, Web of Science Core Collection, and MEDLINE) were searched from each database's inception date until December 12, 2022. All studies that explored the relationship between PD and AIDs were included for quantitative analysis and qualitative review. The pooled relative risk with 95% confidence intervals (CIs) was calculated using a random or fixed effects model. A total of 46 observational studies involving 873,643 patients and 13,402,821 controls were included; ultimately, 38 studies were included in the meta-analysis. The risk of PD combined with AIDs was significantly higher (odds ratio [OR]=1.55, 95% CI: 1.33-1.81), and subgroup analysis found no significant differences in risk by study type, gender, age, and race. Regarding the AID types, the results showed an increased risk of PD combined with bullous pemphigoid (OR=2.67, 95% CI: 2.15-3.31), inflammatory bowel disease (OR=1.30, 95% CI: 1.18-1.45), Crohn's disease (OR=1.30, 95% CI: 1.20-1.42), ulcerative colitis (OR=1.31, 95% CI: 1.14-1.50), Sjögren's syndrome (OR=1.61, 95% CI: 1.24-2.09), and Graves' disease (OR=1.45, 95% CI: 1.24-1.70) than controls. However, there appeared to be no significant association between PD and systemic lupus erythematosus (OR=0.82, 95% CI: 0.66-1.03), multiple sclerosis (OR=2.02, 95% CI: 0.87-4.70), rheumatoid arthritis (OR=0.79, 95% CI: 0.61-1.03), or celiac disease (OR=1.16, 95% CI: 0.79-1.69). This study supports the existence of a strong link between AIDs and PD. When PD and AIDs are identified, clinicians need to be aware of the possibility of coexistence. However, there are some limitations of this study, such as the apparent heterogeneity of some of the results and the fact that most of the included study types were retrospective. Therefore, future larger prospective cohort studies are needed to further explore the interaction between PD and AIDs.

Systematic review registration

INPLASY, identifier INPLASY202280088.

Investigation of comorbid autoimmune diseases in women with autoimmune bullous diseases: An interplay of autoimmunity and practical implications

Autoimmune bullous diseases are a group of skin disorders resulting from an autoimmune reaction against intercellular adhesion molecules or components of the basement membrane of skin and mucosa. Autoimmune disorders often occur in patients with a history of another autoimmune disease and most autoimmune diseases have a striking female predominance. In this review, we aim to analyze the different associations of autoimmune bullous diseases with other autoimmune diseases and highlight the distinctiveness of the female gender in these associations.

Type XVII collagen: Relevance of distinct epitopes, complement-independent effects, and association with neurological disorders in pemphigoid disorders

Pemphigoid diseases (PD) are autoimmune skin blistering diseases characterized by autoantibodies directed against proteins of the cutaneous basement membrane zone (BMZ). One of the major antigens is type XVII collagen (BP180), a transmembrane glycoprotein, which is targeted in four PDs: bullous pemphigoid, mucous membrane pemphigoid, linear IgA dermatosis, and pemphigoid gestationis. To date, different epitopes on BP180 have been described to be recognized by PD disease patients’ autoantibodies. Different BP180 epitopes were associated with distinct clinical phenotypes while the underlying mechanisms are not yet fully understood. So far, the main effects of anti-BP180 reactivity are mediated by Fcγ-receptors on immune cells. More precisely, the autoantibody–antigen interaction leads to activation of complement at the BMZ and infiltration of immune cells into the upper dermis and, by the release of specific enzymes and reactive oxygen species, to the degradation of BP180 and other BMZ components, finally manifesting as blisters and erosions. On the other hand, inflammatory responses independent of Fcγ-receptors have also been reported, including the release of proinflammatory cytokines and internalization and depletion of BP180. Autoantibodies against BP180 can also be found in patients with neurological diseases. The assumption that the clinical expression of PD depends on epitope specificity in addition to target antigens, autoantibody isotypes, and antibody glycosylation is supported by the observation that epitopes of PD patients differ from those of PD patients. The aim of the present review is to describe the fine specificities of anti-BP180 autoantibodies in different PDs and highlight the associated clinical differences. Furthermore, the direct effects after binding of the autoantibodies to their target are summarized.

Comorbidities in Patients with Autoimmune Bullous Disorders: Hospital-Based Registry Study

The incidence of autoimmune bullous disorders has increased over the years, especially in elderly patients with multiple comorbidities, which has stimulated research into their association with other diseases. We performed a retrospective observational study used the Minimum Basic Data Set of hospital discharges to review records of patients admitted to Spanish public hospitals between 2016 and 2019 with a diagnosis of any autoimmune bullous disorder. The objectives were to describe the comorbidity profile and the clinical-epidemiological characteristics of patients with pemphigus and pemphigoid, and analyze the evolution of the incidence of these diseases. The study included 1950 patients with pemphigus and 5424 patients with pemphigoid. Incidence increased from 2016 to 2019. The main comorbidities were hypertension (40.19%) and diabetes mellitus (28.57%). Compared to patients with pemphigoid, those with pemphigus had a higher prevalence of neoplasms, osteoporosis, solid metastases and malignant lymphoma, while the prevalence of hypertension, kidney disease, diabetes, heart failure, dementia, chronic obstructive pulmonary disease and Parkinson’s disease was higher in the pemphigoid group (p < 0.05). Therefore, since autoimmune bullous disorders are associated with diverse comorbidities and their incidence has risen in recent years, the establishment of strategies to prevent the main comorbidities in these patients is justified.

Association between sodium-glucose co-transporter 2 inhibitors and risk of bullous pemphigoid in patients with type 2 diabetes: A nationwide population-based cohort study

BACKGROUND

Certain anti-diabetic agents have been linked to the development of bullous pemphigoid (BP). However, the relationship between BP and sodium-glucose co-transporter 2 inhibitors (SGLT2is) remains inconclusive.

OBJECTIVE

To investigate the association between SGLT2i usage and BP.

METHODS

Participants were recruited from the Taiwan National Health Insurance Database between 2007 and 2018. A total of 149,060 patients with diabetes receiving SGLT2i were matched 1:2 with diabetic patients without SGLT2i usage. Factors such as age, sex, duration of diabetes condition, DPP4i usage, insulin usage, and selected comorbidities were included in the multivariate analysis.

RESULTS

Compared with the control, the 2-year-cumulative incidence was significantly low in patients using SGLT2i after adjustment for competing mortality. Patients with diabetes receiving SGLT2i had a low risk (adjusted hazard ratio [HR] 0·56, 95% confidence interval [CI], 0·33-0·96) for BP after adjustment for potential confounders. Age (HR, 1·06), renal disease (HR, 1·79), cerebrovascular disease (HR, 3·23), epilepsy (HR, 3·07), DPP4i users (HR: 2·55), and insulin users (HR: 2·56) were significant risk factors for BP.

CONCLUSIONS

The risk of BP did not increase in patients receiving SGLT2i. Thus, SGLT2i could be a safe choice for patients with diabetes having additional risk factors or a history of BP.

Potential effects of shift work on skin autoimmune diseases

Shift work is associated with systemic chronic inflammation, impaired host and tumor defense and dysregulated immune responses to harmless antigens such as allergens or auto-antigens. Thus, shift workers are at higher risk to develop a systemic autoimmune disease and circadian disruption with sleep impairment seem to be the key underlying mechanisms. Presumably, disturbances of the sleep-wake cycle also drive skin-specific autoimmune diseases, but epidemiological and experimental evidence so far is scarce. This review summarizes the effects of shift work, circadian misalignment, poor sleep, and the effect of potential hormonal mediators such as stress mediators or melatonin on skin barrier functions and on innate and adaptive skin immunity. Human studies as well as animal models were considered. We will also address advantages and potential pitfalls in animal models of shift work, and possible confounders that could drive skin autoimmune diseases in shift workers such as adverse lifestyle habits and psychosocial influences. Finally, we will outline feasible countermeasures that may reduce the risk of systemic and skin autoimmunity in shift workers, as well as treatment options and highlight outstanding questions that should be addressed in future studies.

The Relationship Between Alzheimer's Disease and Skin Diseases: A Review

Alzheimer's disease is the most common type of dementia placing a heavy burden on the healthcare system worldwide. Skin diseases are also one of the most common health problems. Several skin diseases are associated with Alzheimer's disease through different mechanisms. This review summarizes the relationship between Alzheimer's disease and several types of skin diseases, including bullous pemphigoid, hidradenitis suppurativa, psoriasis, skin cancer, and cutaneous amyloidosis, and provides suggestions based on these associations. Neurologists, dermatologists, and general practitioners should be aware of the relationship between Alzheimer's disease and skin diseases. Dermatology/neurology consultation or referral is necessary when needed.