Pemphigus vulgaris (PV) is a paradigm of autoimmune disease affecting intercellular adhesion. The mechanisms that lead to cell–cell detachment (acantholysis) have crucial therapeutic implications and are currently undergoing major scrutiny. The first part of this review focuses on the classical view of the pathogenesis of PV, which is dominated by the cell adhesion molecules of the desmosome, namely desmogleins (Dsgs). Cloning of the DSG3 gene, generation DSG3 knock-out mice and isolation of monoclonal anti-Dsg3 IgG have aided to clarify the pathogenic mechanisms of PV, which are in part dependent on the fate of desmosomal molecules. These include perturbation of the desmosomal network at the transcriptional, translational, and interaction level, kinase activation, proteinase-mediated degradation, and hyper-adhesion. By the use of PV models, translational research has in turn helped shed light into the basic structure, function, and dynamics of assembly of desmosomal cadherins. The combined efforts of basic and applied research has resulted in tremendous advance into the understanding of epidermal adhesion and helped debunk old myths on the supposedly unique role of desmogleins in the mechanisms of cell–cell detachment in PV.
Human epidermis shows a non-neuronal cholinergic system including keratinocyte (kc) acetylcholine (Ach) axis which is composed by enzymes and two families of Ach receptors (muscarinic and nicotinic receptors). The activity of these two receptors can regulate the interkeratinocytes and kcs-extracellular matrix adhesion modifying the regulation of intercellular adhesion molecules like cadherins and integrins. Some authors demonstrate that acantholysis in pemphigus depends not only on anti desmogleins antibodies (abs) (mostly IgG) but even on other abs directed against kc membrane antigens (e.g. anti Ach receptors Abs). In the early phase of pemphigus pathogenesis, anti Ach receptors Abs block Ach signaling essential for cell shape and intercellular adhesion and increase the phosphorylation of adhesion molecules. Combined with the action of abs antidesmogleins, anti Ach receptors Abs cause the acantholytic phenomenon. In vitro experiments show that high doses of Ach in acantholytic kcs can rapidly reverse this pathologic event. In vivo experiments using neonatal mice model of Pemphigus have demonstrated that cholinergic agonists reduce these lesions. Therapy with pyridostigmine bromide and Nicotinamide per os or pilocarpine used topically, drugs that present cholinomimetic effects, has lead to encouraging results in patients affected by Pemphigus disease. Cholinergic agents could have a strategic role in the therapy of pemphigus since they could be responsible for the early stage of acantholytic diseases.
Full article available at: http://www.ingentaconnect.com/content/ben/aiaamc/2012/00000011/00000003/art00008
Pemphigus vulgaris (PV) is an autoimmune mucocutaneous disease presenting clinically with blisters or erosions of the skin and mucous membrane. The main histopathologic characteristic of this disease is suprabasal vesicles due to loss of cell–cell adhesion between keratinocytes named acantholysis. Studies have shown that apoptosis is increased in PV. The purpose of this study is to investigate the role of apoptosis in blister formation in PV.
This cross-sectional study was conducted on 25 specimens of oral PV. The presence of apoptosis was evaluated using the TUNEL technique in the normal perilesional region, vesicle area, and acantholytic cells. Also, the expression of Bax pro-apoptotic marker was assessed by the biotin–streptavidin immunohistochemical method. SPSS software was used for Wilcoxon test analysis. P values <0.05 were considered significant.
The percentage and intensity staining of TUNEL-positive cells were noteworthy. There were statistically significant differences between basal and parabasal) P = 0.05 (, tombstone with vesicle roof (P = 0.038) and basal with tombstone (P = 0.038). However, the expression and staining intensity of pro-apoptotic marker Bax were weak, and no statistically significant differences were observed between the various areas.
The results obtained in the present study suggest that the process of apoptosis occurs early in PV because it was observed in the perilesional normal appearing tissue. Also, the process of apoptosis may cause exacerbation or speeding of the bulla formation. In other words, inhibition of apoptosis in the patients could reduce the severity of the lesions.
Introduction: Though oral aphthosis is common, it has a significant impact on the quality of life in the patients. It is the most common oral ulcerative condition encountered in clinical practice. This study describes the characteristics and patterns of oral aphthosis seen at a tertiary dermatological centre in Singapore, with emphasis in evaluating the management gaps and in identifying underlying systemic diseases and nutritional deficiencies. Materials and Methods: This is a retrospective review of medical records over a 10-year period between June 2000 and June 2010. Two hundred and thirteen patients were identified using the search terms ‘oral ulcers’, ‘aphthous ulcers’, ‘oral aphthosis’, and ‘Behcet’s disease’. Patients with Behcet’s disease without oral ulcers and other diagnoses such as pemphigus vulgaris, lichen planus and herpes simplex were excluded. The remaining patients were evaluated with regard to demographic characteristics, characteristics of oral ulcers, associated connective tissue disorders and nutritional deficiencies, diagnostic tests results, treatment response as well as follow-up duration. Results: One hundred and seventy-five patients were included in this study. One hundred and one patients had recurrent oral aphthosis, with 77 having simple aphthosis and 24 having complex aphthosis. Fourteen patients (8%) fulfilled the International Study Criteria (ISG) for Behcet’s disease, of which, 85.71% had complex aphthosis. The therapeutic ladder for such patients ranged from topical steroids and colchicine through to oral corticosteroids and/or dapsone therapy. Conclusion: Recurrent oral aphthosis is a niche condition in which dermatologists are well-poised to manage. This study demonstrates that a more definitive management and therapeutic algorithm for oral aphthosis are needed for better management patients in the future. In particular, complex aphthosis needs to be monitored for progression onto Behcet’s disease.
Full article available at: http://www.ncbi.nlm.nih.gov/pubmed/23122017?dopt=Abstract
The present report details the clinical and immunological features of a 53 year old Asian female who developed symptoms and signs of oesophageal PV during therapy with azathioprine and decreasing prednisolone dosage. Oesophageal involvement occurred during stable oral disease.
Oesophageal involvement can occur without significant oro-cutaneous lesions and immunological evidence of PV. This suggests that immunological targets for oesophageal disease may differ from those of other mucocutaneous areas, and that conventional first-line systemic therapy may not be effective for oesophageal lesions.
Full article available at: http://www.ingentaconnect.com/content/ubpl/wlmj/2012/00000004/00000002/art00001
Aim. To characterize the clinical and immunological profile of patients with PF or PV with umbilical involvement.
Methods. In total, 10 patients (7 women, 3 men; age range 24–70 years, disease duration 3–16 years) diagnosed with either PV (n = 5) or mucocutaneous PF (n = 5) were assessed according to their clinical features, histopathology and immunological findings .
Results. Erythema, erosions, crusts and vegetating skin lesions were the main clinical features of the umbilical region. DIF of the umbilical region gave positive results for intercellular epidermal IgG and C3 deposits in eight patients and for IgG alone in the other two. Indirect immunofluorescence with IgG conjugate showing the typical pemphigus pattern was positive in all 10 patients, with titres varying from 1 : 160 to 1 : 2560. ELISA with recombinant Dsg1 gave scores of 24–266 in PF and 0–270 in PV. Reactivity to recombinant Dsg3 was positive in all five patients with PV (ELISA 22–98) and was negative in all PF sera.
Conclusions. All 10 patients with pemphigus with umbilical presentation had the clinical and immunopathological features of either PF or PV. This peculiar presentation, not yet completely elucidated, has rarely been reported in the literature. A possible explanation for this unique presentation may be the presence of either novel epitopes or an association with embryonic or scar tissue located in the umbilical-cord region.
Full article available at: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2230.2012.04468.x/abstract
Full article available at: http://www.ncbi.nlm.nih.gov/pubmed/22779708
There is currently no consensus on the optimal dosage and schedule of rituximab in treatment of pemphigus. The various treatment protocols followed include:
- Lymphoma protocol- Most commonly followed protocol. Rituximab is administered at a dose of 375mg/m 2 body surface area weekly for four weeks.
- Rheumatoid arthritis protocol- Two doses of rituximab 1g is administered at an interval of 15 days. Increasingly used by dermatologists and is the protocol currently followed in our institute. Advantage over the lymphoma protocol include less cost and fewer infusions.
- Combination therapy- Rituximab has been used in combination with IVIG, immunoadsorption and dexamethasone pulse therapy
- Long-term rituximab treatment with regular infusions every 4 or 12 weeks following an induction cycle of infusions every week
Full article can be viewed at: http://www.ijdvl.com/article.asp?issn=0378-6323;year=2012;volume=78;issue=6;spage=671;epage=676;aulast=Kanwar