European Guidelines (S3) on diagnosis and management of mucous membrane pemphigoid, initiated by the European Academy of Dermatology and Venereology - Part II

This guideline has been initiated by the task force Autoimmune Blistering Diseases of the European Academy of Dermatology and Venereology, including physicians from all relevant disciplines and patient organizations. It is a S3 consensus-based guideline that systematically reviewed the literature on mucous membrane pemphigoid (MMP) in the MEDLINE and EMBASE databases until June 2019, with no limitations on language. While the first part of this guideline addressed methodology, as well as epidemiology, terminology, aetiology, clinical presentation and outcome measures in MMP, the second part presents the diagnostics and management of MMP. MMP should be suspected in cases with predominant mucosal lesions. Direct immunofluorescence microscopy to detect tissue-bound IgG, IgA and/or complement C3, combined with serological testing for circulating autoantibodies are recommended. In most patients, serum autoantibodies are present only in low levels and in variable proportions, depending on the clinical sites involved. Circulating autoantibodies are determined by indirect IF assays using tissue substrates, or ELISA using different recombinant forms of the target antigens or immunoblotting using different substrates. The major target antigen in MMP is type XVII collagen (BP180), although in 10-25% of patients laminin 332 is recognized. In 25-30% of MMP patients with anti-laminin 332 reactivity, malignancies have been associated. As first-line treatment of mild/moderate MMP, dapsone, methotrexate or tetracyclines and/or topical corticosteroids are recommended. For severe MMP, dapsone and oral or intravenous cyclophosphamide and/or oral corticosteroids are recommended as first-line regimens. Additional recommendations are given, tailored to treatment of single-site MMP such as oral, ocular, laryngeal, oesophageal and genital MMP, as well as the diagnosis of ocular MMP. Treatment recommendations are limited by the complete lack of high-quality randomized controlled trials.

Exploring the role of immunotherapeutic drugs in autoimmune diseases: A comprehensive review

Autoimmune diseases are group of disorders where an immune response is mounted against the self. The prevalence and burden of this well established and recognised entity is on the rise. Irrespective of being a systemic or organ specific autoimmune disorder, the common underlying mechanism of action, is the imbalance in immune system resulting in loss of tolerance to self-antigens. The oral cavity is no alien to these disorders or to their influences. Pemphigus group of lesions, systemic lupus erythematosus, psoriasis and even Sjogren's syndrome are some of the established autoimmune disorders with prominent oral manifestations. Though these diseases are well documented and enumerated, however addressing them is where the dilemma lies. Science, research and discoveries are a crucial part of medical discipline which help in looking beyond the horizon. With the introduction of selective targeted immunotherapies for autoimmune diseases as a treatment modality either in solitary or in combination with the conventional immunosuppressive treatments, are emerging as a promising elixir for patients enduring them. However, being unique, exploration of these biologics from its inception, to its mechanism of action, recognition of its application and evaluation of its safety norms are equally vital. Therefore, this review aims to provide a comprehensive particular on the novel biologics, the immunotherapies in autoimmune disorders targeting the different cells, their receptors or cytokines of the immune system.

[Therapy of pemphigus]

BACKGROUND

Pemphigus diseases are a heterogeneous group of potentially life-threatening autoimmune bullous disorders. Therefore, rapidly acting and effective therapeutic approaches are essential.

OBJECTIVES

In this review, current therapeutic options in line with available guidelines are presented and new therapeutic approaches are discussed.

METHODS

A literature search was performed using PubMed.

RESULTS

Treatment of pemphigus is based on systemic glucocorticosteroids, frequently combined with potentially corticosteroid-sparing immunosuppressants such as azathioprine and mycophenolate mofetil/mycophenolic acid. Recently, the impressive efficacy of the anti-CD20 antibody rituximab has been shown in a prospective randomized trial. In severe or treatment-refractory cases, immunoadsorption or high-dose intravenous immunoglobulins (IVIG) are recommended. Adjuvant immunoadsorption also seems to be useful within the first 8-12 weeks of therapy in patients with very high autoantibody levels. A variety of new therapeutic approaches is currently evaluated in phase IIa studies.

CONCLUSION

Therapy of pemphigus has been greatly improved by the employment of rituximab. The use of glucocorticosteroids, associated with a high number of adverse events and elevated mortality, could be reduced by the additional use of rituximab. After approval of rituximab for the treatment of pemphigus by the US Food and Drug Administration in 2018, licensing in Europe is expected in 2019.

Rituximab Therapy for Childhood Pemphigus Vulgaris

Pediatric pemphigus vulgaris (PV) is a rare autoimmune bullous dermatosis that poses a diagnostic and therapeutic challenge. Rituximab, an anti-CD20 monoclonal antibody, is an important medication in adult PV but has rarely been used to treat pediatric disease. We describe successful rituximab therapy in a 4-year-old, the youngest patient with PV ever reported to receive rituximab. A live attenuated vaccination was later given without incident. We also review rituximab clinical outcomes, toxicity, dosing protocols, and relapse in children with PV.

Efficacy and safety of rituximab in pemphigus: experience of the German Registry of Autoimmune Diseases

BACKGROUND

Rituximab has been reported to be effective in various small case series of patients with severe and/or refractory pemphigus. However, no systematic evaluation is available to corroborate this observation. The aim of this study was to systematically determine efficacy and safety of rituximab in treatment-resistant pemphigus.

PATIENTS AND METHODS

Multicenter retrospective, observational study of 36 patients with severe pemphigus vulgaris (n = 33) and pemphigus foliaceus (n = 3) treated with rituximab before August 31(st) , 2008 and enrolled in a national observational registery between December 2008 and June 2009.

RESULTS

Within a mean period of observation of 11 (1-37) months, 21 (58 %) pemphigus patients showed complete, 13 (36 %) partial, and 2 (6 %) no response to rituximab treatment. This correlates with a mean improvement of the visual analog scale for well-being of 34 (20-60) at baseline to 75 (40-95) at the last control visit. In 4 (11 %) patients, severe adverse events were recorded including 1 (3 %) serious infection.

CONCLUSIONS

Data collected in this systematic registry indicate that rituximab is an effective and relatively safe adjuvant treatment option for refractory pemphigus. To further extend our knowledge on efficacy and safety of this drug, controlled prospective trials are required.

Urban legends: pemphigus vulgaris

Pemphigus vulgaris (PV) is the most common type of pemphigus. PV pathogenesis is still debated, and treatment remains challenging. We investigated five controversial topics: (1) What are the target antigens in PV? (2) Do desmogleins adequately address PV pathophysiology? (3) How does acantholysis occur in PV? (4) Is PV still a lethal disease? (5) What is the role of rituximab (RTX) in PV treatment? Results from extensive literature searches suggested the following: (1) Target antigens of PV include a variety of molecules and receptors that are not physically compartmentalized within the epidermis. (2) PV is caused by a variety of autoantibodies to keratinocyte self-antigens, which concur to cause blistering by acting synergistically. (3) The concept of apoptolysis distinguishes the unique mechanism of autoantibody-induced keratinocyte damage in PV from other known forms of cell death. (4) PV remains potentially life-threatening largely because of treatment side effects, but it is uncertain which therapies carry the highest likelihood of lethal risk. (5) RTX is a very promising treatment option in patients with widespread recalcitrant or life-threatening PV. RTX's cost is an issue, its long-term side effects are still unknown, and randomized controlled trials are needed to establish the optimal dosing regimen.

[Treatment-refractory anti-laminin 332 mucous membrane pemphigoid. Remission following adjuvant immunoadsorption and rituximab]

Mucous membrane pemphigoid (MMP) is clinically characterized by predominant involvement of mucous membranes which in case of conjunctival lesions can lead to blindness. In MMP, autoantibodies are directed against different proteins of the dermal-epidermal junction; in 25% of cases, laminin 332 is the target. Anti-laminin 332 MMP with ocular involvement is particularly difficult to treat. A 46-year-old Caucasian man with anti-laminin 332 pemphigoid and extensive oral and nasal erosions as well as severe conjunctival involvement did not respond to intravenous dexamethasone-cyclophosphamide pulses combined with oral cyclophosphamide. After initiation of a therapeutic regimen originally established for the treatment of pemphigus, including immunoapheresis and rituximab in combination with intravenous dexamethasone-cyclophosphamide pulses and oral mycophenolate mofetil, lesions cleared within 4 months and circulating autoantibody levels became undetectable 3 months later. This is the first report of the successful use of adjuvant immunoapheresis and rituximab in previously treatment-refractory anti-laminin 332 MMP.

Diagnosis and treatment of patients with autoimmune bullous disorders in Germany

In Germany, more than 2000 new patients per year have been calculated to be diagnosed with autoimmune blistering diseases. In a recent survey, the most frequently applied treatment regimens for bullous pemphigoid were class IV topical corticosteroids and oral prednisolone 0.5 mg or 1.0 mg/kg/d plus dapsone or azathioprine. For pemphigus, two-thirds of the clinics applied oral prednisolone at doses of 1.0 mg or 1.5 mg/kg/d and in more than 80% of departments, azathioprine was chosen as concomitant immunosuppressant. High-dose intravenous immunoglobulin, rituximab, and immunoadsorption are increasingly used for refractory patients. Treatment and diagnostic costs are covered by the health insurances when applied according to published expert recommendations.

The diagnosis and treatment of autoimmune blistering skin diseases

BACKGROUND

Autoimmune blistering skin diseases are a heterogeneous group of disorders associated with autoantibodies that are directed against desmosomal structural proteins (in pemphigus diseases) or hemidesmosomal ones (in pemphigoid diseases and epidermolysis bullosa acquisita), or else against epidermal/ tissue transglutaminases (in dermatitis herpetiformis). Knowledge of the clinical presentation of these disorders and of the relevant diagnostic procedures is important not just for dermatologists, but also for general practitioners, ophthalmologists, ENT specialists, dentists, gynecologists, and pediatricians.

METHODS

The literature on the subject was selectively reviewed. There are no existing guidelines available in Germany.

RESULTS

The recently developed sensitive and specific assays for circulating autoantibodies in these diseases now enable a serological diagnosis in about 90% of cases. The incidence of autoimmune blistering skin diseases in Germany has doubled in the last 10 years, to a current figure of about 25 new cases per million persons per year, because of improved diagnostic techniques as well as the aging of the population. Accurate and specific diagnosis is the prerequisite for reliable prognostication and appropriate treatment. For severe and intractable cases, more effective treatments have recently become available, including immunoadsorption, high-dose intravenous immunoglobulin, the anti-CD20 antibody rituximab, and combinations of the above.

CONCLUSION

The diagnostic assessment of autoimmune blistering skin diseases can be expected to improve in the near future as new serological testing systems are developed that employ recombinant forms of the target antigens. The treatments currently in use still need to be validated by prospective, controlled trials.

Innovative uses of rituximab in dermatology

Since its approval in 1997 by the US Food and Drug Administration, rituximab has been approved for use in certain B-cell lymphomas and treatment-resistant rheumatoid arthritis. Over the past 10 years, many published reports have suggested rituximab's efficacy in several inflammatory conditions in dermatology. This article includes a review of the mechanism of action, dosing, side-effect profile, and the current literature for various off-label uses of this CD20+ B-cell antagonist, rituximab.

[Optimizing therapy in patients with severe autoimmune blistering skin diseases]

Autoimmune bullous diseases are a heterogeneous group of disorders that can be subdivided according to the level of split formation in the intraepidermal blistering pemphigus diseases and subepidermal bullous disorders, latter including pemphigoid diseases, epidermolysis bullosa acquisita (EBA), and dermatitis herpetiformis. In the majority of autoimmune bullous disorders, disease activity can be sufficiently controlled by systemic corticosteroids in combination with further immunsuppressants/-modulants such as dapsone, doxycycline, azathioprine, mycophenolate mofetil, or methotrexate. In contrast, in pemphigus, mucous membrane pemphigoid, and EBA, treatment is challenging and conventional immunosuppressive therapy induces clinical remission only in a minority of patients. Until recently, only cyclosphosphamide and high-dose intravenous immunoglobulin (IVIG) were available as potent second-line therapies. Meanwhile, immunoadsorption and the monoclonal anti-CD20 antibody rituximab have been established as further therapeutic options. The present review focuses on efficacy, adverse events, treatment protocols, and mechanisms of action of IVIG, immunoadsorption, and rituximab in the treatment of severe and/or refractory patients with bullous autoimmune diseases.