Rituximab in Severe Pemphigus

Prevalence of Fungal Infections in Pemphigus Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Pemphigus is a life-threatening autoimmune disease characterised by blistering skin and/or mucous membranes. The present study aimed to determine the prevalence of fungal infections in the pemphigus population.

METHODS

Different databases were searched to gain access to all studies on the prevalence of fungal infections published up to the 31st of May 2024. The pooled rate prevalence of fungal infections with a 95% confidence interval (CI) was calculated using the random effects model.

RESULTS

A total of 1012 studies were identified, out of which 18 were included in meta-analyses. The random-effects estimates of the prevalence of fungal infection in the pemphigus population were 0.18% (95% CI: 9%-31%). Based on the findings, it was determined that four genera of fungal infections were related to mucocutaneous lesions of individuals diagnosed with pemphigus. Among these fungi, the most prevalent were those belonging to the Candida species, with a particular emphasis on Candida albicans (87.61%). Additional isolated fungal species include Trichophyton rubrum (4.5%), Aspergillus species (1.8%), Pneumocystis jirovecii (1.2%), Malassezia furfur (0.78%), Microsporum canis (0.75%), Trichophyton mentagrohytes (0.65%), Microsporum audouinii (0.60%), and Trichophyton concentricum (0.45%).

CONCLUSIONS

The current study highlights the significance of fungal infection in individuals with pemphigus, suggesting that pemphigus and administration of immunosuppressive medicines such as corticosteroids may trigger an increased risk of fungal infections. Additionally, prompt diagnosis of fungal infections in individuals with pemphigus could help healthcare professionals prevent and treat serious infections, such as Pneumocystis jirovecii pneumonia (PJP), and potentially alleviate the economic impact of this condition.

Paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome: Part II. Diagnosis and management

In the second part of this Continuing Medical Education article on paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome (PNP/PAMS), its diagnostic criteria, investigative work-up, and management are reviewed. PNP/PAMS is a rare autoimmune blistering disorder associated with high morbidity and mortality. Recognizing PNP/PAMS's key features and its diagnostic criteria is critical in initiating appropriate work-up. Evaluating PNP/PAMS requires knowledge of its findings on histopathology, direct immunofluorescence, indirect immunofluorescence, and enzyme-linked immunosorbent assay. Lastly, treatments for PNP/PAMS are reviewed with suggestions based on case reports and expert opinions in the literature.

Rituximab in Childhood and Juvenile Pemphigus Vulgaris: A Systematic Review

Pemphigus vulgaris (PV) is a chronic autoimmune blistering disorder characterized by the loss of intraepithelial adhesion, affecting the skin and mucous membranes. Both males and females are affected, although it predominantly affects females in their fifth and sixth decades of life. Approximately 1.4 to 3.7% of PV cases occur in the pediatric population (≤18 years of age), and may be classified into childhood/pediatric PV, which affects individuals under 12 years old, and juvenile/adolescent PV, affecting those between 12 and 18 years old. Due to its rare occurrence in children and adolescents, there is often a delay in diagnosis and treatment in this age group. A systematic literature search was conducted on MEDLINE/PubMed, Web of Science, EMBASE, SCOPUS, and Cochrane Library databases to evaluate the efficacy of rituximab (RTX) in childhood and juvenile PV patients. The Joanna Briggs Institute (JBI) Critical Appraisal Checklist was employed to assess the risk of bias in case reports and series, while the Cochrane ROBINS-I tool was utilized for evaluating observational studies or non-randomized intervention studies. A total of 18 studies encompassing 46 juvenile or childhood PV patients in the pediatric and adolescent age groups were included for qualitative synthesis. The studies included nine case reports, two case series, five retrospective studies, one prospective study, and one open-label pilot study. Almost all cases of childhood and juvenile PV achieved either complete or partial remission after undergoing RTX treatment during the final follow-up periods. Furthermore, most cases reported no relapse, and only minor adverse events were noted in the RTX treatment group. Despite its potential benefits, the utilization of RTX in pediatric patients raises concerns due to the scarcity of evidence and the absence of controlled studies specific to this age group. Further exploration is necessary to establish a standardized treatment regimen for RTX in pediatric PV, which involves identifying the optimal dosage, frequency, treatment cycle duration, and maintenance therapy duration.

Epidermolysis Bullosa Acquisita-Current and Emerging Treatments

Epidermolysis bullosa acquisita (EBA) is a rare chronic autoimmune subepidermal blistering disease of the skin and mucous membranes, usually beginning in adulthood. EBA is induced by autoantibodies to type VII collagen, a major component of anchoring fibrils in the dermal-epidermal junction (DEJ). The binding of autoantibodies to type-VII collagen subsequently leads to the detachment of the epidermis and the formation of mucocutaneous blisters. EBA has two major clinical subtypes: the mechanobullous and inflammatory variants. The classic mechanobullous variant presentation consists of skin fragility, bullae with minimal clinical or histological inflammation, erosions in acral distribution that heal with scarring, and milia formation. The inflammatory variant is challenging to differentiate from other autoimmune bullous diseases, most commonly bullous pemphigoid (BP) but also mucous membrane pemphigoid (MMP), Brunsting-Perry pemphigoid, and linear IgA dermatosis. Due to its recalcitrance conventional treatment of epidermolysis bullosa acquisita is shown to be demanding. Here we discuss novel therapeutic strategies that have emerged and which could potentially improve the quality of life in patients with EBA.

Pediatric Autoimmune Bullous Disease: A Literature Review and Update on Management

Pediatric autoimmune bullous disease is a rare group of blistering skin disorders in children that result from autoimmunity against intercellular and basement membrane antigens in the skin and mucous membranes. Most pediatric cases are treated with oral corticosteroids or longer-term immunosuppressants such as azathioprine or mycophenolate mofetil. Immunomodulating drugs such as rituximab are increasingly being considered as options for refractory disease.

A Case of Severe Bullous Dermatitis With Mixed Bullous Pemphigoid and Pemphigus Vulgaris Cutaneous Manifestations

Bullous dermatoses include the rare, chronic autoimmune diseases pemphigus vulgaris and bullous pemphigoid. These diseases are traditionally taught to be differentiated by the presence of mucosal lesions (pemphigus vulgaris) and bullae without mucosal involvement (bullous pemphigoid). In the clinical setting, however, these diseases often contain overlapping features that present challenges to care teams without access to dermatologic care and leave patients without a clear treatment pathway. The ability to differentiate these two diseases clinically is imperative as it determines treatment regimens which when applied can mitigate unnecessary morbidity and mortality. Identifying these conditions clinically for the correct treatment also allows providers to rely less on laboratory assessments which are often unavailable or may take considerable time to result. This report details the clinical course of a patient who presented with an undifferentiated bullous dermatitis with features of both pemphigus vulgaris and bullous pemphigoid and aims to highlight the features of presentation which overlap between pemphigus vulgaris and bullous pemphigoid and those which are more characteristic for one over the other. 

Comprehensive review on the pathophysiology, clinical variants and management of pemphigus (Review)

Pemphigus represents a group of chronic inflammatory disorders characterized by autoantibodies that target components of desmosomes, leading to the loss of intercellular adhesion between keratinocytes and causing intraepithelial blistering. The pemphigus group consists of four main clinical types with several variants: pemphigus vulgaris (with pemphigus vegetans and pemphigus herpetiformis as variants), pemphigus foliaceus, paraneoplastic pemphigus and IgA pemphigus (with two clinical variants: intraepidermal neutrophilic IgA dermatosis and subcorneal pustular dermatosis). Genetic factors are involved in the pathogenesis, with HLA-DR4 (DRB1*0402) and HLA-DRw6 (DQB1*0503) allele more common in patients with pemphigus vulgaris, HLA class II DRB1*0344 and HLA Cw*1445 correlated with paraneoplastic pemphigus, and HLA-DRB1*04:01, HLA-DRB1*04:06, HLA-DRB1*01:01, HLA-DRB1*14, associated with a higher risk of developing pemphigus foliaceus. Autoantibodies are conducted against structural desmosomal proteins in the skin and mucous membranes, mainly desmogleins, desmocollins and plakins. Cell-mediated immunity may also play a role, especially in paraneoplastic pemphigus. Patients may present erythema, blisters, erosions, and ulcers that may affect the skin, as well as mucosal surfaces of the oral cavity, eyes, nose, leading to severe complaints including pain, dysphagia, and fetor. Oral mucosal postbullous erosive lesions are frequently the first sign of disease in pemphigus vulgaris and in paraneoplastic pemphigus, without skin involvement, making the diagnosis difficult. Treatment options classically include immunosuppressive agents, such as corticosteroids and corticosteroid-sparing agents such as azathioprine, mycophenolate mofetil, cyclophosphamide, methotrexate or dapsone. Newer therapies focus on blocking cell signaling events induced by pathogenic autoantibodies and/or targeting specific autoantibodies. The disease evolution is conditioned by the treatment with maximum doses of corticosteroids and the side effects associated with long-term immunosuppressive therapy, which is why patients need a multidisciplinary approach in following the treatment. In this review, we provide a comprehensive overview of the epidemiology, pathophysiology, clinical aspect, diagnosis and management of the main intraepidermal blistering diseases from the pemphigus group.

Long-term experience with rituximab therapy for treatment-resistant moderate-to-severe pemphigus

BACKGROUND

Rituximab appears to be effective for treating pemphigus, although there are limited long-term data.

METHODS

This retrospective single-center study evaluated patients with conventional treatment-resistant pemphigus who received rituximab during September 2010-December 2019. The first rituximab cycle was based on the rheumatoid arthritis protocol in all patients except one patient, and additional single doses (500 mg or 1000 mg) were administered after clinical and/or serological relapse. The consensus definitions were used for complete remission off therapy, complete remission on minimal therapy, and clinical relapse. Serological relapse was defined as a progressive ≥2-fold increase in anti-desmoglein titers (vs. previous the measurement).

RESULTS

The study included 52 patients with pemphigus vulgaris and 1 patient with pemphigus foliaceus. The mean number of infusions was 5 and the average follow-up after the first infusion was 56 months. The average time to clinical and/or serological relapse was 12 months. Complete remission was achieved in 84.9% of patients, including after the first rituximab cycle in 25 patients (47.1%). Two patients died during the follow-up period.

CONCLUSION

Additional rituximab cycles may help achieve and prolong remission in patients with moderate-to-severe pemphigus resistant to conventional therapies. However, prospective trials are needed to identify the optimal dosing protocol.

Rare Diseases of Larynx, Trachea and Thyroid

This review article covers data on rare diseases of the larynx, the trachea and the thyroid. In particular, congenital malformations, rare manifestations of inflammatory laryngeal disorders, benign and malignant epithelial as well as non-epithelial tumors, laryngeal and tracheal manifestations of general diseases and, finally, thyroid disorders are discussed. The individual chapters contain an overview of the data situation in the literature, the clinical appearance of each disorder, important key points for diagnosis and therapy and a statement on the prognosis of the disease. Finally, the authors indicate on study registers and self-help groups.

The evolving role of rituximab in the treatment of pemphigus vulgaris: a comprehensive state-of-the-art review

INTRODUCTION

Pemphigus vulgaris (PV) is a life-threatening autoimmune mucocutaneous blistering disease. Systemic corticosteroids (CS), while life-saving, have several serious side effects. To improve treatment and prognosis, recently rituximab (RTX), a chimeric monoclonal antibody against CD20 molecule on B cells, has become popular. This Expert Opinion discusses clinical and scientifically relevant aspects of RTX treating PV.

AREA COVERED

This presentation describes the mechanism of action, clinical efficacy, safety, adverse events, protocols used, and clinical outcomes. Concerns for infection, reactivation of latent or previous infections, and high relapse rate are discussed.

EXPERT OPINION

Use of RTX in PV is still a work in progress. There are many unanswered questions. FDA did not provide a protocol or guidelines. Whenever RTX is used, systemic corticosteroids are simultaneously used, albeit for a shorter duration and lower dose. Used in these doses for these durations they can cause immunosuppression. Would it be more appropriate if instead of 'First Line Therapy' it would be more advisable to use the term 'First Adjunctive Immunosuppressive Agent'?

A Comparative Study to Evaluate the Efficacy and Cost of Rituximab versus Dexamethasone Cyclophosphamide Pulse in Patients of Pemphigus Vulgaris

Introduction:

Rituximab is slowly getting recognized as a promising steroid-sparing agent in the treatment of moderate to severe cases of pemphigus vulgaris (PV). We evaluated and compared the effectiveness, safety, and cost of therapy of rituximab versus dexamethasone cyclophosphamide pulse (DCP) in Indian patients with PV.

Materials and Methods:

It is a retrospective data analysis, from the Immunobullous disease clinic in a tertiary centre of eastern India, of management of PV. In our institute we use either rituximab or DCP for the management of moderate to severe cases of PV, depending on that we retrospectively divided the treated cases of PV in two groups. Patients who were treated with rheumatoid arthritis (RA) protocol of rituximab were considered to be group 1. Patients who were treated with DCP were included in group 2. Response was assessed by pemphigus area, and activity score (PAAS), Dermatology life quality index (DLQI); photographic documentation, and blood parameters were monitored.

Results:

Both groups showed significant improvement in PAAS and DLQI, the improvement was faster and well sustained in the rituximab group. In terms of safety and development of new vesicles, rituximab had a better profile with only 1 patient having adverse effects and none with new vesicles as compared to DCP (3 had adverse effects and 2 developed new vesicles).

Conclusions:

Rituximab offers the advantage of early and prolonged remission, lesser adverse effects, better effectiveness, less risk of relapses, faster improvement of PAAS, and DLQI. Though rituximab is an expensive drug, but on evaluating the cost of whole therapy, it was seen that rituximab infusions are actually cheaper compared to DCP pulse. We suggest, rituximab can be used as the first-line of therapy for pemphigus vulgaris in the Indian context.

Ocular surface involvement in pemphigus vulgaris: An interdisciplinary review

PURPOSE

A review of the published literature on the history, pathogenesis, and treatment of pemphigus vulgaris (PV) and its ocular involvement.

METHODS

Literature searches were conducted in MEDLINE (Ovid), and google scholar for pemphigus vulgaris and ocular PV. Inclusion criteria were given to meta-analysis, case-controlled studies, and documented case reports. The data were examined and independently analyzed by more than two of the authors.

RESULTS

PV is a humoral autoimmune disease with a preponderance of IgG4 anti-desmoglein 3 antibodies. Upon antibody binding, there is an intracellular signaling mechanism that leads to blister formation. Ocular findings are seen in up to 16% of PV patients with conjunctivitis being the most common clinical presentation. New steroid-sparing agents have helped with the control of this deadly disease, and with better understanding of the pathogenesis of PV, other cytokine blockers currently available are promising steroid-sparing agents.

CONCLUSIONS

Ocular pemphigus can occasionally present prior to mucocutaneous findings. Recalcitrant conjunctivitis with conjunctival blisters should warrant a workup for systemic PV.

Pemphigus

Pemphigus consists of a group of rare and severe autoimmune blistering diseases mediated by pathogenic autoantibodies mainly directed against two desmosomal adhesion proteins, desmoglein (Dsg)1 and Dsg3 (also known as DG1 and DG3), which are present in the skin and surface-close mucosae. The binding of autoantibodies to Dsg proteins induces a separation of neighbouring keratinocytes, in a process known as acantholysis. The two main pemphigus variants are pemphigus vulgaris, which often originates with painful oral erosions, and pemphigus foliaceus, which is characterised by exclusive skin lesions. Pemphigus is diagnosed on the basis of either IgG or complement component 3 deposits (or both) at the keratinocyte cell membrane, detected by direct immunofluorescence microscopy of a perilesional biopsy, with serum anti-Dsg1 or anti-Dsg3 antibodies (or both) detected by ELISA. Corticosteroids are the therapeutic mainstay, which have recently been complemented by the anti-CD20 antibody rituximab in moderate and severe disease. Rituximab induces complete remission off therapy in 90% of patients, despite rapid tapering of corticosteroids, thus allowing for a major corticosteroid-sparing effect and a halved number of adverse events related to corticosteroids.

Targeted Therapies for Autoimmune Bullous Diseases: Current Status

Autoimmune bullous skin disorders are rare but meaningful chronic inflammatory diseases, many of which had a poor or devastating prognosis prior to the advent of immunosuppressive drugs such as systemic corticosteroids, which down-regulate the immune pathogenesis in these disorders. Glucocorticoids and adjuvant immunosuppressive drugs have been of major benefit for the fast control of most of these disorders, but their long-term use is limited by major side effects such as blood cytopenia, osteoporosis, diabetes mellitus, hypertension, and gastrointestinal ulcers. In recent years, major efforts were made to identify key elements in the pathogenesis of autoimmune bullous disorders, leading to the identification of their autoantigens, which are mainly located in desmosomes (pemphigus) and the basement membrane zone (pemphigoids). In the majority of cases, immunoglobulin G, and to a lesser extent, immunoglobulin A autoantibodies directed against distinct cutaneous adhesion molecules are directly responsible for the loss of cell-cell and cell-basement membrane adhesion, which is clinically related to the formation of blisters and/or erosions of the skin and mucous membranes. We describe and discuss novel therapeutic strategies that directly interfere with the production and regulation of pathogenic autoantibodies (rituximab), their catabolism (intravenous immunoglobulins), and their presence in the circulation and extravascular tissues such as the skin (immunoadsorption), leading to a significant amelioration of disease. Moreover, we show that these novel therapies have pleiotropic effects on various proinflammatory cells and cytokines. Recent studies in bullous pemphigoid suggest that targeting of immunoglobulin E autoantibodies (omalizumab) may be also beneficial. In summary, the introduction of targeted therapies in pemphigus and pemphigoid holds major promise because of the high efficacy and fewer side effects compared with conventional global immunosuppressive therapy.

Pemphigus: Current and Future Therapeutic Strategies

Pemphigus encompasses a heterogeneous group of autoimmune blistering diseases, which affect both mucous membranes and the skin. The disease usually runs a chronic-relapsing course, with a potentially devastating impact on the patients' quality of life. Pemphigus pathogenesis is related to IgG autoantibodies targeting various adhesion molecules in the epidermis, including desmoglein (Dsg) 1 and 3, major components of desmosomes. The pathogenic relevance of such autoantibodies has been largely demonstrated experimentally. IgG autoantibody binding to Dsg results in loss of epidermal keratinocyte adhesion, a phenomenon referred to as acantholysis. This in turn causes intra-epidermal blistering and the clinical appearance of flaccid blisters and erosions at involved sites. Since the advent of glucocorticoids, the overall prognosis of pemphigus has largely improved. However, mortality persists elevated, since long-term use of high dose corticosteroids and adjuvant steroid-sparing immunosuppressants portend a high risk of serious adverse events, especially infections. Recently, rituximab, a chimeric anti CD20 monoclonal antibody which induces B-cell depletion, has been shown to improve patients' survival, as early rituximab use results in higher disease remission rates, long term clinical response and faster prednisone tapering compared to conventional immunosuppressive therapies, leading to its approval as a first line therapy in pemphigus. Other anti B-cell therapies targeting B-cell receptor or downstream molecules are currently tried in clinical studies. More intriguingly, a preliminary study in a preclinical mouse model of pemphigus has shown promise regarding future therapeutic application of Chimeric Autoantibody Receptor T-cells engineered using Dsg domains to selectively target autoreactive B-cells. Conversely, previous studies from our group have demonstrated that B-cell depletion in pemphigus resulted in secondary impairment of T-cell function; this may account for the observed long-term remission following B-cell recovery in rituximab treated patients. Likewise, our data support the critical role of Dsg-specific T-cell clones in orchestrating the inflammatory response and B-cell activation in pemphigus. Monitoring autoreactive T-cells in patients may indeed provide further information on the role of these cells, and would be the starting point for designating therapies aimed at restoring the lost immune tolerance against Dsg. The present review focuses on current advances, unmet challenges and future perspectives of pemphigus management.

[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.

A sensitive and specific assay for the serological diagnosis of antilaminin 332 mucous membrane pemphigoid

BACKGROUND

Antilaminin 332 mucous membrane pemphigoid (MMP) is an autoimmune subepidermal blistering disease with predominant mucosal involvement and autoantibodies against laminin 332. Malignancies have been associated with this disease; however, no standardized detection system for antilaminin 332 serum antibodies is widely available.

OBJECTIVES

Development of a sensitive and specific assay for the detection of antilaminin 332 antibodies.

METHODS

An indirect immunofluorescence (IF) assay using recombinant laminin 332 was developed and probed with a large number of antilaminin 332 MMP patient sera (n = 93), as well as sera from patients with antilaminin 332-negative MMP (n = 153), bullous pemphigoid (n = 20), pemphigus vulgaris (n = 20) and noninflammatory dermatoses (n = 22), and healthy blood donors (n = 100).

RESULTS

In the novel IF assay, sensitivities with the laminin 332 heterotrimer and the individual α3, β3 and γ2 chains were 77%, 43%, 41% and 13%, respectively, with specificities of 100% for each substrate. The sensitivity for the heterotrimer increased when an anti-IgG4 enriched antitotal IgG conjugate was applied. Antilaminin 332 reactivity paralleled disease activity and was associated with malignancies in 25% of patients with antilaminin 332 MMP.

CONCLUSIONS

The novel IF-based assay will facilitate the serological diagnosis of antilaminin 332 MMP and may help to identify patients at risk of a malignancy.

Emerging treatment options for the management of pemphigus vulgaris

Pemphigus vulgaris (PV) is a life-threatening disease belonging to the pemphigus group of autoimmune intra-epidermal bullous diseases of the skin and mucosae. The therapeutic management of PV remains challenging and, in some cases, conventional therapy is not adequate to induce clinical remission. The cornerstone of PV treatment remains systemic corticosteroids. Although very effective, long-term corticosteroid administration is characterized by substantial adverse effects. Corticosteroid-sparing adjuvant therapies have been employed in the treatment of PV, aiming to reduce the necessary cumulative dose of corticosteroids. Specifically, immunosuppressive agents such as azathioprine and mycophenolate mofetil are widely used in PV. More recently, high-dose intravenous immunoglobulins, immunoadsorption, and rituximab have been established as additional successful therapeutic options. This review covers both conventional and emerging therapies in PV. In addition, it sheds light on potential future treatment strategies for this disease.

Consequences of B-cell-depleting therapy: hypogammaglobulinemia and impaired B-cell reconstitution

Rituximab is a chimeric monoclonal antibody used to treat hematologic and autoimmune diseases by depleting CD20-expressing B cells. Patients may develop hypogammaglobulinemia following treatment, with some demonstrating failure of B-cell recovery. The true frequency of hypogammaglobulinemia and/or impaired B-cell reconstitution post rituximab is unknown due to the lack of prospective studies in different patient cohorts. The clinical significance remains controversial; some patients have recurrent infections while others are relatively asymptomatic. The aim of this review is to describe the prevalence of hypogammaglobulinemia and the associated risk for developing severe infection, in patients with differing underlying clinical conditions treated with rituximab. This may facilitate classification and prognostication of patients who develop these conditions and identify patients who may be at high risk of developing these complications, including those who may benefit from immunoglobulin replacement therapy.

Robust memory responses against influenza vaccination in pemphigus patients previously treated with rituximab

Rituximab is a therapeutic anti-CD20 monoclonal antibody widely used to treat B cell lymphoma and autoimmune diseases, such as rheumatic arthritis, systemic lupus erythematosus, and autoimmune blistering skin diseases (AIBD). While rituximab fully depletes peripheral blood B cells, it remains unclear whether some preexisting B cell memory to pathogens or vaccines may survive depletion, especially in lymphoid tissues, and if these memory B cells can undergo homeostatic expansion during recovery from depletion. The limited data available on vaccine efficacy in this setting have been derived from rituximab-treated patients receiving concomitant chemotherapy or other potent immunosuppressants. Here, we present an in-depth analysis of seasonal influenza vaccine responses in AIBD patients previously treated with rituximab, who generally did not receive additional therapeutic interventions. We found that, despite a lack of influenza-specific memory B cells in the blood, patients mount robust recall responses to vaccination, comparable to healthy controls, both at a cellular and a serological level. Repertoire analyses of plasmablast responses suggest that they likely derive from a diverse pool of tissue-resident memory cells, refractory to depletion. Overall, these data have important implications for establishing an effective vaccine schedule for AIBD patients and the clinical care of rituximab-treated patients in general and contribute to our basic understanding of maintenance of normal and pathogenic human B cell memory.

Shifting Focus in the Therapeutics of Immunobullous Disease

Therapeutics of autoimmune bullous disease has seen a major shift of focus from more global immunosuppression to targeted immunotherapy. Anti CD 20 monoclonal antibody Rituximab revolutionized the therapeutics of autoimmune bullous disease particularly pemphigus. Though it is still being practiced off-label, evidences in the form of RCT and meta analysis are now available. Other novel anti CD 20 monoclonal antibodies like ofatumumab, veltuzumab, and ocrelizumab, tositumomab or obinutuzumab/GA101 may add to the therapeutic options in coming days. Beyond anti CD 20 monoclonal antibodies other options that show promise at least in select scenario are omalizumab, TNF inhibitors plasmapheresis and intravenous immunoglobulin. The present article will discuss the role of rituximab and other newer therapeutics in the treatment of autoimmune blistering disease, especially pemphigus and suggests their positions in the therapeutic ladder.

Clinical and immunological outcomes of high- and low-dose rituximab treatments in patients with pemphigus: a randomized, comparative, observer-blinded study

BACKGROUND

Rituximab is a promising therapy in pemphigus. However, there is no consensus on optimum dose.

OBJECTIVES

To compare the efficacy, in terms of clinical and immunological outcomes in patients with pemphigus, of a high (2 × 1000 mg) vs. a low dose (2 × 500 mg) of rituximab.

METHODS

This was a randomized, observer-blinded trial wherein 22 patients with pemphigus were randomized into two treatment groups. Patients received either two doses (day 0 and day 15) of 1000 mg rituximab or 500 mg rituximab, and were followed up for 48 weeks. Clinical activity was assessed by a blinded investigator. Indices of enzyme-linked immunosorbent assays (ELISAs) for desmoglein (Dsg)1 and Dsg3, and CD19 cell count were examined at regular intervals.

RESULTS

There was no statistically significant difference in early and late clinical end points, and total cumulative dose of corticosteroids between the two groups. At week 40, the fall in Ikeda severity score was significantly more in the 2 × 1000 mg group than in 2 × 500 mg group (P = 0·049). Patients in the 2 × 500 mg group received a significantly higher cumulative dose of azathioprine (P = 0·018). The ELISA indices of Dsg1 and Dsg3 showed a statistically significant decline in the 2 × 1000 mg group only. B cell repopulation occurred earlier in the 2 × 500 mg group by 8 weeks.

CONCLUSIONS

A few clinical and immunological study parameters have suggested improved outcomes in patients receiving high-dose (2 × 1000 mg) rituximab.

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.

Management of pemphigus vulgaris: challenges and solutions

The main objective in the treatment of pemphigus vulgaris is to control the disease, prevent relapses, and avoid adverse events associated with the prolonged use of steroids and immunosuppressive agents. Systemic corticosteroids remain the gold standard treatment for pemphigus vulgaris. Azathioprine and mycophenolate mofetil are the first line of steroid-sparing treatment. Rituximab is extremely effective in recalcitrant pemphigus, when other treatments fail to control the disease. The European Dermatology Forum recommends tapering prednisolone by 25% every 2 weeks after the consolidation phase, and a 5 mg reduction every 4 weeks when the dose is reduced to <20 mg. If the patient relapses, options include increasing steroids back to the previous dose, adding an immunosuppressant if using steroid monotherapy, or replacing a first-line immunosuppressant by another if already on combination therapy.

Refractory pemphigus vulgaris treated with rituximab and mycophenolate mofetil

The main treatment for pemphigus vulgaris are systemic corticosteroids and immunosuppressive agents, but due to adverse reactions and therapeutic failure, new drugs such as rituximab and mycophenolate mofetil have been used. In this case report are described two cases of severe pemphigus vulgaris refractory to various treatments, with resolution after use of rituximab and mycophenolate mofetil, associated with corticosteroids. A higher-than-usual dose of rituximab was employed, without the occurrence of serious adverse reactions. Mycophenolate mofetil was added as adjunctive therapy due to lack of response to azathioprine.

B-cell targeted therapeutics in clinical development

B lymphocytes are the source of humoral immunity and are thus a critical component of the adaptive immune system. However, B cells can also be pathogenic and the origin of disease. Deregulated B-cell function has been implicated in several autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis. B cells contribute to pathological immune responses through the secretion of cytokines, costimulation of T cells, antigen presentation, and the production of autoantibodies. DNA-and RNA-containing immune complexes can also induce the production of type I interferons, which further promotes the inflammatory response. B-cell depletion with the CD20 antibody rituximab has provided clinical proof of concept that targeting B cells and the humoral response can result in significant benefit to patients. Consequently, the interest in B-cell targeted therapies has greatly increased in recent years and a number of new biologics exploiting various mechanisms are now in clinical development. This review provides an overview on current developments in the area of B-cell targeted therapies by describing molecules and subpopulations that currently offer themselves as therapeutic targets, the different strategies to target B cells currently under investigation as well as an update on the status of novel therapeutics in clinical development. Emerging data from clinical trials are providing critical insight regarding the role of B cells and autoantibodies in various autoimmune conditions and will guide the development of more efficacious therapeutics and better patient selection.

Epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is a chronic autoimmune subepidermal bullous disease with clinical features similar to the genetic form of dystrophic epidermolysis bullosa. EBA is characterized by the presence of autoantibodies against type VII collagen which is a major component of the anchoring fibrils at the dermal-epidermal junction. EBA can be divided into two main clinical types; mechanobullous and inflammatory EBA. Mechanobullous EBA, referred to as classic EBA, presents with skin fragility, blisters and dystrophic changes on trauma-prone areas. Inflammatory EBA resembles other autoimmune subepidermal bullous diseases. Compelling evidence from mouse models supports a pathogenic role of autoantibodies against type VII collagen in EBA. Treatment of EBA is often unsatisfactory. The most widely used systemic treatment is corticosteroids. Colchicine and dapsone have been reported to be good treatment modalities when combined with corticosteroids. Some intractable cases of EBA have successfully been treated with intravenous immunoglobulin or rituximab.

Peptide-mediated desmoglein 3 crosslinking prevents pemphigus vulgaris autoantibody-induced skin blistering

In pemphigus vulgaris, a life-threatening autoimmune skin disease, epidermal blisters are caused by autoantibodies primarily targeting desmosomal cadherins desmoglein 3 (DSG3) and DSG1, leading to loss of keratinocyte cohesion. Due to limited insights into disease pathogenesis, current therapy relies primarily on nonspecific long-term immunosuppression. Both direct inhibition of DSG transinteraction and altered intracellular signaling by p38 MAPK likely contribute to the loss of cell adhesion. Here, we applied a tandem peptide (TP) consisting of 2 connected peptide sequences targeting the DSG adhesive interface that was capable of blocking autoantibody-mediated direct interference of DSG3 transinteraction, as revealed by atomic force microscopy and optical trapping. Importantly, TP abrogated autoantibody-mediated skin blistering in mice and was effective when applied topically. Mechanistically, TP inhibited both autoantibody-induced p38 MAPK activation and its association with DSG3, abrogated p38 MAPK-induced keratin filament retraction, and promoted desmosomal DSG3 oligomerization. These data indicate that p38 MAPK links autoantibody-mediated inhibition of DSG3 binding to skin blistering. By limiting loss of DSG3 transinteraction, p38 MAPK activation, and keratin filament retraction, which are hallmarks of pemphigus pathogenesis, TP may serve as a promising treatment option.

Randomized double blind trial of prednisolone and azathioprine, vs. prednisolone and placebo, in the treatment of pemphigus vulgaris

BACKGROUND

The classic treatment for pemphigus vulgaris is prednisolone. Immunosuppressive drugs can be used in association.

OBJECTIVE

To compare the efficacy of Azathioprine in reducing the Disease Activity Index (DAI).

PATIENTS AND METHODS

A double blind randomized controlled study was conducted on 56 new patients, assigned to two therapeutic groups: (i) prednisolone plus placebo; (ii) prednisolone plus Azathioprine. Patients were checked regularly for 1 year. 'Complete remission' was defined as healing of all lesions after 12 months, and prednisolone <7.5 mg daily, (DAI ≤ 1). Analysis was done by 'Intention To Treat' (ITT) and 'Treatment Completed Analysis' (TCA).

RESULTS

Both groups were similar in age, gender, disease duration, and DAI. Primary endpoint: By ITT and TCA, the mean DAI improved in both groups with no significant difference between them. The difference became significant for the last trimester (3 months; ITT: P = 0.033, TCA: P = 0.045). Secondary endpoint: The total steroid dose decreased significantly in both groups, with no significant difference between them, except for the last trimester (ITT: P = 0.011, TCA: P = 0.035). The mean daily steroid dose decreased gradually in both groups becoming statistically significant in favour of azathioprine, in the last trimester, especially at 12th months (ITT: P = 0.002, TCA: P = 0.005). Complete remission was significant at 12 months only for TCA (AZA/Control: 53.6%/39.9%, P = 0.043).

LIMITATIONS

Sample size was rather small to demonstrate all differences. Other limitations include the choice of primary and secondary endpoints and the unavailability to measure thiopurine methyltransferase activity.

CONCLUSION

Azathioprine helps to reduce prednisolone dose in long-run.

Successful treatment of pemphigus with biweekly 1-g infusions of rituximab: a retrospective study of 47 patients

BACKGROUND

Rituximab is increasingly being appreciated as a remarkably effective treatment for pemphigus, mostly concomitantly with other immunosuppressive medications. The majority of studies have used a single cycle of rituximab with the same dosage as approved for the treatment of lymphomas, ie, 375 mg/m(2) weekly × 4 weeks. Rituximab is also approved for the treatment of rheumatoid arthritis, with a different dosing regimen: 1000 mg × 2, days 1 and 15.

OBJECTIVE

We aimed to assess the clinical response of patients with pemphigus to a single cycle of rituximab at the dosage used in rheumatoid arthritis. We also evaluated the response to repeated cycles of rituximab.

METHODS

A total of 47 patients with pemphigus who were treated with rituximab at a dosage of 1000 mg × 2, days 1 and 15, most with concurrent immunosuppressive medications, were retrospectively studied.

RESULTS

Remission rates after the first treatment cycle reached 76%. Repeating the treatment further increased the remission rates to 91%. There was a 22% relapse rate at a median time of 8 months, but 75% of relapsing patients achieved remission again with additional cycles. The side-effect profile was similar to previous reports, except for an immediate postinfusion pemphigus exacerbation in 4 patients.

LIMITATIONS

This was a retrospective study with a limited follow-up period.

CONCLUSION

The rheumatoid arthritis dosage of rituximab was efficacious and well tolerated in patients with pemphigus. Patients who fail to achieve remission after 1 cycle or patients who relapse seem to benefit from repeated rituximab cycles.

Serological diagnosis of autoimmune bullous skin diseases: prospective comparison of the BIOCHIP mosaic-based indirect immunofluorescence technique with the conventional multi-step single test strategy

BACKGROUND

Various antigen-specific immunoassays are available for the serological diagnosis of autoimmune bullous diseases. However, a spectrum of different tissue-based and monovalent antigen-specific assays is required to establish the diagnosis. BIOCHIP mosaics consisting of different antigen substrates allow polyvalent immunofluorescence (IF) tests and provide antibody profiles in a single incubation.

METHODS

Slides for indirect IF were prepared, containing BIOCHIPS with the following test substrates in each reaction field: monkey esophagus, primate salt-split skin, antigen dots of tetrameric BP180-NC16A as well as desmoglein 1-, desmoglein 3-, and BP230gC-expressing human HEK293 cells. This BIOCHIP mosaic was probed using a large panel of sera from patients with pemphigus vulgaris (PV, n=65), pemphigus foliaceus (PF, n=50), bullous pemphigoid (BP, n=42), and non-inflammatory skin diseases (n=97) as well as from healthy blood donors (n=100). Furthermore, to evaluate the usability in routine diagnostics, 454 consecutive sera from patients with suspected immunobullous disorders were prospectively analyzed in parallel using a) the IF BIOCHIP mosaic and b) a panel of single antibody assays as commonly used by specialized centers.

RESULTS

Using the BIOCHIP mosaic, sensitivities of the desmoglein 1-, desmoglein 3-, and NC16A-specific substrates were 90%, 98.5% and 100%, respectively. BP230 was recognized by 54% of the BP sera. Specificities ranged from 98.2% to 100% for all substrates. In the prospective study, a high agreement was found between the results obtained by the BIOCHIP mosaic and the single test panel for the diagnosis of BP, PV, PF, and sera without serum autoantibodies (Cohen's κ between 0.88 and 0.97).

CONCLUSIONS

The BIOCHIP mosaic contains sensitive and specific substrates for the indirect IF diagnosis of BP, PF, and PV. Its diagnostic accuracy is comparable with the conventional multi-step approach. The highly standardized and practical BIOCHIP mosaic will facilitate the serological diagnosis of autoimmune blistering diseases.