Autoantibodies to Collagen XVII Are Present in Parkinson's Disease and Localize to Tyrosine-Hydroxylase Positive Neurons

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.

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.

The significance of preclinical anti-BP180 autoantibodies

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease. Although the pathomechanism of BP onset has yet to be elucidated in detail, BP autoantibodies targeting two hemidesmosomal components, BP180 and BP230, are known to play a pivotal role in BP pathogenesis. Thus, the detection and measurement of BP autoantibodies are necessary for diagnosing BP and monitoring the disease activity. Immune assays such as immunofluorescence microscopy, immunoblotting, and ELISAs using BP180 and BP230 detect BP autoantibodies in most BP cases with high specificity; however, BP autoantibodies are sometimes detected in BP patients before the onset of this disease. BP autoantibodies that are detected in patients without typical tense blisters are defined as “preclinical BP autoantibodies”. These preclinical BP autoantibodies are detected even in a low percentage of normal healthy individuals. Although the importance of preclinical BP autoantibodies remains elusive, these autoantibodies might be a potential risk factor for subsequent BP development. Therefore, previous comparative epidemiological studies have focused on the prevalence of preclinical BP autoantibodies in populations susceptible to BP (e.g., the elderly) or in diseases with a higher risk of comorbid BP. This mini-review summarizes the literature on the prevalence of preclinical BP autoantibodies in patients with various conditions and diseases, and we discuss the significance of preclinical BP autoantibody detection.

Use of gliptins reduces levels of SDF-1/CXCL12 in bullous pemphigoid and type 2 diabetes, but does not increase autoantibodies against BP180 in diabetic patients

The use of dipeptidyl peptidase 4 (DPP4) inhibitors, (also known as gliptins), is associated with an increased risk of bullous pemphigoid (BP), an autoimmune blistering skin disease. To explore the mechanism behind gliptin-associated BP we investigated circulating autoantibodies against the major BP autoantigen BP180 in serum samples from patients with type 2 diabetes (T2D) with preceding gliptin medication (n = 136) or without (n = 136). Sitagliptin was the most frequently prescribed gliptin (125/136 patients). Using an ELISA assay, we showed that IgG autoantibodies against the immunodominant NC16A domain of BP180 were found in 5.9% of gliptin treated and in 6.6% of non-gliptin treated T2D patients. We found that 28% of gliptin treated patients had IgG autoantibodies recognizing the native full-length BP180 in ELISA, but among non-gliptin treated the seropositivity was even higher, at 32%. Further ELISA analysis of additional serum samples (n = 57) found no major changes in the seropositivity against BP180 during a follow-up period of about nine years. In immunoblotting, full-length BP180 was recognized by 71% of gliptin treated and 89% of non-gliptin treated T2D patients, but only by 46% of the age-and sex-matched controls. The chemokine stromal derived factor-1(SDF-1/CXCL12) is one of the major substrates of DPP4. Immunostainings showed that the expression of SDF-1 was markedly increased in the skin of BP patients, but not affected by prior gliptin treatment. We found that the use of gliptins decreased the serum level of SDF-1α in both BP and T2D patients. Our results indicate that the autoantibodies against the linear full-length BP180 are common in patients with T2D, but seropositivity is unaffected by the use of sitagliptin.

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.

BP180/Collagen XVII: A Molecular View

BP180 is a type II collagenous transmembrane protein and is best known as the major autoantigen in the blistering skin disease bullous pemphigoid (BP). The BP180 trimer is a central component in type I hemidesmosomes (HD), which cause the adhesion between epidermal keratinocytes and the basal lamina, but BP180 is also expressed in several non-HD locations, where its functions are poorly characterized. The immunological roles of intact and proteolytically processed BP180, relevant in BP, have been subject to intensive research, but novel functions in cell proliferation, differentiation, and aging have also recently been described. To better understand the multiple physiological functions of BP180, the focus should return to the protein itself. Here, we comprehensively review the properties of the BP180 molecule, present new data on the biochemical features of its intracellular domain, and discuss their significance with regard to BP180 folding and protein-protein interactions.

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.

Comorbidities of bullous pemphigoid: A single-center retrospective case-control study from Turkey

Although significant associations between bullous pemphigoid (BP) and certain comorbidities, primarily subtypes of neurological disorders, have been reported in several populations, it has yet to be demonstrated whether a correlation exists between pre-existing comorbidities and serum titers of anti-BP180 and 230 immunoglobulin G (IgG) antibodies among BP patients. The aim of the current study is to investigate the demographic and clinical features of BP patients in a large series from Turkey, determine the prevalence of pre-existing neurological and systemic disorders, and assess the correlation between the existence of certain comorbidities and basal serum titers of anti-BP180 and 230 IgG autoantibodies. Thus, data from 145 BP patients diagnosed in the study's center between 1987 and 2017 were retrospectively analyzed and compared with 310 age- and sex-matched control subjects. The serum titers of anti-BP 180 and 230 IgG autoantibodies were compared between the patients with and without comorbidities and its subtypes among 55 patients with available serum basal anti-BP levels. Twenty-eight of the BP patients (19.3%) had already been diagnosed with at least one neurological disorder at the onset of BP. According to regression analysis, preexisting neurological disorders (p = 0.017), stroke (p = 0.017), and malignancies (p = 0.005) were found to be higher among the study's BP patients than the controls. The serum titers of anti-BP180 and 230 that were measured at the time of diagnosis were significantly higher in patients with neurological disorders than in patients without neurological disorders (p = 0.042; p = 0.018). Among the pre-existing comorbidities, neurological disorders, particularly stroke, and malignancies were found to be significantly connected to the occurrence of BP in the selected Turkish population. The high titers of serum anti-BP180 and 230 IgG antibodies at the time of BP diagnoses may highlight undiagnosed pre-existing neurological disorders by provoking suspicion.

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

BACKGROUND

While clustering of bullous pemphigoid (BP) with neuropsychiatric diseases is well-established, the clinical and immunological profile of BP patients with this comorbidity remains to be decisively determined.

OBJECTIVES

To evaluate the burden of neurological and psychiatric comorbidities among patients with BP and to elucidate the clinical, immunological and immunopathological features of patients with BP and comorbid neuropsychiatric conditions.

METHODS

We performed a retrospective study encompassing patients diagnosed with BP throughout the years 2009-2020 in a specialized tertiary referral centre. Multivariate logistic regression model was used to identify predictors of neuropsychiatric conditions among patients with BP.

RESULTS

The study included 273 patients with BP, of whom 123 (45.1%) presented with comorbid neuropsychiatric disease. Compared to the remaining patients with BP (n = 150), those with pre-existing neuropsychiatric diseases demonstrated older mean [standard deviation (SD)] age [81.7 (9.1) vs. 76.9 (10.1); P < 0.001], female preponderance (65.0% vs. 49.3%; P = 0.009), higher seropositivity rate of anti-BP230 (67.7% vs. 36.5%; P = 0.006) and higher levels of anti-BP180 NC16A IgG [651.3 (1279.6) vs. 370.4 (818.6) U/mL; P = 0.039]. In multivariate analysis, anti-BP230 seropositivity was independently associated with coexistence of BP with neuropsychiatric conditions [adjusted odds ratio (OR), 3.43; 95% CI, 1.24-9.52; P = 0.018]. In a sensitivity analysis confined to patients with neurological diseases (n = 103), older age [82.1 (8.4) vs. 77.2 (10.3); P < 0.001] and increased anti-BP230 seropositivity (68.0% vs. 39.7%; P = 0.018) were identified.

CONCLUSIONS

The coexistence of BP with neuropsychiatric diseases is independently associated with the generation of anti-BP230 antibodies.

MicroRNA-185 activates PI3K/AKT signalling pathway to alleviate dopaminergic neuron damage via targeting IGF1 in Parkinson's disease

OBJECTIVES

Studies have extensively explored the role of microRNAs (miRs) in Parkinson's disease (PD) and miR-185 is related to autophagy and apoptosis of dopaminergic neurons in PD. However, the role of miR-185 mediating insulin-like growth factor 1 (IGF1)/phosphatidylinositol-3-kinase/protein kinase B signalling pathway (PI3K/AKT) in PD still needs in-depth exploration.

METHODS

Rat PD models were established by injection of 6-hydroxydopamine. PD rats were injected with miR-185 or insulin-like growth factor 1 (IGF1)-related sequences. Behaviour tests were performed, oxidative stress-related factors, tyrosine hydroxylase (TH)-, glial fibrillary acidic protein (GFAP)-, ionised calcium-binding adaptor molecule-1 (Iba-1)- and TUNEL-positive cells in the substantia nigra were determined. Levels of miR-185, IGF1 and phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) signalling pathway-related factors were also detected.

RESULTS

miR-185 level was reduced in rats with PD. Restoring miR-185 promoted behaviour functions, ameliorated pathological damages and oxidative stress, increased TH-positive dopaminergic neurons, decreased GFAP- and Iba-1-positive cells and restrained neuronal apoptosis in the substantia nigra in PD rats. miR-185 targeted IGF1 to activate PI3K/AKT signalling pathway. Up-regulation of IGF1 mitigated restored miR-185-mediated effects on PD rats.

CONCLUSION

This study illustrates that miR-185 ameliorates dopaminergic neuron damage via targeting IGF1 and activating PI3K/AKT signalling pathway in PD, which renews the therapy for PD.

Analysis of the autoimmune response against BP180 in patients with Alzheimer's disease

Background

Current epidemiological studies suggest a significant correlation between Alzheimer's disease (AD) and bullous pemphigoid (BP). However, the autoimmune response against BP180 in patients with AD has not been fully understood. investigated.

Methods

We randomly enrolled 48 patients with AD and 50 sex- and age-matched healthy controls. We detected the presence/absence and the level of anti-BP180/BP230 immunoglobulin G (IgG) autoantibodies in the patients' serum to determine whether said antibodies possess reactivity against the BP180 protein in the human brain and skin.

Results

The enzyme-linked immunosorbent assay (ELISA) results revealed that the positive rate of anti-BP180 autoantibodies in patients with AD (23/48, 47.9%) was significantly higher than that in controls (4/50, 8.0%; P<0.0001). These ELISA-positive patients were further examined through immunoblotting. Sera from nine patients with AD (9/23, 39.1%) and one control (1/4, 25.0%) reacted with human cutaneous recombinant full-length BP180 and BP180-noncollagenous 16A (NC16A). Sera from 11 (11/23, 47.8%) patients with AD reacted with a 180-kDa protein from the human brain extract, but none of the controls' sera recognized the corresponding protein band. The majority of the patients in the anti-BP180-positive AD group were men (14/23, 60.9%) who were older (74.0 years) compared with those in the control group (6/25, 24.0%; P<0.05) (72.2 years; P<0.01).

Conclusions

Anti-BP180 autoantibodies are present in AD and recognize human recombinant full-length BP180 and a 180-kDa protein from the human brain extract, suggesting that BP180 is a shared autoantigen in AD and BP and may help clarify the mechanism to explain why a high risk of BP exists in AD. Elderly male patients with AD are significantly more likely to develop BP180 serum autoreactivity compared with other patients with AD.

Autoantibodies Against the Immunodominant Bullous Pemphigoid Epitopes Are Rare in Patients With Dermatitis Herpetiformis and Coeliac Disease

Dermatitis herpetiformis (DH) is an extraintestinal manifestation of coeliac disease (CD). Patients with DH have an elevated risk of development of another autoimmune blistering skin disease, bullous pemphigoid (BP). In this study we investigated whether patients with DH and CD (mean age for both 49 years) have circulating autoantibodies against BP180, the major BP autoantigen. ELISA tests showed that only a few DH (3/46) and CD (2/43) patients had BP180-NC16A IgG autoantibodies. Immunoblotting found that more than half of the DH samples contained IgG autoantibodies against full-length BP180. Epitope mapping with 13 fusion proteins covering the BP180 polypeptide revealed that in DH and CD patients, IgG autoantibodies did not target the NC16A or other epitopes typical of BP but recognized other intracellular and mid-extracellular regions of BP180. None of the analyzed DH and CD patients with either ELISA or immunoblotting positivity had IgG or IgA reactivity against the cutaneous basement membrane in indirect immunofluorescence analysis or skin symptoms characteristic of BP. Although only a minority of middle-aged DH patients had IgG autoantibodies against the immunodominant epitopes of BP180, our results do not exclude the possibility that intermolecular epitope spreading could explain the switch from DH to BP in elderly patients.

Parkinson's Disease and Its Dermatological Associations: Is Your Skin Whispering You a Diagnosis?

Parkinson's disease (PD) is a neurodegenerative disease characterized clinically by the triad of resting tremor, rigidity, and bradykinesia. Although PD is primarily known for motor disturbance, 98.6% of patients experience one or more non-motor symptoms at all stages of the disease. Dermatological disorders are discussed as common non-motor associations of PD since the 20th century. Many studies have shown that patients of PD are predisposed to skin disorders. This article is a traditional review done to analyze the association between PD and its dermatological manifestations. We did a literature search using six keywords in the PubMed database and took the relevant articles published in the last 10 years. We reviewed more than 100 articles, which also included animal studies. On meticulous review, we observed an increased incidence of certain skin disorders like seborrheic dermatitis, bullous pemphigoid, rosacea, and melanoma in patients of PD. These disorders share either common risk factors or underlying mechanisms revolving around genetics, immunology, inflammation, and pathophysiology of PD, but the exact causation yet seems obscured. We believe that this opens a horizon for more research in the link between the skin and nervous system. We also emphasize that the dermatologists, neurologists and general physicians should address the cutaneous disorders in PD timely, educate their patients, help them lessen the psychosocial distress, and improve their quality of life.

Demographics and Autoantibody Profiles of Pemphigoid Patients with Underlying Neurologic Diseases

Bullous pemphigoid (BP) is an autoantibody-mediated blistering disease that is often associated with neurologic disease. BP antibodies target two epidermal adhesion molecules, known as BP180 and BP230. Homologues to these proteins are found in the brain, and it is hypothesized that neurologic disease leads to the production of autoantibodies that can cross-react with their cutaneous forms. To better understand the link between BP and neurologic disease, we evaluated primary demographic features (age, sex, race, ethnicity, and elapsed time between onset of skin symptoms and BP diagnosis), severity of BP, and IgG and IgE autoantibody levels in BP control individuals and patients with BP with preceding Parkinson disease, dementia, and stroke. The main findings of this study are that patients with BP with preceding neurologic disease have a shorter elapsed time between onset of skin disease and BP diagnosis and that patients with preceding Parkinson disease or dementia, but not stroke, are significantly older than patients with BP without neurologic disease. However, no significant differences in clinical presentation, BP severity scores, or autoantibody (IgG and IgE) responses were observed among the groups. These findings suggest that, despite the age difference, the clinical phenotype of BP is not affected by preceding neurologic disease.

Dipeptidyl Peptidase-4 Inhibitor-Associated Bullous Pemphigoid

Bullous pemphigoid (BP) is an organ-specific autoantibody-mediated blistering skin disease that mainly affects the elderly. Typical clinical features include the widespread blisters, often preceded by and/or associated with itchy urticarial or eczema-like lesions. BP patients have circulating autoantibodies against BP180 and/or the plakin family protein BP230 both of which are components of hemidesmosomes in basal keratinocytes. Most BP autoantibodies particularly target the epitopes within the non-collagenous NC16A domain of BP180. Clinical findings and murine models of BP have provided evidence of a pathogenic role of anti-NC16A autoantibodies. However, it is largely unknown what triggers the breakage of immunotolerance against BP180 in elderly individuals. The incidence of BP has been increased over the past two decades in several countries. Aside from aging populations, the factors behind this phenomenon are still not fully understood. Neurodegenerative diseases such as multiple sclerosis, Parkinson's disease, and certain dementias are independent risk factors for BP. Recently several case reports have described BP in patients with diabetes mellitus (DM) patients who have been treated with dipeptidyl peptidase-4 inhibitors (DPP-4i or gliptins), which are a widely used class of anti-DM drugs. The association between the use of DPP-4is, particularly vildagliptin, and BP risk has been confirmed by several epidemiological studies. Evidence suggests that cases of gliptin-associated BP in Japan display certain features that set them apart from cases of “regular” BP. These include a “non-inflammatory” phenotype, targeting by antibodies of different immunodominant BP180 epitopes, and a specific association with the human leukocyte antigen (HLA) types. However, recent studies in European populations have found no major differences between the clinical and immunological characteristics of gliptin-associated BP and “regular” BP. The DPP-4 protein (also known as CD26) is ubiquitously expressed and has multiple functions in various cell types. The different effects of the inhibition of DPP-4/CD26 activity include, for example, tissue modeling and regulation of inflammatory cells such as T lymphocytes. Although the pathomechanism of gliptin-associated BP is currently largely unknown, investigation of the unique effect of gliptins in the induction of BP may provide a novel route to better understanding of how immunotolerance against BP180 breaks down in BP.

Neurological disorders are associated with bullous pemphigoid

BACKGROUND

Bullous pemphigoid (BP) is the most common subepidermal autoimmune blistering disease with an increased incidence particularly among the elderly. Several studies have recently reported an association between BP and neurological disorders.

OBJECTIVE

To evaluate the association between BP and neurological disorders in a single centre in Germany.

METHODS

We retrospectively assessed 183 patients with BP (diagnosed between 2011 and 2015) and 348 age- and sex-matched controls for neurological disorders. The latter were confirmed either by a neurologist or psychiatrist.

RESULTS

Overall, there was a highly statistically significant association between BP and neurological disorders (P < 0.0001). These included dementia (P < 0.0001), Parkinson`s disease (P = 0.0434), stroke (P = 0.0015) and other neurological disorders but not Alzheimer's diseases, which was more common among patients in the control group.

CONCLUSION

Our cohort of bullous pemphigoid and neurological disorders demonstrates a significant association between bullous pemphigoid and neurological disorders, including dementia, Parkinson's disease and stroke. These observations support the need for future studies in order to elucidate the immunological mechanisms responsible for these comorbidities.

Anti-BP180 Autoantibodies Are Present in Stroke and Recognize Human Cutaneous BP180 and BP180-NC16A

Objective: Current evidence has revealed a significant association between bullous pemphigoid (BP) and neurological diseases (ND), including stroke, but the incidence of BP autoantibodies in patients with stroke has not previously been investigated. Our study aimed to assess BP antigen-specific antibodies in stroke patients. Design: One hundred patients with stroke and 100 matched healthy controls were randomly selected for measurement of anti-BP180/BP230 IgG autoantibodies by enzyme-linked immunosorbent assay (ELISA), salt-split indirect immunofluorescence (IIF), and immunoblotting against human cutaneous BP180 and BP180-NC16A. Results: Anti-BP180 autoantibodies were found in 14 (14.0%) patients with stroke and 5 (5.0%) of controls by ELISA (p < 0.05). Sera from 13 (13.0%) patients with stroke and 3 (3.0%) controls reacted with 180-kDa proteins from human epidermal extract (p < 0.05). 11 (11.0%) of stroke and 2 (2.0%) of control sera recognized the human recombinant full length BP180 and NC16A (p < 0.05). The anti-BP180-positive patients were significantly younger than the negative patients at the time of stroke (p < 0.001). Conclusion: Development of anti-BP180 autoantibodies occurs at a higher frequency after stroke, suggesting BP180 as a relatively common autoantigen after stroke and providing novel insights into BP pathogenesis in aging.

BP180 Autoantibodies Target Different Epitopes in Multiple Sclerosis or Alzheimer's Disease than in Bullous Pemphigoid

Neurologic patients have an increased risk for bullous pemphigoid (BP), in which autoantibodies target BP180, a cutaneous basement membrane protein also expressed in the brain. Here we show that 53.6% of sera from patients with multiple sclerosis (MS) (n = 56) had IgG reactivity against full-length BP180 in immunoblotting, while in BP180 non-collagenous 16A ELISA (n = 143), only 7.7% of MS samples studied were positive. Epitope mapping with 13 fusion proteins covering the entire BP180 polypeptide revealed that in MS and Alzheimer's disease (AD) patients, IgG autoantibodies target regions located in the intracellular and mid-extracellular parts of BP180, but not the well-known BP epitopes located in the non-collagenous 16A domain and the distal part of extracellular domain. In indirect immunofluorescence analysis, 8.1% of MS sera recognized the cutaneous basement membrane and in full-length BP180 ELISA analysis, 7.5% MS and AD sera were positive, indicating that these autoantibodies rarely recognize BP180 in its native conformation. Thus, in MS and AD patients, BP180 autoantibodies have a different epitope profile than in patients with BP, and seldom bind to native BP180. This explains the inability of these autoantibodies to cause skin symptoms. Our results suggest that the autoantibodies against BP180 alone are not sufficient to induce BP in MS and AD patients.

Autoimmune Subepidermal Bullous Diseases of the Skin and Mucosae: Clinical Features, Diagnosis, and Management

Autoimmune subepidermal blistering diseases of the skin and mucosae constitute a large group of sometimes devastating diseases, encompassing bullous pemphigoid, gestational pemphigoid, mucous membrane pemphigoid, epidermolysis bullosa acquisita, and anti-p200 pemphigoid. Their clinical presentation is polymorphic. These autoimmune blistering diseases are associated with autoantibodies that target distinct components of the basement membrane zone of stratified epithelia. These autoantigens represent structural proteins important for maintenance of dermo-epidermal integrity. Bullous pemphigoid (BP) is the most common subepidermal autoimmune blistering disease of the skin and mucosae. Although the disease typically presents with a generalized blistering eruption associated with itch, atypical variants with either localized bullous lesions or "non-bullous" presentations are observed in approximately 20% of patients. A peculiar form of BP typically associated with pregnancy is pemphigoid gestationis. In anti-p200 pemphigoid, patients present with tense blisters on erythematosus or normal skin resembling BP, with a predilection for acral surfaces. These patients have antibodies targeting the 200-kDa basement membrane protein. Epidermolysis bullosa is a rare autoimmune blistering disease associated with autoantibodies against type VII collagen that can have several phenotypes including a classical form mimicking dystrophic epidermolysis bullosa, an inflammatory presentation mimicking BP, or mucous membrane pemphigoid-like lesions. Mucous membrane pemphigoid (MMP) is the term agreed upon by international consensus for an autoimmune blistering disorder, which affects one or more mucous membrane and may involve the skin. The condition involves a number of different autoantigens in the basement membrane zone. It may result in severe complications from scarring, such as blindness and strictures. Diagnosis of these diseases relies on direct immunofluorescence microscopy studies and immunoserological assays. Management of affected patients is often challenging. We will here review the clinical and immunopathological features as well as the pathophysiology of this group of organ-specific autoimmune diseases. Finally, we will discuss the diagnostic approach and the principles of management in clinical practice.

Type I Gaucher disease with bullous pemphigoid and Parkinson disease: A case report

RATIONALE

Gaucher disease (GD) is a rare genetic lysosomal storage disorder inherited in an autosomal recessive pattern. GD is due to the deficiency of a lysosomal enzyme, acid beta-glucosidase (or glucocerebrosidase). Type 1 Gaucher disease (GD1) is characterized by thrombocytopenia, anemia, an enlarged spleen, and liver as well as bone complications (Erlenmeyer flask deformity, osteoporosis, lytic lesions, pathological and vertebral fractures, bone infarcts, and avascular necrosis leading to degenerative arthropathy). The diagnosis is usually made in first decades but is sometimes delayed. Parkinson disease, neoplasia, and immune system abnormalities may be associated with GD1.

PATIENT CONCERNS

A patient known for hepatosplenomegaly with hyperferritinemia, anemia, and thrombocytopenia was admitted for Lewy body dementia and bullous pemphigoid.

DIAGNOSES

Type 1 Gaucher disease.

INTERVENTION

No specific treatment started.

OUTCOMES

patient died ten months later due to pneumonia.

LESSONS

To the best of our knowledge, this is the first case of the association between GD1, bullous pemphigoid, and Lewy body dementia. We discuss the central role of alpha-synuclein in these pathologies.

A case report of bullous pemphigoid associated with a melanoma and review of the literature

The association of bullous pemphigoid with melanoma remains controversial and poorly understood. Recent studies report the presence of the bullous pemphigoid antigen, BP180, in melanoma cells, yet not normal melanocytes, suggesting an underlying mechanism for cases of melanoma-associated bullous pemphigoid. We report on an 88-year-old woman who showed a temporal relationship between the development of bullous pemphigoid and melanoma. The patient did not receive programmed death ligand 1 inhibitor therapy and improved rapidly following complete excision of her melanoma, with clobetasol, doxycycline, and niacinamide. We review the literature on the relationship between bullous pemphigoid and melanoma, and propose a mechanism underlying a melanoma-associated bullous pemphigoid.

The Association Between Frontotemporal Lobar Degeneration and Bullous Pemphigoid

Recent studies have shown an epidemiological and immunological association between bullous pemphigoid (BP) and several neurological or psychiatric diseases. Here, our aim was for the first time to specify whether an association exists between BP and frontotemporal lobar degeneration (FTLD). Medical histories of FTLD patients (N = 196) were screened for clinical comorbidity, and BP180 and BP230 autoantibodies were analyzed in the sera of FTLD patients (N = 70, including 24 C9orf72 repeat expansion carriers) by BP180-NC16A-ELISA and BP230-ELISA. One FTLD patient (C9orf72 repeat expansion carrier) had a comorbid diagnosis of BP. Increased levels of serum BP180 autoantibodies (cutoff value >9 U/ml) were detected more often in FTLD patients (10.0%) than in controls (4.9%). Moreover, elevated levels of both BP180 and BP230 autoantibodies were found more often in C9orf72 repeat expansion-carrying FTLD than non-carrying patients or controls. However, none of these differences reached a statistical significance likely due to our limited cohort size. In conclusion, our findings suggest that subset of FTLD patients especially with the C9orf72 repeat expansion may have an immunological association with BP.

Neurological and psychiatric associations in bullous pemphigoid-more than skin deep?

In elderly patients, bullous pemphigoid (BP) is associated with several comorbidities; the strongest association occurs between BP and neurological diseases. Different types of dementia, Parkinson's disease, cerebrovascular disorders and epilepsy all have a significant association with BP, but patients with multiple sclerosis have the highest risk of BP. An existing neurological disorder appears to increase the risk for subsequent BP, but an increased risk for developing some neurological diseases has also been reported following BP diagnosis. BP seems to be associated with several psychiatric diseases such as schizophrenia, uni- and bipolar disorder, schizotypal and delusional disorders, and personality disorders, but the risk ratios are usually lower than with neurological diseases. In addition to the skin, the BP autoantigens BP180 and BP230 are expressed in the central nervous system. This finding together with the strong epidemiological association between neurological disorders and BP has led to an assumption that neurodegeneration or neuroinflammation could lead to a cross-reactive immunoresponse between neural and cutaneous antigens and the failure of self-tolerance. A subpopulation of patients with Alzheimer's disease or Parkinson's disease have circulating IgG autoantibodies against BP180, but currently their significance for the development of BP is unclear, because these antineural BP180 antibodies neither bind to the cutaneous basement membrane nor cause BP-like symptoms. Further studies analysing large and well-characterized populations of neurological and psychiatric patients are required to understand better the role of autoimmunization against neural BP autoantigens in the pathogenesis of BP.

Mortality in bullous pemphigoid and prognostic factors in 1st and 3rd year of follow-up in specialized centre in Poland

Bullous pemphigoid (BP) is associated with higher mortality and coexisting comorbidities, some of them affecting poor prognosis. The aim of the study was to identify prognostic factors causing greater mortality both in the 1st and 3rd year of follow-up and to determine the 1-, 2-, 3-year mortality rates, standardized mortality ratio (SMR) in Polish BP patients. All patients with BP (a cohort of 205 patients, mean age 76.2 years) diagnosed between 5 January 2000 and 10 December 2013 in a referral unit for autoimmune bullous diseases at the university hospital in Poland were included retrospectively. Mortality data were obtained from the Centre for Document Personalization at the Minister of Interior and Administration. Our original observation was that prednisone in moderate dose (0.5 mg kg^-1) in monotherapy was an independent risk factor of fatal prognosis in the 1st year of follow-up, assessed using multivariate analysis. We confirmed the strong correlation between neurological diseases and greater mortality. Both in the 1st and 3rd year of follow-up, dementia and Parkinson disease resulted in increased mortality. We also found that arrhythmias significantly increased mortality in the 1st and 3rd year of follow-up. The prognostic factors in BP changed over time of follow-up. In the 3rd year of observation, the age above 77, longer hospitalization and BP severity were associated with greater mortality. We observed poorer prognosis in BP patients than age-matched general Polish population. The 1-, 2-, 3-year mortality rates were 22.4, 31.2, 39.5% and SMR was 3.8 (95% CI 3.4-3.7).

A multi-hit hypothesis of bullous pemphigoid and associated neurological disease: Is HLA-DQB1*03:01, a potential link between immune privileged antigen exposure and epitope spreading?

Bullous pemphigoid (BP) is the most common autoimmune blistering disease and is linked to IgG recognition of 2 hemidesmosomal antigens, that is, BP230 (BP antigen 1) and BP180 (BP antigen 2, collagen XVII). The association of BP with other systemic diseases, particularly neurocognitive diseases, provides a potential clue in the underlying pathogenesis of BP. The role of HLA-DQB1*03:01 binding to the immunogenic portion of BP180 provides a potential mechanism by which exposure to neuronal collagen BP180 may lead to cutaneous disease. In our proposed multi-hit hypothesis, patients with underlying neuronal disease are exposed to previously sequestered self-antigen, most importantly BP180. Patients with the HLA-DQB1*03:01 allele show an increased T-cell avidity to several epitopes of BP180, particularly the BP180-NC16a domain. Thus, they have a genetic susceptibility to developing BP upon exposure to the target antigen. In a patient with dysregulation of Th1/Th2 balance, anergy is lost and T-cells are subsequently primed resulting in the development of functional autoimmunity against the BP180-NC16a domain leading to clinically overt disease.

Increased Levels of the Bullous Pemphigoid BP180 Autoantibody Are Associated with More Severe Dementia in Alzheimer's Disease

Bullous pemphigoid (BP) is a subepidermal blistering skin disease, which has shown a strong association with neurological diseases in epidemiological studies. The BP autoantigens BP180 and BP230 are expressed in the cutaneous basement membrane and the central nervous system. Using BP180 and BP230 ELISA assays and immunoblotting against BP180, we analyzed the IgG reactivity in the sera of 115 patients with Alzheimer's disease (AD) and 40 neurologically healthy controls. BP180 autoantibodies were found in 18% of patients with AD, whereas only 3% of controls had positive results (P = 0.019). BP230 values were higher and more often elevated in patients with AD than controls, but not significantly. None of the positive AD sera that recognized the full-length human BP180 in immunoblotting reacted with the cutaneous basement membrane in indirect immunofluorescence analysis. Moreover, a retrospective evaluation of the hospital records of the patients with AD revealed neither BP diagnosis nor BP-like symptoms. Interestingly, increased BP180-NC16A autoantibody values correlated with cognitive decline measured by mini-mental state examination scores, but not with the concentration of AD biomarkers in cerebrospinal fluid. Our findings further the understanding of the role of BP180 as a shared autoantigen in neurodermatological interactions and the association between BP and neurodegenerative diseases.

Psychiatric and neurological disorders are associated with bullous pemphigoid - a nationwide Finnish Care Register study

Bullous pemphigoid (BP) is an autoimmune blistering skin disease with increasing incidence. BP is associated with neurological disorders, but it has not been established, what subtypes of dementia and stroke are associated with BP, and what is the temporal relation between these diseases. Also, the association between BP and psychiatric disorders is controversial. We conducted a retrospective nationwide study, using the Finnish Care Register for Health Care diagnoses between 1987 and 2013. The study population of 4524 BP patients were compared with 66138 patients with basocellular carcinoma (BCC), neurological and psychiatric comorbid disorders were evaluated for both groups, and associations were estimated by Cox regression and logistic regression analyses. The strongest risk of developing BP was found after diagnosis of multiple sclerosis (MS) (OR=5.9, 95% CI 3.9–8.5). Among psychiatric diseases, the corresponding risk was strongest in schizophrenia (OR=2.7, 95% CI 2.0–3.5), and as a novel finding, also personality disorders (OR=2.2, 95% CI 1.3–3.3) preceded BP. In conclusion, many psychiatric disorders, especially schizophrenia, carry heightened risk for BP. Furthermore, several neurological diseases which cause central nervous system inflammation or degeneration were related to BP, and the association was strongest between MS and BP.