Skin Of Pemphigus Vulgaris Patients Research Articles

Trichoscopy of pemphigus vulgaris in remission. A tool for treatment-cessation decision making. Preliminary results

Background: One of the controversies in the treatment of Pemphigus Vulgaris (PV), is the time of treatment cessation. Scalp involvement is often the most stubborn to treatment human area and may reflect disease activity. Trichoscopy (Dermoscopy of hair and scalp) features have not been studied in clinically “healthy-looking” skin of PV patients in full remission. Aims and Objectives:To find out if there are any trichoscopy features in PV patients in clinical and immunologic remission, and accommodate treatment decision. Methods: The age and disease duration of 3 women with PV were correspondingly 62, 63, 55 and 5, 6, 15 years. Treatment at examination was 2,5 mg prednisone(Pr), for the last 22, 5 and 7 months. The 2nd patient was also taking 1 mg/kg/d of Azathioprine. Anti Desmoglein antibodies turned to negative since Oct/2017, Feb/2017, Sept/2015. Contact dermoscopy and hand lens X10 magnifier for clinical evaluation, were used. Results: A red hue background, peripillar scales and tubular casts were observed by trichoscopy in the first 2 patients. Only peripilar scales on a small brown round area were the features in the 3rd patient. Treatment cessation was decided only in this patient, since casts observed in the other two patients, were considered as a consequence of outer root sheath acantholysis and a sign of disease activity. Patients’ follow up justified the aforementioned treatment decisions. Conclusions: Areas of red hue skin background and movable cylindical scales (casts) around hair shafts may be observed, even in the absence of apparent scalp clinical involvement, in PV patients in remission. Since these features may drive physicians to treatment continuation, dermoscopy of the scalp is required in clinically “healthy-looking” PV patients, before a decision of treatment cessation is made. Future studies with greater number of patients, furtherly validated by long term disease course outcome, are needed.

Downregulation of aquaporin 3 in patients with pemphigus vulgaris.

Pemphigus vulgaris (PV) is an autoimmune bullous skin disease. Aquaporin 3 (AQP3) is a glycerol/water channel involved in several physiological functions. Evaluation of the tissue expression and localization of AQP3 in the skin of PV patients. Twenty-seven PV patients and 30 controls were included. The patients were subjected to history taking, clinical evaluation, Autoimmune Bullous Skin Disorder Intensity Score and 4-mm punch biopsy. The biopsies were stained using anti-human AQP3 antibody and the immunofluorescence pattern and intensity were evaluated using a scoring system and ImageJ software analysis. AQP3 was expressed in the basal epidermis in 27 (100%) and in the suprabasal epidermis in 19 PV patients (70.4%). It was expressed in all controls in basal and suprabasal layers. Intensity of AQP3 immunofluorescence was strong in 2 (7.4%), moderate in 19 (70.4%) and weak in 6 patients (22.2%) while it was strong in 18 (60%) and moderate in 12 controls (40%). AQP3 expression was significantly lower in patients than controls in the suprabasal epidermis (p= 0.001). Patients with extensive disease had significantly weaker AQP3 intensity than those with marked disease (p= 0.005) Downregulation of AQP3 in patients with PV, especially in the suprabasal layers and in extensive clinical disease, suggests a potential role of AQP3 in the pathogenesis of PV.

Up-regulation of ST18 in pemphigus vulgaris drives a self-amplifying p53-dependent pathomechanism resulting in decreased desmoglein 3 expression

Pemphigus vulgaris (PV) is a life-threatening autoimmune mucocutaneous blistering disease which is to a large extent genetically determined, and results, at least in part, from the deleterious activity of autoantibodies directed against desmoglein (DSG)3, a prominent intra-epidermal adhesion molecule. Those autoantibodies lead to decreased membranal DSG3 expression in keratinocytes (KCs), thereby destabilizing cell–cell adhesion within the epidermis and leading to blister formation. We previously showed that rs17315309, a strong risk variant for PV within the promoter of the ST18 transcription factor gene, promotes epidermal ST18 up-regulation in a p53/p63-dependent manner. Accordingly, ST18 was found to be overexpressed in the skin of PV patients. Increased ST18 expression was then shown to markedly augment PV autoantibodies-mediated loss of KCs cohesion. Here, we demonstrate that ST18 overexpression significantly increases autoantibody-mediated DSG3 down-regulation in keratinocytes. In addition, DSG3 decreased expression boosts p53 function through p38 mitogen-activated protein kinase (p38MAPK) activation and dramatically augments p53-dependent ST18 promoter activity. Finally, the PV risk variant rs17315309 is associated with increased p53 expression in PV skin. Taken collectively, these observations reveal a novel self-amplifying pathomechanism involving ST18, DSG3, p38 and p53, capable of perpetuating disease activity, and therefore indicative of novel actionable molecular targets in PV.

004 Up-regulation of ST18 drives pemphigus vulgaris pathogenesis: a perpetuum mobile model

Pemphigus vulgaris (PV) is a life-threatening autoimmune mucocutaneous blistering disease. We previously showed that a genetic variant within the ST18 promoter promotes ST18 up-regulation in a p53/p63-dependent manner and is associated with a 6-fold increased risk to develop PV. ST18 was also found to be overexpressed in the skin of PV patients. In addition, it has been shown that desmoglein 3 (DSG3) down-regulation is associated with increased p53 expression and activity. Based on these data, using a combination of reporter assays, Western blotting, confocal immunofluorescence microscopy, we investigated the possibility that ST18, DSG3 and p53 may be jointly involved on the pathogenesis of PV.

Identification of a Functional Risk Variant for Pemphigus Vulgaris in the ST18 Gene.

Pemphigus vulgaris (PV) is a life-threatening autoimmune mucocutaneous blistering disease caused by disruption of intercellular adhesion due to auto-antibodies directed against epithelial components. Treatment is limited to immunosuppressive agents, which are associated with serious adverse effects. The propensity to develop the disease is in part genetically determined. We therefore reasoned that the delineation of PV genetic basis may point to novel therapeutic strategies. Using a genome-wide association approach, we recently found that genetic variants in the vicinity of the ST18 gene confer a significant risk for the disease. Here, using targeted deep sequencing, we identified a PV-associated variant residing within the ST18 promoter region (p<0.0002; odds ratio = 2.03). This variant was found to drive increased gene transcription in a p53/p63-dependent manner, which may explain the fact that ST18 is up-regulated in the skin of PV patients. We then discovered that when overexpressed, ST18 stimulates PV serum-induced secretion of key inflammatory molecules and contributes to PV serum-induced disruption of keratinocyte cell-cell adhesion, two processes previously implicated in the pathogenesis of PV. Thus, the present findings indicate that ST18 may play a direct role in PV and consequently represents a potential target for the treatment of this disease.

Population-Specific Association between a Polymorphic Variant in ST18, Encoding a Pro-Apoptotic Molecule, and Pemphigus Vulgaris

Pemphigus vulgaris (PV) is a severe autoimmune blistering disease caused by anti-epithelial antibodies, leading to disruption of cell-cell adhesion. Although the disease is exceedingly rare worldwide, it is known to be relatively prevalent in Jewish populations. The low prevalence of the disease represents a significant obstacle to a genome-wide approach to the mapping of susceptibility genes. We reasoned that the study of a genetically homogeneous cohort characterized by a high prevalence of PV may help exposing associated signals while reducing spurious results due to population sub-structure. We performed a genome-wide association study using 300K single-nucleotide polymorphisms (SNPs) in a case-control study of 100 PV patients of Jewish descent and 397 matched control individuals, followed by replication of significantly associated SNPs in three additional cohorts of Jewish, Egyptian, and German origin. In addition to the major histocompatibility complex locus, a genomic segment on 8q11.23 that spans the ST18 gene was also found to be significantly associated with PV. This association was confirmed in the Jewish and Egyptian replication sets but not in the German sample, suggesting that ST18-associated variants may predispose to PV in a population-specific manner. ST18 regulates apoptosis and inflammation, two processes of direct relevance to the pathogenesis of PV. Further supporting the relevance of ST18 to PV, we found this gene to be overexpressed in the skin of PV patients as compared with healthy individuals.

Pemphigus vulgaris: accumulation of apoptotic cells in dermis and epidermis possibly relates to pathophysiology through TNF-alpha production by phagocytes

Apoptotic cells are present in the epidermis of pemphigus vulgaris (PV) patients and their accumulation has been linked to chronic inflammatory disorders. TNF-α is elevated in sera of PV patients and has only been detected in acantholytic and periacantholytic keratinocytes (KC), therefore another TNF-α source might exist. We analyzed, in lesional and perilesional skin of 5 active untreated PV patients, the presence of apoptotic cells, TNF-α and phagocytic infiltrate. In vitro, we analyzed whether phagocytosis of apoptotic KCs by monocytes causes TNF-α release. We found a significant increase of apoptotic cells in the epidermis and dermis of PV patients, by TUNEL, and activated caspase-3. TNF-α was present in the skin of PV patients, especially in the dermis. Phagocytic CD14+ cells were increased, mostly in the dermis of PV patients. In vitro phagocytosis of apoptotic KCs by monocytes caused enhanced TNF-α production, which correlated with the number of apoptotic KCs in the co-culture. Thus, accumulation of apoptotic cells in PV could promote TNF-α production by monocytes, which could, in turn, cause further apoptosis, closing a vicious circle.

IgG-induced clustering of desmogleins 1 and 3 in skin of patients with pemphigus fits with the desmoglein nonassembly depletion hypothesis

In pemphigus circulating IgG is present with the desmosomal cadherins desmoglein (Dsg) 1 and 3. In the epidermis of patients, this IgG deposits in a pattern that is often partly granular and does not reflect the normal Dsg distribution. To understand why the IgG deposits in a granular pattern in the skin of patients with pemphigus. We analysed the distribution of IgG and desmosomal adhesion molecules in skin biopsies of 18 patients with pemphigus vulgaris (PV) and 10 with pemphigus foliaceus (PF) by double staining immunofluorescence. The effect of IgG on desmosomal proteins was studied in an in vitro skin model. In PF skin Dsg1, but not Dsg3, was aberrantly distributed in the same partly granular pattern as the IgG. Vice versa, in skin of PV patients with anti-Dsg3 antibodies, Dsg3, but not Dsg1, colocalized with the granular IgG. Plakoglobin also coclustered with IgG and Dsg, but this was far more prominent with Dsg1 than with Dsg3. In areas of heavy Dsg1 clustering, but not in areas of heavy Dsg3 clustering, intercellular widening between keratinocytes was present. Patient IgG, but not Fab fragments, induced the same Dsg clustering in vitro. The IgG-induced clustering of the Dsg autoantigens underlies the granular IgG deposition in patient skin. In PF and in mucocutaneous PV, Dsg1 clustering, but not Dsg3 clustering, correlates with nonacantholytic intercellular widening between desmosomes. In the patient the Dsg becomes sequestered from desmosomal components which fits in with the desmoglein nonassembly depletion hypothesis, indicating that targeted nonjunctional Dsg is no longer available to be incorporated into desmosomes and this leads to disturbed assembly, and Dsg-depleted desmosomes.

Synergistic actions of pemphigus vulgaris IgG, Fas-ligand and tumor necrosis factor-α during induction of basal cell shrinkage and acantholysis

This study tested a recently proposed “Basal Cell Shrinkage” hypothesis of pemphigus acantholysis through a quantitative analysis of individual and cooperative effects of pemphigus vulgaris (PV) IgG, Fas-ligand (Fas-L) and tumor necrosis factor-α (TNFα) on keratinocyte (KC) volume (i.e. cell size) and adhesive properties. Exposure of KC monolayers and MatTek EpiDermFT™ tissues cultures to the physiologic concentrations of Fas-L, TNFα or IgGs from two PV patients resulted in various degrees of reversible changes, which were not observed in control cultures either exposed to normal IgG or left intact. Within 12–24 h of exposure, basal cells in experimental cultures lost their ability to form stress fibers, retracted cytoplasmic aprons and formed keratin aggregates, indicating that their cytoskeleton collapsed. The cell volume decreased significantly (p < 0.05) as the polygonal cell shape changed to a round one. The shrunk cells detached from their neighbors and the substrate, resulting in a reciprocal increase of both the areas of acantholysis and the number of detached KCs, respectively. Since in the skin of PV patients, KCs are targeted by autoantibodies concomitantly with being exposed to autocrine and paracrine pro-apoptotic and pro-inflammatory cytokines, we combined PV IgG with Fas-L and/or TNFα in the cell culture experiments. This amplified several fold an ability of PV IgG to cause basal cell shrinkage and detachment. The obtained results demonstrated for the first time that PV IgG works together with Fas-L and TNFα to induce acantholysis via basal cell shrinkage, which provides a novel mechanism explaining successful treatment of PV patients with TNFα inhibitors.