Interleukin-36 cytokines are overexpressed in the skin and sera of patients with bullous pemphigoid.

Bullous pemphigoid (BP) is an autoimmune bullous disease, characterized by autoantibodies targeting BP180 and BP230. The role of interleukin (IL)-36, a potent chemoattractant for granulocytes, in BP remains elusive.The expression of IL-36 cytokines (IL-36α, ß, γ) and their antagonists (IL-36Ra and IL-38) was analysed in the skin and serum samples of patients with BP (n = 31), psoriasis (n = 10) and healthy controls (HC) (n = 14) by quantitative polymerase chain reaction and enzyme linked immunosorbent assay, respectively. Skin and serum levels of all cytokines were correlated with the Bullous Pemphigoid Disease Area Index (BPDAI) score and with the serum concentration of pathogenic antibodies.IL-36α, IL-36ß, IL-36γ and IL-36Ra were significantly (p < 0.05) overexpressed in BP skin compared to HC, without remarkable differences relative to psoriasis skin. The expression of IL-38 was significantly (p < 0.05) higher in BP compared to psoriasis skin.IL-36α and γ, but not ß, serum concentrations were significantly (p < 0.05) higher in BP compared to HC. IL-36γ was significantly (p < 0.05) more expressed in the serum of psoriasis patients than BP. The serum concentration of IL-36Ra and IL-38 were similar between BP and HC, while IL-38 serum levels were significantly (p < 0.05) higher in BP compared to psoriasis patients. Serum IL-36α correlated significantly with BPDAI (r = 0.5 p = 0.001).IL-36 agonists are increased in BP patients, both locally and systemically. Serum IL-36α might represent a potential biomarker for BP. An inefficient balance between IL-36 agonists and antagonists is likely to occur during BP inflammation.

Pilot study investigating BP-180 in extracellular vesicles derived from blister fluid of bullous pemphigoid patients.

Bullous pemphigoid (BP) is an autoimmune blistering disease that targets the haemidesmosomal proteins, mainly BP180. Extracellular vesicles (EVs) have been demonstrated to carry tissue-specific autoantigens in the setting of autoimmune diseases and transplant organ rejection; this phenomenon was demonstrated to have pathogenic implications in autoimmune diseases and to correlate with transplant rejection severity. The purpose of this study was to identify the presence of BP targeted autoantigens in blister fluid derived EVs. We isolated, by size exclusion chromatography, EVs derived from blisters of BP-patients and from suction blisters of healthy donors. EV characterization was performed by flow cytometry and nanoparticle tracking analysis. Western blot analysis was used to investigate the presence of autoantigens. A suspension enriched in EVs was efficiently obtained from blister fluid from patients and healthy donors. EV-enriched fractions were enriched in particles with a size distribution characterizing small-EVs (main peak was present at 94.5 nm). BP180 was found, by western blot analysis, in EVs derived from blister fluid of 3 out 6 BP patients and in none of EVs isolated from suction blister fluid of healthy donors. BP230 and Dsg1 were not detectable in EVs of any of the samples. No specific clinical characteristics seemed to correlate to the presence of BP180 in EVs. The discovery of BP180 in EVs derived from blister fluid might help understanding BP pathogenesis.

Pemphigus: trigger and predisposing factors.

Pemphigus is a life-threatening autoimmune blistering disease affecting skin and mucous membranes. Despite its etiopathogenesis remains largely unknown, several trigger and predisposing factors have been reported. Pemphigus is caused by autoantibodies that target desmoglein 1 and desmoglein 3, impacting desmosome function. However, circulating autoantibodies are often the consequence of a precipitating factor that occurs in predisposed individuals. This review aims to describe and discuss almost all trigger and predisposing factors reported as possible or probable cause of the disease. Among the reported trigger factors that may induce or exacerbate pemphigus, we have found of particular interest: drug intake (especially thiol- and phenol-containing compounds), vaccines, infections, as well as some reports about pregnancy, radiations, emotional stress, pesticides and physical trauma. Moreover, we discuss the possible role of food intake in pemphigus onset and particular attention is given to dietary factors containing thiol, phenol and tannin compounds. A trigger factor is "the straw that breaks the camel's back," and often acts together with predisposing factors. Here we discuss how pemphigus onset may be influenced by genetic susceptibility and comorbidities like thyroid diseases, malignancies and other autoimmune disorders. To identify other hitherto unknown trigger and predisposing factors, well designed prospective studies are needed. In this context, future research should explore their connection with the aim to advance our understanding of pemphigus pathogenesis.

Case report: A rare case of imiquimod-induced atypical pemphigus vulgaris.

Background: Pemphigus vulgaris is an autoimmune intraepithelial bullous disease involving the skin and the mucous membranes. Imiquimod, a topical therapy for skin basal cell carcinoma, is an amine that induces the production of tumor necrosis factor alfa, interleukin-1 and other cytokines. Pemphigus induced by drugs has been frequently reported, mostly after systemic therapy. Case presentation: We present the case of a 50-year-old man who developed skin, intraoral, and genital mucosae lesions 3 days after a treatment with Imiquimod for multiple superficial basal cell carcinoma of the trunk. Direct and indirect immunofluorescence results were compatible with the diagnosis of pemphigus vulgaris. Enzyme-linked immunosorbent assay was negative for desmoglein 1 and 3, but interestingly, by immunoblotting on keratinocyte extracts a band of 170 kDa was obtained by IgG. The patient, after interrupting Imiquimod application, started a treatment with prednisolone and in 4 weeks showed a complete remission. Conclusion: Topical Imiquimod therapy might induce atypical pemphigus vulgaris in some patients.

Gliptin-associated bullous pemphigoid shows peculiar features of anti-BP180 and -BP230 humoral response: Results of a multicenter study.

BACKGROUND: Recently, several case-control studies demonstrated an association between gliptins and bullous pemphigoid (BP) occurrence. However, data on the clinical and immunologic features of gliptin-associated bullous pemphigoid (GABP) are controversial. OBJECTIVE: This study aimed to clinically and immunologically characterize a large cohort of GABP patients to get an insight into the pathophysiology of this emerging drug-induced variant of BP. METHODS: Seventy-four GABP patients were prospectively enrolled and characterized from 9 different Italian dermatology units between 2013 and 2020. RESULTS: Our findings demonstrated the following in the GABP patients: (1) a noninflammatory phenotype, which is characterized by low amounts of circulating and skin-infiltrating eosinophils, is frequently found; (2) immunoglobulin (Ig)G, IgE, and IgA humoral responses to BP180 and BP230 antigens are reduced in frequency and titers compared with those in patients with idiopathic BP; (3) IgG reactivity targets multiple BP180 epitopes other than noncollagenous region 16A. LIMITATIONS: A limitation of the study is that the control group did not comprise only type 2 diabetes mellitus patients with BP. CONCLUSION: GABP patients show peculiar features of anti-BP180 and -BP230 humoral responses, laying the foundation for diagnostic improvements and getting novel insights into understanding the mechanism of BP onset.

Anti-laminin 332 antibody detection using biochip immunofluorescence microscopy in a real-life cohort of Italian patients with mucous membrane pemphigoid

Background: Mucous membrane pemphigoid (MMP) with anti-laminin 332 autoantibodies may be associated with malignancies, however, current serological assays have considerable limitations. At present, no commercial test for anti-laminin 332 antibodies is available, restricting the diagnosis to specialized laboratories worldwide. Biochip immunofluorescence microscopy has shown promising results in selected cohorts of laminin 332-MMP patients. Objectives: To detect anti-laminin 332 antibodies by biochip immunofluorescence microscopy in a real-life cohort of MMP patients and compare the results with those from traditional immunoblotting. Materials & Methods: Sera were obtained from 31 patients with MMP, 28 with bullous pemphigoid, five with pemphigus vulgaris, five with paraneoplastic pemphigus, five with linear IgA bullous dermatosis, and 10 controls, and analysed by biochip immunofluorescence using human cells expressing laminin 332. Immunoblotting was performed using purified laminin 332. Results: MMP involved the oral mucosa in 65%, ocular mucosa in 9%, oral and ocular mucosae extensively in 13% as well as other mucosae in 13% of patients. Concomitant cutaneous involvement was reported in 35% of patients. Three MMP patients had an underlying malignancy. Anti-laminin 332 antibodies were detected in 2/31 (6%) cases by both methods. Based on immunoblotting, both laminin 332-positive sera reacted with α3 chain (in one case also with ß3 chain). Both patients with anti-laminin 332 antibodies had extensive mucosal involvement and only one had cancer. Anti-laminin 332 antibodies were not detected in control groups. Conclusion: Biochip immunofluorescence is an appropriate technique to detect anti-laminin 332 antibodies which should be tested in patients with MMP.

Case Report: Management of Malignancy-Exacerbated Pemphigus Vulgaris During COVID-19 Pandemic.

Pemphigus vulgaris is an intraepidermal autoimmune mucocutaneous blistering disease whose etiopathogenesis includes various trigger factors, i.e., drugs and malignancies. We present a case of malignancy-exacerbated pemphigus vulgaris which required a careful diagnostic process in order to rule out paraneoplastic pemphigus, along with the challenges posed by the need of treating both cutaneous and oncologic diseases. Possible post-operative complications post-poned the start of first-line immunosuppressive treatment of pemphigus. Moreover, the infective risks had to be minimized during the peak of the COVID-19 pandemic in Italy. Intravenous immunoglobulins were chosen as "bridge" therapy before the tumor surgical excision, followed by rituximab in post-operative phase.

Case Report: Complete and Fast Recovery From Severe COVID-19 in a Pemphigus Patient Treated With Rituximab.

COVID-19 is characterized by a severe pulmonary disease due to severe acute respiratory syndrome (SARS)-CoV-2 infection. For clinicians involved in the management of patients with chronic autoimmune diseases the risk linked to the conditions itself and to drug-induced immunosuppression during the COVID-19 pandemic is a major topic. Pemphigus is a rare autoimmune blistering disease (AIBD) of the skin and mucous membranes caused by autoantibodies to desmosomal components, desmoglein 1 and 3. Among immunosuppressant therapies, rituximab (RTX) is considered a highly effective treatment with a favorable safety profile, but it induces a prolonged B-cell depletion that can lead to higher susceptibility to infections. For this reason, concerns about its use during the pandemic have been raised. We describe a case of a pemphigus patient in which RTX-induced B cell depletion led to the severe inflammatory phase, whereas corticosteroid treatment allowed a favorable outcome.

Pemphigus vulgaris in two pairs of siblings from two unrelated Italian families: Human leukocyte antigen genotypes, ST18 mutation and immunological profile.

Pemphigus vulgaris (PV) is an autoimmune intraepithelial bullous disease. Associations with the class II human leukocyte antigen (HLA) alleles and pemphigus vulgaris have been described. Furthermore, an association between the single nucleotide polymorphism of the ST18 gene and pemphigus vulgaris has been reported. We report two pairs of siblings from two unrelated Italian families affected by pemphigus vulgaris, characterizing their genetic and immunological profile. In order to assess the genetic background, HLA-DQA1, HLA-DQB1, HLA-DRB1 and a relevant ST18 polymorphism were investigated. As for the immunological profiles, anti-desmoglein antibodies were analyzed. In family A, the two pemphigus vulgaris patients had the same HLA genetic profile: HLA-DQA1 *01:04/*03:01, HLA-DQB1 *03:02/*05:03 and HLA-DRB1 *04:02/*14:01. The male patient was heterozygous for the ST18 mutation while the female patient had a wild genotype. In family B, the two pemphigus vulgaris patients were both wild type for the ST18 mutation and showed the same HLA genotype: HLA-DQA1 *03:01/*05:08, HLA-DQB1 *03:01/*03:03 and HLA-DRB1 *04:02/*11:01. Our data show a relevant relationship between the HLA profile and pemphigus vulgaris in our Italian families. In family A, all six alleles are frequently associated with pemphigus vulgaris and were expressed only in the two pemphigus patients; and in family B, two of the six alleles are frequently associated with pemphigus vulgaris. No relevant relationship was found between ST18 polymorphism and pemphigus disease.

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.

Antioxidant Activity of Synthetic Polymers of Phenolic Compounds.

In recent years, developing potent antioxidants has been a very active area of research. In this context, phenolic compounds have been evaluated for their antioxidant activity. However, the use of phenolic compounds has also been limited by poor antioxidant activity in several in vivo studies. Polymeric phenols have received much attention owing to their potent antioxidant properties and increased stability in aqueous systems. To be truly effective in biological applications, it is important that these polymers be synthesized using benign methods. In this context, enzyme catalyzed synthesis of polymeric phenols has been explored as an environmentally friendly and safer approach. This review summarizes work in enzymatic syntheses of polymers of phenols. Several assays have been developed to determine the antioxidant potency of these polymeric phenols. These assays are discussed in detail along with structure-property relationships. A deeper understanding of factors affecting antioxidant activity would provide an opportunity for the design of versatile, high performing polymers with enhanced antioxidant activity.

Autoantibody Profile of a Cohort of 54 Italian Patients with Linear IgA Bullous Dermatosis: LAD-1 Denoted as a Major Auto-antigen of the Lamina Lucida Subtype.

Linear IgA bullous dermatosis (LABD) is characterized by presence of multiple IgA autoantibodies, and a comparatively lesser number of IgG antibodies, directed against different hemidesmosomal antigens. The main autoantigens are LAD-1, LABD-97, BP180 and BP230, type VII collagen and laminin 332. We retrospectively studied the serology of 54 Italian patients with LABD using enzyme-linked immunosorbent assay (ELISA), immunoblotting assay, and indirect immunofluorescence on monkey oesophagus and salt-split skin. Among these, indirect immunofluorescence of salt-split skin elicits the greatest sensitivity. Sixty-three percent of the sera were observed to be positive, with a lamina lucida pattern observed in 48%, a sub-lamina densa pattern in 2% and a mixed pattern in 13% of the cases. IgA reactivity to LAD-1 on immunoblotting was found in 52% of sera, to BP180-NC16A by ELISA in 32% and to BP230 in 26%. Only 17% of patients possessed circulating IgG autoantibodies. LAD-1 was determined to be a major autoantigen of the lamina lucida subtype. Combined serological assays demonstrated a high sensitivity (82%), suggesting that this approach could support diagnosis when a biopsy is not feasible or direct immunofluorescence results are negative.

Anti-inflammatory effects and antioxidant activity of dihydroasparagusic acid in lipopolysaccharide-activated microglial cells.

The activation of microglia and subsequent release of toxic pro-inflammatory factors are crucially associated with neurodegenerative disease, characterized by increased oxidative stress and neuroinflammation, including Alzheimer and Parkinson diseases and multiple sclerosis. Dihydroasparagusic acid is the reduced form of asparagusic acid, a sulfur-containing flavor component produced by Asparagus plants. It has two thiolic functions able to coordinate the metal ions, and a carboxylic moiety, a polar function, which may enhance excretion of the complexes. Thiol functions are also present in several biomolecules with important physiological antioxidant role as glutathione. The aim of this study is to evaluate the anti-inflammatory and antioxidant potential effect of dihydroasparagusic acid on microglial activation in an in vitro model of neuroinflammation. We have used lipopolysaccharide to induce an inflammatory response in primary rat microglial cultures. Our results suggest that dihydroasparagusic acid significantly prevented lipopolysaccharide-induced production of pro-inflammatory and neurotoxic mediators such as nitric oxide, tumor necrosis factor-α, prostaglandin E2, as well as inducible nitric oxide synthase and cyclooxygenase-2 protein expression and lipoxygenase activity in microglia cells. Moreover it effectively suppressed the level of reactive oxygen species and affected lipopolysaccharide-stimulated activation of mitogen activated protein kinase, including p38, and nuclear factor-kB pathway. These results suggest that dihydroasparagusic acid's neuroprotective properties may be due to its ability to dampen induction of microglial activation. It is a compound that can effectively inhibit inflammatory and oxidative processes that are important factors of the etiopathogenesis of neurodegenerative diseases.

4-Methylcoumarin derivatives with anti-inflammatory effects in activated microglial cells.

Inflammation contributes to the pathogenesis of neurodegenerative diseases and anti-inflammatory compounds may have a role in prevention or treatment of these pathologies. 4-Methylcoumarins are effective antioxidants with anti-inflammatory properties. In this study, the inhibitory effects of two 4-methylcoumarin derivatives, 7,8-dihydroxy-3-ethoxycarbonylmethyl-4-methylcoumarin (DHEMC) and 7,8-diacetoxy-3-ethoxycarbonylmethyl-4-methylcoumarin (DAEMC) were examined on the inflammatory processes induced by lipopolysaccharide (LPS) in activated primary rat microglial cultures. LPS-induced production of nitric oxide (NO, measured by Griess method) and other pro-inflammatory mediators, thromboxane (TX) B2 and prostaglandin (PG) E2 (both determined by radioimmunoassay (RIA)), as well as tumor necrosis factor (TNF)-α (determined by enzyme-linked immunosorbent assay (ELISA)) were inhibited in the presence of 100 µM DHEMC and DAEMC. DAEMC was able to significantly inhibit NO, TXB2 and TNF-α production also at 50 µM. Both compounds at 100 µM significantly lowered cyclooxygenase-2 (COX-2) protein expression in LPS-stimulated microglial cells measured by Western blot, but only DAEMC showed an inhibitory effect on inducible nitric oxide synthase (iNOS) protein expression at 100 µM. In conclusion, our findings show that 4-methylcoumarin derivatives can modulate inflammatory pathways in microglial cells, probably by acting at the protein expression level.

In vitro morphine metabolism by rat microglia.

Morphine is mainly transformed to morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) in the liver. Glucuronidation is also performed by rat brain homogenates and UDP-glucuronosyltransferases (UGTs) are present in the brain. Here we investigated the possibility that microglia transforms morphine into its metabolites M3G and M6G. Primary cultures of neonatal rat microglia were incubated for different intervals of time in basal conditions or with different concentrations of morphine. The following measures were performed on these cultures and/or in the medium: (i) morphine as well as M3G and M6G concentrations; (ii) levels of mRNA coding for UGT1A1, UGT1A6, UGT1A7, and UGT2B1 as well as their protein levels; (iii) released prostaglandin (PG)E2 and nitrite concentrations. Results show that in basal conditions morphine and M3G are produced by microglia; accordingly, these cells expressed UGT1A1, UGT1A6 and UGT1A7, but not UGT2B1. When cultures were exposed to different concentrations of exogenous morphine, M6G was also synthesized. This shift in the glucuronidation was associated with variations in the expression of UGT isozymes. In particular, UGT1A7 expression was rapidly upregulated and this event was translated into enhanced protein levels of UGT1A7; lesser effects were exerted on UGT1A1 and UGT1A6. Upon prolonged exposure to morphine, microglial cell UGT expression returned to baseline conditions or even to reduced levels of expression. Morphine exposure did not affect the synthesis of both PGE2 and nitrites, ruling out a generalized priming of microglia by morphine. In conclusion, this study suggests that morphine glucuronides found in the cerebrospinal liquor upon peripheral morphine administration may at least in part be brain-born, reconciling the conceptual gap between the high hydrophilic features of morphine glucuronides and their presence beyond the blood-brain barrier.