The Second Study of Clinical and Immunological Findings in Anti-laminin 332-Type Mucous Membrane Pemphigoid Examined at Kurume University-Diagnosis Criteria Suggested by Summary of 133 Cases.

Background: Recently, we published an article retrospectively summarizing the results in 55 anti-laminin 332 (LM332)-type mucous membrane pemphigoid (MMP) cases examined at Kurume University, which were diagnosed by strict inclusion criteria, including positive reactivity in direct immunofluorescence and absence of antibodies to non-LM332 autoantigens. However, indirect immunofluorescence using 1M-NaCl-split normal human skin (ssIIF) is also valuable for diagnosis of anti-LM332-type MMP. Methods: In this second study, we selected 133 anti-LM332-type MMP cases, which were diagnosed by our different inclusion criteria: (i) immunoglobulin G (IgG) deposition to basement membrane zone (BMZ) by direct immunofluorescence or IgG reactivity with dermal side of split skin by ssIIF, (ii) positivity for at least one of the three subunits of LM332 by immunoblotting of purified human LM332, and (iii) the presence of mucosal lesions. Clinical, histopathological, and immunological findings were summarized and analyzed statistically. Although these cases included the 55 previous cases, the more detailed study for larger scale of patients was conducted for further characterization. Results: Clinically, among the 133 patients, 89% and 43% patients had oral and ocular mucosal lesions, respectively, 71% had cutaneous lesions, and 17% had associated malignancies. Histopathologically, 93% patients showed subepidermal blisters. The sensitivities of ssIIF and direct immunofluorescence are similar but are significantly higher than indirect immunofluorescence using non-split human skin (both p < 0.001). In immunoblotting of purified LM332, patient IgG antibodies most frequently reacted with LMγ2 subunit (58%), followed by LMα3 (49%) and LMß3 (36%). Thirty-four percent patients recognized additional non-LM332 autoantigens. Statistical analysis revealed that autoantibodies against non-LM332 autoantigens might stimulate the production of anti-LMγ2 antibodies. Conclusions: This retrospective study further characterized in more detail the clinical and immunological features of 133 cases of anti-LM332-type MMP, in which the new diagnostic criteria without positive direct immunofluorescence reactivity were useful for the diagnosis. Higher frequency with anti-LMγ2 antibodies suggested more significant pathogenic role of this subunit. Additional autoantibodies to non-LM332 autoantigens detected in one-third of the patients may contribute to complexity in anti-LM332-type MMP, including the induction of anti-LMγ2 antibodies.

Comparison of Two Diagnostic Assays for Anti-Laminin 332 Mucous Membrane Pemphigoid.

Anti-laminin 332 mucous membrane pemphigoid (MMP) is an autoimmune blistering disease characterized by predominant mucosal lesions and autoantibodies against laminin 332. The exact diagnosis of anti-laminin 332 MMP is important since nearly 30% of patients develop solid cancers. This study compared two independently developed diagnostic indirect immunofluorescence (IF) tests based on recombinant laminin 332 expressed in HEK239 cells (biochip mosaic assay) and the migration trails of cultured keratinocytes rich in laminin 332 (footprint assay). The sera of 54 anti-laminin 332 MMP, 35 non-anti-laminin 332 MMP, and 30 pemphigus vulgaris patients as well as 20 healthy blood donors were analyzed blindly and independently. Fifty-two of 54 and 54/54 anti-laminin 332 MMP sera were positive in the biochip mosaic and the footprint assay, respectively. In the 35 non-anti-laminin 332 MMP sera, 3 were positive in both tests and 4 others showed weak reactivity in the footprint assay. In conclusion, both assays are easy to perform, highly sensitive, and specific, which will further facilitate the diagnosis of anti-laminin 332 MMP.

Subunit-Specific Reactivity of Autoantibodies Against Laminin-332 Reveals Direct Inflammatory Mechanisms on Keratinocytes.

Laminin-332 pemphigoid is a rare and severe autoimmune blistering disease, caused by IgG autoantibodies targeting laminin-332 in the dermal-epidermal basement zone. Laminin-332 pemphigoid is characterized by variable inflammatory infiltrate and the predominance of non-complement-fixing antibodies. Given these findings, we hypothesized that IgG autoantibodies to laminin-332 directly resulted in keratinocyte expression of inflammatory factors. We performed RNA-seq on primary human keratinocytes treated with IgG from patients with laminin-332 pemphigoid. Genes for numerous cytokines and chemokines were upregulated, including CSF2, CSF3, CXCL1, CXCL5, CXCL3, CXCL8, CXCL10, CXCL1, IL6, IL7, IL15, IL23, IL32, IL37, TGFB2 as well as metalloproteases. Considering the pro-inflammatory and proteolytic effect of autoantibodies from patients with laminin-332 pemphigoid identified in our initial experiment, we next questioned whether the reactivity against specific laminin subunits dictates the inflammatory and proteolytic keratinocyte response. Then, we treated keratinocytes with IgG from a separate cohort of patients with reactivity against individual subunits of laminin-332. We identified upregulation of IL-1α, IL-6, IL-8, CXCL1, MMP9, TSLP, and GM-CSF at the protein level, most notably in keratinocytes treated with IgG from laminin ß3-reactive patients. We for the first time demonstrated a pro-inflammatory response, similar to that described in keratinocytes treated with IgG autoantibodies from patients with bullous pemphigoid, providing novel insight into the pathogenesis of laminin-332 pemphigoid and laminin-332 biology.

Mucous membrane pemphigoid in a patient with chronic hepatitis B virus infection: A case report.

RATIONALE: Mucous membrane pemphigoid (MMP) is a rare, autoimmune bullous disease that affects mucosal surfaces and skin. Early and aggressive treatment initiation may be warranted due to the risks of serious complications. However, it can be challenging to make an initial diagnosis. Viral infection such as hepatitis B virus (HBV) infection has been found to be associated with the formation of autoimmune bullous diseases. PATIENT CONCERNS: The patient was a 43-year-old male with gingivitis and recurrent swelling over the neck, cheeks, lips, and eyelids. The patient presented at oral medicine, otolaryngology, plastic surgery, and ophthalmology sequentially, and was later referred to the rheumatology, dermatology, and family medicine departments. Recurrent hemorrhagic bullae on oral mucosa and skin scarring occurred 2 years after the onset of the initial symptoms. DIAGNOSIS: Skin biopsy with direct immunofluorescence was performed under the suspicion of MMP. Lesional hematoxylin and eosin stain and perilesional direct immunofluorescence were consistent with MMP. INTERVENTIONS: Systemic Prednisolone and topical corticosteroid were used to control the disease. OUTCOMES: A flare-up of hepatitis B developed as a result of systemic prednisolone use. The disease went through relapses and remissions. The patient is on low-dose prednisolone (5 mg/day) with a monthly outpatient visit in the family medicine department. LESSONS: It would be useful for medical practitioners in different specialties to be alert of the heterogeneous presentations of MMP. Chronic HBV infection might be a risk factor for MMP. In patients with chronic HBV infection, treatment of MMP must be closely monitored for the risk of reactivation of HBV.

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.

A Review Comparing International Guidelines for the Management of Bullous Pemphigoid, Pemphigoid Gestationis, Mucous Membrane Pemphigoid, and Epidermolysis Bullosa Acquisita.

Autoimmune blistering disease management can be challenging as treatment modalities vary greatly and no single standard of care exists. We consolidated the recommendations of international management guidelines in order to provide optimal management suggestions to physicians. A comprehensive literature search in PubMed/MEDLINE for published blistering disease management guidelines and consensus statements was conducted in November 2019. Search terms included "guideline or guidelines" or "consensus" and "pemphigoid" or "autoimmune blistering disease" or "epidermolysis bullosa acquisita". We included guidelines from established dermatologic societies and expert consensus groups. We excluded literature reviews, guidelines established by an association without dermatologists, or those specific to a single treatment. Guidelines in all languages were considered. Eleven guidelines from dermatologic associations and consensus groups meeting our inclusion criteria were selected. Several differences between recommendations, most notably when to introduce adjuvants for refractory disease, were found in bullous pemphigoid. In mucous membrane pemphigoid, treatment was directed to the sites involved and managed with systemic corticosteroids and immunosuppressants/biologics. There was no universal consensus on the first-line treatment for epidermolysis bullosa acquisita, but a combination of immunosuppressive, anti-inflammatory, and anti-neutrophil therapy was utilized. Comparison of the management guidelines revealed underrepresentation of guidelines from developing nations and key differences between the management styles among dermatologists from Europe and Asia. We attribute these discrepancies to the time elapsed between guidelines, regional differences, and demands of the local healthcare systems.

Conjunctival Biopsy Site in Mucous Membrane Pemphigoid.

PURPOSE: To investigate if there is an association between the location of the conjunctival biopsy site (lesional, perilesional, or nonaffected) and the result of the direct immunofluorescence (DIF) test in patients with suspected mucous membrane pemphigoid (MMP) involving the ocular surface. DESIGN: Retrospective case series. METHODS: Records of patients with clinically suspected ocular MMP were reviewed to determine the location of the conjunctival biopsy. Conjunctival biopsy locations were defined as "lesional," "perilesional," and "nonaffected" conjunctiva. The DIF was considered positive when there was deposition of at least 1 of either IgM, IgG, IgA, or C3 at the basement membrane of the specimen; nondiagnostic when only fibrinogen was found at the same location; and negative when none of these features were present. RESULTS: The records of 41 patients were analyzed. Of these, 32 were eligible to be included in the study. Biopsies were lesional in 22% of cases (7/32), perilesional in 22% (7/32), and from nonaffected conjunctiva in 56% (18/32). DIF results were positive in 14% of lesional biopsies, in 86% of perilesional biopsies, and in 17% of those from nonaffected conjunctiva (P = .003). Perilesional biopsies gave higher positive DIF than lesional biopsies (P = .029). CONCLUSIONS: Perilesional conjunctival biopsies are associated with an increase in positive DIF results. These results support the need to sample perilesional conjunctival tissue in patients with suspected MMP.

Endoplasmic reticulum stress promotes inflammation-mediated proteolytic activity at the ocular surface.

A growing body of evidence implicates endoplasmic reticulum (ER) stress in the pathogenesis of chronic inflammatory and autoimmune disorders. Here, we demonstrate that the proinflammatory cytokine TNFα stimulates matrix metalloproteinase 9 (MMP9) at the ocular surface through a c-Fos-dependent mechanism of ER stress. We found positive reactivity of the molecular chaperone BiP/GRP78 in conjunctival epithelium of patients with ocular cicatricial pemphigoid and increased levels of BiP/GRP78, sXBP1 and GRP94 in human corneal epithelial cells treated with TNFα. Pharmacological blockade of ER stress in vitro using dexamethasone or the chemical chaperones TUDCA and 4PBA attenuated MMP9 expression and secretion in the presence of TNFα. Moreover, expression analysis of genes associated with inflammation and autoimmunity identified the c-Fos proto-oncogene as a mediator of ER stress responses in epithelial cells. Substantially less TNFα-induced MMP9 expression occurred when c-Fos signaling was suppressed with a function-blocking antibody. Taken together, these results indicate that activation of ER stress contributes to promote inflammation-mediated proteolytic activity and uncovers a target for restoring tissue homeostasis in ocular autoimmune disease.

Detection of IgE autoantibodies in mucous membrane pemphigoid and their association with disease severity.

BACKGROUND: Mucous membrane pemphigoid (MMP) is an autoimmune disease characterized by scarring lesions at mucosal sites. Although the pathogenic role of specific IgG and/or IgA has been already demonstrated and the detection of these immunoglobulins is a criterion in the diagnosis of MMP, little is known about IgE role in this disease. Therefore, the main purpose of this study was to assess the presence of circulating and tissue bound IgE in patients with MMP and their possible correlations with clinical presentation and disease course. METHODS: We conducted a retrospective study on 29 patients affected by MMP, recruited from a single center. Direct and indirect immunofluorescence studies were assessed to analyze the presence of specific IgE directed against the basal membrane zone. For each patient, fluorescence data were compared to clinical features. RESULTS: Linear deposits of C3, IgG and IgA were present in 86.2%, 62% and 37.9% of cases respectively, while IgE linear deposits were detected in 17 out of 29 patients (58.6%) including one case with isolated IgE positivity. Circulating IgE and IgA anti-BMZ were present in 7 (24.1%) and 5 (17.2%) patients, respectively. Both the presence of circulating IgA and of tissue bound IgE deposits correlated with disease activity index (P<0.014). CONCLUSIONS: Our results demonstrated the presence of IgE autoantibodies in MMP, particularly in more severe cases. Thus, IgE detection may represent an additional useful diagnostic tool in this disease.

Ectodermal Dysplasia: Association with Anti-Basement Membrane Autoantibodies.

Ectodermal dysplasia (ED) is a group of several genetic conditions with absence or dysgenesis of at least two ectodermal derivatives: teeth, skin and its appendages including hair, nails, eccrine and sebaceous glands. The most important clinical findings in patients with ED are hypodontia, hypotrichosis, and hypohidrosis, which can lead to episodes of hyperthermia. Few reports have focused on the progressive keratopathy in ED. Cicatrizing conjunctivitis associated with anti-basement membrane autoantibodies has been described. We report a series of three ectodermal dysplasia patients with an ocular phenotype typically seen in ocular mucous membrane pemphigoid; conjunctival immunohistopathology revealed anti-basement membrane autoantibodies in all of them, and systemic immunosuppression proved to be effective in improving symptoms and helping to stabilize ocular surface disease.

Targeting interleukin 4 receptor α: A new approach to the treatment of cutaneous autoimmune bullous diseases?

Bullous pemphigoid, mucous membrane pemphigoid, and pemphigus vulgaris are different cutaneous autoimmune blistering diseases, with complex pathogenic mechanisms. In all of them, a type-2 response is thought to have a central role. Interleukin 4 and Interleukin 13 are crucial cytokines in type-2 response. Treatment of these conditions is often challenging. Dupilumab, a recombinant fully human IgG4 monoclonal antibody with binding specificity to human interleukin-4 receptor IL-4Rα, has the potential to inhibit both IL-4 and IL-13. We propose IL-4Rα as a theoretical drug target for cutaneous autoimmune bullous diseases.

A Retrospective Study of Patient-Reported Data of Bullous Pemphigoid and Mucous Membrane Pemphigoid From a US-Based Registry.

Bullous pemphigoid (BP) and mucous membrane pemphigoid (MMP) are rare chronic autoimmune disorders characterized by subepidermal blistering. For the United States, there is a limited amount of studies in BP and MMP that address disease demographics and clinical data. In order to more comprehensively examine disease demographics and clinical factors, we performed a retrospective analysis of patient-reported data of 138 BP and 165 MMP patients enrolled in the International Pemphigus & Pemphigoid Foundation (IPPF) disease registry from 2010-2016. Patient-reported data was compared to Physician/Investigator reported data generated in our own local patient population (Western New York; 19 BP and 43 MMP patients). We confirm a female predominance in BP (M:F ratio 1:2.1) and MMP (M:F ratio 1:4.3), and a late onset within the 6th decade of life (average age at diagnosis, 59.1 ± 17.5 years for BP and 54.8 ± 11.2 years for MMP). MMP patients were significantly more likely to have a delay in diagnosis >12 months than BP patients (38 vs. 21%, respectively). Similar to other autoimmune conditions, a large number of BP (34%) and MMP (35%) patients present with other co-existing autoimmune disorders, with the most common being thyroid disease for both groups. Increased illness activity was paralleled by an increase in severe limitations of daily activities. The vast majority of of both BP and MMP patients received high intensity immunosuppression (49%). However, the majority of BP patients reported therapy with prednisone combined with other immunosuppressants (40%), while the majority of MMP patients received immunosuppressants other than prednisone (55%). With the exception of age at diagnosis, the clinical and demographic findings from both the national and local datasets were largely consistent with each other, and support those reported in other countries.