Coexistence of bullous pemphigoid with neuropsychiatric comorbidities is associated with anti-BP230 seropositivity

Unraveling the Link Between Bullous Pemphigoid and Neurological Disease: A Single-center Study of 257 Patients

BACKGROUND

Multiple studies have corroborated the association between bullous pemphigoid (BP) and neurological diseases; patients with both diseases (BP-N) have been associated with a worse prognosis and specific clinical and immunological characteristics, defining a different subtype of BP.

OBJECTIVES

We aimed to determine the prevalence and characteristics of BP cases with neurological comorbidities (BP-N) and review the related published literature.

METHODS

We conducted a retrospective, observational study of BP cases treated at a referral center for autoimmune blistering diseases from January 2000 through June 2020.

RESULTS

We collected epidemiological, clinical, histopathological, progression and laboratory data from a total of 257 cases, 102 of which were BP-N. Senile dementia, Alzheimer's disease and vascular dementia were the most frequent neurological comorbidities. Compared with cases without neurological comorbidities, BP-N cases had more intense tissue eosinophilia (p=0.012) and higher concentrations of circulating eosinophils (p=0.000), and anti-BP180 IgG antibodies (p=0.007). At the time of data collection, 78 BP-N were deceased.

CONCLUSIONS

Our case series highlighted the relevance of neurological comorbidities in BP patients; although the pathogenesis is still to be elucidated, the neuroinflammation present in neurodegenerative diseases could explain the neurocutaneous link and the chronological relationship between these entities.

Clinical characteristics of bullous pemphigoid patients of different ages and the possible mechanism

Bullous pemphigoid (BP) is an acquired autoimmune bullous disease that often occurs in elderly patients. Some BP patients with early age of disease onset were observed to have difficulty in receiving applicable disease control. It remains challenging for clinicians to choose the appropriate treatment for these patients. This study aimed to analyze the differences between patients of different ages at disease onset and further explore the possible mechanism of these differences between patients of different ages. A total of 215 BP patients seen at the dermatology department of Peking Union Medical College Hospital between January 2009 and September 2020 were included. The patients were allocated to five groups according to the age at disease onset. Clinical data were collected through medical records and telephone follow-up interviews. Analyses of anti-BP180 antibody subclasses, anti-BP230 antibodies, complement fixation, serum cytokine levels, and single nucleotide polymorphisms (SNPs) were conducted. Nearly 52% of patients under 60 were misdiagnosed on their first visit, often presenting with oral mucosal involvement. The anti-BP180 immunoglobulin (Ig) E titers and C3 deposition increased in patients under 60 (p = 0.044 and p = 0.014, respectively), while the anti-BP230 IgG titers decreased (p = 0.043). The hospitalization rate of patients under 50 was significantly higher than that of patients aged 80 and older (p < 0.001). The patients under 60 had a significantly higher serum concentration of interleukin (IL)-13, tumor necrosis factor (TNF)-α, and interferon gamma (IFN-γ) (p < 0.005, respectively). We observed significant differences in the distribution of genotypes or alleles of TNF-α rs1799964, TNF-α rs1800630, and IFN-γ rs2069705. Approximately one-third of the elderly patients suffered from neurological diseases. Elderly patients usually presented with peripheral eosinophilia (p = 0.013). No significant difference was identified in the recurrence rate and complement-activating capacity among the age groups. In conclusion, the early age of BP onset was associated with a more severe clinical presentation, higher titers of anti-BP180 IgE, lower titers of anti-BP230 IgG, and significantly higher serum concentrations of IL-13, TNF-α, and IFN-γ. It may also be associated with the presence of SNPs of cytokines, including TNF-α rs1799964, TNF-α rs1800630, and IFN-γ rs2069705 variants.

Bullous pemphigoid burden of disease, management and unmet therapeutic needs

Bullous pemphigoid (BP) is an autoimmune blistering disease that can have a profound negative impact on quality of life. BP most often affects the elderly, a population with a high medical burden and special safety concerns. In this review, we outline the BP disease course, diagnosis, epidemiology and comorbidities, and describe tools commonly used to assess BP disease activity and severity and the impact of BP on health-related quality of life. We also outline biologic treatments currently under investigation for the treatment of BP and highlight the importance of considering safety when treating elderly patients.

Associated factors related to production of autoantibodies and dermo-epidermal separation in bullous pemphigoid

Bullous pemphigoid (BP) is a debilitating autoimmune skin blistering disease, characterized by the deposition of specific autoantibodies at the dermal-epidermal junction. This leads to an inflammatory cascade involving the activation of complement proteins, mast cell degranulation, immune cell recruitment, and the release of proteases by granulocytes. While several cytokines and signaling pathways have been implicated in the pathogenesis of BP, the precise mechanism behind autoantibody production remains unclear. A variety of factors, including natural aging, genetic polymorphisms, microbiota, medications, vaccinations, and infection, may contribute to disease onset. Recent evidence also suggests that both vaccination against severe acute respiratory syndrome coronavirus-2 and infection with severe acute respiratory syndrome coronavirus-2 may also play a role in BP's development. This review aims to elucidate the mechanism underlying the production of autoantibodies in BP, address gaps in understanding disease progression, and explore opportunities for improving diagnosis and prognosis to enhance patient care.

Pathophysiology of Bullous Pemphigoid: Role of Type 2 Inflammation and Emerging Treatment Strategies (Narrative Review)

Bullous pemphigoid (BP) is an autoimmune blistering disease that most often affects elderly individuals and has a significant negative impact on quality of life. The disease is characterized primarily by autoantibodies to hemidesmosomal proteins BP180 and/or BP230, and an inflammatory reaction with notable features of type 2 inflammation, including elevated serum IgE, increased numbers of eosinophils in lesions and peripheral blood, and elevated expression of type 2 cytokines and chemokines in skin lesions. In this review, we present what is known about BP pathophysiology, including the role of type 2 inflammation, and discuss how findings from studies of biologics targeting type 2 immune mediators have helped to clarify the biological mechanisms driving BP pathophysiology. Future studies of these targeted therapies and others in development will help to further elucidate the mechanisms underlying BP pathophysiology and potentially provide better treatment options for patients.

Burden of Disease of Bullous Pemphigoid: A Targeted Literature Review

BACKGROUND

Bullous pemphigoid (BP) is a rare, chronic, autoimmune, blistering disease characterized by heterogenous lesions including the formation of fluid-filled blisters on frequently flexed areas of the skin and involvement of the mucosa in 10-25% of patients. BP mainly affects older patients and is associated with increased morbidity and mortality. The aim of the targeted literature review was to assess the clinical, humanistic, and economic burden associated with BP.

SUMMARY

Targeted searches were conducted in Embase and MEDLINE for studies published in English up to November 2022 that reported burden of illness of BP. A total of 42 publications on the clinical (n = 37), humanistic (n = 6), and economic (n = 8) burden of BP were identified. BP was associated with a high mortality rate (27-72%) and an increased risk of death compared to matched controls. The majority of patients had at least one comorbidity, including hypertension, diabetes mellitus, stroke, and neurological disorders, and showed severe symptoms such as itching and pain. BP was associated with a negative impact on BP- and pruritus-related quality of life and mental health, with 31% and 38% of patients with BP experiencing depression and anxiety in the "borderline/abnormal" range, respectively. BP was further associated with high economic burden, reflected by increased healthcare resource utilization, such as longer hospital stays (7.3 days in patients with BP vs. 4.7 days in those without BP), and direct disease-related costs.

KEY MESSAGES

This review provides a detailed assessment of the evidence base for BP, characterizing key aspects of the disease burden including clinical, humanistic, and economic burden. The results emphasize that this rare disease is associated with a substantial burden to patients and have implications for clinical practice in the management of BP.

Assessment of relationships between bullous pemphigoid and neurological diseases: A bidirectional two-sample Mendelian randomization study

Bullous pemphigoid (BP) is the most prevalent autoimmune vesiculobullous skin illness that tends to affect the elderly. Growing evidence has hinted a correlation between BP and neurological diseases. However, existing observational studies contained inconsistent results, and the causality and direction of their relationship remain poorly understood. To assess the causal relationship between BP and neurological disorders, including Alzheimer's disease (AD), multiple sclerosis (MS), Parkinson's disease (PD), and stroke. A bidirectional two-sample Mendelian randomization (MR) adopted independent top genetic variants as instruments from the largest accessible genome-wide association studies (GWASs), with BP (n = 218 348), PD (n = 482 730), AD (n = 63 926), stroke (n = 446 696), and MS (n = 115 803). Inverse variance weighted (IVW), MR-Egger, weighted mode methods, weighted median, and simple mode were performed to explore the causal association. Multiple sensitivity analyses, MR-Pleiotropy Residual Sum and Outlier (PRESSO) was used to evaluate horizontal pleiotropy and remove outliers. With close-to-zero effect estimates, no causal impact of BP on the risk of the four neurological diseases was discovered. However, we found that MS was positively correlated with higher odds of BP (OR = 1.220, 95% CI: 1.058-1.408, p = 0.006), while no causal associations were observed between PD (OR = 0.821, 95% CI: 0.616-1.093, p = 0.176), AD (OR = 1.066, 95% CI: 0.873-1.358, p = 0.603), stroke (OR = 0.911, 95% CI: 0.485-1.713, p = 0.773) and odds of BP. In summary, no causal impact of BP on the risk of PD, AD, MS and stroke was detected in our MR analysis. However, reverse MR analysis identified that only MS was positively correlated with higher odds of BP, but not PD, AD and stroke.

Pemphigus and pemphigoids: Clinical presentation, diagnosis and therapy

Pemphigus and pemphigoid are two potentially life-threatening groups of autoimmune diseases, characterized by autoantibodies targeting structural components of desmosomes or hemidesmosomes, respectively. Affected patients typically show itchy/painful plaques or blistering skin lesions and/or impairing mucosal blistering and erosions, which may strongly impact their quality of life. Since the milestone work of Walter Lever in 1953, who differentiated these two groups of diseases by histopathological analysis of the level of antibody-mediated skin cleavage, enormous progresses occurred. Achievements made in laboratory diagnostics now allow to identify antigen specific structural proteins of the skin that are targeted by pathogenic autoantibodies. These progresses were accompanied by an increased understanding of the pathogenesis of these diseases thanks to the establishment of animal models reproducing disease and on studies on skin and blood of affected individuals, which have been leading to novel and disease-specific treatments. Yet, given their phenotypical overlap with more common dermatological diseases, correct diagnosis and appropriate treatment are often delayed, in some cases leading to irreversible sequelae, including organ dysfunction (i.e., loss of vision in mucous membrane pemphigoid). Here, we provide a concise overview of the clinical appearance, diagnosis and therapeutic management of pemphigus and pemphigoid diseases.

Pemphigus- und Pemphigoid-Erkrankungen: Klinik, Diagnostik und Therapie: Pemphigus and pemphigoids: Clinical presentation, diagnosis and therapy

Pemphigus und Pemphigoid sind seltene Autoimmunkrankheiten der Haut mit potenziell lebensbedrohlichem Verlauf. Autoantikörper gegen epidermale und junktionale Strukturproteine (Desmosomen sowie Hemidesmosomen) führen bei Betroffenen typischerweise zu juckenden, schmerzhaften Plaques oder Blasen an der Haut und/oder Blasenbildung und Erosionen der Schleimhäute mit möglicher Einschränkung der Lebensqualität. Seit der bahnbrechenden Arbeit von Walter Lever im Jahr 1953, dem es gelang, mittels histopathologischer Untersuchung diese beiden Krankheitsgruppen anhand des Musters der Antikörper‐vermittelten Blasenbildung zu differenzieren, wurden enorme Fortschritte im Verständnis der Erkrankungen erzielt. Die Errungenschaften in der Labordiagnostik ermöglichten die Identifikation von Zielstrukturen zur präzisen Unterscheidung verschiedener Varianten der bullösen Autoimmunerkrankungen. Diese Fortschritte gingen dank der Entwicklung von Tiermodellen mit einem besseren Verständnis der Pathogenese einher. Außerdem haben Studien an Haut und Blut betroffener Patienten zu neuen und krankheitsspezifischen Behandlungen geführt. Aufgrund ihrer Seltenheit und der klinischen Ähnlichkeit mit anderen dermatologischen Erkrankungen verzögern sich die korrekte Diagnosestellung und die Einleitung einer entsprechenden Therapie häufig, was in einigen Fällen zu irreversiblen Folgeerscheinungen, einschließlich Funktionsstörungen von Organen (zum Beispiel Verlust des Sehvermögens beim Schleimhautpemphigoid) führt. Wir geben hier einen Überblick über das klinische Erscheinungsbild, den Diagnosealgorithmus und das therapeutische Management von Pemphigus‐ und Pemphigoid‐Erkrankungen.

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.

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.

Bullous pemphigoid in a patient with a neuropsychological disorder and a possible novel drug trigger: A case report and review of the literature

A 59-year-old woman with schizoaffective disorder presented with an itchy, blistering generalised rash. One month prior, she had started empagliflozin, a sodium glucose transporter-2 (SGLT-2) inhibitor, used in type-2-diabetes. She was already established on paliperidone, an atypical antipsychotic, for 1 year. Serology at presentation was positive for anti-pemphigoid antibodies. Histology demonstrated subepidermal blistering, perivascular inflammation and eosinophils. Direct immunofluorescence was characteristic of bullous pemphigoid (BP), with linear IgG and C3 at the basement membrane. Both empagliflozin and paliperidone were discontinued. However, the blisters persisted. Treatment included: topical Dermovate and Eumovate ointment for the body and face respectively, alongside oral doxycycline 200 mg and prednisolone 40 mg for a week (reducing by 5 mg/week over 8 weeks). Nevertheless, new blisters continued developing, hence dapsone 50 mg was introduced, with significant improvement. Increasingly, several neurological and psychiatric disorders have been linked with BP, complicating aetiology and management. The underlying mechanism for these associations is not fully understood. Bullous pemphigoid autoantigens BP180 and BP230 are expressed in the central nervous system and it is thought that neurodegeneration may expose antigens to the immune system, generating a cross-reactive immune response. However, there also appears to be bidirectional causality between BP and neuropsychological conditions. Furthermore, as there was an association of empagliflozin initiation and BP onset, this further complicates the aetiology and presents a potential novel drug cause of BP. This case emphasises the neuropsychological issues associated with managing complex BP cases, a possible novel cause of drug-induced BP and highlights the likelihood of these issues becoming increasingly prevalent for the future.

Serum autoantibody reactivity in bullous pemphigoid is associated with neuropsychiatric disorders and the use of antidiabetics and antipsychotics: a large prospective cohort study

BACKGROUND

Bullous pemphigoid (BP), the by far most frequent autoimmune blistering skin disease (AIBD), is immunopathologically characterized by autoantibodies against the two hemidesmosomal proteins BP180 (collagen type XVII) and BP230 (BPAG1 or dystonin). Several comorbidities and potentially disease-inducing medication have been described in BP, yet, a systematic analysis of these clinically relevant findings and autoantibody reactivities has not been performed.

OBJECTIVE

To determine associations of autoantibody reactivities with comorbidities and concomitant medication.

METHODS

In this prospective multicenter study, 499 patients diagnosed with BP in sixteen European referral centers were included. The relation between anti-BP180 NC16A and anti-BP230 IgG ELISA values at the time of diagnosis as well as comorbidities and concomitant medication collected by a standardized form were analyzed.

RESULTS

An association between higher serum anti-BP180 reactivity and neuropsychiatric but not atopic and metabolic disorders was observed as well as with the use of insulin or antipsychotics but not with dipeptidyl peptidase-4 (DPP4) inhibitors, inhibitors of platelet aggregation and L-thyroxine. The use of DPP4 inhibitors was associated with less anti-BP180 and anti-BP230 reactivity compared to BP patients without these drugs. This finding was even more pronounced when compared with diabetic BP patients without DPP4 inhibitors. Associations between anti-BP180 and anti-BP230 reactivities were also found in patients using insulin and antipsychotics, respectively, compared with patients without this medication, but not for the use of inhibitors of platelet aggregation, and L-thyroxine.

CONCLUSION

Taken together, these data imply a relation between autoantibody reactivities at the time of diagnosis and both neuropsychiatric comorbidities as well as distinct concomitant medication suggesting a link between the pathological immune mechanisms and clinical conditions that precede the clinically overt AIBD.

Deciphering the Contribution of BP230 Autoantibodies in Bullous Pemphigoid

Bullous pemphigoid (BP) is a subepidermal autoimmune blistering disease predominantly affecting elderly patients and carries significant morbidity and mortality. Patients typically suffer from severe itch with eczematous lesions, urticarial plaques, and/or tense blisters. BP is characterized by the presence of circulating autoantibodies against two components of the hemidesmosome, BP180 and BP230. The transmembrane BP180, also known as type XVII collagen or BPAG2, represents the primary pathogenic autoantigen in BP, whereas the intracellular BP230 autoantigen is thought to play a minor role in disease pathogenesis. Although experimental data exist suggesting that anti-BP230 antibodies are secondarily formed following initial tissue damage mediated by antibodies targeting extracellular antigenic regions of BP180, there is emerging evidence that anti-BP230 IgG autoantibodies alone directly contribute to tissue damage. It has been further claimed that a subset of patients has a milder variant of BP driven solely by anti-BP230 autoantibodies. Furthermore, the presence of anti-BP230 autoantibodies might correlate with distinct clinical features. This review summarizes the current understanding of the role of BP230 and anti-BP230 antibodies in BP pathogenesis.