Bullous Pemphigoid Triggered by Thermal Burn Under Medication With a Dipeptidyl Peptidase-IV Inhibitor: A Case Report and Review of the Literature

Skin-Related Adverse Reactions Induced by Oral Antidiabetic Drugs-A Review of Literature and Case Reports

Type 2 diabetes (T2DM) is a chronic metabolic disease with a steadily increasing prevalence worldwide. Diabetes affects the function of many organs, including the skin. Pharmacotherapy for T2DM is mainly based on oral hypoglycemic drugs. The therapeutic strategy is chosen taking into account the individual patient's characteristics, among other comorbidities. Antidiabetic drugs can induce cutaneous adverse reactions (CADRs) ranging in severity from mild erythema to serious disorders such as DRESS or Stevens-Johnson syndrome. CADRs can result from hypersensitivity to the drug but can also be related to the mechanism of action of the drug or cross-reactivity with drugs of similar structure. This paper reviews CADRs induced by oral antidiabetic drugs, considering their dermatological manifestations and possible pathomechanisms. Particular attention was paid to specific dermatological conditions such as dipeptidylpeptidase 4 inhibitor-associated bullous pemphigoid or Fournier's gangrene associated with sodium-glucose cotransporter 2 inhibitor therapy. Knowledge of the dermatological manifestations of CADRs is important in clinical practice. Recognition of a skin lesion resulting from an adverse drug reaction allows for appropriate management, which in this case is primarily related to drug discontinuation. This is particularly important in the treatment of T2DM since this disease has a high prevalence in the elderly, who are at higher risk of adverse drug reactions.

Absence of Epidermal Antibodies in Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis Patients but Beware of Single Positive Results

Background

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare and potentially life-threatening mucocutaneous blistering diseases that clinically can resemble autoimmune bullous diseases. Moreover, it has been shown that autoantibodies against epidermal proteins are present in SJS/TEN.

Objectives

To establish the presence of antibodies against desmosomal and hemidesmosomal proteins in confirmed SJS/TEN patients.

Methods

Serum of SJS/TEN patients diagnosed based on clinical criteria, e.g., epidermal detachment with erosions and severe mucosal lesions, (suspicion of) a culprit drug, and matching histologic results was evaluated by various techniques, e.g., indirect immunofluorescence on monkey esophagus, salt split skin and rat bladder, immunoblotting (IB) and immunoprecipitation (IP), ELISAs against desmogleins and BP180, keratinocyte footprint assay, and keratinocyte binding assay.

Results

A total of 28 patients were included in this study, 15 men and 13 women with a mean age of 56 years. In most patients, none of the serological tests were positive. In two patients, an elevated DSG3 titer was found suspicious for pemphigus vulgaris. Three patients had elevated NC16a titers, suggesting bullous pemphigoid. However, in all these patients, no other tests were positive and in these patients, the biopsy for direct immunofluorescence showed no evidence for an autoimmune bullous disease. Three patients showed reactivity against rat bladder rat bladder; these were, however, completely negative for A2ML1, envoplakin, and periplakin in the IB as well as the IP.

Conclusions

Serological analysis for desmosomal and hemidesmosomal antibodies is reliable to rule an autoimmune bullous disease in patients with suspected SJS/TEN. However, one should not rely on one single test method since false positive results can occur. Moreover, this study also makes it less plausible that antibodies against desmosomal and/or hemidesmosomal components are involved in the pathogenesis of SJS/TEN.

Association of Genetic Variants of HLA-DQA1 with Bullous Pemphigoid Induced by Dipeptidyl Peptidase-4 Inhibitors

Bullous pemphigoid (BP) is the most common autoimmune blistering disorder. Several factors, including an antidiabetic (dipeptidyl peptidase-4 inhibitor [DPP-4i]), have been reported to trigger BP. To identify the genetic variants associated with BP, GWAS and HLA fine-mapping analyses were conducted. The 21 cases of noninflammatory BP induced by DPP-4i (i.e., DPP-4i-induced noninflammatory BP) and 737 controls (first cohort) and the 8 cases and 164 controls (second cohort) were included in the GWAS. Combining GWAS satisfied the genome-wide significant association of HLA-DQA1 (chromosome 6, rs3129763 [T/C]) with the risk of DPP-4i-induced noninflammatory BP (allele T carrier of 72.4% [21 of 29] in cases vs. 15.3% [138 of 901] in controls; dominant model, OR = 14, P = 1.8 × 10-9). HLA fine mapping revealed that HLA-DQA1∗05 with serine at position 75 of HLA-DQα1 (Ser75) had the most significant association with the combined cohort of DPP-4i-induced noninflammatory BP (79.3% [23 of 29] cases vs. 16.1% [145 of 901] controls; dominant model, OR = 21, P = 2.0 × 10-10). HLA-DQα1 Ser75 polymorphism was located inside the functional pocket of HLA-DQ molecules, suggesting the impact of HLA-DQα1 Ser75 on DPP-4i-induced noninflammatory BP.

Case Report: Localized bullous pemphigoid induced by local triggers: a case series and a proposal for diagnostic criteria based on a literature review

Introduction

Localized bullous pemphigoid (LBP) is an infrequent bullous pemphigoid (BP) variant restricted to a body region. According to the most compelling evidence, LBP occurs in patients with pre-existent serum antibodies against the basement membrane zone, which occasionally acquire the capacity to induce disease after the influence of different local factors acting as triggers.

Methods

We hereby present a multicenter cohort of 7 patients with LBP developed after local triggers: radiotherapy, thermal burns, surgery, rosacea, edema and a paretic leg. In addition, we conducted a review of the literature, and we propose a set of diagnostic criteria for LBP, also based on our case series and the 2022 BP guidelines from the European Academy of Dermatology and Venereology.

Results

During follow-up, three of the patients from our series evolved to a generalized BP, with only one requiring hospitalization. Our literature search retrieved 47 articles including a total of 108 patients with LBP, with a 63% with a potential local precipitating factor previous to their diagnosis. LBP mostly affected older females, and a subsequent generalized progression occurred in 16.7% of the cases. The most frequently involved areas were the lower limbs. Radiation therapy and surgery were responsible for the inducement of nearly 2 in 3 cases of LBP. We observed a significantly higher risk of generalization in cases where the trigger led to the developing of LBP earlier (p=0.016). Our statistical analysis did not detect any other prognosis factor for generalization when assessing direct immunofluorescence, histological and serological results, or other patient related factors.

Conclusion

LBP should be suspected in patients with recurrent localized bullous eruptions. The presence of a trauma history in the same anatomic area is reported in most cases.

Classification and Antigen Molecules of Autoimmune Bullous Diseases

Autoimmune bullous diseases (AIBDs), which are a group of tissue-specific autoimmune diseases of the skin, present with various blistering lesions on the skin and mucous membranes, and show autoantibodies of IgG, IgA and IgM against epidermal cell surfaces and basement membrane zone. To date, AIBDs have been classified into a number of distinct subtypes by clinical and histopathological findings, and immunological characteristics. In addition, various biochemical and molecular biological studies have identified various novel autoantigens in AIBDs, which has resulted in proposals of new subtypes of AIBDs. In this article, we summarized various distinct AIBDs, and proposed the latest and most comprehensive classification of AIBDs with their autoantigen molecules.

What's new in the pathogeneses and triggering factors of bullous pemphigoid

Bullous pemphigoid (BP) is a subepidermal blistering disease induced by autoantibodies to type XVII collagen (COL17, also called BP180) and BP230. Previous studies using patients' samples and animal disease models elucidated the complement-dependent and complement-independent pathways of blister formation, the pathogenic roles of immune cells (T and B cells, macrophages, mast cells, neutrophils, eosinophils), and the pathogenicity of IgE autoantibodies in BP. This review introduces the recent progress on the mechanism behind the epitope-spreading phenomenon in BP, which is considered to be important to understand the chronic and intractable disease course of BP, and the pathogenicity of anti-BP230 autoantibodies, mainly focusing on studies that used active disease models. To clarify the pathogenesis of BP, the mechanism behind the breakdown of immune tolerance to BP antigens should be investigated. Recent studies using various experimental models have revealed important roles for regulatory T cells in the maintenance of self-tolerance to COL17 and BP230 as well as in the suppression of inflammation triggered by the binding of antibodies to COL17. Notably, physical stresses such as trauma, thermal burns, bone fractures, irradiation and ultraviolet exposure, some pathologic conditions such as neurological diseases and hematological malignancies, and the use of dipeptidyl peptidase-IV inhibitors and immune checkpoint inhibitors have been reported as triggering factors for BP. These factors and certain underlying conditions such as genetic background, regulatory T-cell dysfunction or aging might synergistically affect some individuals and eventually induce BP. Further studies on the breakdown of self-tolerance and on the identification of key molecules that are relevant to blister formation and inflammation may expand our understanding of BP's etiology and may lead to the development of novel therapeutic approaches.

Imiquimod-induced bullous pemphigoid: A case report

A 72-year-old man treated with 3.5% imiquimod cream for scalp actinic keratoses developed the usual crusted and erosive reaction but developed bullae on the scalp, as well as the limbs and torso after several weeks into treatment. Biopsy confirmed bullous pemphigoid. He was treated with clobetasol ointment, prednisone and methotrexate, with eventual disease control. He had a severe disease course. Bullous pemphigoid is usually idiopathic, but can be induced by skin trauma, as well as by several medications; this is the first report of imiquimod as a trigger. Imiquimod is a toll-like receptor 7 agonist that induces cellular apoptosis and recruits pro-inflammatory cytokines including tumour necrosis factor-alpha and interferon-alpha, which have been implicated in autoimmunity. This case highlights an unusual but severe adverse effect from topical imiquimod.

[Trigger factors associated with bullous autoimmune dermatoses]

BACKGROUND

Blistering autoimmune dermatoses are a heterogeneous group of rare diseases. Pemphigus diseases are distinguished from pemphigoid diseases as well as dermatitis herpetiformis. In pemphigus diseases, cutaneous blistering is caused by an intraepidermal loss of adhesion between keratinocytes. In pemphigoid diseases, blister formation is due to a subepidermal loss of adhesion of keratinocytes from the basement membrane.

OBJECTIVES

This article reviews the most important trigger factors associated with bullous autoimmune dermatoses and discusses their role in their initial manifestation as well as exacerbation.

MATERIALS AND METHODS

A focused review of the literature including original articles, guidelines, reference works and previously published review articles was performed.

RESULTS

Vaccinations, viral infections, ultraviolet light (UV) exposure and radiation therapies are possible triggers of pemphigus vulgaris in predisposed patients. For the much rarer pemphigus foliaceus, UV exposure is of particular importance. Thiols and phenols are drugs that can induce pemphigus usually resembling pemphigus foliaceus clinically. Age is the most important risk factor of bullous pemphigoid. In addition, in bullous pemphigoid associations with dipeptidyl peptidase 4 inhibitors, programmed cell death protein‑1 or programmed death-ligand‑1 inhibitors as well as neurological diseases are particularly relevant. Severe mucosal damage, certain drugs and in particular cases neoplasms might play a role in mucous membrane pemphigoid.

CONCLUSION

Knowing possible trigger factors facilitates a timely diagnosis upon initial manifestation and supports the prevention of relapse of bullous autoimmune dermatoses.

Bullous Pemphigoid Complicated by Sepsis

Patients with bullous pemphigoid face many challenges when managing their disorder, one of which is balancing medication with their ailments. Because the patient population with bullous pemphigoid are primarily elderly, the current first-line treatment of corticosteroids tends to increase their rates of morbidity and mortality. During the acute process of the disease, providers must also consider the increased chance of infections caused by the opening in the skin. These patient cases are often complicated further by secondary symptoms such as pruritis and pain. Here we present a case in which we provided care to a 38-year-old female with a history of bullous pemphigoid and multiple medical problems who presented to the emergency department with nausea, vomiting, fevers, abdominal pain, and blisters on her forearm. Due to concern for sepsis and her past failure of outpatient therapy, the patient was hospitalized and treated for her possible infection, bullous pemphigoid, nausea, and pain.

Unmet Medical Needs in Chronic, Non-communicable Inflammatory Skin Diseases

An estimated 20-25% of the population is affected by chronic, non-communicable inflammatory skin diseases. Chronic skin inflammation has many causes. Among the most frequent chronic inflammatory skin diseases are atopic dermatitis, psoriasis, urticaria, lichen planus, and hidradenitis suppurativa, driven by a complex interplay of genetics and environmental factors. Autoimmunity is another important cause of chronic skin inflammation. The autoimmune response may be mainly T cell driven, such as in alopecia areata or vitiligo, or B cell driven in chronic spontaneous urticaria, pemphigus and pemphigoid diseases. Rare causes of chronic skin inflammation are autoinflammatory diseases, or rheumatic diseases, such as cutaneous lupus erythematosus or dermatomyositis. Whilst we have seen a significant improvement in diagnosis and treatment, several challenges remain. Especially for rarer causes of chronic skin inflammation, early diagnosis is often missed because of low awareness and lack of diagnostics. Systemic immunosuppression is the treatment of choice for almost all of these diseases. Adverse events due to immunosuppression, insufficient therapeutic responses and relapses remain a challenge. For atopic dermatitis and psoriasis, a broad spectrum of innovative treatments has been developed. However, treatment responses cannot be predicted so far. Hence, development of (bio)markers allowing selection of specific medications for individual patients is needed. Given the encouraging developments during the past years, we envision that many of these challenges in the diagnosis and treatment of chronic inflammatory skin diseases will be thoroughly addressed in the future.

A Case of Drug-Induced Bullous Pemphigoid With an Isomorphic Response and Updated Review of Koebnerization in Bullous Diseases

Bullous pemphigoid (BP) can be a challenging diagnosis as it can mimic a variety of other inflammatory conditions. An isomorphic response may be seen in a variety of cutaneous diseases; however, there is a paucity of reports associated with BP. We present a case of recurrent drug-induced BP with an isomorphic response to trauma in a 73-year-old Caucasian male. Bumetanide was determined to be the inciting cause of the initial disease. The patient was initially treated with prednisone tapers and topical steroids. Mycophenolate Mofetil was eventually started after numerous flares. He later developed isomorphic bullous lesions at the periphery of a skin graft that was completed following a traumatic fall. He was started on clobetasol ointment with full resolution over the following month.

Bullous pemphigoid: An immune disorder related to aging (Review)

Bullous pemphigoid (BP) is the most frequent subepidermal autoimmune blistering disease and is caused by autoantibodies directed against two principal antigens of the hemidesmosome, BP antigen 180 and BP antigen 230. The pathogenesis of BP is dependent upon the interaction between genetic predisposition, physiological skin alterations due to aging and specific triggers. Several triggers have already been reported to induce this disease and include drugs, thermal or electrical burns, surgical procedures, trauma, UV radiation, radiotherapy, chemicals and infections. Data from the current literature support the hypothesis that alterations of the skin barrier associated with aging increase individual susceptibility to these aforementioned triggers. Consequently, this has been reported to lead to the attack of autoantibodies, demonstrating the predilection of BP for the elderly population. The identification of triggering factors and comorbidities may aid in understanding the pathogenesis of BP and improve clinical management by encouraging their prompt recognition and removal. Moreover, the present review has indicated that current management of BP should be aimed at counteracting the detrimental effects of aging on the skin by restoring skin barrier integrity and maintaining cutaneous homeostasis, for example with systematic applications of topical emollients and photoprotection. This strategy could prove even more beneficial in the elderly, in which frequent comorbidities associated with age often narrow available immunosuppressive treatment options. Furthermore, the safety of treatment regimens may significantly affect outcome and prognosis.

Dipeptidyl peptidase-4 inhibitor-induced autoimmune diseases: Current evidence

Dipeptidyl peptidase-4 inhibitors (DPP-4i) have an important place in the management of type 2 diabetes. The DPP-4 enzyme is ubiquitously distributed throughout the human body and has multiple substrates through which it regulates several important physiological functions. DPP-4 regulates several immune functions, including T-cell activation, macrophage function, and secretion of cytokines. Studies have reported an increase in autoimmune diseases like bullous pemphigoid, inflammatory bowel disease, and arthritis with DPP-4i use. The relationship of DPP-4i and autoimmune diseases is a complex one and warrants further research into the effect of DPP-4 inhibition on the immune system to understand the pathogenesis more clearly. Whether a particular cluster of autoimmune diseases is associated with DPP-4i use remains an important contentious issue. Nevertheless, a heightened awareness from the clinicians is required to identify and treat any such diseases. Through this review, we explore the clinical and pathophysiological characteristics of this association in light of recent evidence.

Selenium Deficiency Due to Diet, Pregnancy, Severe Illness, or COVID-19-A Preventable Trigger for Autoimmune Disease

The trace element selenium (Se) is an essential part of the human diet; moreover, increased health risks have been observed with Se deficiency. A sufficiently high Se status is a prerequisite for adequate immune response, and preventable endemic diseases are known from areas with Se deficiency. Biomarkers of Se status decline strongly in pregnancy, severe illness, or COVID-19, reaching critically low concentrations. Notably, these conditions are associated with an increased risk for autoimmune disease (AID). Positive effects on the immune system are observed with Se supplementation in pregnancy, autoimmune thyroid disease, and recovery from severe illness. However, some studies reported null results; the database is small, and randomized trials are sparse. The current need for research on the link between AID and Se deficiency is particularly obvious for rheumatoid arthritis and type 1 diabetes mellitus. Despite these gaps in knowledge, it seems timely to realize that severe Se deficiency may trigger AID in susceptible subjects. Improved dietary choices or supplemental Se are efficient ways to avoid severe Se deficiency, thereby decreasing AID risk and improving disease course. A personalized approach is needed in clinics and during therapy, while population-wide measures should be considered for areas with habitual low Se intake. Finland has been adding Se to its food chain for more than 35 years-a wise and commendable decision, according to today's knowledge. It is unfortunate that the health risks of Se deficiency are often neglected, while possible side effects of Se supplementation are exaggerated, leading to disregard for this safe and promising preventive and adjuvant treatment options. This is especially true in the follow-up situations of pregnancy, severe illness, or COVID-19, where massive Se deficiencies have developed and are associated with AID risk, long-lasting health impairments, and slow recovery.

Prevalence and presumptive triggers of localized bullous pemphigoid

Bullous pemphigoid (BP) is an autoimmune skin disease, caused by autoantibodies to BP180 and/or BP230. While both these autoantigens are expressed in the entire skin, only some parts of the body become affected. Rare clinical observations indicate that BP may also manifest locally, usually following exposure to triggers. Here, we evaluated the occurrence and potential triggers of localized BP (LBP) in a cohort of 285 BP patients. Medical records of all BP patients hospitalized between 2009 and 2019 were reviewed. In 7/285 BP patients, a localized variant was identified. In 5/7 LBP patients, the disease remained local, while in 2/7 patients, an initial LBP subsequently spread. All cases were preceded by presumptive triggers, including previously described triggers and bacterial infections. Overall, LBP is rare. LBP, however, might be underdiagnosed and should thus be considered in the differential diagnosis, particularly when trigger factors preceded.

Efficacy and safety of tetracyclines for pemphigoid: a systematic review and meta-analysis

The aim of this review was to evaluate the efficacy and safety of tetracyclines for treatment of pemphigoid. We searched PubMed, EMBASE, Ovid, Web of Science, and the Cochrane Library for studies involving pemphigoid patients treated with tetracyclines published in English before 29 February 2020. References of included studies were also screened to widen the scope of the literature search. Data regarding predefined clinical outcomes of 341 patients from 77 studies were extracted and analyzed. A meta-analysis was conducted on the basis of 4 studies including 2 randomized controlled trials and 2 comparative studies. The patients had a mean age of 74.60 ± 13.18 years, 45.4% were males, and 54.6% were females. There were 185 patients with mild-to-moderate and 143 patients with severe disease. The average initial doses were 1.62 ± 0.39 g/day for tetracycline, 0.20 ± 0.01 g/day for doxycycline, and 0.11 ± 0.05 g/day for minocycline. The average time on tetracyclines was 3.74 ± 5.99 months, and 261 (81.3%) patients reported partial or complete remission. Relapses occurred in 72 (28.3%) cases. Adverse effects were experienced by 130 (41.9%) patients. The pooled ORs for short-term effectiveness, relapse, adverse effects, and 1-year survival in patients treated with oral tetracyclines vs. systemic corticosteroids were 0.40 (95% CI, 0.22-0.76), 0.69 (95% CI, 0.44-1.10), 0.47 (95% CI, 0.27-0.82) and 2.02 (95% CI, 1.16-3.50), respectively. Compared to doxycycline and minocycline, tetracycline was significantly associated with better treatment outcomes and fewer adverse effects (p < 0.05). This review revealed tetracyclines' efficacy and safety in pemphigoid treatment and may offer support for clinical use of tetracyclines in pemphigoid.

Subepithelial autoimmune blistering dermatoses: Clinical features and diagnosis

Subepithelial autoimmune blistering dermatoses are a group of rare skin disorders that are characterized by the disruption of the dermal-epidermal junction through the action of autoantibodies. The third article in this continuing medical education series explores the background, epidemiology, clinical features, and diagnostic criteria of each of the major subepithelial autoimmune blistering dermatoses, including bullous pemphigoid, pemphigoid gestationis, lichen planus pemphigoides, mucous membrane pemphigoid, linear IgA bullous dermatosis, and dermatitis herpetiformis.

Peristomal Punctate Pemphigus

ABSTRACT

Cutaneous reactions surrounding abdominal stoma sites are typically irritant, allergic, infectious, traumatic or pathergic in etiology. Pemphigus, which encompasses a group of vesiculobullous autoimmune skin disorders, is seldom encountered as a peristomal dermatosis. Direct immunofluorescence (DIF) studies of pemphigus generally show continuous intercellular net-like depositions of IgG. However, punctate or dot-like intercellular deposition of IgG can also be seen in cases of pemphigus. The punctuate pattern is underreported in the literature and little is known about its implication. We describe a case of a 58-year-old Caucasian man with a history of bowel obstruction, status postcolostomy, who presented with a sharply demarcated, erythematous, crusted plaque surrounding his abdominal stoma. The patient endorsed persistent pruritus. A punch biopsy of the lesion was performed for clinical suspicion of fungal infection versus irritant dermatitis. Histopathology revealed a predominantly subcorneal acantholytic dermatitis. Periodic acid-Schiff with diastase and Grocott methenamine silver histochemical stains were negative for fungi. DIF was positive for IgG and C3 detected in a punctate intercellular pattern. In conjunction with the patient's clinical presentation and DIF, a diagnosis of peristomal pemphigus foliaceous was rendered. Herein, we describe a case of punctate pemphigus presenting as a peristomal dermatosis and include a review of the literature to raise awareness of this phenomenon.

Autoantibodies to BPAG1e Trigger Experimental Bullous Pemphigoid in Mice

Bullous pemphigoid (BP) is an autoimmune blistering disease that targets the hemidesmosomal proteins BP180 and BP230/BPAG1e. Whereas the role of anti-BP180 antibodies has been extensively characterized, the pathogenicity of anti-BPAG1e antibodies remains unclear. The purpose of this study is to elucidate the role of antibodies to BPAG1e in the experimental bullous pemphigoid models. We generated Bpag1 conditional knockout mice, where the knockout of Bpag1 is restricted to keratin 5-expressing epithelial cells. Bpag1 conditional knockout mice were immunized with the C-terminal portion of BPAG1e, and the splenocytes were injected into Rag2^-/- mice intravenously. The recipient mice presented with erosion on the feet and tails. Microscopic examination showed subepidermal blisters and a linear deposition of IgG at the dermal-epidermal junction. To assess the potential role of trauma on BP development, we inflicted surface wounds on the dorsum of the Rag2^-/- recipient mice after adoptive transfer. The wounded Rag2^-/- mice had increased morbidity and severity of BP-like symptoms. Moreover, the depletion of B cells from splenocytes abolished a subepidermal blistering phenotype in vivo. These findings demonstrate that antibodies to BPAG1e might play a pathogenic role in causing subepidermal blistering, and external factors, including trauma, might be a trigger for BP development.

Bullous Pemphigoid: Trigger and Predisposing Factors

Bullous pemphigoid (BP) is the most frequent autoimmune subepidermal blistering disease provoked by autoantibodies directed against two hemidesmosomal proteins: BP180 and BP230. Its pathogenesis depends on the interaction between predisposing factors, such as human leukocyte antigen (HLA) genes, comorbidities, aging, and trigger factors. Several trigger factors, such as drugs, thermal or electrical burns, surgical procedures, trauma, ultraviolet irradiation, radiotherapy, chemical preparations, transplants, and infections may induce or exacerbate BP disease. Identification of predisposing and trigger factors can increase the understanding of BP pathogenesis. Furthermore, an accurate anamnesis focused on the recognition of a possible trigger factor can improve prognosis by promptly removing it.

Efficacy assessment of mesenchymal stem cell transplantation for burn wounds in animals: a systematic review

Background

Clinically, severe burns remain one of the most challenging issues, but an ideal treatment is yet absent. Our purpose is to compare the efficacy of stem cell therapy in a preclinical model of burn wound healing.

Methods

Research reports on mesenchymal stem cells (MSCs) for burn wound healing were retrieved from 5 databases: PubMed, Embase, MEDLINE, Web of Science, and the Cochrane Library. The primary outcomes reported in this article include the un-healing rate of the wound area, the closure rate, and the wound area. Secondary outcomes included CD-31, vascular density, interleukin (IL)-10, thickness of eschar tissue, vascular endothelial growth factor (VEGF), and white blood cell count. Finally, a subgroup analysis was conducted to explore heterogeneity that potentially impacted the primary outcomes. A fixed-effects model with a 95% confidence interval (CI) was performed when no significant heterogeneity existed. Otherwise, a random-effects model was used. All data analysis was conducted by using Engauge Digitizer 10.8 and R software.

Results

Twenty eligible articles were finally included in the analysis. Stem cell therapy greatly improved the closure rate (2.00, 95% CI 0.52 to 3.48, p = 0.008) and compromised the wound area (− 2.36; 95% CI − 4.90 to 0.18; p = 0.069) rather than the un-healing rate of the wound area (− 11.10, 95% CI − 32.97 to 10.78, p = 0.320). Though p was 0.069, there was a trend toward shrinkage of the burn wound area after stem cell therapy. Vascular density (4.69; 95% CI 0.06 to 9.31; p = 0.047) and thickness of eschar tissue (6.56, 95% CI 1.15 to 11.98, p = 0.017) were also discovered to be significantly improved in the burn site of stem cell-treated animals. Moreover, we observed that animals in the stem cell group had an increased white blood cell count (0.84, 95% CI 0.01 to 1.66, p = 0.047) 5 days post treatment. Other indicators, such as VEGF (p = 0.381), CD-31 (p = 0.335) and IL-10 (p = 0.567), were not significantly impacted.

Conclusions

Despite limited data from preclinical trials, this meta-analysis suggests that stem cell therapy is curative in decreasing the burn wound area and provides some insights into future clinical studies of stem cell therapy for burns.

A Monocentric Retrospective Observational Study of Comorbidities in Patients Affected by Autoimmune Bullous Diseases

BACKGROUND/AIM

Autoimmune bullous diseases (AIBDs) of the skin and mucosae include a heterogeneous group of chronic diseases, which could be associated with various comorbidities. The purpose of this study was to evaluate the comorbidity profiles of patients affected by AIBDs, who referred to the Dermatological Clinic of Padua from December 2015 to June 2018.

PATIENTS AND METHODS

A monocentric retrospective observational study was conducted on 157 patients with diagnosis of AIBDs. Patients' comorbidities were investigated during the periodic visits of follow-up and through the analysis of computerized medical records.

RESULTS

Among the 157 patients, 40 (25.5%) were diagnosed with PV, 15 (9.6%) with PF, and 102 (64.9%) with BP. Nine different comorbidities were observed, but only two of these were statistically significantly associated with BP: type 2 diabetes (p=0.0142) and neuropsychiatric disorders (p=0.015).

CONCLUSION

BP is statistically significantly associated with type 2 diabetes mellitus and neuropsychiatric diseases. The correlation with neuropsychiatric pathologies is interesting for the possible bidirectional role in their etiology. The association with type 2 diabetes mellitus could suggest more caution in the administration of systemic corticosteroids, especially in elderly patients.

Collagen XVII Processing and Blistering Skin Diseases

Collagen XVII (COL17) is a hemidesmosomal transmembrane protein in the skin, which, in several autoimmune blistering skin diseases, may be targeted by autoantibodies. In addition, loss-of-function mutations in the COL17A1 gene induce a subtype of junctional epidermolysis bullosa. The extracellular domain of COL17 can be physiologically cleaved from the cell surface by ADAM family proteins in a process known as ectodomain shedding. COL17 ectodomain shedding is thought to be associated with the migration and proliferation of keratinocytes. Furthermore, the C-terminal cleavage of COL17 may be associated with basement membrane formation. COL17 can be targeted by various proteases, including MMP9, neutrophil elastase, plasmin and granzyme B, which may be associated with blister formation in pemphigoid diseases. Interestingly, cleavage of COL17 may induce neoepitopes on the proteolysed fragments, and such induction is associated with dynamic structural changes. This review summarizes the current understanding of cleavage of COL17, and how such cleavage relates to blistering skin diseases.

Radiation-Associated Pemphigus Vulgaris in a Patient With Preceding Malignancy: Treatment With Rituximab as a Valuable Option

Pemphigus is a chronic autoimmune blistering disorder, characterized by (muco-)cutaneous erosions due to autoantibodies against desmoglein 3 and/or 1. Pemphigus induction might be associated with drugs, malignancy or radiation therapy (RT); the latter being only rarely described. A rigorous literature review revealed around 30 cases of RT-associated pemphigus, which had been primarily treated with topical and/or systemic steroids, in some cases also dapsone or few other immunosuppressive agents were given. The most common underlying cancer type was breast cancer. We here present a 63-year-old male patient, who was pre-treated with adjuvant RT for larynx carcinoma 3 months before admission. He developed extensive cutaneous, ocular, and oral erosions. Despite the clinical picture comparable to a paraneoplastic pemphigus, the diagnosis of pemphigus vulgaris of mucocutaneous type was established based on the direct immunofluorescence, showing positive cell surface IgG and discrete C3 deposits, with matching cell surface IgG pattern on monkey esophagus. Serum autoantibodies to desmoglein 1 and 3 were highly positive. No further autoantibodies were found, thus paraneoplastic pemphigus was excluded. The patient was treated with high dose prednisolone, partially given intravenously up to 2 mg/kg per day, as well as topical disinfectants and class IV steroid cream. To stabilize the disease rituximab 2 × 1,000 mg was given, leading to clinical and serological remission for up to 2 years now. We show that rituximab represents a good treatment option for the frequently treatment-refractory RT-associated pemphigus, a clinically and immunologically specific RT-induced skin disorder, resulting in long-term clinical, and serological remission.

Association Between Bullous Pemphigoid and Dipeptidyl Peptidase 4 Inhibitors: A Retrospective Cohort Study

BACKGROUND

The association between dipeptidyl peptidase 4 inhibitors (DPP-4i) and bullous pemphigoid (BP) has been demonstrated in several studies. The main aim of this study was to estimate the use of DPP-4i treatment in patients diagnosed with BP in our setting.

METHODS

We selected patients histologically diagnosed with BP in our department between October 2015 and October 2018 and performed a retrospective chart review to assess clinical and epidemiological data and direct immunofluorescence (DIF) patterns.

RESULTS

Of the 70 patients diagnosed with BP during the study period, 50% were diabetic and 88.57% of these were being treated with a DPP-4i when diagnosed with BP. The most common DPP-4i was linagliptin (used in 18.6% of patients), followed by vildagliptin (17.1%). The median latency period between initiation of DPP-4i treatment and diagnosis of BP was 27.5 months for all treatments, 16 months for linagliptin, and 39 months for vildagliptin (log rank < 0.01). A negative DIF result was significantly more common in patients not being treated with a DPP-4i. The DIF pattern most strongly (and significantly) associated with DPP-4i treatment was linear immunoglobulin G deposits along the dermal-epidermal junction. DPP-4i treatment was withdrawn in 87% of patients and 96% of these achieved a complete response.

CONCLUSIONS

DPP-4i treatment is very common in patients with BP in our setting. The latency period between start of treatment and onset of BP seems to be shorter with linagliptin than with other types of gliptins. Patients receiving DPP-4i treatment may show different DIF patterns to those not receiving treatment.

The pathogenesis of bullous skin diseases

Bullous skin diseases are a group of dermatoses characterized by blisters and bullae in the skin and mucous membranes. The etiology and pathogenesis of bullous skin diseases are not completely clear. The most common are pemphigus and bullous pemphigoid (BP). Autoantibodies play critical roles in their pathogenesis. Abnormalities in the adhesion between keratinocytes in patients with pemphigus leads to acantholysis and formation of intra-epidermal blisters. Anti-desmoglein autoantibodies are present both in the circulation and skin lesions of patients with pemphigus. The deficient adhesion of keratinocytes to the basement membrane in BP patients gives rise to subepidermal blisters. Autoantibodies against the components of hemidesmosome can be detected in BP patients. Many novel therapeutics based on knowledge of the pathogenesis have emerged in recent years.

Proteases in Pemphigoid Diseases

Pemphigoid diseases are a subgroup of autoimmune skin diseases characterized by widespread tense blisters. Standard of care typically involves immunosuppressive treatments, which may be insufficient and are often associated with significant adverse events. As such, a deeper understanding of the pathomechanism(s) of pemphigoid diseases is necessary in order to identify improved therapeutic approaches. A major initiator of pemphigoid diseases is the accumulation of autoantibodies against proteins at the dermal-epidermal junction (DEJ), followed by protease activation at the lesion. The contribution of proteases to pemphigoid disease pathogenesis has been investigated using a combination of in vitro and in vivo models. These studies suggest proteolytic degradation of anchoring proteins proximal to the DEJ is crucial for dermal-epidermal separation and blister formation. In addition, proteases can also augment inflammation, expose autoantigenic cryptic epitopes, and/or provoke autoantigen spreading, which are all important in pemphigoid disease pathology. The present review summarizes and critically evaluates the current understanding with respect to the role of proteases in pemphigoid diseases.

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.

Dipeptidyl peptidase IV inhibitor-associated bullous pemphigoid: a recently recognized autoimmune blistering disease with unique clinical, immunological and genetic characteristics

Bullous pemphigoid (BP) is an organ-specific autoantibody-mediated autoimmune blistering skin disorder that tends to affect the elderly. Tense blister formation associated with itchy urticarial erythema is clinically observed in BP, and subepidermal blister formation with eosinophilic infiltration is a histopathological characteristic. BP autoantibodies target two hemidesmosomal components in basal keratinocytes: BP180 and BP230. Anti-BP180 autoantibodies play major roles in blister formation. Although the autoantibody-mediated pathomechanism of blister formation has been extensively studied, little is known about how and why immune tolerance to BP180 may be broken in certain elderly individuals. Recently, BP has been increasingly reported in diabetes mellites (DM) patients receiving dipeptidyl peptidase-IV inhibitors (DPP4is), which are widely used anti-DM drugs. Pharmacovigilance and cohort studies have revealed that DPP4is, especially vildagliptin, teneligliptin, and linagliptin, are a potential risk factor for BP onset. Interestingly, it has been revealed that Japanese DPP4i-BP tends to show a non-inflammatory phenotype, with less erythema than normal BP, and that DPP4i-BP autoantibodies target distinct epitopes on BP180. In addition, human leukocyte antigen-DQB1*03:01 was identified as the major haplotype in Japanese DPP4i-BP. This review summarizes the latest understanding of the pathogenesis of BP, with a special focus on the recently recognized DPP4i-BP.

Cutaneous Adverse Effects of Diabetes Mellitus Medications and Medical Devices: A Review

Diabetes mellitus is one of the most prevalent chronic diseases in the USA. If uncontrolled, diabetes can lead to devastating complications. Diabetes medications and medical devices largely contribute to the significant financial expense that the disease inflicts on affected individuals and society. Alongside significant economic burden, there are numerous cutaneous adverse effects associated with diabetes medications and medical devices. Despite the large and increasing number of individuals living with diabetes and the wide use of the related medications and medical devices, there is limited literature that comprehensively documents their cutaneous adverse effects. These cutaneous adverse effects are significant as they can worsen glycemic control, increase disease distress, and may increase risk of associated complications. Thus, it is important that providers can recognize these cutaneous adverse effects, identify the culprit agents, and can properly manage them. In this article, we provide a critical review of the cutaneous adverse effects of medications and devices used in the management of diabetes and provide insight into risk factors and prevention and an overview of therapeutic management. An emphasis is placed on clinical recognition and treatment for use of the medical providers who, regardless of practice setting, will treat patients with diabetes.

Dermatitis Herpetiformis and Celiac Disease Increase the Risk of Bullous Pemphigoid

Bullous pemphigoid (BP) and dermatitis herpetiformis (DH) are autoimmune bullous skin diseases. DH has been described to evolve into BP and the two diseases can have overlapping clinical appearances and diagnostic findings, but the association between DH and BP has not previously been studied in a large population. To evaluate DH and celiac disease as risk factors for BP, we conducted a retrospective case-control study of patients with BP and matched controls with basal cell carcinoma diagnosed in Finland between 1997 and 2013. A total of 3,397 patients with BP and 12,941 controls were included in the study. Forty-one (1.2%) BP patients and 7 (0.1%) controls had preceding DH. Diagnosed DH increased the risk of BP 22-fold (odds ratio = 22.30; 95% confidence interval = 9.99-49.70) and celiac disease 2-fold (odds ratio = 2.54; 95% confidence interval = 1.64-3.92) compared to controls. Eighteen (43.9%) of the patients who had DH and subsequent BP had bought dapsone during the 2 years prior to their BP diagnosis. Mean time between diagnosed DH and BP was 3 years. We conclude that diagnosis of DH is associated with a striking increase in the risk for BP.