Bullous and mucous membrane pemphigoid show a mixed response to rituximab: experience in seven patients

Anti-Laminin 332-Type Mucous Membrane Pemphigoid

Anti-laminin (LM) 332-type mucous membrane pemphigoid (MMP) is a rare autoimmune bullous disease and was originally discovered as anti-epiligrin cicatricial pemphigoid. Anti-LM332-type MMP has clinical manifestations similar to those of other types of MMP and can only be distinguished through the detection of circulating autoantibodies against LM332. Our group and others have established a number of immunological methods with varying sensitivity and specificity for detection of anti-LM332 autoantibodies; however, none of the established methods has been widely used for clinical diagnosis. There is currently no unified standard treatment, and it is very difficult to completely cure anti-LM332-type MMP. In addition, an increasing body of evidence suggests that there may be a strong correlation between anti-LM332-type MMP and tumors. In this article, we review the current progression of diagnosis and treatment of anti-LM332-type MMP, as well as the possible correlation between anti-LM332-type MMP and tumors.

Off-Label Uses of Rituximab in Dermatology

Purpose of Review

Rituximab has transformed the treatment of B-cell malignancies and rheumatoid arthritis in the past 2 decades. More recently, this anti-CD20 monoclonal antibody has seen increasing usage in the field of dermatology. This review highlights the evidence supporting its use in several important dermatologic conditions.

Recent Findings

Key recent findings include the 2018 FDA approval of rituximab for the treatment of moderate-to-severe pemphigus.

Summary

Data from randomized controlled trials have demonstrated the efficacy of rituximab in pemphigus, ANCA-associated vasculitis, and cryoglobulinemic vasculitis. More limited data suggests its use in recalcitrant cases of diseases such as pemphigoid, epidermolysis bullosa acquisita, and dermatomyositis. There is scarce evidence and mixed results for rituximab when studied in cutaneous polyarteritis nodosa and cutaneous lupus erythematosus.

Rituximab, Omalizumab, and Dupilumab Treatment Outcomes in Bullous Pemphigoid: A Systematic Review

Background

Bullous pemphigoid (BP) is the most common autoimmune subepidermal bullous disease of the skin. First-line treatment of systemic corticosteroids may cause serious adverse events. Rituximab, omalizumab, and dupilumab should be explored as alternative treatment options to improve outcomes.

Objective

To systematically review the rituximab, omalizumab, and dupilumab treatment outcomes in bullous pemphigoid.

Methods

A PubMed, Embase, Web of Science, and Cochrane library search were conducted on March 10, 2022. A total of 75 studies were included using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

Results

Use of rituximab (n=122), omalizumab (n=53) and dupilumab (n=36) were reported in 211 patients with BP. Rituximab led to complete remission in 70.5% (n=86/122) and partial remission in 23.8% (n=29/122) of patients within 5.7 months, with a recurrence rate of 20.5% (n=25/122). 9.0% (n=11/122) of patients died and infection (6.6%, n=8/122) was the most common adverse event. Omalizumab led to complete remission in 67.9% (n=36/53) and partial remission in 20.8% (n=11/53) of patients within 6.6 months, with a recurrence rate of 5.7% (n=3/53). 1.9% (n=1/53) of patients died and thrombocytopenia (1.9%, n=1/53) was observed as the most common adverse event. Dupilumab led to complete remission in 66.7% (n=24/36) and partial remission in 19.4% (n=7/36) of patients within 4.5 months of treatment without any reported adverse events, with a recurrence rate of 5.6% (n=2/36).

Conclusions

Rituximab, omalizumab, and dupilumab have similar clinical benefits for BP patients. However, rituximab resulted in higher recurrence rates, adverse events, and mortality rates.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022316454.

Use of rituximab in the treatment of mucous membrane pemphigoid: An analytic review

Mucous Membrane Pemphigoid (MMP) is a potentially fatal mucocutaneous autoimmune blistering disease. Autoantibodies are produced against various components of the dermo-epidermal or mucosal-submucosal junction are referred to as basement membrane zone (BMZ). The hallmark is deposition of of Ig and C3 on the perilesional tissues and in some patients detection of anti-BMZ autoantibodies. A unique characteristic of MMP is that as the blisters or erosions heal, they leave irreversible scarring. This scarring results in serious and catastrophic sequelae that affect the quality of life. Conventional therapy consists of anti-inflammatory and immunosuppressive agents (ISA). In patients who fail conventional therapy or develop significant side effects to them, rituximab (RTX) has been used off label. In this review, the clinical outcomes of patients with MMP treated with RTX were studied. 124 patients were identified, 47.58% being male. 72 patients were treated by the Lymphoma Protocol and 51 by Rheumatoid Arthritis (RA) protocol. Follow up for the entire cohort was 36 months (range 0.5-72). On follow-up 64 patients (51.61%) achieved complete clinical remission (CR) off therapy, 25 patients (20.16%) were in CR on therapy, 5 patients (4.03%) were non-responders, and 9 patients (7.25%) were failures. 52 patients (41.93%) experienced a relapse, after 36 months follow-up. Duration between last RTX infusion and relapse was 10.5 months (range 1-30). Most patients with relapses were treated with additional RTX. A statistically significant better outcome was observed in patients treated with RTX as monotherapy compared to those who received RTX with ISA. Clinical outcomes in patients treated with Lymphoma protocol were better than RA protocol at a statistically significant level. Data on CD20+ B cell depletion and repopulation was limited. Interestingly relapses were seen in patients with CD20+ B cell depletion and after repopulation. In the final analysis, 89 patients (71.77%) were in complete remission. Data in this review indicated that RTX was a useful agent to treat MMP. While a randomized control trial may not be practically possible, better and disease specific protocols need to be developed. When publishing, authors should attempt to provide complete and detailed information. In doing so, they will benefit their colleagues and the patients with MMP they treat with RTX.

Clinical Effectiveness and Safety of Initial Combination Therapy with Corticosteroids and Rituximab in Bullous Pemphigoid: A Retrospective Cohort Study

BACKGROUND

Rituximab is a potential initial adjuvant therapy for bullous pemphigoid, yet clinical experience is scarce.

OBJECTIVE

We aimed to examine the clinical outcomes and safety of initial combination therapy with systemic corticosteroids and adjuvant rituximab for the treatment of bullous pemphigoid.

METHODS

A retrospective cohort study was performed on 84 patients with bullous pemphigoid, who received systemic corticosteroids with or without initial adjuvant rituximab therapy (defined as rituximab use within 12 weeks after initiation of systemic corticosteroids).

RESULTS

Among the 84 patients included (37 received systemic corticosteroids with rituximab and 47 were treated with systemic corticosteroids without rituximab), the median time to complete remission on minimal therapy or off therapy was 215 days (95% confidence interval 176.9-253.1) in patients receiving rituximab vs 529 days (95% confidence interval 338.6-719.4) in those not receiving rituximab. A Cox regression analysis showed an increased probability of reaching complete remission on minimal therapy or off therapy with the combined therapy (hazard ratio = 2.28 [1.28-4.07], p = 0.005) after age, Bullous Pemphigoid Disease Activity Index score, and underlying diseases were controlled. In multivariate logistic/linear regressions, initial adjuvant rituximab therapy was associated with a higher complete remission rate (odds ratio = 6.63 [2.09-21.03]) and lower cumulative prednisolone (mg)/body weight (kg) (B = -24.86 [-44.06 to -8.29]) within 48 weeks. Risk of hospitalization for infection was not elevated in the group treated with adjuvant rituximab.

CONCLUSIONS

Rituximab use as adjuvant therapy within 12 weeks after initiation of systemic corticosteroids was associated with a faster and higher rate of achieving complete remission on minimal therapy or off therapy, as well as a significant corticosteroid-sparing effect and a comparable safety profile in this retrospective study. Hence, initial combination therapy with corticosteroids and adjuvant rituximab could serve as an effective treatment option for bullous pemphigoid, but this requires confirmation in randomized controlled studies.

Efficacy and Safety of Dupilumab in Moderate-to-Severe Bullous Pemphigoid

Background

Bullous pemphigoid (BP) is an autoimmune blistering disorder that predominantly affects the elderly. As the main treatment for BP, systemic corticosteroids are often limited by their side effects. Safer treatment modalities are therefore needed. Dupilumab is a biologic agent used to treat BP in recent years.

Methods

Medical records of patients with moderate-to-severe BP were retrospectively reviewed. Twenty-four patients were included (follow-up period: 32 weeks), eight of whom received dupilumab in combination with methylprednisolone and azathioprine (dupilumab group) while the other 16 patients received methylprednisolone and azathioprine (conventional group). Response to dupilumab was evaluated by comparison of several parameters (time to stop new blister formation, time to reduce the systemic glucocorticoids to minimal dose, and total amount of methylprednisolone).

Results

The median age of patients in the dupilumab and conventional groups were 64.50 years (range: 22–90 years) and 64.50 years (range: 17–86 years), respectively. The median duration of disease before admission in the dupilumab group was 2 months (range: 1–240 months) and 2.5 months (range: 1–60 months) in the conventional group. The median time to stop new blister formation was 8 days (range: 1–13 days) and 12 days (range: 5–21 days) in patients of the dupilumab and conventional groups, respectively (p = 0.028 by Kaplan-Meier analysis). In addition, the median time to reduce the systemic glucocorticoids to minimal dose (methylprednisolone 0.08 mg/kg/day) was 121.5 and 148.5 days for the dupilumab and conventional therapy groups, respectively (p = 0.0053 by Kaplan-Meier analysis). The median total amount of methylprednisolone (at the time of reaching the minimal dose) used in the dupilumab group was 1,898 mg (range: 1,624–2,932 mg) while the cumulative dose of conventional group was 2,344 mg (range: 1,708–4,744 mg) (p = 0.036 by Mann-Whitney U test). The median total amount of azathioprine (at the time of reaching the minimal dose) used in dupilumab group was 8,300 mg (range: 7,100–10,400 mg) while the total dose of conventional group was 10,300 mg (range: 8,900–14,400 mg) (p = 0.0048 by Mann-Whitney U test). No adverse event related to dupilumab was recorded.

Conclusions

Dupilumab in addition to methylprednisolone and azathioprine seems superior to methylprednisolone/azathioprine alone in controlling disease progression and accelerating the tapering of glucocorticoids.

Ocular mucous membrane pemphigoid: novel treatment strategies

PURPOSE OF REVIEW

To describe current treatments of ocular mucous membrane pemphigoid (OMMP), including conventional systemic immunosuppression (CIST) and novel biologic agents.

RECENT FINDINGS

CIST remains the main stay therapy for the management of OMMP. The choice of agents is tailored to disease severity - mild disease is treated with dapsone, whereas moderately severe cases are often treated with mycophenolate mofetil or sulfa-based drugs and severe cases are treated with cyclophosphamide. In recalcitrant disease newer biologics such as Rituximab, intravenous immunoglobins and tumour necrosis alpha antagonists have proven to be effective in disease control. Control of inflammation with topical therapy and halting conjunctival fibrosis remain as areas of unmet clinical needs.

SUMMARY

OMMP is largely treated with CIST. The recent introduction of new biologic agents could shape the way the disease is treated in the near future.

Laryngeal mucous membrane pemphigoid serves as a prognostic factor for poor response to treatment with rituximab

Mucous membrane pemphigoid (MMP) is an autoimmune blistering, scarring and occasionally mutilating disease that may progress to blindness or airway obstruction. Over the past few years, rituximab (RTX) has emerged as a potential therapeutic solution for MMP; however, the literature regarding its efficacy in the treatment of severe MMP is sparse. We studied four patients with recalcitrant MMP who were treated with RTX. Three of these had recalcitrant laryngeal disease; two were unresponsive to RTX, while the third patient achieved complete remission (CR) but relapsed twice. The fourth patient, who had oral and ocular disease, also achieved CR. In addition, we reviewed 143 cases of MMP treated with RTX reported in the literature to date. Of these, 120 had late observation endpoints, of whom 81 (67.5%) achieved CR, 24 (20%) received partial remission and 15 (12.5%) had no remission. Based on this study, the presence of laryngeal MMP seems to predict refractoriness to RTX treatment. In conclusion, we found that RTX can ameliorate the MMP course and that laryngeal involvement, which is known to be a prognostic factor for severe MMP, may also predict poor response to RTX.

Treatment of Bullous Pemphigoid in People Aged 80 Years and Older: A Systematic Review of the Literature

BACKGROUND

Bullous pemphigoid commonly affects older adults and has a detrimental effect on both quality of life and longevity. Systemic corticosteroids, the mainstay of therapy, may cause significant adverse effects, especially in older patients. Therefore, safer therapeutic options are being sought.

OBJECTIVE

The objective of this article was to systematically review the published evidence on the efficacy and safety of different treatment modalities for bullous pemphigoid in older patients.

METHODS

We performed a systematic review of all publications until May 2020 in PubMed, Google Scholar, and the ongoing trials registry of the US National Institutes of Health databases evaluating the efficacy and safety of bullous pemphigoid treatments in patients aged older than 80 years. The primary outcome was complete response. The secondary outcomes were partial response, complete remission on minimal therapy or during tapering, recurrence, adverse events, and mortality.

RESULTS

Twenty-eight publications were included: 2 randomized controlled trials, 5 prospective cohort studies, 10 retrospective cohort studies, and 11 case series, with a total of 153 older patients. The overall complete response rate was 31%. Topical corticosteroids had the highest complete response rate (55%) with a low side-effect profile. Biologics (omalizumab and rituximab) were effective in achieving complete remission on minimal therapy (29%) without recurrence, although rituximab was associated with a relatively high mortality rate (29%).

CONCLUSIONS

Current data suggest that topical corticosteroids are effective and safe and should remain the first line of treatment for bullous pemphigoid in older adults. However, their application is difficult and requires a high-functioning patient, third-party assistance, or a relatively mild disease. Biological agents are effective but warrant meticulous patient selection owing to the relatively high mortality rate associated with rituximab.

CLINICAL TRIAL REGISTRATION

PROSPERO registration number CRD42020186686.

The Intersection of IgE Autoantibodies and Eosinophilia in the Pathogenesis of Bullous Pemphigoid

Bullous pemphigoid (BP) is an autoimmune blistering disease characterized by autoantibodies targeting cellular adhesion molecules. While IgE autoantibodies are occasionally reported in other autoimmune blistering diseases, BP is unique in that most BP patients develop an IgE autoantibody response. It is not known why BP patients develop self-reactive IgE and the precise role of IgE in BP pathogenesis is not fully understood. However, clinical evidence suggests an association between elevated IgE antibodies and eosinophilia in BP patients. Since eosinophils are multipotent effector cells, capable cytotoxicity and immune modulation, the putative interaction between IgE and eosinophils is a primary focus in current studies aimed at understanding the key components of disease pathogenesis. In this review, we provide an overview of BP pathogenesis, highlighting clinical and experimental evidence supporting central roles for IgE and eosinophils as independent mediators of disease and via their interaction. Additionally, therapeutics targeting IgE, the Th2 axis, or eosinophils are also discussed.

Rituximab in autoimmune pemphigoid diseases: Indications, optimized regimens, and practice gaps

Rituximab is a monoclonal antibody targeting CD20 on B cells with proven efficacy for pemphigus vulgaris, now an FDA-approved indication. Other autoimmune bullous diseases can be challenging to treat and have significant associated morbidity and mortality, but data supporting the use of rituximab in pemphigoid group diseases remain limited. Although rituximab demonstrates efficacy for clinical improvement and remission in pemphigoid, concern for adverse events may also limit the use of this medication. We review the current evidence fo rthe use of rituximab in pemphigoid diseases, pertinent dosing schedules and laboratory monitoring, and the associated common and rare adverse events. Review of the literature to date not only supports consideration of rituximab for treatment of refractory pemphigoid group diseases but also reflects tolerability and an acceptable safety profile.

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.

Rituximab and Omalizumab for the Treatment of Bullous Pemphigoid: A Systematic Review of the Literature

BACKGROUND

Bullous pemphigoid (BP) is the most common autoimmune blistering skin disease worldwide. Systemic corticosteroids are considered the mainstay of therapy; however, they may cause significant adverse effects and treatment failures, so additional therapeutic modalities with better safety profiles are required. Rituximab and omalizumab are novel biologic agents administered in recent years for the treatment of BP, yet data regarding their use in the disease are limited.

OBJECTIVE

Our objective was to systematically review the current literature regarding the use of rituximab and omalizumab for the treatment of BP to evaluate their safety and efficacy.

METHODS

A systematic review of all publications evaluating patients with BP treated with rituximab or omalizumab was performed. The primary outcome was clinical response; secondary outcomes were adverse events and recurrence rate.

RESULTS

The systematic review included 35 publications (84 patients: 62 receiving rituximab and 22 receiving omalizumab). In total, 61 of 63 patients had not experienced disease control with systemic corticosteroids before receiving the biologic treatment. Complete response rates were 85% and 84% for rituximab and omalizumab, respectively. The recurrence rate was considerably lower with rituximab (29%) than with omalizumab (80%). Mean time to recurrence was 10.2 and 3.4 months, and adverse effects occurred in 24% and 20% of the patients, respectively.

CONCLUSIONS

Available data, although potentially limited because of publication bias, suggest that rituximab and omalizumab have similar safety profiles and provide clinical benefit for patients with BP. The reviewed data indicated that rituximab resulted in lower recurrence rates and a longer time until recurrence than omalizumab.

Autoimmune Subepidermal Bullous Diseases of the Skin and Mucosae: Clinical Features, Diagnosis, and Management

Autoimmune subepidermal blistering diseases of the skin and mucosae constitute a large group of sometimes devastating diseases, encompassing bullous pemphigoid, gestational pemphigoid, mucous membrane pemphigoid, epidermolysis bullosa acquisita, and anti-p200 pemphigoid. Their clinical presentation is polymorphic. These autoimmune blistering diseases are associated with autoantibodies that target distinct components of the basement membrane zone of stratified epithelia. These autoantigens represent structural proteins important for maintenance of dermo-epidermal integrity. Bullous pemphigoid (BP) is the most common subepidermal autoimmune blistering disease of the skin and mucosae. Although the disease typically presents with a generalized blistering eruption associated with itch, atypical variants with either localized bullous lesions or "non-bullous" presentations are observed in approximately 20% of patients. A peculiar form of BP typically associated with pregnancy is pemphigoid gestationis. In anti-p200 pemphigoid, patients present with tense blisters on erythematosus or normal skin resembling BP, with a predilection for acral surfaces. These patients have antibodies targeting the 200-kDa basement membrane protein. Epidermolysis bullosa is a rare autoimmune blistering disease associated with autoantibodies against type VII collagen that can have several phenotypes including a classical form mimicking dystrophic epidermolysis bullosa, an inflammatory presentation mimicking BP, or mucous membrane pemphigoid-like lesions. Mucous membrane pemphigoid (MMP) is the term agreed upon by international consensus for an autoimmune blistering disorder, which affects one or more mucous membrane and may involve the skin. The condition involves a number of different autoantigens in the basement membrane zone. It may result in severe complications from scarring, such as blindness and strictures. Diagnosis of these diseases relies on direct immunofluorescence microscopy studies and immunoserological assays. Management of affected patients is often challenging. We will here review the clinical and immunopathological features as well as the pathophysiology of this group of organ-specific autoimmune diseases. Finally, we will discuss the diagnostic approach and the principles of management in clinical practice.

Effectiveness and Safety of Rituximab in Recalcitrant Pemphigoid Diseases

Introduction

Rituximab (RTX) is a monoclonal antibody targeting CD20, a transmembrane protein expressed on B cells, causing B cell depletion. RTX has shown great efficacy in studies of pemphigus vulgaris, but data of pemphigoid diseases are limited.

Objective

To assess the effectiveness and safety of RTX in pemphigoid diseases.

Methods

The medical records of 28 patients with pemphigoid diseases that were treated with RTX were reviewed retrospectively. Early and late endpoints, defined according to international consensus, were disease control (DC), partial remission (PR), complete remission (CR), and relapses. Safety was measured by reported adverse events.

Results

Patients with bullous pemphigoid (n = 8), mucous membrane pemphigoid (n = 14), epidermolysis bullosa acquisita (n = 5), and linear IgA disease (n = 1) were included. Treatment with 500 mg RTX (n = 6) or 1,000 mg RTX (n = 22) was administered on days 1 and 15. Eight patients received additional 500 mg RTX at months 6 and 12. Overall, DC was achieved in 67.9%, PR in 57.1%, and CR in 21.4% of the cases. During follow-up, 66.7% patients relapsed. Repeated treatment with RTX led to remission (PR or CR) in 85.7% of the retreated cases. No significant difference in response between pemphigoid subtypes was found. IgA-dominant cases (n = 5) achieved less DC (20 vs. 81.3%; p = 0.007), less PR (20 vs. 62.5%; p = 0.149), and less CR (0 vs. 18.8%; p = 0.549) compared to IgG-dominant cases (n = 16). Five severe adverse events and three deaths were reported. One death was possibly related to RTX and one death was disease related.

Conclusion

RTX can be effective in recalcitrant IgG-dominant pemphigoid diseases, however not in those where IgA is dominant.

Rituximab therapy in pemphigus and other autoantibody-mediated diseases

Rituximab, a monoclonal antibody targeting the B cell marker CD20, was initially approved in 1997 by the United States Food and Drug Administration (FDA) for the treatment of non-Hodgkin lymphoma. Since that time, rituximab has been FDA-approved for rheumatoid arthritis and vasculitides, such as granulomatosis with polyangiitis and microscopic polyangiitis. Additionally, rituximab has been used off-label in the treatment of numerous other autoimmune diseases, with notable success in pemphigus, an autoantibody-mediated skin blistering disease. The efficacy of rituximab therapy in pemphigus has spurred interest in its potential to treat other autoantibody-mediated diseases. This review summarizes the efficacy of rituximab in pemphigus and examines its off-label use in other select autoantibody-mediated diseases.

The 2016 Bowman Lecture Conjunctival curses: scarring conjunctivitis 30 years on

This review is in two sections. The first section summarises 35 conditions, both common and infrequent, causing cicatrising conjunctivitis. Guidelines for making a diagnosis are given together with the use of diagnostic tests, including direct and indirect immunofluorescence, and their interpretation. The second section evaluates our knowledge of ocular mucous membrane pemphigoid, which is the commonest cause of cicatrizing conjunctivitis in most developed countries. The clinical characteristics, demographics, and clinical signs of the disease are described. This is followed by a review and re-evaluation of the pathogenesis of conjunctival inflammation in mucous membrane pemphigoid (MMP), resulting in a revised hypothesis of the autoimmune mechanisms causing inflammation in ocular MMP. The relationship between inflammation and scarring in MMP conjunctiva is described. Recent research, describing the role of aldehyde dehydrogenase (ALDH) and retinoic acid (RA) in both the initiation and perpetuation of profibrotic activity in MMP conjunctival fibroblasts is summarised and the potential for antifibrotic therapy, using ALDH inhibition, is discussed. The importance of the management of the ocular surface in MMP is briefly summarised. This is followed with the rationale for the use of systemic immunomodulatory therapy, currently the standard of care for patients with active ocular MMP. The evidence for the use of these drugs is summarised and guidelines given for their use. Finally, the areas for research and innovation in the next decade are reviewed including the need for better diagnostics, markers of disease activity, and the potential for biological and topical therapies for both inflammation and scarring.

Advances in understanding and managing bullous pemphigoid

Bullous pemphigoid (BP) is the commonest subtype of autoimmune blistering disease in most countries of the world. It occurs most frequently in elderly patients and is characterised clinically by large, tense blisters in the skin preceded by urticarial plaques and pruritus. Immunopathologically, it is characterised by autoantibodies directed against the 180 kD antigen (BP180) and the 230 kD antigen (BP230). New knowledge regarding BP is being continually uncovered. This article reviews the recent advances in BP, including newer diagnostic tests, standardised outcome measures and emerging therapeutic options, as well as the evidence supporting their use.

The emerging role of rituximab in autoimmune blistering diseases

Rituximab is a chimeric monoclonal antibody that selectively binds to the CD20 molecule on B cells, resulting in their lysis. In autoimmune blistering diseases, the auto-antibody-producing B cells are destroyed and auto-antibody levels are reduced or eliminated. In the majority of patients, rituximab produces rapid clinical response and early resolution. In part, this accounts for the increased use of rituximab. Rituximab does not distinguish normal from pathologic B cells. Hence, shortly after its use, B-cell levels are zero and remain so for several months. In most patients, the use of systemic corticosteroids and immunosuppressive agents are continued after rituximab therapy, while their dosages are significantly decreased. In the majority of patients rituximab is used according to the protocol used in treating lymphoma patients or patients with rheumatoid arthritis. Approximately 50% of patients experience a relapse, requiring additional therapy. Serious adverse events and fatal outcomes have been reported, although their incidence is less than that observed with conventional therapy. Nonetheless, the causes, i.e. infections and septicemia, are similar. Several gaps exist in our understanding of how to optimally benefit from the use of this valuable biological agent. Future studies need to be targeted in designing and implanting protocols that maximize the benefit of rituximab and result in producing sustained prolonged remissions with minimal adverse events and a high quality of life.

Revisiting the role of B cells in skin immune surveillance

Whereas our understanding of the skin immune system has increased exponentially in recent years, the role of B cells in cutaneous immunity remains poorly defined. Recent studies have revealed the presence of B cells within lymphocytic infiltrates in chronic inflammatory skin diseases and cutaneous malignancies including melanoma, and have examined their functional significance in these settings. We review these findings and discuss them in the context of the current understanding of the role of B cells in normal skin physiology, as well as in both animal and human models of skin pathology. We integrate these findings into a model of cutaneous immunity wherein crosstalk between B cells and other skin-resident immune cells plays a central role in skin immune homeostasis.

Refractory childhood pemphigoid successfully treated with rituximab

Bullous pemphigoid is an acquired autoimmune blistering disorder affecting mostly elderly people that is rare in children. There have been fewer than 100 cases of childhood bullous pemphigoid reported. Childhood bullous pemphigoid (CBP) generally has a good prognosis. Remission is usually achieved within several weeks to a few months, and relapses are rare, although refractory cases can occur, and the disease may be life threatening, particularly when lesions generalize. Herein we describe the case of an infant with severe CBP refractory to multiple treatments. In our case, therapy with azathioprine and intravenous immunoglobulin resulted in a slight clinical response, but only combined with high doses of prednisolone. Administration of rituximab led to a complete clinical response and allowed almost complete steroid tapering. There are no current guidelines indicating what doses and frequency of rituximab are safest or most effective in children with blistering diseases.

Rituximab in dermatology

Rituximab was introduced into clinical practice as a medication with considerable potential. Its use in patients with B-cell lymphoma and rheumatoid arthritis revealed numerous indications in autoimmune diseases, many of which involve the skin, thus requiring dermatologists to become familiar with both the characteristics of anti-CD20 antibodies and the role of B cells in multiple skin diseases. Thanks to these developments, we will be able to use rituximab more frequently and appropriately in our patients and draw up consensus guidelines based on large case series. In other words, establishing the indications for rituximab will make it possible to shorten disease course and reduce morbidity due to more specific drugs.

Rituximab in the treatment of pemphigus vulgaris

INTRODUCTION

Rituximab is increasingly used in patients with pemphigus vulgaris (PV) who are nonresponders to conventional therapy.

METHODS

A PubMed search was conducted using the words pemphigus vulgaris and rituximab therapy from papers published between 2000 and 2012. Two protocols were used. In the lymphoma protocol, patients received four weekly infusions of rituximab (dose 375 mg/m(2)). The rheumatoid arthritis (RA) protocol consisted of two infusions of 1,000 mg each 15 days apart. The variables recorded from each study included clinical remission off or on therapy, relapse rate, incidence of serious adverse events, concomitant therapies, duration of follow-up, and when available, levels of B cells and autoantibodies.

RESULTS

Forty-two studies were found, which reported 272 patients; 180 were treated by the lymphoma protocol and 92 by the RA protocol. Both protocols were effective in treating recalcitrant PV. The lymphoma protocol had a lower response rate, relapse rate and serious infections, but higher mortality, and there were nonresponders. The RA protocol produced a higher response rate, relapse rate, number of infections, but lower mortality rate, and lacked nonresponders. The cumulative follow-up for patients treated with the lymphoma protocol was 15.44 months (range 1-41) and 21.04 months (range 8.35-29) for the RA protocol. A major concern in both protocols was the high infection rates, some of which were fatal. A different protocol using a combination of rituximab with intravenous immunoglobulin in a defined manner with a definitive endpoint, used in a limited cohort of patients, showed promising results.

CONCLUSION

Neither protocol produced a sustained clinical remission and both required continued systemic therapy. Before initiation of treatment, physicians should have a specific goal and endpoint and be aware of its potential side effects and lack of information on its long-term effects. Patients should be carefully monitored during and after therapy.

Critical analysis of the use of rituximab in mucous membrane pemphigoid: a review of the literature

BACKGROUND

Mucous membrane pemphigoid (MMP) is an autoimmune blistering disease. In patients who do not respond to conventional therapy, rituximab (RTX) may be an option. The current literature on the treatment of MMP with RTX is limited.

OBJECTIVE

In this review, the data on 28 patients with MMP treated with RTX are critically analyzed. The goal is to provide objective information useful in decision making and treatment.

METHODS

A PubMed search using the key words "rituximab" and "mucous membrane pemphigoid" was made in the English language only. The studies were divided into case reports and case series.

RESULTS

In the final analysis, 20 of 28 patients had a complete response, 3 had a partial response, 2 were nonresponders, and 1 had stabilization of disease. In 1 patient, stabilization of upper airway disease was observed but the patient developed bilateral blindness as a result of progression of disease. Hence, the patient was considered a treatment failure. One died from infection. At least half of the patients were treated with a second cycle because of relapse or lack of response.

LIMITATIONS

Long-term follow-up after RTX therapy is lacking. Hence, the clinical benefit of inducing long-term remissions cannot be assessed. Responses of individual mucosal sites cannot be differentiated. Studies on B-cell levels and antibody responses are lacking.

CONCLUSION

Using the protocol described, RTX benefits patients with recalcitrant MMP. Some patients fail treatment or experience a relapse. The ability of RTX to influence the clinical course of MMP remains to be determined.

Treatment of subepidermal immunobullous diseases

The subepidermal immunobullous diseases are a group of autoimmune blistering disorders of the skin and mucous membranes that share the common features of autoantibody deposition and blister formation at the dermal-epidermal junction or basement membrane. This group includes bullous pemphigoid, linear IgA disease, dermatitis herpetiformis, and epidermolysis bullosa acquisita, among others. Although these disorders share some common features, each disease is unique in its clinical presentation, histopathology, and immunofluorescence patterns, which allows for accurate diagnosis and disease-specific treatment strategy. Treatment of these disorders is complex and requires expert knowledge of disease pathogenesis. We review common treatment approaches for each of these disorders.

[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.