Interleukin 1 components in cicatricial pemphigoid. Role in intravenous immunoglobulin therapy

Proteases in Pemphigoid Diseases

Pemphigoid diseases are a subgroup of autoimmune skin diseases characterized by widespread tense blisters. Standard of care typically involves immunosuppressive treatments, which may be insufficient and are often associated with significant adverse events. As such, a deeper understanding of the pathomechanism(s) of pemphigoid diseases is necessary in order to identify improved therapeutic approaches. A major initiator of pemphigoid diseases is the accumulation of autoantibodies against proteins at the dermal-epidermal junction (DEJ), followed by protease activation at the lesion. The contribution of proteases to pemphigoid disease pathogenesis has been investigated using a combination of in vitro and in vivo models. These studies suggest proteolytic degradation of anchoring proteins proximal to the DEJ is crucial for dermal-epidermal separation and blister formation. In addition, proteases can also augment inflammation, expose autoantigenic cryptic epitopes, and/or provoke autoantigen spreading, which are all important in pemphigoid disease pathology. The present review summarizes and critically evaluates the current understanding with respect to the role of proteases in pemphigoid diseases.

Sera and salivary matrix metalloproteinases are elevated in patients with vesiculoerosive disease: a pilot study

BACKGROUND

Oral vesiculoerosive (VE) diseases, such as lichen planus and mucous membrane pemphigoid, are immune-mediated pathoses. Matrix metalloproteinase (MMP)-2 and MMP-9 are elevated in oral lesional biopsy specimens of patients with VE disease. However, the systemic levels and activity of MMP-2 and MMP-9 in this patient population are poorly understood. We performed a pilot study to determine whether the levels and activity of MMP-2 and MMP-9 are elevated in the sera and saliva of patients with VE disease.

STUDY DESIGN

We recruited patients with VE disease (n = 10) and healthy controls (n = 19). We collected sera and saliva and performed enzyme-linked immunosorbent assays to measure MMP levels. We used gelatin zymography and Biotrak assays to determine enzyme activity. Data were analyzed using the Mann-Whitney test.

RESULTS

There was no difference in the activity of either MMP in the sera or saliva of patients with VE disease compared with controls. Significantly, MMP-2 levels were elevated in the sera of patients with VE disease (P < .0001), whereas MMP-9 was elevated in their saliva (P = .003).

CONCLUSIONS

MMP-2 is elevated in the sera of patients with VE disease, and MMP-9 is increased in their saliva. Therefore, these enzymes may be potential markers of disease or therapeutic targets.

Autoimmunity at the ocular surface: pathogenesis and regulation

A healthy ocular surface environment is essential to preserve visual function, and as such the eye has evolved a complex network of mechanisms to maintain homeostasis. Fundamental to the health of the ocular surface is the immune system, designed to respond rapidly to environmental and microbial insults, whereas maintaining tolerance to self-antigens and commensal microbes. To this end, activation of the innate and adaptive immune response is tightly regulated to limit bystander tissue damage. However, aberrant activation of the immune system can result in autoimmunity to self-antigens localized to the ocular surface and associated tissues. Environmental, microbial and endogenous stress, antigen localization, and genetic factors provide the triggers underlying the immunological events that shape the outcome of the diverse spectrum of autoimmune-based ocular surface disorders.

High-dose intravenous immunoglobulin (IVIG) therapy in autoimmune skin blistering diseases

Treatment of autoimmune bullous skin diseases can often be challenging and primarily consists of systemic corticosteroids and a variety of immunosuppressants. Current treatment strategies are effective in most cases but hampered by the side effects of long-term immunosuppressive treatment. Intravenous immunoglobulin (IVIG) is one potential promising therapy for patients with autoimmune bullous skin diseases, and evidence of its effectiveness and safety is increasing. A number of autoimmune bullous skin diseases have been identified in which IVIG treatment may be beneficial. However, experience with IVIG in patients with autoimmune skin blistering disease is limited, where it is recommended for patients not responding to conventional therapy. The mode of action of IVIG in autoimmune diseases, including bullous diseases is far from being completely understood. We here summarize the clinical evidence supporting the notion, that IVIG is a promising therapeutic agent for the treatment of patients with autoimmune bullous skin disease. In addition, we review the proposed modes of action. In the future, randomized controlled trials are necessary to better determine the efficacy and adverse effects of IVIG in the treatment of autoimmune bullous skin diseases. In addition, insights into IVIG's mode of action might enable us to develop novel therapeutics to overcome the current shortage of IVIG.

Oral mucosal diseases: Mucous membrane pemphigoid

Subepithelial vesiculobullous conditions are chronic autoimmune disorders that arise from reactions directed against components of the hemidesmosomes or basement membrane zones (BMZ) of stratified squamous epithelium to which the term immune-mediated subepithelial blistering diseases (IMSEBD) has been given. Mucous membrane pemphigoid (MMP) is the most common, but variants do exist. Non-immune disorders that involve these epithelial components typically have a genetic basis--the main example being epidermolysis bullosa. All subepithelial vesiculobullous disorders present as blisters and erosions, and diagnosis must be confirmed by biopsy examination with immunostaining, sometimes supplemented by other investigations. No single treatment reliably controls all subepithelial vesiculobullous disorders; the immunological differences within IMSEBD may account for differences in responses to treatment. Currently, as well as improving oral hygiene, immunomodulatory treatment is used to control the oral lesions of MMP, but it is not known if its specific subsets reliably respond to different agents.

The use of i.v. IG therapy in dermatology

The intravenous administration of exogenous pooled human immunoglobulin (i.v. IG) was originally licensed as antibody replacement therapy in patients with primary immunodeficiencies and there are currently six FDA-approved uses for this agent. Despite a current lack of FDA approval, off-label treatment of a multitude of dermatologic disorders with i.v. IG has shown exciting potential for this unique treatment modality. The diseases successfully treated with i.v. IG include autoimmune bullous diseases, connective tissue diseases, vasculitides, toxic epidermal necrolysis, and infectious disorders (such as streptococcal toxic shock syndrome). Currently the biggest drawback in the consideration of i.v. IG therapy in dermatologic disorders is the lack of randomized controlled trials. Nevertheless, there is a significant body of evidence demonstrating the efficacy of i.v. IG in patients with dermatologic disorders that are resistant to treatment with standard agents. In summary, i.v. IG constitutes a valuable and potentially life-saving agent in managing patients with a variety of dermatologic disorders under the appropriate circumstances.

p38 MAPK signaling in oral-related diseases

Multiple dental diseases are characterized by chronic inflammation, due to the production of cytokines, chemokines, and prostanoids by immune and non-immune cells. Membrane-bound receptors provide a link between the extracellular environment and the initiation of intracellular signaling events that activate common signaling components, including p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and nuclear factor (NF)-kappaB. Although ERK pathways regulate cell survival and are responsive to extracellular mitogens, p38 MAPK, JNK, and NF-kappaB are involved in environmental stress responses, including inflammatory stimuli. Over the past decade, significant advances have been made relative to our understanding of the fundamental intracellular signaling mechanisms that govern inflammatory cytokine expression. The p38 MAPK pathway has been shown to play a pivotal role in inflammatory cytokine and chemokine gene regulation at both the transcriptional and the post-transcriptional levels. In this review, we present evidence for the significance of p38 MAPK signaling in diverse dental diseases, including chronic pain, desquamative disorders, and periodontal diseases. Additional information is presented on the molecular mechanisms whereby p38 signaling controls post-transcriptional gene expression in inflammatory states.

Off-label uses of biologics in dermatology: Interferon and intravenous immunoglobulin (Part 1 of 2)

The introduction of a number of biologic therapies into the market has revolutionized the practice of dermatology. These therapies include interferons, intravenous immunoglobulin, infliximab, adalimumab, etanercept, efalizumab, alefacept, and rituximab. Most dermatologists are familiar with the Food and Drug Administration-approved indications of these medications. However, numerous off-label uses have evolved. As part 1 of a 2-part series, this article will review the literature regarding the off-label uses of the interferons and intravenous immunoglobulin in dermatology.

Intravenous immunoglobulin in eye involvement

Ocular inflammation may affect all eye layers: conjunctiva, sclera, uvea, and orbital tissues. The main eye involvement requiring a systemic treatment is uveitis, which represents a heterogeneous group of rare diseases, most of which are sight-threatening. In around 40% of uveitis cases an underlying systemic disease, often of autoimmune origin, can be identified. In autoimmune diseases with intraocular inflammation (IOI), uveitis may be the first clinical manifestation and may represent the most severe sign. Studies in animal models, especially in experimental autoimmune uveitis (EAU), offer the opportunity to investigate the pathogenicity of these disorders. The conventional treatment of IOI includes corticosteroids and immunosuppressive agents, which are efficient in around one-half of the patients; however, their effectiveness is also limited by their iatrogenicity. The effects of intravenous immunoglobulin (IVIg) on ocular inflammation have been investigated in a wide spectrum of autoimmune/systemic diseases. Most publications are case series or open trials. They show favorable results in a subset of indications including mainly ocular cicatricial pemphigoid, Vogt-Koyanagi-Harada syndrome, or birdshot disease. Efficacy results are more debated in other conditions, such as inflammatory demyelinating optic neuritis. In other diseases with IOI (Wegener disease, Behcet's disease, inflammatory myositis), only case reports are available, suggesting that IVIg may be of some interest. These observations support the need for controlled trials to demonstrate the efficacy of IVIg and assess their potential steroid-sparing effect.

Evaluation of mucous membrane pemphigoid with ocular involvement in young patients

OBJECTIVES

Mucous membrane pemphigoid with ocular involvement (MMPO) is a sight-threatening autoimmune disease that may lead to severe conjunctival cicatrization and keratopathy. The peak age of onset is in the seventh decade, although the disease may also occur in younger patients (< 60 years). This study was designed to evaluate the clinical features of young patients with MMPO and to assess the clinical outcome when compared with patients in the > 70 age group.

DESIGN

Retrospective, comparative, interventional case series.

PARTICIPANTS

Eighteen patients under the age of 60 years and 18 patients above the age of 70.

METHODS

Patients with documented MMPO were identified from the External Diseases Immunosuppression Database.

MAIN OUTCOME MEASURES

Stage of disease (Foster, Mondino), visual acuity, and ocular complications (lid, conjunctival, corneal) were evaluated at presentation, the time when immunosuppression was commenced, and final follow-up. Disease progression, control of ocular inflammation with systemic immunosuppression, the incidence of mucocutaneous lesions, and surgical intervention were also assessed.

RESULTS

Patients in the 2 groups (young and classic age groups) were observed for 61 (range, 29-218) and 69 (range, 12-193) months, respectively (P = 0.94). Median ages at the start of immunosuppression were 48.7 (range, 29-60) and 77.6 (range, 71-85) years. Mucocutaneous involvement was more common in the young than in the classic age group (13 [72%], 7 [39%]; P < 0.05). Ocular staging (Mondino, Foster) at presentation, the start of immunosuppression, and final follow-up was more advanced in the younger patients. There was no statistical difference in visual acuity, individual ocular complications, or incidence of surgical intervention between the 2 groups throughout the course of the study.

CONCLUSION

Younger patients with MMPO present with more severe ocular and systemic disease and, despite immunosuppression, progress more rapidly.

Number III Mucous membrane pemphigoid

Mucous membrane pemphigoid (MMP) is a sub-epithelial vesiculobullous disorder. It is now quite evident that a number of sub-epithelial vesiculobullous disorders may produce similar clinical pictures, and also that a range of variants of MMP exist, with antibodies directed against various hemidesmosomal components or components of the epithelial basement membrane. The term immune-mediated sub-epithelial blistering diseases (IMSEBD) has therefore been used. Immunological differences may account for the significant differences in their clinical presentation and responses to therapy, but unfortunately data on this are few. The diagnosis and management of IMSEBD on clinical grounds alone is impossible and a full history, general, and oral examination, and biopsy with immunostaining are now invariably required, sometimes supplemented with other investigations. No single treatment regimen reliably controls all these disorders, and it is not known if the specific subsets of MMP will respond to different drugs. Currently, apart from improving oral hygiene, immunomodulatory-especially immunosuppressive-therapy is typically used to control oral lesions. The present paper reviews pemphigoid, describing the present understanding of this fascinating clinical phenotype, summarising the increasing number of subsets with sometimes-different natural histories and immunological features, and outlining current clinical practice.

Ocular cicatricial pemphigoid: pathogenesis, diagnosis and treatment

Understanding of ocular cicatricial pemphigoid (OCP) has changed dramatically over the last three decades. Progress in basic science research in mucous membrane pemphigoid has been instrumental in outlining the key immune processes that participate in the autoimmune response. Immunomodulatory therapy has provided an avenue for preserving vision and preventing potentially fatal consequences of systemic pemphigoid. In this chapter we focus attention on the immunologic basis for disease and treatment strategies. We propose an algorithmic approach to diagnosis and management of OCP.

Use of IGIV in the treatment of immune-mediated dermatologic disorders

Immunoglobulin (Ultravenous, IGIV) is now used in a variety of immune-mediated diseases. Its presumed mechanism of action involves both anti-inflammatory and immunomodulatory activities. A number of dermatologic conditions are believed to be immune mediated and in these disorders, IGIV has shown benefit in reducing symptoms and the need for cortecosteroids or cytotaxic drugs. In many of these diseases, the initial benefits seen in open-labeled trials must be confirmed in controlled clinical trials.

Cytokine profile and supposed contribution to scarring in cicatricial pemphigoid

BACKGROUND

The progressive scarring observed in cicatricial pemphigoid (CP) is still partially unexplained but recently the release of soluble fibrogenic factors by inflammatory infiltrating cells has been considered as pathogenically relevant. In the present study we evaluated the expression of mRNA for IL-4, IL-5, TGF-beta1, IFN-gamma in CP in comparison to bullous pemphigoid (BP) patients, investigating the role of cytokine profile as possible cause of the different disease evolution.

METHODS

Biopsies from patients with oral (n = 10), preputial (n = 3) and cutaneous (n = 1) CP were studied by in situ hybridisation performing a new amplification system based on biotinyl-tyramide. As control, four patients affected by BP were also examined, together with healthy tissue from two CP and two BP patients, respectively.

RESULTS

In CP IL-4 mRNA expression was present in 4 out of 14 cases analysed. IL-5 was detected in 12 CP biopsies. TGF-beta1 and IFN-gamma mRNAs were identified in 9 and 11 CP cases, respectively. In BP, IL-4 hybridisation signal could not be observed in any of the cases. By contrast IL-5, TGF-beta1 and IFN-gamma mRNA analyses were positive in all BP cases. Healthy specimens did not show any expression for IL-4, IL-5 and IFN-gamma, while a poor staining for TGF-beta was found in epithelium and subjunctional areas.

CONCLUSIONS

Our results highlight the presence of a mixed cytokine pattern in the cellular infiltrate of both blistering diseases, with a corresponding increase of Th2-like activity in fully developed lesions, irrespective of the different sites involved. In addition, the constant presence of TGF-beta1 mRNA in the different lesional phases of CP, and its overlapping expression in BP suggest that the involvement of additional factors is responsible for the scarring course typical of CP.