Ocular cicatricial pemphigoid antigen: partial sequence and biochemical characterization

Elevated serum BAFF in patients with ocular cicatricial pemphigoid

OBJECTIVE

The efficiency of B-cell depletion therapy for severe ocular cicatricial pemphigoid (OCP) highlights the key role of B lymphocytes in the immunopathogenesis of OCP. B-cell activating factor (BAFF) is a potent B-cell growth factor and costimulator of immunoglobulin production. Elevated serum BAFF is associated with systemic autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis and bullous pemphigoid. We hypothesize that serum BAFF levels are also increased in patients with OCP.

METHODS

Sera were collected from 30 patients with new-onset active OCP, 9 with disease in remission, 10 with OCP relapse, and 15 healthy control individuals. An enzyme-linked immunosorbent assay was performed to measure the concentration of serum BAFF.

RESULTS

BAFF was significantly higher in patients with new-onset active OCP (700.8 ± 181.8 pg/mL) than in healthy control individuals (564.1 ± 133.2 pg/mL; p = 0.014). No significant difference was found between patients with OCP in remission (585.4 ± 216.2 pg/mL) and healthy control individuals. Patients with disease relapse treated with rituximab had an extremely high concentration of BAFF (1721.9 ± 790.8 pg/mL). Longitudinal analysis of serum BAFF from 6 patients showed that BAFF decreased as the disease went from new onset (895.0 ± 240.8 pg/mL) to remission (625.4 ± 199.8 pg/mL; p = 0.003).

CONCLUSIONS

BAFF is involved in the active inflammation of OCP. Targeting BAFF with an antagonist may be therapeutically beneficial for patients with refractory OCP, especially those resistant to rituximab.

Survey: Preferred practice patterns in the diagnosis of mucous membrane pemphigoid amongst cornea specialists

PURPOSE

To evaluate preferred diagnostic tools and treatment decision-making factors in cases suspicious of mucous membrane pemphigoid (MMP) amongst ophthalmologists and cornea specialists.

METHODS

Web-based survey, consisting of 14 multiple choice questions, posted to the Cornea Society Listserv Keranet, the Canadian Ophthalmological Society Cornea Listserv, and the Bowman Club Listserv.

RESULTS

One hundred and thirty-eight ophthalmologists participated in the survey. Eighty-six percent (86%) of respondents were cornea trained and practiced in either North America or Europe (83%). Most respondents (72%) routinely perform conjunctival biopsies for all suspicious cases of MMP. For those who do not, fear that biopsy will exacerbate inflammation was the most common reason to defer investigation (47%). Seventy-one percent (71%) performed biopsies from perilesional sites. Ninety-seven percent (97%) ask for direct (DIF) studies and 60% for histopathology in formalin. Most do not recommend biopsy at other non-ocular sites (75%), nor do they perform indirect immunofluorescence for serum autoantibodies (68%). Immune-modulatory therapy is started following positive biopsy results for most (66%), albeit most (62%) would not let a negative DIF influence the choice of starting treatment should there be clinical suspicion of MMP. Differences in practice patterns as they relate to level of experience and geographical location are contrasted to the most up-to-date available guidelines.

CONCLUSION

Responses to the survey suggest that there is heterogeneity in certain practice patterns for MMP. Biopsy remains an area of controversy in dictating treatment plans. Identified areas of need should be targeted in future research.

Ocular Cicatricial Pemphigoid With IgM-Positive Biopsy

PURPOSE

The aim of this study was to investigate the prevalence of IgM along the basement membrane zone (BMZ) of patients with ocular cicatricial pemphigoid (OCP) and the outcomes of these patients with immunomodulatory therapy.

METHODS

This study is a retrospective chart review of patients with conjunctival biopsy-proven OCP. Clinical data, including the presence of linear IgM deposition along the BMZ on either direct immunofluorescence or avidin-biotin complex immunohistochemistry, were recorded. Response to IMT was also recorded.

RESULTS

A total of 817 patients with documented conjunctival biopsies were identified, with 93 (11.4%) positive for OCP with linear IgM deposition along the BMZ. Forty-six patients with sufficient follow-up were evaluated for clinical outcomes, with 35 (76.1%) able to achieve durable remission an average of 24.3 months after initiation of IMT. Most of these patients, 82.9%, were able to achieve durable remission with first-line antimetabolite therapy. Three patients were identified with solely IgM-positive conjunctival biopsies.

CONCLUSIONS

Our study suggests that IgM positivity is seen in a minority of patients with OCP and that outcomes are comparable for these patients to the general OCP patient population.

Autoimmune blistering diseases: promising agents in clinical trials

INTRODUCTION

Treatment options for autoimmune bullous diseases (AIBD) are currently limited to corticosteroids and traditional immunomodulants and immunosuppressants that are associated with unfavorable adverse effect profiles. The most frequent AIBDs, i.e. bullous pemphigoid, pemphigus vulgaris, and mucous membrane pemphigoid, impose a high disease burden onto affected patients and can be detrimental due to infections, exsiccosis, and impaired food intake. Significant progress has been made in elucidating disease mechanisms and key mediators by in vivo and in vitro models, thus identifying a multifaceted range of possible drug targets. However, except for rituximab for pemphigus vulgaris, no new drugs have been approved for the treatment of AIBDs in the last decades.

AREAS COVERED

This review covers new drug developments and includes ongoing or completed phase 2 and 3 clinical trials. Studies were identified by querying the registries of ClinicalTrials.gov and Cochrane Library.

EXPERT OPINION

Promising results were shown for a variety of new agents including nomacopan, efgartigimod, omalizumab, dupilumab, as well as chimeric autoantibody receptor T cells. Clinical translation in the field of AIBDs is highly active, and we anticipate significant advances in the treatment landscape.

DISEASE ENDOTYPES PREDICT SEVERITY OF MUCOUS MEMBRAND PEMPHIGOID

Mucous membrane pemphigoid (MMP) is an autoimmune disease with variable clinical presentation and multiple autoantigens. To determine if disease endotypes could be identified based on the pattern of serum reactivity, the clinical and diagnostic information of 70 MMP patients was collected, and reactivity to dermal or epidermal antigens, using indirect immunofluorescence (IIF), and specific reactivity to BP180, BP230, collagen VII and laminin 332 was evaluated. Most patients had lesions at multiple mucosae with the most prevalent being the oropharyngeal (mouth, gingiva, pharynx, 98.6%), followed by ocular (38.6%), nasal (32.9%), genital or anal (31.4%), laryngeal (20%), and esophageal (2.9%) sites, and skin (45.7%). Autoantigen profiling identified BP180 (71%) as the most common autoantigen, followed by laminin 332 (21.7%), collagen VII (13%), and BP230 IgG (11.6%). Reactivity to dermal antigens predicted a more severe disease characterized by a higher number of total sites involved, especially high-risk sites, and a decreased response to rituximab (RTX). In most cases, identification of dermal IIF reactivity is an accurate predictor of disease course; however, confirmation of laminin 332 reactivity is important with dermal IIF positivity due to an increased risk of solid tumors. Additionally, the ocular mucosae should be monitored in patients with IgA on DIF.

Ocular Manifestations Related to Antibodies Positivity and Inflammatory Biomarkers in a Rheumatological Cohort

Purpose

Ocular involvement is frequent in autoimmune diseases and even can be the first manifestation. There are multiple descriptions in the literature around the world regarding this topic. However, we evidenced a lack of studies analyzing the relationship between the ocular manifestations and systemic biomarkers, especially in Latinamerica. Therefore, this study aimed to examine the relationship between the positivity of inflammatory biomarkers and the ocular manifestations in a Colombian cohort of rheumatological patients.

Patients and Methods

We conducted an observational, descriptive, non-comparative cross-sectional study in a rheumatology center, in Bogotá, Colombia, from 2013 to 2019. We calculated a sample size of 797 patients to assess the prevalence of ocular manifestations and inflammatory biomarkers. We performed univariate analyses for categorical and continuous variables and bivariate analyses using the Chi-square and Fisher’s exact test for categorical variables.

Results

Women represented 84% of the population, and the mean age was 54.61± 15.64 years. Of 797 patients, 21.45% reported one or more ophthalmological diagnoses, being keratoconjunctivitis sicca (KCS) the most common (15.93%), followed by uveitis, and cataract (1.38%, each one). Regarding ophthalmological symptoms, 35% presented at least one, being dry eye sensation (DE) the most common (30.86%), followed by ocular pain (2.76%), red eye, and decreased visual acuity (2.63%, each one). The antibodies or inflammatory biomarkers most frequently found were antinuclear antibodies (ANAs) (35.3%), C-reactive protein (28.7%), and rheumatoid factor (27.9%). We found statistical associations between consumption of complement 3, anti-CCP, anti-RO, and anti-LA antibodies with ocular manifestations such as photophobia, DE, conjunctivitis, KCS, uveitis, retinal vasculitis, and maculopathy.

Conclusion

Ocular manifestations are frequently found in patients with positive antibodies and inflammatory biomarkers. Our results suggest antibodies and inflammatory molecules could be biomarkers for ocular manifestations in patients with rheumatological diseases. This study provides the basis for future longitudinal studies.

Mucous membrane pemphigoid

Mucous membrane pemphigoid (MMP) is a clinically and immunopathologically heterogenous disease with an incidence of about 2/million inhabitants/year in central Europe. Pemphigoid diseases are characterized by autoantibodies against structural proteins of the epidermis and/or surface-close epithelia. MMP has been defined as pemphigoid disease with predominant mucosal lesions. Most frequently, the oral cavity and the conjunctivae are affected. Lesions outside the mouth tend to heal with scarring leading to visual impairment and finally blindness, as well as, more rarely, impairment of breathing and food intake. Autoantibodies target BP180 (collagen type XVII), laminin 332, BP230 (nearly always in conjunction with other antigens), and type VII collagen in about 75%, 10-20%, 10-30%, and <5% of MMP patients, respectively. While the main autoantibody isotype is IgG, additional, and less frequently, exclusive IgA autoantibodies can be detected in the majority of patients. Assaying for anti-laminin 332 reactivity is pivotal, since in about a quarter of patients with anti-laminin 332 MMP, a malignancy, mainly solid cancers, is associated. The pathophysiology of MMP is yet incompletely understood. A recent mouse model of anti-laminin 332 MMP replicating characteristic clinical and immunopathological findings of the human disease may be helpful to close this knowledge gap. Diagnosis is established by the clinical picture with predominant mucosal lesions and visualization of tissue-bound anti-basement membrane zone antibodies by direct immunofluorescence microscopy. In recent S3 guidelines initiated by the European Academy of Dermatology and Venereology, the clinical spectrum and diagnostic strategies are detailed. In addition, treatment regimens for different clinical situations including patients with exclusive oral or ocular involvement are outlined. Future studies are needed to better understand the clinal complexity and associations as well as to establish widely available diagnostic assays and evidence-based therapeutic strategies.

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

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

Ocular cicatricial pemphigoid (Review)

Ocular cicatricial pemphigoid is a particular form of mucous membrane pemphigoid and it is characterized by a chronic bilateral conjunctivitis with relapsing-remitting periods. Without therapy 75% of the cases develop visual loss due to major ocular complications (e.g. severe dry-eye syndrome, corneal erosions, corneal keratinization, entropion, symblepharon). Pathogenesis remains uncertain and probably linked to an autoimmune type II hypersensitivity response in patients with a genetic predisposition and exposure to different environmental triggers. With a worldwide distribution, no racial predilection and an estimated incidence that largely varies from 1/10,000-1/60,000, ocular cicatricial pemphigoid predominantly affects women aged ~60 years. Conjunctival biopsy with direct immunofluorescence is the gold standard in diagnosis confirmation, but up to 40% of the patients have a negative biopsy result that does not rule out the diagnosis. The skin and many other mucous membranes (e.g. oral, trachea, esophagus, pharynx, larynx, urethra, vagina and anus) may be involved. The disease grading relies on Foster staging system (based on clinical signs) and Mondino and Brown system (based on the inferior fornix depth loss). The differential diagnosis includes atopy, allergies, trauma, chemical burns, radiation, neoplasia, infectious, inflammatory and autoimmune etiologies. The main goals of the treatment are to stop disease progression, to relieve symptoms and to prevent complications. With long-term systemic therapy 90% of the cases can be efficiently controlled. While Dapsone is the first-line treatment in mild to moderate disease in patients without G6PD deficiency, more severe cases require immunosuppressant therapy with azathioprine, mycophenolate mofetil, methotrexate or cyclosporine. Cyclophosphamide, biologics (etanercept or rituximab) and intravenous immunoglobulin therapy are usually reserved for recalcitrant disease and unsatisfactory results to conventional therapy. Dry eye syndrome requires constant lubricating medication and topical steroids, cyclosporine-A and tacrolimus. Surgery should be planed only in quiescent phase as minor conjunctival trauma can significantly worsen the disease.

Autoantibody Detection for Diagnosis in Direct Immunofluorescence-Negative Mucous Membrane Pemphigoid: Ocular and Other Sites Compared

PURPOSE

To assess whether a panel of serum pemphigoid autoantibody tests could be used to confirm an immunopathologic diagnosis of mucous membrane pemphigoid (MMP) in direct immunofluorescent negative (DIF-) MMP patients.

DESIGN

Prospective cross-sectional study.

PARTICIPANTS

Seventy-six patients with multisite MMP with 45 matched control participants.

METHODS

Enzyme-linked immunosorbent assays (ELISAs) for BP180 and BP230 (MBL International), immunoglobulin A (IgA) A and immunoglobulin G indirect immunofluorescence (IIF) on human salt-split skin and the keratinocyte footprint assay for anti-laminin 332 antibodies.

MAIN OUTCOME MEASURES

Sensitivity and specificity of autoantibody detection and significant differences for individual tests and test combinations for MMP involving different sites.

RESULTS

All DIF- patients (24/73 [31.8%]) had either ocular-only disease or ocular involvement in multisite disease. Serum pemphigoid autoantibodies were detected in 29 of 76 MMP patients (38.2%) compared with 3 of 45 control participants (6.7%). Autoantibody reactivity detected by any 1 or more of the tests was present in 6 of 24 DIF- patients (25%) compared with 22 of 49 DIF positive (DIF+) patients (44.9%). Ocular-only MMP serum reactivity was not significantly different for any test or test combination compared with control participants, whereas DIF- multisite ocular MMP differed for 1 ELISA and 3 of 7 test combinations. By contrast, for DIF+ nonocular MMP patients, all the individual tests, apart from IgA IIF, and all test combinations were significantly different compared with those for control participants. For the entire MMP cohort, the sensitivity of all individual tests was low, having a maximum of 21.05% for BP180 reactivity but increasing to 38.16% for an optimal test combination. Disease activity was associated strongly with positive serologic findings.

CONCLUSIONS

Pemphigoid serum autoantibody tests did not provide immunopathologic evidence of MMP in ocular-only MMP patients but showed limited value in DIF- multisite ocular MMP patients. The requirement for immunopathologic confirmation of MMP by autoantibody detection is inappropriate for DIF- ocular-only MMP patients, resulting in missed diagnoses, delayed therapy, and poor outcomes. Alternative diagnostic criteria for ocular-only MMP are required to exclude the other causes of scarring conjunctivitis until more sensitive and specific immunopathologic tests become available.

Integrin: Basement membrane adhesion by corneal epithelial and endothelial cells

Integrins mediate adhesion of cells to substrates and maintain tissue integrity by facilitating mechanotransduction between cells, the extracellular matrix, and gene expression in the nucleus. Changes in integrin expression in corneal epithelial cells and corneal endothelial cells impacts their adhesion to the epithelial basement membrane (EpBM) and Descemet's membrane, respectively. Integrins also play roles in assembly of basement membranes by both activating TGFβ1 and other growth factors. Over the past two decades, this knowledge has been translated into methods to grow corneal epithelial and endothelial cells in vitro for transplantation in the clinic thereby transforming clinical practice and quality of life for patients. Current knowledge on the expression and function of the integrins that mediate adhesion to the basement membrane expressed by corneal epithelial and endothelial cells in health and disease is summarized. This is the first review to discuss similarities and differences in the integrins expressed by both cell types.

Reliability of Conjunctival Biopsy for Diagnosis of Ocular Mucous Membrane Pemphigoid: Redetermination of the Standard for Diagnosis and Outcomes of Previously Biopsy-Negative Patients

Purpose: To demonstrate the reliability of conjunctival biopsy analyzed by direct immunofluorescence (DIF) and supplemented with avidin-biotin complex immunoperoxidase (ABC) in diagnosing oMMP, and report therapy response in biopsy-positive patients, particularly when previously biopsy-negative elsewhere.Methods: Retrospective outcomes review of 136 consecutive patients after conjunctival biopsy for suspected oMMP.Results: Among 136 patients, 66% were diagnosed with oMMP by DIF and 13% via supplemental ABC immunoperoxidase. Sensitivity increased from 79.6% with DIF to 95.6% with supplemental ABC. Among 57 biopsy-positive patients, 77% were in remission at 1-year follow-up and 88% after 2 years. Of 34 previous biopsy-negative but now biopsy-positive patients with a 2-year follow-up, 91% achieved remission, including all 16 diagnosed via DIF and ABC.Conclusion: Conjunctival biopsy analyzed by histopathology and DIF supplemented by ABC has high reliability for diagnosing oMMP and is a useful tool to use before starting long-term immunomodulatory therapy in a patient with suspected oMMP.

Role of immune cells in the ocular manifestations of pemphigoid diseases

Pemphigoid disease is classified according to the phenotypical location of the disease and the presence of different types of antibodies. The ocular distribution of pemphigoid mainly occurs in patients with bullous pemphigoid and mucous membrane pemphigoid. Several immune cells, including the cells of the innate immune system (neutrophils and γδ T cells) and the adaptive immune system (T and B cells), are involved in pemphigoid disease. The treatment of pemphigoid is still wide-ranging, and the most utilized treatment is the use of immunosuppressants and corticosteroids. In this scenario, it is absolutely important to screen the immune cells that are involved in this group of diseases and to determine if a targeted treatment approach is plausible. In conclusion, this review will identify some newer treatment possibilities for the whole spectrum of pemphigoid diseases.

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.

The Diagnosis and Blistering Mechanisms of Mucous Membrane Pemphigoid

Mucous membrane pemphigoid (MMP) is a mucous membrane-dominated autoimmune subepithelial blistering disease that is caused by autoantibodies against various autoantigens in basement membrane zone (BMZ) proteins, including collagen XVII (COL17). Clinicians face diagnostic problems in detecting circulating antibodies and targeted antigens in MMP. The diagnostic difficulties are mainly attributed to the low titers of MMP autoantibodies in sera and to heterogeneous autoantigens. Additionally, no unanimous diagnostic criteria have been drawn for MMP, which can result in delayed diagnoses or misdiagnoses. This review aims to integrate and present currently available data to clarify diagnostic strategies and to present diagnostic criteria for MMP. The ultimate blistering mechanism in MMP has not been elucidated, and such mechanism is especially obscure in COL17-type MMP. In bullous pemphigoid (BP), which is the most common autoimmune subepidermal blistering disease, some patients show oral lesion as well as predominant skin lesions. However, there is no fundamental explanation for the onset of oral lesions in BP. This article summarizes innovative research perspectives on the pathogenesis of oral lesions in pemphigoid. Finally, we propose a potential pathogenesis for COL17-type MMP.

Molecular diagnosis of anti-laminin 332 (epiligrin) mucous membrane pemphigoid

BACKGROUND

Mucous membrane pemphigoid is a group of chronic subepithelial autoimmune blistering diseases that mainly affect mucous membranes. Laminin 332-specific autoantibodies are present in approximately 1/3 of the patients, being associated with an increased risk of malignancy. Because of the severe complications, an early recognition of the disease allowing a timely therapy is essential. The gold standard methods for detection of laminin 332-specific autoantibodies, including the immunoprecipitation and immunoblotting are non-quantitative, laborious and restricted to a few specialized laboratories worldwide. In addition, the use of radioimmunoassays, although highly sensitive and specific, are laborious, expensive and tightly regulated. Therefore, there is a stringent need for a quantitative immunoassay for the routine detection of laminin 332-specific autoantibodies more broadly available to diagnostic laboratories. The aim of this study was to compare different antigenic substrates, including native, recombinant laminin 332 and laminin 332-rich keratinocyte extracellular matrix, for development of an ELISA to detect autoantibodies in mucous membrane pemphigoid.

RESULTS

Using a relatively large number of sera from MMP patients with well-characterized autoantibody reactivity we show the suitability of ELISA systems using laminin 332 preparations as adjunct diagnostic tools in MMP. While glycosylation of laminin 332 does not appear to influence its recognition by MMP autoantibodies, ELISA systems using both purified, native and recombinant laminin 332 demonstrated a high sensitivity and good correlation with the detection of autoantibodies by immunoblotting. ELISA systems using different laminin 332 preparations represent a feasible and more accessible alternative for a broad range of laboratories.

CONCLUSIONS

Our findings qualify the use of immunoassays with the laminin 332-rich preparations as an ancillary diagnostic tool in mucous membrane pemphigoid.

TFOS DEWS II pathophysiology report

The TFOS DEWS II Pathophysiology Subcommittee reviewed the mechanisms involved in the initiation and perpetuation of dry eye disease. Its central mechanism is evaporative water loss leading to hyperosmolar tissue damage. Research in human disease and in animal models has shown that this, either directly or by inducing inflammation, causes a loss of both epithelial and goblet cells. The consequent decrease in surface wettability leads to early tear film breakup and amplifies hyperosmolarity via a Vicious Circle. Pain in dry eye is caused by tear hyperosmolarity, loss of lubrication, inflammatory mediators and neurosensory factors, while visual symptoms arise from tear and ocular surface irregularity. Increased friction targets damage to the lids and ocular surface, resulting in characteristic punctate epithelial keratitis, superior limbic keratoconjunctivitis, filamentary keratitis, lid parallel conjunctival folds, and lid wiper epitheliopathy. Hybrid dry eye disease, with features of both aqueous deficiency and increased evaporation, is common and efforts should be made to determine the relative contribution of each form to the total picture. To this end, practical methods are needed to measure tear evaporation in the clinic, and similarly, methods are needed to measure osmolarity at the tissue level across the ocular surface, to better determine the severity of dry eye. Areas for future research include the role of genetic mechanisms in non-Sjögren syndrome dry eye, the targeting of the terminal duct in meibomian gland disease and the influence of gaze dynamics and the closed eye state on tear stability and ocular surface inflammation.

Anti-BP180-type mucous membrane pemphigoid immunoglobulin G shows heterogeneity of internalization of BP180/collagen XVII into keratinocyte cytoplasm

Anti-BP180-type mucous membrane pemphigoid (BP180-MMP) is a rare autoimmune subepidermal blistering disease that targets the C terminus of BP180/collagen XVII. Currently, the pathomechanism of BP180-MMP is not well understood. We reported previously that immunoglobulin G (IgG) from patients with bullous pemphigoid (BP) can induce internalization of BP180 via a macropinocytic pathway, which depletes BP180 and weakens epidermal cell-matrix integrity. The purpose of the present study was to elucidate the pathomechanism of BP180-MMP. Immunohistochemistry of biopsy specimens from two patients with BP180-MMP revealed that one patient had BP180 internalization, but the other did not. In live-cell imaging using IgG from patients with BP180-MMP on several keratinocyte cell lines, IgG from only three out of the seven patients was associated with BP180 internalization into the cytoplasm. Our results suggest that IgG from patients with BP180-MMP shows heterogeneity of internalization of BP180. This variability in BP180 internalization in patients with BP or BP180-MMP may lead to differences in clinical presentation.

Salivary IgA and IgG antibodies to bullous pemphigoid 180 noncollagenous domain 16a as diagnostic biomarkers in mucous membrane pemphigoid

BACKGROUND

Mucous membrane pemphigoid (MMP) is an uncommon mucocutaneous immunobullous disorder. Use of saliva for diagnosis by enzyme-linked immunosorbent assay (ELISA) using the noncollagenous (NC) domain 16a of bullous pemphigoid antigen II (BP180) is not well described.

OBJECTIVE

To establish whether whole or parotid saliva is a suitable alternative to serum for diagnosis of MMP.

METHODS

Precoated BP180-NC16a ELISA plates were used to test serum, and whole and parotid saliva for IgG, IgA and secretory IgA antibodies. Patients with MMP (n = 64) provided matched serum and whole saliva. In addition 18 of the MMP patients also provided matched parotid saliva. Healthy controls (n = 50) provided matched serum and whole saliva and 6 of these additionally provided matched parotid saliva. An additional 16 disease controls provided matched serum, and whole and parotid saliva.

RESULTS

In whole saliva, IgG antibodies were detected in 11/64 (17%), IgA in 23/64 (36%) and a combined positivity in 29/64 (45%). In parotid saliva, IgA antibodies were found in 8/18 (44%). Serum IgG antibodies were detected in 27/64 (42%), serum IgA antibodies in 18/64 (28%) and a combined positivity in 33/64 (52%). Combined use of serum and saliva increased detection of specific antibodies by 30%. Control samples were all negative (positive predictive value of 100% for all tests). The negative predictive values were 62% for IgA saliva, 65% for IgG serum, 59% for IgA serum and 56% for IgG saliva.

CONCLUSIONS

IgG and IgA antibodies may provide a suitable diagnostic marker in MMP. Assay of salivary IgA antibodies to NC16a offers a similar diagnostic predictive value to serum.

Blistering disease: insight from the hemidesmosome and other components of the dermal-epidermal junction

The hemidesmosome is a specialized transmembrane complex that mediates the binding of epithelial cells to the underlying basement membrane. In the skin, this multiprotein structure can be regarded as the chief adhesion unit at the site of the dermal-epidermal junction. Focal adhesions are additional specialized attachment structures located between hemidesmosomes. The integrity of the skin relies on well-assembled and functional hemidesmosomes and focal adhesions (also known as integrin adhesomes). However, if these adhesion structures are impaired, e.g., as a result of circulating autoantibodies or inherited genetic mutations, the mechanical strength of the skin is compromised, leading to blistering and/or tissue inflammation. A particular clinical presentation emerges subject to the molecule that is targeted. None of these junctional complexes are simply compounds of adhesion molecules; they also play a significant role in signalling pathways involved in the differentiation and migration of epithelial cells such as during wound healing and in tumour invasion. We summarize current knowledge about hereditary and acquired blistering diseases emerging from pathologies of the hemidesmosome and its neighbouring proteins as components of the dermal-epidermal junction.

Molecular diagnosis in autoimmune skin blistering conditions

Blister formation in skin and mucous membranes results from a loss of cell-cell or cell-matrix adhesion and is a common outcome of pathological events in a variety of conditions, including autoimmune and genetic diseases, viral and bacterial infections, or injury by physical and chemical factors. Autoantibodies against structural components maintaining cell-cell and cell-matrix adhesion induce tissue damage in autoimmune blistering diseases. Detection of these autoantibodies either tissue-bound or circulating in serum is essential to diagnose the autoimmune nature of disease. Various immunofluorescence methods as well as molecular immunoassays, including enzyme-linked immunosorbent assay and immunoblotting, belong to the modern diagnostic algorithms for these disorders. There is still a considerable need to increase awareness of the rare autoimmune blistering diseases, which often show a severe, chronic-relapsing course, among physicians and the public. This review article describes the immunopathological features of autoimmune bullous diseases and the molecular immunoassays currently available for their diagnosis and monitoring.

Mucous membrane pemphigoid

Mucous membrane pemphigoid (MMP) is chronic and frequently associated with exacerbations and remissions of clinical signs and symptoms. Clinicians should use pathologic and immunonologic techniques to help diagnose patients. Multidisciplinary collaboration is often necessary for the diagnosis and proper treatment of MMP. Systemic adjuvant immunosuppressive therapy is necessary for patients with progressive disease. In spite of the advances in available immunosuppressive medications and biologics, scarring is a significant complication in many cases. Surgical intervention is not curable; however, it may be necessary for restoring function and improving quality of life.

Outcomes of cataract surgery in ocular cicatricial pemphigoid

PURPOSE

To report the outcomes of cataract surgery in ocular cicatricial pemphigoid (OCP).

SETTING

L. V. Prasad Eye Institute, Hyderabad, India.

DESIGN

Retrospective, interventional case series.

METHODS

Patients diagnosed with OCP who had undergone cataract surgery were included. Staging of disease, type of surgery, pre- and postoperative best-corrected visual acuity (BCVA), and number and duration of topical and systemic medications were recorded. Complications and any exacerbation or worsening of disease were noted.

RESULTS

Nine eyes of 7 patients (3 male, 4 female) were included in the study, with mean age of 60.44 ± 2.6 years (range 56-64 years). Follow-up ranged from 6 months to 10 years (mean 52.9 ± 46.25 months). Surgery performed was extracapsular cataract extraction with posterior chamber intraocular lens implantation (n = 5) or phacoemulsification with posterior chamber intraocular lens implantation (n = 4). Best-corrected visual acuity improved by more than 2 lines in 6 of 9 (66.67%) eyes, which remained stable till the last follow-up. Three eyes had no visual improvement due to corneal scar in 2 patients and preexisting posterior staphyloma in 1 eye. Disease progression was noted in 2 of 9 operated eyes by one stage at the end of 1 year.

CONCLUSION

In this series, cataract surgery could be safely performed with no major intra- or postoperative complications. While the surgical intervention itself was not associated with acute exacerbations of inflammation, progression of disease was noted in some cases over time. In spite of ongoing disease, cataract surgery in OCP was associated with stable visual outcomes.

Ocular cicatricial pemphigoid masquerading as chronic conjunctivitis: a case report

Conjunctivitis is often considered an innocuous condition which is self-limiting. This report describes misdiagnosis of ocular cicatricial pemphigoid as chronic conjunctivitis. Ocular cicatricial pemphigoid is a rare autoimmune condition. The clinical features which are useful to distinguish this condition from infective conjunctivitis are discussed. The investigation and treatment of ocular cicatricial pemphigoid is discussed. It is important to recognize nonocular symptoms and signs that may indicate the presence of a more serious underlying pathological condition necessitating specialized ophthalmic referral and subsequent investigation and treatment.

Ocular mucous membrane pemphigoid after Lyell syndrome: occasional finding or predisposing event?

PURPOSE

Ocular mucous membrane pemphigoid (OMMP) is an autoimmune disease involving the eye and characterized by subepithelial detachment resulting from an immunologic reaction against conjunctival basal membrane zone (BMZ) antigens. Lyell syndrome (LS) is a drug-induced, T cell-mediated, cytotoxic reaction involving the mucocutaneous areas. Two patients with LS are presented in whom OMMP developed.

DESIGN

Report of 2 cases.

PARTICIPANTS

Two male patients, 80 and 60 years old, with persistent corneal ulcerations, corneal melting, and inflammation some months after an LS episode.

METHODS

Conjunctival biopsy samples were obtained to perform direct immunofluorescence (DIF) and histologic analyses. Indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) also were performed.

MAIN OUTCOME MEASURES

Immunodeposit findings on the conjunctival BMZ obtained by DIF and IIF, inflammatory infiltration of the corneoconjunctival samples studied by histologic analysis, and autoantibodies of patient sera directed against BMZ antigens tested by ELISA.

RESULTS

Direct immunofluorescence analyses showed immunoglobulin G and complement 3 component deposits along the BMZ in a linear pattern. Histologic analysis revealed the presence of eosinophils, neutrophils, and mast cells with fibrin deposition in the substantia propria of both patients; the data confirmed the clinical suspicion of OMMP. The IIF and ELISA results were negative.

CONCLUSIONS

Chronic eye surface injury associated with LS may promote autoimmunization against ocular epithelial BMZ antigens, playing a strategic role in the subsequent onset of OMMP. The occurrence of OMMP after LS could be an occasional finding, or conversely, LS could be an underestimated predisposing factor in the development of OMMP.

Role of MHC Class II genes in the pathogenesis of pemphigoid

Pemphigoid (Pg) is an autoimmune subepidermal blistering disease that affects the elderly population. The phenotype can be Bullous Pemphigoid (BP), which primarily involves the skin, or Mucous Membrane Pemphigoid (MMP), which primarily involves mucus membranes. Ocular Cicatricial Pemphigoid (OCP) and Oral Pemphigoid (OP) are subsets of MMP. The known antigens in BP are Bullous Pemphigoid Antigen 1 (BPAG1, also known as BP230), Bullous Pemphigoid Antigen 2 (BPAG2, also known as BP180), and subunits of human integrins α6 and β4. The Human Leukocyte Antigen (HLA) allele HLA-DQβ1*0301 has been reported to be associated with enhanced susceptibility to all of these subsets. Sera of patients with the four subsets are characterized by the presence of anti-Basement Membrane Zone (anti-BMZ) antibodies. In this manuscript, we present a model in which relevant portions of the four different antigens involved in pemphigoid have potential sites that could be presented by an antigen presenting cell (APC) in conjunction with DQβ1*0301 to a T cell receptor to initiate the process that results in anti-BMZ antibody production. Thus, this model provides a hypothetical computer-based mechanism to explain how a single HLA allele can be associated with the production of antibodies to four different antigens that result in four different subsets of a disease with four different clinical profiles and prognoses.

Treatment strategies in mucous membrane pemphigoid

Mucous membrane pemphigoid (MMP) is an autoimmune blistering disorder that is characterized by subepithelial bullae. Various basement membrane zone components have been identified as targets of autoantibodies in MMP. Considerable variability exists in the clinical presentation of MMP. Mucous membranes that may be involved include the oral cavity, conjunctiva, nasopharynx, larynx, esophagus, genitourinary tract, and anus. A multidisciplinary approach is essential in the management of MMP. Early recognition of this disorder and treatment may decrease disease-related complications. The choice of agents for treatment of MMP is based upon the sites of involvement, clinical severity, and disease progression. For more severe disease, or with rapid progression, systemic corticosteroids are the agents of choice for initial treatment, combined with steroid-sparing agents for long-term maintenance. Due to the rarity of this disease, large controlled studies comparing the efficacy of various agents are lacking.

Autoimmune bullous diseases the spectrum of infectious agent antibodies and review of the literature

Pemphigus and bullous pemphigoid are two autoimmune diseases that have a similar pathogenesis. Both have a genetic predisposition which promotes the production of auto-antibodies targeted against different components of the epidermal desmosome and hemidesmosome. Environmental factors play an important role in the pathogenesis of this autoimmune disease. Among these, the role of infectious agents was debated as a causative factor. We sought to determine a possible connection between various infectious agents and autoimmune bullous disease (ABD). A cohort of 148 serum samples of patients with pemphigus, bullous pemphigoid and controls was screened for evidence of a prior infection with HBV, HCV, EBV, CMV, Helicobacter pylori, Toxoplasma gondii and Treponema pallidum, utilizing the Bio-Rad BioPlex 2200 system as well as ELISA assays to complete the panel. HBV, HCV, H. pylori, T. gondii and CMV were demonstrated to have significantly higher prevalence of antibodies in patients with pemphigus and bullous pemphigoid in comparison to controls. Among them, we found a novel association between H. pylori and ABD. Our study suggests a contributing role for HBV, HCV, H. pylori, T. gondii and CMV in inducing ABD in the genetically susceptible host.

Relationship between target antigens and major histocompatibility complex (MHC) class II genes in producing two pathogenic antibodies simultaneously

In this report,we present 15 patients with histological and immunopathologically proven pemphigus vulgaris (PV). After a mean of 80 months since the onset of disease, when evaluated serologically, they had antibodies typical of PV and pemphigoid (Pg). Similarly, 18 patients with bullous pemphigoid (BP) and mucous membrane pemphigoid (MMP) were diagnosed on the basis of histology and immunopathology.After a mean of 60 months since the onset of disease, when their sera were evaluated they were found to have Pg and PV autoantibodies. In both groups of patients the diseases were characterized by a chronic course, which included several relapses and recurrences and were non-responsive to conventional therapy. The major histocompatibility complex class II (MHC II) genes were studied in both groups of patients and phenotypes associated typically with them were observed. Hence, in 33 patients, two different pathogenic autoantibodies were detected simultaneously. The authors provide a computer model to show that each MHC II gene has relevant epitopes that recognize the antigens associated with both diseases. Using the databases in these computer models, the authors present the hypothesis that these two autoantibodies are produced simultaneously due to the phenomena of epitope spreading.

The neonatal Fc receptor as therapeutic target in IgG-mediated autoimmune diseases

Therapy approaches based on lowering levels of pathogenic autoantibodies represent rational, effective, and safe treatment modalities of autoimmune diseases. The neonatal Fc receptor (FcRn) is a major factor regulating the serum levels of IgG antibodies. While FcRn-mediated half-life extension is beneficial for IgG antibody responses against pathogens, it also prolongs the serum half-life of IgG autoantibodies and thus promotes tissue damage in autoimmune diseases. In the present review article, we examine current evidence on the relevance of FcRn in maintaining high autoantibody levels and discuss FcRn-targeted therapeutic approaches. Further investigation of the FcRn-IgG interaction will not only provide mechanistic insights into the receptor function, but should also greatly facilitate the design of therapeutics combining optimal pharmacokinetic properties with the appropriate antibody effector functions in autoimmune diseases.

Transscleral diode laser cyclophotocoagulation in a patient with ocular cicatricial pemphigoid

The authors present a case of secondary glaucoma associated with silicone oil in a patient with ocular cicatricial pemphigoid successfully managed with transscleral diode laser cyclophotocoagulation. Six months following treatment, the patient remained satisfied and free of pain, with an intraocular pressure of 24 mm Hg without topical drops or oral acetazolamide. There was no evidence of exacerbation of ocular cicatricial pemphigoid and no adjustment was required to the patient's immunosuppressive therapy. This case suggests that transscleral diode laser cyclophotocoagulation may be safely used to control raised intraocular pressure in patients with ocular cicatricial pemphigoid without causing an exacerbation of the condition.

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.

Relative risk for cancer in mucous membrane pemphigoid associated with antibodies to the beta4 integrin subunit

BACKGROUND

Mucous membrane pemphigoid (MMP) is a mucocutaneous vesiculobullous autoimmune disease characterized by autoantibodies to components of the basement membrane zone (BMZ). Recently, it has been reported that patients with MMP who have autoantibodies to laminin 5, known as anti-epiligrin cicatricial pemphigoid (AECP) have a high incidence of malignancy.

OBJECTIVE

The purpose of this study was to determine the association between malignancy and MMP in patients with antibodies to beta4 integrin.

METHODS

The incidence of cancer was studied in 79 patients with MMP and/or ocular cicatricial pemphigoid (OCP) who had antibodies to human beta4 integrin subunit. In each patient, the diagnosis was made by histology and confirmed by immunopathology of affected tissues. It was compared to the expected incidence, for age- and gender-matched individuals, in the National Cancer Institute's Surveillance, Epidemiology and End Results (NCISEER) database.

RESULTS

Of 79 patients, 3 had cancer. The relative risk (RR) for cancer in patients with MMP and/or OCP, with autoantibodies to human beta4 integrin subunit was 0.29 (95% CI 0.62-8.77). The expected number in the NCISEER database was 10.37. This difference was statistically significant (P < 0.01).

CONCLUSION

This incidence of cancer in MMP/OCP patients, with antibodies to human beta4 integrin subunit is considerably lower than expected. Preliminary observations in this and other studies suggest that serological subsets of MMP, based on antigen reactivity, have a different clinical course, prognosis and associations with cancer.

Expression of selected integrins and selectins in bullous pemphigoid

Blister development in bullous pemphigoid (BP) results from destruction of hemidesmosomes and basement membrane components within the dermoepidermal junction by autoantibodies. Adhesion molecules can take part in pathogenesis of this disease. The aim of the study was to determine the localization and expression of L- and E-selectins and β1, β3, and β4 integrins by immunohistochemistry in skin lesions of 21 patients with BP, compared with 10 healthy subjects. Expression of L and E selectins and β1, β3 integrins was detected mainly in basal keratinocytes and in inflammatory infiltrates in the dermis, expression of β4 integrin was irregular and was detected mainly in dermal part of the blister, while in the control group only weak and single expression of the examined molecules was detected in basal keratinocytes and endothelium cells. The obtained results reveal the important role of selected selectins and integrins in development of skin lesions in BP.

Immunopathology and molecular diagnosis of autoimmune bullous diseases

Autoimmune bullous diseases are associated with autoimmunity against structural components maintaining cell-cell and cell matrix adhesion in the skin and mucous membranes. Pemphigus diseases are characterized by autoantibodies against the intercellular junctions and intraepithelial blisters. In pemphigoid diseases and epidermolysis bullosa acquisita, sub-epidermal blistering is associated with autoantibodies targeting proteins of the hemidesmosomal anchoring complex. The autoantigens in autoimmune blistering diseases have been extensively characterized over the past three decades. In general, the pathogenicity of autoantibodies, already suggested by clinical observations, has been conclusively demonstrated experimentally. Detection of tissue-bound and circulating serum autoantibodies and characterization of their molecular specificity is mandatory for the diagnosis of autoimmune blistering diseases. For this purpose, various immunofluorescence methods as well as immunoassays, including immunoblotting, enzyme-linked immunosorbent assay and immunoprecipitation have been developed. This review article describes the immunopathological features of autoimmune bullous diseases and the immunological and molecular tests used for their diagnosis and monitoring.

Anti-p200 pemphigoid: a novel autoimmune subepidermal blistering disease

Anti-p200 pemphigoid is a recently defined autoimmune subepidermal blistering disease characterized by circulating and tissue-bound autoantibodies to a 200-kDa protein (p200) of the dermal-epidermal junction (DEJ). This DEJ constituent is thought to be important for adhesion of basal keratinocytes to the underlying dermis. While the exact identity of p200 remains unknown, it has been demonstrated to be immunologically and biochemically distinct from all major autoantigens of the DEJ, including bullous pemphigoid antigens 180 and 230, laminin 1, 5 and 6, alpha6beta4 integrin, and type VII collagen. Clinically, most reported cases present with tense blisters as well as urticarial papules and plaques, closely resembling bullous pemphigoid. Histopathological examination of lesional skin biopsies shows subepidermal split formation and superficial inflammatory infiltrate typically dominated by neutrophils. Immunopathologically, linear deposits of immunoglobulin (Ig)G and C3 are detected along the DEJ by direct immunofluorescence microscopy of perilesional skin. Indirect immunofluorescence microscopy of patients' sera on NaCl-split human skin demonstrates circulating IgG autoantibodies labeling the dermal side of the split. By immunoblotting, these autoantibodies recognize a 200-kDa protein of human dermis. Biochemical characterization of the p200 molecule revealed a noncollagenous N-glycosylated acidic protein with an isoelectric point of approximately 5.5. We present an overview of the pathogenesis, clinical features, diagnosis and treatment of this new disease entity.

Detection of pemphigus desmoglein 1 and desmoglein 3 autoantibodies and pemphigoid BP180 autoantibodies in saliva and comparison with serum values

Although there is much literature on the detection of pemphigus and pemphigoid autoantibodies by enzyme-linked immunosorbent assay (ELISA) in serum, nothing is known about their presence in saliva. The aim of this study was to evaluate the salivary levels of these autoantibodies in pemphigus and pemphigoid patients. Autoantibodies against desmoglein3, desmoglein1, and BP180 were assayed, by ELISA, in serum and saliva samples of patients and healthy controls. The titres of autoantibodies against Dsg1/3 found in both serum and saliva of pemphigus patients showed a statistically significant correlation, suggesting that saliva may be a useful biological material for diagnostic purposes, in monitoring disease activity, as well as for the early detection of relapses. By contrast, the titres of autoantibodies against BP180 in the serum and saliva of bullous pemphigoid patients were not statistically related, and further study of the usefulness of the BP180 ELISA for saliva in this disease is needed. In addition, based on our results, the BP180 ELISA with a recombinant NC16a epitope failed to detect the autoantibodies against BP180 in the serum and saliva of mucous membrane pemphigoid patients.

Comparison of reactivity and epitope recognition between sera from American and Italian patients with oral pemphigoid

Mucous membrane pemphigoid (MMP) (also known as cicatricial pemphigoid) is a rare autoimmune mucocutaneous blistering disease that affects mucous membranes derived from stratified squamous epithelium and the skin. A subset of MMP affects only the oral cavity and is referred to as the oral pemphigoid (OP). MMP and OP are characterized by subepithelial vesicles on histology and in vivo deposition of immunoglobulins and complement at the basement membrane zone (BMZ) on immunopathology. Previous studies have shown that sera of patients with MMP bind to human integrin beta4, while sera of patients with oral pemphigoid bind to the integrin alpha6 component of the heterodimer. The prognosis in MMP is grave but excellent in OP. In this study we compare the binding of sera from patients with OP from Boston, MA, USA to Naples, Italy, and attempt to identify an epitope to which the anti-integrin alpha6 human autoantibody binds. Our results indicate that the sera from Boston and Naples are identical in their reactivity. They recognize a fragment I (AA 23-462) and its subfragment IB (AA 217-462) only, in the human integrin alpha6 molecule. Blocking studies, immunoprecipitation and immunoabsorbtion studies confirm the presence of this single 245 AA region. Antibodies to subfragment IB cause BMZ separation in organ culture using normal human oral mucosa as substrate. This preliminary study indicates that patients on both continents may have similar reactivity and suggests that an intercontinental study group could be established to advance our understanding of the pathogenesis of OP and the biology of anti-alpha6 integrin autoantibodies.

Bullous pemphigoid antigen II (BP180) and its soluble extracellular domains are major autoantigens in mucous membrane pemphigoid: the pathogenic relevance to HLA class II alleles and disease severity

BACKGROUND

Mucous membrane pemphigoid (MMP), a chronic autoimmune subepithelial blistering disease, is associated with circulating IgG and/or IgA autoantibodies against several basement membrane zone antigens. The heterogeneity of clinical presentation and diversity of target autoantigens have contributed to difficulties in characterizing this condition immunologically.

OBJECTIVES

To analyse serum autoantibody profile and HLA class II alleles in MMP patients and to correlate this with the clinical presentation of disease.

METHODS

Well-defined subgroups consisting of 124 patients with MMP were examined for IgG and IgA reactivity with immunoblotting using human epidermal, dermal and placental amnion proteins. The results were further analysed on the basis of detailed clinical (sites of involvement and disease severity) and immunopathological criteria (immunofluorescence study and HLA class II alleles).

RESULTS

Immunoblot assay revealed that the majority of MMP patients had IgG (93 of 124, 75%) and/or IgA autoantibodies (63 of 124, 51%) to BP180 (including its soluble ectodomains, 120-kDa LAD-1 and 97-kDa LABD97 antigens). Other antigens targeted predominantly by IgG autoantibodies included: BP230 in 34 (27%), beta4 integrin in 26 (21%), and laminin 5 in three (2%). All the BP230+ sera and 23 (88%) beta4 integrin+ sera also reacted with at least one of the BP180 antigens. Over 85% of patients with reactivity to beta4 integrin had ocular involvement. In most cases of MMP, more severe clinical features were associated with antibody reactivity to multiple basement membrane zone antigens, as well as reactivity to multiple BP180 component antigens. Dual BP180/LAD-1 reactivity with IgG and IgA was associated with a more severe phenotype. In addition, the subset-dependent autoantibody reactivity correlated well with specific HLA class II alleles, DQB1*0301, DRB1*04 and DRB1*11.

CONCLUSIONS

Our results confirmed that BP180 is a major autoantigen targeted by the sera of patients with MMP. The disease-prevalent HLA class II alleles and humoral autoimmune response against the particular subsets of antigenic epitope(s) within BP180 ectodomain may contribute to the clinicopathological significance and disease severity of MMP.

Comparison of cost of immune globulin intravenous therapy to conventional immunosuppressive therapy in treating patients with autoimmune mucocutaneous blistering diseases

Autoimmune mucocutaneous blistering diseases (AMBD) are a group of potentially fatal diseases that affect the skin and mucous membranes. AMBD have different target antigens as well as variable clinical presentation, course, and prognosis. The mainstay of conventional immunosuppressive therapy (CIST) for AMBD is long-term high-dose systemic corticosteroids and immunosuppressive agents. Such therapy has proven effective in many patients; however, in some patients, the disease continues to progress with significant sequelae such as blindness, loss of voice, anal, and vaginal stenosis which causes poor quality of life. Furthermore, the CIST may have some serious side effects including opportunistic infections which may cause death. Immune globulin intravenous (IGIV) therapy has been reportedly used in the management of patients with AMBD refractory to CIST. IGIV has shown to be more clinically beneficial than CIST by bringing about long-term clinical remission and less recurrence. The high cost of the IGIV is of concern to patients, physicians, and insurance companies. In this report, we compare the cost of IGIV to that of CIST in treating a cohort of 15 mucous membrane pemphigoid (MMP), 10 ocular cicatricial pemphigoid (OCP), 15 bullous pemphigoid (BP), and 32 pemphigus vulgaris (PV) patients. In each cohort of patients, CIST had significant side effects, many of which were hazardous and required prolonged and frequent hospitalizations. Some of these side effects were severe enough to require discontinuation of the treatment. We consider the total cost of CIST to be the actual cost of the drug, plus the cost of management of the side effects produced by CIST. In the same patient cohort, no significant side effects to IGIV were observed. None of the IGIV treated patients required physician visits, laboratory tests, or hospitalizations specifically related to IGIV therapy. Hence, the total cost of the IGIV therapy is the actual cost of the IGIV only. The mean total cost of treatment of IGIV therapy is statistically significantly less than that of CIST during the entire course of the disease and on an annual basis. In conclusion, IGIV therapy is a safe, clinically beneficial, and a cost effective alternative treatment in patients with AMBD, non-responsive to CIST.