Mortality and clinical response of patients with bullous pemphigoid treated with rituximab

Anti-interleukin 4 receptor α antibody for the treatment of Chinese bullous pemphigoid patients with diverse comorbidities and a 1-year follow-up: a monocentric real-world study

Background

Bullous pemphigoid (BP) is a common subepidermal bullous disorder that lacks adequate treatment alternatives. Dupilumab, an anti-interleukin (IL) 4 receptor α antibody blocking Th2 molecules IL-4 and 13, has been used off-label and shown to be effective in refractory BP cases.

Methods

BP patients with various disease severities and comorbidities were included in this case series. All patients received dupilumab alone or in combination with immunosuppressants in a real-world setting. Complete remission (CR) was defined as the absence of pruritus symptoms and previous BP eruptions, with only hyperpigmentation patches and without newly occurring lesions for at least 4 weeks. Disease relapse was classified as the appearance of three or more new lesions within 1 month or at least one large urticarial or eczematous lesion that did not resolve within a week.

Findings

Ten individuals were enrolled in this case series. Pruritus symptoms and BP eruptions improved significantly in nine patients (90%). Seven patients (70%) attained CR, including all mild-to-moderate (100%) cases and three of six (50%) severe BP cases. At the dupilumab monotherapy stage, eosinophilia was observed in two severe cases. One patient out of seven (14.3%) relapsed after 1 year of follow-up after CR.

Conclusion

Treatment of BP with diverse comorbidities with anti-IL-4 receptor α antibody provides further credentials to a prospective randomized study. More impressive efficacy and safety profiles were observed in patients with mild-to-moderate disease after 1 year of follow-up. Eosinophilia may occur in patients receiving dupilumab monotherapy.

The cytokine milieu of bullous pemphigoid: Current and novel therapeutic targets

Bullous pemphigoid (BP) is the most common autoimmune bullous disease, characterized by severe pruritus and skin blistering. The loss of tolerance against Collagen XVII, also referred to as BP180, is the main pathogenic event of BP, leading to production of IgG autoantibodies which mainly target the juxtamembranous extracellular non-collagenous 16th A (NC16A) domain of BP180. A complex inflammatory network is activated upon autoantibody binding to the basement membrane zone; this inflammatory loop involves the complement cascade and the release of several inflammatory cytokines, chemokines and proteases from keratinocytes, lymphocytes, mast cells and granulocytes. Collectively, these events disrupt the integrity of the dermal-epidermal junction, leading to subepidermal blistering. Recent advances have led to identify novel therapeutic targets for BP, whose management is mainly based on the long-term use of topical and systemic corticosteroids. As an example, targeting type-2 T-helper cell-associated cytokines, such as Interleukin-4 and interleukin-13 has shown meaningful clinical efficacy in case series and studies; targeting IL-17 and IL-23 has also been tried, owing to an important role of these cytokines in the chronic maintenance phase of BP. In this review article, we discuss the complex cytokine milieu that characterized BP inflammation, highlighting molecules, which are currently investigated as present and future therapeutic targets for this life-threatening disease.

Understanding CD4+ T cells in autoimmune bullous diseases

Autoimmune bullous diseases (AIBDs) are a group of life-threatening blistering diseases caused by autoantibodies that target proteins in the skin and mucosa. Autoantibodies are the most important mediator in the pathogenesis of AIBDs, and various immune mechanisms contribute to the production of these pathogenic autoantibodies. Recently, significant progress has been made in understanding how CD4⁺ T cells drive autoantibody production in these diseases. Here, we review the critical role of CD4⁺ T cells in the production of pathogenic autoantibodies for the initiation and perpetuation of humoral response in AIBDs. To gain an in-depth understanding of CD4⁺ T-cell pathogenicity, antigen specificity, and mechanisms of immune tolerance, this review covers comprehensive mouse and human studies of pemphigus and bullous pemphigoid. Further exploration of pathogenic CD4⁺ T cells will potentially provide immune targets for improved treatment of AIBDs.

Low-Dose Rituximab for Bullous Pemphigoid. Protocol and Single-Center Experience

BACKGROUND

Low-dose rituximab is a protocol used in several autoimmune diseases, that has also shown to be effective and safe in pemphigus vulgaris.

OBJECTIVES

To study whether low-dose rituximab is also effective for bullous pemphigoid.

METHODS

Patients with BP were treated with a single cycle of two infusions of rituximab 500mg at an interval of 2 weeks. Early and late end points were monitored.

RESULTS

Six patients, five males and a female, with a mean age of 78.6 years (range 65-89) and a mean history of BP of 6.7 months (range 2-16) were included. A rapid and marked response was observed after a single cycle of treatment, with a mean time to disease control and to end of consolidation phase of 1.9 (range 1-3), and 4 weeks (range 3-5), respectively. Four patients achieved a late end point at a mean of 15.75 weeks (range 13-20). Three of them achieved partial remission with no therapy (two patients) or with minimal therapy (one patient), and one of them achieved complete remission with no therapy. One patient has 6 weeks of clinical follow-up after rituximab administration. The remaining patient relapsed 4 weeks after the rituximab treatment, and remains in complete remission with more than minimal therapy. One patient had a herpetic gingivostomatitis related to rituximab.

CONCLUSIONS

Low-dose rituximab for BP achieved acceptable remission rates and steroid-sparing activity, with a better safety profile and a lower cost, compared to standard doses. This pilot study suggests that low-dose rituximab could be a therapeutic option for BP.

Retrospective analysis of the long-term therapeutic effectiveness and safety profile of rituximab in the treatment of mucous membrane pemphigoid in a German university center between 2008 and 2019

Background

The B-cell-depleting anti-CD20 antibody rituximab (RTX) is often used as an adjuvant drug for the treatment of refractory cases of mucous membrane pemphigoid (MMP).

Objective

This study aims to determine the therapeutic effectiveness and the safety profile of RTX in MMP.

Methods

The medical records of all cases of MMP treated with RTX between 2008 and 2019 in our university medical center located in northern Germany, which specialized in autoimmune blistering skin diseases, were retrieved and systemically analyzed for treatment responses and potential adverse events over a median period of 27 months.

Results

We identified 18 MMP patients who received at least one cycle of RTX to treat MMP. RTX was always used as an adjuvant treatment, and its application did not change concomitant treatments. Under treatment with RTX, 67% of the patients achieved an improvement in their disease activity within 6 months. This was also reflected in a statistically significant reduction in the Mucous Membrane Pemphigoid Disease Index (MMPDAI) activity score. The frequency of infections under RTX treatment increased only slightly.

Conclusions

The use of RTX is associated with an attenuation of MMP in a large proportion of MMP patients in our study. At the same time, its application was not found to further increase the susceptibility of the most strongly immunocompromised population of MMP patients to opportunistic infections. Collectively, our results suggest that the potential benefits of RTX outweigh its risks in patients with refractory MMP.

Low-Dose Rituximab for Bullous Pemphigoid. Protocol and Single-Center Experience

BACKGROUND

Low-dose rituximab is a protocol used in several autoimmune diseases, that has also shown to be effective and safe in pemphigus vulgaris.

OBJECTIVES

To study whether low-dose rituximab is also effective for bullous pemphigoid.

METHODS

Patients with BP were treated with a single cycle of two infusions of rituximab 500 mg at an interval of 2 weeks. Early and late end points were monitored.

RESULTS

Six patients, five males and a female, with a mean age of 78.6 years (range 65-89) and a mean history of BP of 6.7 months (range 2-16) were included. A rapid and marked response was observed after a single cycle of treatment, with a mean time to disease control and to end of consolidation phase of 1.9 (range 1-3), and 4 weeks (range 3-5), respectively. Four patients achieved a late end point at a mean of 15.75 weeks (range 13-20). Three of them achieved partial remission with no therapy (two patients) or with minimal therapy (one patient), and one of them achieved complete remission with no therapy. One patient has 6 weeks of clinical follow-up after rituximab administration. The remaining patient relapsed 4 weeks after the rituximab treatment, and remains in complete remission with more than minimal therapy. One patient had a herpetic gingivostomatitis related to rituximab.

CONCLUSIONS

Low-dose rituximab for BP achieved acceptable remission rates and steroid-sparing activity, with a better safety profile and a lower cost, compared to standard doses. This pilot study suggests that low-dose rituximab could be a therapeutic option for BP.

Review of an Anti-CD20 Monoclonal Antibody for the Treatment of Autoimmune Diseases of the Skin

Biologic therapies targeting B-cells are emerging as an effective strategy to treat a variety of immune-mediated diseases. One of the most studied B-cell-targeted therapies is rituximab, an anti-CD20 monoclonal antibody that exemplifies B-cell depletion therapy and has served as the prototype for other anti-CD20 monoclonal antibodies and the development of biosimilars. While there are multiple studies on the use of rituximab in dermatology, a comprehensive review of rituximab therapy in autoimmune skin conditions is lacking. In this literature review, we summarize indications, treatment efficacy, and safety of rituximab among common autoimmune diseases of the skin: pemphigus vulgaris, cutaneous lupus erythematous, dermatomyositis, systemic sclerosis, thyroid dermopathy, autoimmune pemphigoid diseases, and cutaneous vasculitis diseases. Existing data on rituximab support the approach of rituximab, biosimilars, and newer B-cell-targeting therapies in immune-mediated cutaneous diseases. Overall, rituximab, which targets CD20, provides an effective alternative or concomitant option to traditional immunosuppressants in the management of various autoimmune diseases of the skin. Further studies are necessary to expand the understanding and possible utility of B-cell-targeted therapies among autoimmune skin diseases.

Three cases of refractory bullous pemphigoid in the elderly treated successfully with ultra‐low‐dose rituximab

Rituximab has proven effective for the treatment of steroid-refractory bullous pemphigoid (BP), but there is controversy over the dosing protocol. We report three cases of refractory BP treated successfully with ultra-low-dose rituximab (100 mg weekly for 4 weeks). Our cases confirmed the efficacy and good follow-up outcomes of this treatment strategy for refractory BP. The ultra-low-dose rituximab regimen (100 mg weekly for 4 weeks) may be a useful alternative therapy in patients with refractory BP.

Clinical effect of omalizumab as an adjuvant treatment to rituximab in patient with refractory bullous pemphigoid

Patients with refractory bullous pemphigoid (BP) achieve remission after rituximab treatment but require high-dose systemic corticosteroids until the remission. The aim of this retrospective study was to examine the clinical efficacy of omalizumab as an adjuvant treatment to rituximab in patients with refractory BP. Patients with BP receiving treatment with either rituximab monotherapy or rituximab plus omalizumab were considered for the study. The total dose of corticosteroids received for 60 days after administration of rituximab, mortality and relapse rates, and median time to relapse were also investigated. Of 49 patients included in the study, 25 received rituximab monotherapy and 17 received the combination therapy with rituximab and omalizumab. The rituximab plus omalizumab group showed shorter time to disease control with minimal treatment (15 days vs. 67.5 days, p < 0.001) and lower corticosteroid dose for 60 days after administration of rituximab (698.4 mg vs. 1087.4 mg of methylprednisolone, p < 0.001) compared to the rituximab monotherapy group. The results of this study suggest that combination therapy with rituximab and omalizumab can achieve disease control status faster than the rituximab monotherapy, reducing the total dose of corticosteroids.

Case Report: Omalizumab Successfully Treated Recalcitrant Bullous Pemphigoid in an Elderly Patient with Multiple Comorbidities

Bullous pemphigoid (BP) is an autoimmune blistering disease mainly affecting elderly individuals. Comorbidities are common in patients with BP and have been found to complicate the management and prognosis. We describe a patient with multiple comorbidities who was successfully treated with omalizumab and suggest omalizumab as a good alternative therapy for BP to prevent treatment-related complications in elderly patients with a poor general condition.

Rituximab Therapy for Mucous Membrane Pemphigoid: A Retrospective Monocentric Study With Long-Term Follow-Up in 109 Patients

Mucous membrane pemphigoid (MMP) is a heterogeneous group of rare, chronic, subepithelial autoimmune blistering diseases (AIBDs) with predominant involvement of mucous membranes that can be sight-threatening and life-threatening. Rituximab (RTX) has demonstrated its efficacy in severe MMP refractory to conventional immunosuppressants in small series that differed in RTX scheme, concomitant therapies, and outcome definitions. In a meta-analysis involving 112 patients with MMP treated with RTX, complete remission (CR) was reported in 70.5% of cases. Herein, we report the largest retrospective monocentric study on RTX efficacy in a series of 109 severe and/or refractory patients with MMP treated with RTX with a median follow-up period of 51.4 months. RTX was administered in association with immunomodulatory drugs (dapsone, salazopyrine) without any other systemic immunosuppressant in 104 patients. The RTX schedule comprised two injections (1 g, 2 weeks apart), repeated every 6 months until CR or failure, with a unique consolidation injection (1 g) after CR. The median survival times to disease control and to CR were 7.1 months and 12.2 months, respectively. The median number of RTX cycles required to achieve CR in 85.3% of patients was two. The larynx was the lesional site that took the longest time to achieve disease control. One year after RTX weaning, CR off RTX was obtained in 68.7% of cases. CR off RTX with only minimum doses of immunomodulatory drugs was achieved in 22.0% of patients. Further, 10.1% of patients were partial responders and 4.6% were non-responders to RTX. Relapse occurred in 38.7% of cases, of whom 91.7% had achieved CR again at the last follow-up. In MMP, CR was achieved in a longer time and after more rituximab cycles than in pemphigus, especially for patients with MMP with anti-type VII collagen reactivity. RTX with concomitant immunomodulatory drugs was not responsible for an unusual proportion of adverse events. This large study confirms that RTX is an effective therapy in patients with severe and/or refractory MMP, corroborating previous findings regarding the effects of RTX on AIBDs such as pemphigus.

Unmet Medical Needs in Chronic, Non-communicable Inflammatory Skin Diseases

An estimated 20-25% of the population is affected by chronic, non-communicable inflammatory skin diseases. Chronic skin inflammation has many causes. Among the most frequent chronic inflammatory skin diseases are atopic dermatitis, psoriasis, urticaria, lichen planus, and hidradenitis suppurativa, driven by a complex interplay of genetics and environmental factors. Autoimmunity is another important cause of chronic skin inflammation. The autoimmune response may be mainly T cell driven, such as in alopecia areata or vitiligo, or B cell driven in chronic spontaneous urticaria, pemphigus and pemphigoid diseases. Rare causes of chronic skin inflammation are autoinflammatory diseases, or rheumatic diseases, such as cutaneous lupus erythematosus or dermatomyositis. Whilst we have seen a significant improvement in diagnosis and treatment, several challenges remain. Especially for rarer causes of chronic skin inflammation, early diagnosis is often missed because of low awareness and lack of diagnostics. Systemic immunosuppression is the treatment of choice for almost all of these diseases. Adverse events due to immunosuppression, insufficient therapeutic responses and relapses remain a challenge. For atopic dermatitis and psoriasis, a broad spectrum of innovative treatments has been developed. However, treatment responses cannot be predicted so far. Hence, development of (bio)markers allowing selection of specific medications for individual patients is needed. Given the encouraging developments during the past years, we envision that many of these challenges in the diagnosis and treatment of chronic inflammatory skin diseases will be thoroughly addressed in the future.

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.

Immunopathology and Immunotherapy of Inflammatory Skin Diseases

Recently, there have been impressive advancements in understanding of the immune mechanisms underlying cutaneous inflammatory diseases. To understand these diseases on a deeper level and clarify the therapeutic targets more precisely, numerous studies including in vitro experiments, animal models, and clinical trials have been conducted. This has resulted in a paradigm shift from non-specific suppression of the immune system to selective, targeted immunotherapies. These approaches target the molecular pathways and cytokines responsible for generating inflammatory conditions and reinforcing feedback mechanisms to aggravate inflammation. Among the numerous types of skin inflammation, psoriasis and atopic dermatitis (AD) are common chronic cutaneous inflammatory diseases. Psoriasis is a IL-17–mediated disease driven by IL-23, while AD is predominantly mediated by Th2 immunity. Autoimmune bullous diseases are autoantibody-mediated blistering disorders, including pemphigus and bullous pemphigoid. Alopecia areata is an organ-specific autoimmune disease mediated by CD8⁺ T-cells that targets hair follicles. This review will give an updated, comprehensive summary of the pathophysiology and immune mechanisms of inflammatory skin diseases. Moreover, the therapeutic potential of current and upcoming immunotherapies will be discussed.

Risk Factors for Mucosal Involvement in Bullous Pemphigoid and the Possible Mechanism: A Review

Bullous pemphigoid (BP) is the most common type of autoimmune bullous disease and is characterized by the presence of circulating anti-BP180 and/or anti-BP230 autoantibodies. Patients with BP often present with tense blisters and erythema, mainly on the trunk and limbs, but a few patients also have mucosal involvement. In this article, we discuss the fact that BP patients with mucosal involvement tend to have more serious conditions and their disease is more difficult to control. Potential risk factors for mucous involvement include earlier age at onset, drugs such as dipeptidyl peptidase-4 inhibitors, cancer, and blood/serum biomarkers, including lower eosinophil count, higher erythrocyte sedimentation rate, IgG autoantibodies against both the NH₂- and COOH-termini of BP180, and the absence of anti-BP230 antibodies. IgA and C3 deposition at the dermo-epidermal junction may also be present. Understanding these risk factors may benefit earlier diagnosis of these patients and promote the development of novel treatments. What's more, it's helpful in deeper understanding of BP development and the relationship between BP and mucous membrane pemphigoid (MMP).