Pathophysiology and therapy of pemphigus in the 21st century

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Tannic Acid Induces in vitro Acantholysis of Keratinocytes via IL-1α and TNF-α

The mechanism of acantholysis in pemphigus vulgaris (PV) is an intriguing argument since several chemical mediators are implicated. We previously reported a central role for IL-1α and TNF-α, both able to regulate complement activation and plasminogen activators. Very little is known about what triggers the disease (drugs, viruses or food). In this study, we evaluate the molecular role of tannins in acantholysis. By HPLC chromatography we measured tannic acid (TA) and gallic acid (GA) in blister fluid of 4 groups of patients divided according to their dietary habits, including a regular diet, a diet rich in tannins, a diet free of tannins, and a group of pemphigus patients. Blister fluid was obtained from patients using a suction blister apparatus. We show that people with a diet rich in tannins have increased tannin metabolites (TA and GA) in the skin in respect to controls (tannin-rich diet: GA = 194.52±2.39 nmol/ml; TA = 348.28±1.4 nmol/ml versus tannin-Mediterranean diet: GA = 15.28±1.63 nmol/ml; TA = 22.81±1.68 nmol/ml). PV patients showed similar values to the Mediterranean diet population (PV patients: GA = 95.8±1.97 nmol/ml; TA = 199.09±4.15 nmol/ml versus Mediterranean diet: GA = 83.53±2.35 nmol/ml; TA = 195.1±2.50 nmol/ml). In an in vitro acantholysis system using TA and PV-IgG we show that TA 0.1 mM in NHEK culture is able to induce acantholysis. This effect was able to amplify the acantholytic action of PV-IgG in vitro. A blocking study using anti IL-1α and anti TNF-α antibodies showed a reduction in TA-induced acantholysis. Taken together, these results suggest that a diet rich in tannins could be a trigger in genetically predisposed patients. If these data are confirmed, a complementary diet poor in tannins may be useful in patients affected by PV.

The molecular composition and function of desmosomes

Desmosomes are intercellular adhesive junctions that are particularly prominent in tissues experiencing mechanical stress, such as the heart and epidermis. Whereas the related adherens junction links actin to calcium-dependent adhesion molecules known as classical cadherins, desmosomes link intermediate filaments (IF) to the related subfamily of desmosomal cadherins. By tethering these stress-bearing cytoskeletal filaments to the plasma membrane, desmosomes serve as integrators of the IF cytoskeleton throughout a tissue. Recent evidence suggests that IF attachment in turn strengthens desmosomal adhesion. This collaborative arrangement results in formation of a supracellular network, which is critical for imparting mechanical integrity to tissues. Diseases and animal models targeting desmosomal components highlight the importance of desmosomes in development and tissue integrity, while the downregulation of individual protein components in cancer metastasis and wound healing suggests their importance in cell homeostasis. This chapter will provide an update on desmosome composition, function, and regulation, and will also discuss recent work which raises the possibility that desmosome proteins do more than play a structural role in tissues where they reside.

Guidelines on the use of therapeutic apheresis in clinical practice--evidence-based approach from the Apheresis Applications Committee of the American Society for Apheresis

The American Society for Apheresis (ASFA) Apheresis Applications Committee is charged with a review and categorization of indications for therapeutic apheresis. Beginning with the 2007 ASFA Special Issue (fourth edition), the subcommittee has incorporated systematic review and evidence-based approach in the grading and categorization of indications. This Fifth ASFA Special Issue has further improved the process of using evidence-based medicine in the recommendations by refining the category definitions and by adding a grade of recommendation based on widely accepted GRADE system. The concept of a fact sheet was introduced in the Fourth edition and is only slightly modified in this current edition. The fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis. The article consists of 59 fact sheets devoted to each disease entity currently categorized by the ASFA as category I through III. Category IV indications are also listed.

Guidelines on the use of therapeutic apheresis in clinical practice—Evidence-based approach from the apheresis applications committee of the American society for apheresis

The American Society for Apheresis (ASFA) Apheresis Applications Committee is charged with a review and categorization of indications for therapeutic apheresis. This elaborate process had been undertaken every 7 years resulting in three prior publications in 1986, 1993, and 2000 of "The ASFA Special Issues." This article is the integral part of the Fourth ASFA Special Issue. The Fourth ASFA Special Issue is significantly modified in comparison to the previous editions. A new concept of a fact sheet has been introduced. The fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis. A detailed description of the fact sheet is provided. The article consists of 53 fact sheets devoted to each disease entity currently categorized by the ASFA. Categories I, II, and III are defined as previously in the Third Special Issue. However, a few new therapeutic apheresis modalities, not yet approved in the United States or are currently in clinical trials, have been assigned category P (pending) by the ASFA Clinical Categories Subcommittee. The diseases assigned to category IV are discussed in a separate article in this issue.

Preliminary data on Pemphigus vulgaris treatment by a proteomics-defined peptide: a case report

Background

Although described by Hippocrates in 400 B.C., pemphigus disease still needs a safe therapeutical approach, given that the currently used therapies (i.e. corticosteroids and immunosuppressive drugs) often provoke collateral effects. Here we present preliminary data on the possible use of a proteomics derived desmoglein peptide which appears promising in halting disease progression without adverse effects.

Methods

The low-similarity Dsg3_49–60REWVKFAKPCRE peptide was topically applied for 1 wk onto a lesion in a patient with a late-stage Pemphigus vulgaris (PV) complicated by diabetes and cataract disease. The peptide was applied as an adjuvant in combination with the standard corticosteroid-based immunosuppressive treatment.

Results

After 1 wk, the treated PV eroded lesion appeared dimensionally reduced and with an increased rate of re-epithelization when compared to adjacent non-treated lesions. Short-term benefits were: decrease of anti-Dsg antibody titer and reduction of the corticosteroid dosage. Long-term benefits: after two years following the unique 1-wk topical treatment, the decrease of anti-Dsg antibody titer persists. The patient is still at the low cortisone dosage. Adverse effects: no adverse effect could be monitored.

Conclusion

With the limits inherent to any preliminary study, this case report indicates that topical treatment with Dsg3_49–60REWVKFAKPCRE peptide may represent a feasible first step in the search for a simple, effective and safe treatment of PV.

Nothing but skin and bone

Skin and bone - what comes to mind at hearing this phrase? While certainly a metaphor for disease, it also defines two very different tissues, one a flexible and contiguous outer covering, the other a morphologically diverse hard tissue distributed at over 200 sites in the body. As the accompanying series of Reviews highlights, these tissues are indeed diverse, but there are also surprising similarities. Skin is the interface between the internal organs and the environment, and as such plays a crucial role in the body's defense mechanism. The skin and its many appendages are responsible for functions as diverse as epidermal barrier and defense, immune surveillance, UV protection, thermoregulation, sweating, lubrication, pigmentation, the sensations of pain and touch, and, importantly, the protection of various stem cell niches in the skin. Bone serves a number of purposes: it provides protection for vital organs, a lever for locomotion, a reservoir for calcium, and the site of adult hematopoiesis. The tissue is composed of osteoblasts, osteoclasts, and their individual precursors plus a complex mixture of mesenchymal, myeloid, and lymphoid cells in the marrow space. Finally, the endothelial microenvironment provides nutrition and is a conduit for the influx and emigration of cells that impact bone biology in several important ways. This Review series guides the reader through these various facets of 2 diverse, yet interdependent, tissues.

Target proteins in inherited and acquired blistering skin disorders

Maintenance of an intact epidermis depends on secure adhesion between adjacent keratinocytes, and between basal keratinocytes and the underlying epidermal basement membrane. The major adhesion units that achieve this are the hemidesmosomes and desmosomes, but when these structures are disrupted, e.g., by gene mutations or autoantibodies, the resilience of the epidermis is lost and blisters develop. Recently, there have been considerable advances in our knowledge of the proteins and glycoproteins that contribute to maintaining keratinocyte adhesion via hemidesmosomes and desmosomes, as well as new insights into the molecular pathogenesis of several inherited and autoimmune blistering skin diseases. These new basic scientific data are clinically relevant, helping to improve patient management and to provide a rationale for developing better and more specific treatments for patients with inherited or acquired blistering skin diseases. In addition, there have also been improvements in our understanding of the organization and assembly of these adhesion structures, and their involvement in signalling pathways, intricately linked to skin development, wound healing and tumour invasion. This review provides an update on the structure and organization of hemidesmosomes and desmosomes, and on the molecular pathology of their various components that result in bullous skin diseases.

Treatment of pemphigus vulgaris: current and emerging options

BACKGROUND

Pemphigus vulgaris is a rare, chronic, autoimmune mucocutaneous blistering disease. The disease can progress to involve the skin and multiple mucosae. Pemphigus vulgaris can be associated with a high morbidity and significant mortality rate. Treatment of the condition can be challenging. Conventional therapy primarily consists of systemic corticosteroids and immunosuppressant agents. In some patients with pemphigus vulgaris, these agents fail to provide an effective clinical response or have significant adverse effects.

METHODS

We evaluated data on 792 patients with pemphigus vulgaris retrieved from PubMed, covering the period 1973-2004. Only patients reported in the English literature were included in this review. Recently, several new therapeutic agents and treatment modalities have been described for the treatment of patients with pemphigus vulgaris. Some therapeutic agents that were used in the past and abandoned have recently regained favor. This review focuses on the therapeutic uses of dapsone, methotrexate, mycophenolate mofetil, chlorambucil, dexamethasone-cyclophosphamide pulse therapy, immunoablative therapy with cyclophosphamide, plasmapheresis, and extracorporeal photochemotherapy. Newer agents, such as intravenous immunoglobulin (IVIg) therapy and rituximab (an anti-CD20 chimeric monoclonal antibody), are also discussed.

RESULTS AND CONCLUSIONS

Among the oral agents, dapsone may be considered a first-line agent. This is primarily because the risk of potentially fatal adverse effects with this drug is lower than that associated with other available chemotherapeutic agents. In patients who are refractory to oral agents, alternative treatments have been used to prevent further disease progression. Recently, the use of IVIg therapy, with a defined protocol, has been reported to be beneficial. This therapy is promising since it may allow for discontinuation of all other therapies and is safe. The adverse effects from IVIg therapy are minimal. Furthermore, compared with other therapies, it provides a better quality of life.

Lipid peroxidation and antioxidants in plasma and red blood cells from patients with pemphigus vulgaris

In pemphigus vulgaris, the increased production of reactive oxygen species from activated neutrophils decreases concentrations of antioxidant vitamins and enzymes in plasma and red blood cells (RBC), resulting in oxidative stress. We compared lipid peroxidation, a measure of reactive oxygen species production, antioxidant vitamins, reduced glutathione (GSH), glutathione peroxide (GSH-Px), and catalase enzyme activity in blood samples obtained from 18 nonsmoking pemphigus vulgaris patients and an equal number of age- and gender-matched, healthy control subjects. Plasma and RBC lipid peroxidation levels (malonyl dialdehyde) were significantly higher (p < 0.05) in pemphigus vulgaris patients than in control subjects. Significantly lower concentrations of plasma antioxidant vitamins (vitamin E and beta-carotene) and vitamin A (p < 0.001), antioxidant enzymes (catalase in RBC and plasma, GSH-Px in RBC [p < 0.05]), and respective GSH activities in both RBC and plasma (p < 0.05 and p < 0.01) were found in pemphigus vulgaris patients than in control subjects. GSH-Px in plasma did not change significantly. The results provide evidence for a potential role of increased lipid peroxidation and peroxidation and decreased antioxidants in pemphigus vulgaris by its inflammatory character.

Plasmapheresis therapy in pemphigus vulgaris and bullous pemphigoid

Blistering dermatitises are characterized by the presence of blisters that begin owing to acantholysis (intraepidermic blister) such as pemphigus vulgaris (PV) or owing to dermoepidermic detachment (subepidermic blister) such as bullous pemphigoid (BP). Both diseases are autoimmune pathologies characterized by the presence of autoantibodies against specific adhesion molecules of the skin and mucous membranes. PV, in which oral lesions are always present, has a progressive course that, if the disease is not treated, nearly always brings to death from sepsis within a few years. In BP, oral lesions are rare and the disease, that is most frequent in older individuals, has a chronic course with spontaneous remissions. Systemic corticosteroids and immunosuppressants are the mainstay of treatment of these two diseases. Although this therapy had reduced the mortality of the two pathologies it is associated with serious side effects. To reduce the corticosteroids dose and to improve the symptomatology in resistant therapy cases, we treated five patients with several procedures of plasma exchange. Four patients were affected by BP and one by PV. Their disease severity at onset of plasmapheresis ranged from mild to severe. One of 5 patients suffered a plasmapheresis side effect. All patients responded with complete remission of symptomatology and had a prednisone dosage reduction until 70%. Plasmapheresis is an effective treatment for PV and BP patients who have been unresponsive to conventional therapy, for those for whom conventional drugs are contraindicated, for those who show severe clinical manifestations and for those who need high doses of corticosteroids and immunosuppressants to keep the disease under control.