Identification of Risk Factors for Gliptin-associated Bullous Pemphigoid among Diabetic Patients.

Drug-associated bullous pemphigoid has been shown to follow long-term gliptin (dipeptidyl-peptidase 4 inhibitors) intake. This study aimed at identifying risk factors for gliptin-associated bullous pemphigoid among patients with type 2 diabetes. A retrospective study was conducted in a tertiary centre among diabetic patients exposed to gliptins between the years 2008-2021. Data including demographics, comorbidities, medications, and laboratory results were collected using the MDClone platform. Seventy-six patients with type 2 diabetes treated with dipeptidyl-peptidase 4 inhibitors who subsequently developed bullous pemphigoid were compared with a cohort of 8,060 diabetic patients exposed to dipeptidyl-peptidase 4 inhibitors who did not develop bullous pemphigoid. Based on a multivariable analysis adjusted for age and other covariates, Alzheimer's disease and other dementias were significantly more prevalent in patients with bullous pemphigoid (p = 0.0013). Concomitant use of either thiazide or loop diuretics and gliptin therapy was associated with drug-associated bullous pemphigoid (p < 0.0001 for both). While compared with sitagliptin, exposure to linagliptin and vildagliptin were associated with bullous pemphigoid with an odds ratio of 5.68 and 6.61 (p < 0.0001 for both), respectively. These results suggest gliptins should be prescribed with caution to patients with type 2 diabetes with coexisting Alzheimer's and other dementias, or patients receiving long-term use of thiazides and loop diuretics. The use of sitagliptin over linagliptin and vildagliptin should be preferred in these patients.

Oral mucous membrane pemphigoid: updates in diagnosis and management.

Mucous membrane pemphigoid (MMP) is a rare, immune-mediated, vesiculobullous disease that predominantly affects the oral cavity and conjunctiva. In MMP, autoantibodies are directed against hemidesmosomal proteins in the basement membrane zone, most commonly BP180. Clinical signs and symptoms include gingival desquamation, erosions, and ulcerations. Differential diagnoses include other immune-mediated blistering diseases, such as bullous pemphigoid. Definitive diagnosis is reached through history taking, physical examination, tissue biopsy and/or serology testing. MMP, although not curable, is typically managed with topical or systemic corticosteroids, in addition to immunosuppressive therapies and biologic agents in recalcitrant cases. Untreated MMP can lead to life-threatening complications, such as blindness. As a condition that affects the oral cavity, it is important that dentists understand how to recognise, diagnose and manage the disease.

Gliptin-induced bullous pemphigoid.

OBJECTIVES: Bullous pemphigoid (BP) is a rare, autoimmune, blistering disease in elderly patients that can be triggered by external factors including drugs. Drug-induced bullous pemphigoid (DIBP) does not always follow a self-limiting course after the withdrawal of the offending drug. Dipeptidyl peptidase-4 (DPP-4) inhibitors or gliptins seem to be associated with a significant risk of inducing BP. CASE PRESENTATION: We report 2 cases of BP attributed to the DPP-4 inhibitor linagliptin. In both cases, the clinical manifestation was strongly suggestive of BP. The diagnosis was verified by histology and direct immunofluorescence (DIF). Linagliptin and all other possible drug triggers of BP were discontinued after consultation with an endocrinologist and a cardiologist. Systemic treatment of BP consisted of methylprednisolone and tetracycline. During the follow-up period, one of the patients suffered a fatal brain stroke while the other was managed with reduced doses of corticosteroids. CONCLUSION: The proper management of autoimmune bullous skin disorders in elderly patients includes a scrupulous assessment of plausible drug triggers. Systemic corticosteroids for treating severe cases of DIBP can worsen concomitant diseases which often necessitates multidisciplinary care.

Is it Possible to Obtain Immunofluorescence Data in Formalin-Fixed Paraffin-Embedded Skin Samples for the Diagnosis of Pemphigus Vulgaris and Bullous Pemphigoid.

OBJECTIVE: The gold-standard method for assessment of autoimmune bullous disease is direct/indirect immunofluorescence (IF) examination applied to fresh frozen tissue. Since the sensitivity of IF is greatly reduced in formalin-fixed paraffin-embedded (FFPE) tissues, IF cannot be relied upon in these samples. However, immunohistochemistry with the C4d antibody is a promising marker used as a surrogate for immune complex deposition, in nephropathology practice, and the paraffin IF method is also used as a `salvage` technique when fresh frozen tissue is not available or lacks glomeruli. We aimed to investigate whether it is possible to obtain immunofluorescence data from FFPE tissues diagnosed with bullous pemphigoid (BP) and pemphigus vulgaris (PV) and its relationship with inflammatory parameters in the skin. MATERIAL AND METHODS: Eighty-nine in-house cases with both IgG and C3 positivity by routine immunofluorescence examination were included in the study. Inflammation parameters were evaluated in hematoxylin-eosin sections. Immunofluorescence study with IgG protease digestion and C4d immunohistochemistry were performed. RESULTS: Results of 83 biopsies were obtained by paraffin immunofluorescence with IgG. There were positive reactions in 28 (34%) of these 83 biopsies. Five of the 28 positive results belonged to BP (18%), and 23 were PV (82%). Ten positive results were on lesional skin (36%), and 18 (64%) were on non-lesional skin. In the immunohistochemical study with C4d, 84 biopsy results were obtained. There were positive reactions in 34 (40.4%) of 84 biopsies. Of the 34 positive results, 12 belonged to BP (35.3%) and 22 to PV (64.7%). Again, 22 (64.7%) of 34 positive results belonged to lesional skin, and 12 (35.3%) belonged to non-lesional skin. When both techniques were used together, 44 (54%) of 81 biopsies yielded positive results for at least one of the two studies, while in 37 (46%), both tests showed negative results. CONCLUSION: The sensitivity of both IgG and C4d was less than in the literature, especially in BP-diagnosed biopsies. Positive samples were mostly PV. In conclusion, obtaining immunofluorescence data in FFPE samples is possible and is independent of the related skin being lesional or not, however, negative results should not be relied upon.

Evaluation of Dry Eye Severity and Ocular Surface Inflammation in Patients with Pemphigus and Pemphigoid.

PURPOSE: To evaluate ocular surface involvement, tear cytokine levels, and histopathological changes in pemphigus and pemphigoid patients. METHODS: A total of 22 patients (15 pemphigus and 7 pemphigoids) and 21 non-diseased controls were enrolled in our study. All participants underwent ocular surface evaluation, which included ocular surface disease index test, slit lamp observation, dry eye-related examination, tear multicytokine analysis, and conjunctival impression cytology. RESULTS: Pemphigus and pemphigoid patients presented much more severe conjunctivochalasis, corneal epithelial defects, corneal opacity, symblepharon   and dry eye. Severe ocular surface squamous metaplasia and a significant increase of tear macrophage inflammatory protein-1beta, tumor necrosis factor-alpha, interleukin (IL)-1ß, IL -6, and IL-8 occurred in pemphigus and pemphigoid patients. CONCLUSIONS: Our results revealed that ocular surface inflammation and dry eye persist in most pemphigus and pemphigoid patients, and do not occur in parallel with the systemic course. Regular ophthalmological examinations and local anti-inflammatory should be provided for pemphigus and pemphigoid patients.

Omalizumab in the treatment of bullous pemphigoid resistant to first-line therapy: a French national multicentre retrospective study of 100 patients.

BACKGROUND: Interest in the use of omalizumab to treat bullous pemphigoid (BP) in the event of resistance or contraindication to conventional therapies is currently based on limited evidence. OBJECTIVES: To assess the effectiveness and safety of omalizumab in BP and to identify predictive factors in response to treatment. METHODS: We conducted a French national multicentre retrospective study including patients with a confirmed diagnosis of BP treated with omalizumab after failure of one or several treatment lines. We excluded patients with clinically atypical BP, as per Vaillant's criteria. The criteria for clinical response to omalizumab were defined according to the 2012 international consensus conference. Anti-BP180-NC16A IgE enzyme-linked immunosorbent assay was performed on sera collected before initiating omalizumab, when available. RESULTS: Between 2014 and 2021, 100 patients treated in 18 expert departments were included. Median age at diagnosis was 77 years (range 20-98). Complete remission (CR) was achieved in 77% of patients, and partial remission in an additional 9%. CR was maintained 'off therapy' in 11.7%, 'on minimal therapy' in 57.1%, and 'on non-minimal therapy' in 31.2%. Median time to CR was 3 months (range 2.2-24.5). Relapse rate was 14%, with a median follow-up time of 12 months (range 6-73). Adverse events occurred in four patients. CR was more frequently observed in patients with an increased serum baseline level of anti-BP180-NC16A IgE (75% vs. 41%; P = 0.011). Conversely, urticarial lesions, blood total IgE concentration or eosinophil count were not predictive of CR. Patients with an omalizumab dosage > 300 mg every 4 weeks showed a similar final outcome to those with a dosage ≤ 300 mg every 4 weeks, but control of disease activity [median 10 days (range 5-30) vs. 15 days (range 10-60); P < 0.001] and CR [median 2.4 months (range 2.2-8.2) vs. 3.9 months (range 2.3-24.5); P < 0.001] were achieved significantly faster. CONCLUSIONS: We report the largest series to date of BP treated by omalizumab and confirm its effectiveness and safety in this indication. Serum baseline level of anti-BP180-NC16A IgE may predict response to treatment.

Accurate diagnosis of bullous pemphigoid requires multiple health care visits.

Introduction: Accurate use of diagnostic codes is crucial for epidemiological and genetic research based on electronic health record (EHR) data. Methods: This retrospective study validated the International Classification of Diseases (ICD)-10 diagnostic code L12.0 for bullous pemphigoid (BP) using EHR data from two Finnish university hospitals. We found 1225 subjects with at least one EHR entry of L12.0 between 2009 and 2019. BP diagnosis was based on clinical findings characteristic of BP and positive findings on direct immunofluorescence (DIF), BP180-NC16A enzyme-linked immunosorbent assay (ELISA) or indirect immunofluorescence (IIF) assay. Results: True BP was found in 901 patients; the positive predictive value (PPV) for L12.0 was 73.6% (95% CI 71.0-76.0). L12.0 was more accurately registered in dermatology units than any specialized health care units (p<0.001). Including patients with multiple L12.0 registrations (≥3), increased the accuracy of the L12.0 code in both dermatology units and other settings. Discussion: One diagnostic code of L12.0 is not enough to recognize BP in a large epidemiological data set; including only L12.0 registered in dermatology units and excluding cases with <3 L12.0 record entries markedly increases the PPV of BP diagnosis.

Clinical and immunopathological characteristics of autoimmune blistering skin diseases.

Autoimmune blistering skin diseases (AIBDs) encompass several heterogeneous conditions clinically characterized by blisters and erosions on the skin and mucous membranes and are immunopathologically characterized by autoantibodies against structural proteins of the skin. Those proteins are responsible for the intercellular contact between epidermal keratinocytes and adhesion of the basal keratinocytes to the dermis. Therefore, AIBDs are divided into two main groups: intraepidermal (the pemphigus group) and subepidermal (the pemphigoid) groups. The diagnostic methods for AIBDs have made tremendous progress in the last 2 decades due to the availability of standardized serological assays that allow precise diagnosis in most patients. If left untreated, these diseases are potentially life-threatening due to superinfections and loss of body fluids, and in some severe cases due to restricted food intake. Based on the available literature, this paper provides an overview of the clinical and immunopathological characteristics of the most common AIBDs.

Pemphigus and pemphigoid are associated with Alzheimer's disease in older adults: evidence from the US Nationwide inpatient sample 2016-2018.

BACKGROUND: Pemphigus and pemphigoid are rare autoimmune skin disorders caused by autoantibodies against structural proteins and characterized by blistering of the skin and/or mucous membranes. Associations have been noted between skin diseases and Alzheimer's dementia (AD). Dementia is a neurological disorder of progressive cognitive impairment with increasing incidence among older adults. This study aimed to assess the potential associations between pemphigus, pemphigoid and AD in a large, nationally representative US cohort. METHODS: All data of hospitalized patients aged 60 years or older were extracted from the US Nationwide Inpatient Sample (NIS) database 2016-2018. Patients with a history of head trauma, diagnosis of vascular dementia, history of cerebrovascular disease, or malformation of cerebral vessels were excluded. The study population was divided into those with and without pemphigus (cohort 1) and with and without pemphigoid (cohort 2). RESULTS: Pemphigus was independently associated with a 69% increased risk of AD. Adults ≥80 years old with pemphigus were 72% more likely to develop AD than adults without pemphigus. Women with pemphigus were 78% more likely to develop AD than women without pemphigus. On the other hand, pemphigoid was independently associated with a 39% increased risk for AD and subjects ≥80 years with pemphigoid were 40% more likely to have AD than those without pemphigoid. Females with pemphigoid were 63% more likely to have AD than those without pemphigoid. Moreover, Hispanic older adults with pemphigus were 3-times more likely to have AD than those without pemphigoid. CONCLUSIONS: Pemphigus and pemphigoid were both independently associated with AD in older adults, especially among females and octogenarians. Further studies addressing the etiology and mechanisms underlying these associations are highly warranted.

Risk factors predisposing relapse of bullous pemphigoid at initial diagnosis: A retrospective cohort study of 205 patients.

BACKGROUND: Previous studies have revealed the factors associated with the relapse of bullous pemphigoid (BP). This study aims to assess the characteristics of BP patients at the time of initial diagnosis and a potential association with subsequent relapse occurrences. METHODS: A retrospective cohort study was conducted on 205 BP patients from January 2009 to May 2022 at the Peking Union Medical College Hospital in Beijing, China. The median follow-up duration was 2.7 years. We conducted univariate and multivariate analyses on various clinical indicators (e.g., lesional involvements and medical history) and laboratory test results. RESULTS: Among the 205 patients, 118 (57.6 %) relapsed during the follow-up period. Univariate analysis revealed several factors associated with relapse, which were greater age [Hazard Ratio (HR)1.018, 95 % confidence interval (CI) 1.004-1.032] (p = 0.010), a past medical history of thyroid diseases [HR 3.674, 95 % CI 1.472-9.167] (p = 0.005), hematological disease complications [HR 4.123, 95 % CI 1.301-13.061] (p = 0.016), negative C3 deposition in direct immunofluorescence [HR 0.574, 95 % CI 0.374-0.883] (p = 0.011) and prealbumin level less than 200 mg/L[HR 0.580, 95 % CI 0.351-0.957] (p = 0.033). Multivariate analysis demonstrated that patients with negative C3 deposition in direct immunofluorescence [HR 0.524, 95 % CI 0.296-0.927] (p = 0.026) and prealbumin levels below 200 mg/L [HR 0.541, 95 % CI 0.301-0.974] (p = 0.041) were associated with further relapses of BP. CONCLUSIONS: Negative C3 deposition in direct immunofluorescence and a prealbumin level below 200 mg/L at initial diagnosis served as predictive markers for future relapses of BP. Systemic evaluation of BP patients at initial diagnosis could be essential in helping prevent recurrences and achieve more effective disease management.

[The main autoimmune bullous diseases]. / Les principales maladies bulleuses auto-immunes.

Autoimmune bullous diseases are disorders in which the immune system mistakenly attacks certain molecules that act as "glue" in the various layers of the skin, leading to the formation of bullae or vesicles. A bulla is a liquid-containing lesion over five millimeters in size on the skin or mucous membranes. It forms due to a loss of cohesion between the epidermis and dermis, or between keratinocytes within the epidermis. Diagnosis is based on biopsies, which show the presence of autoantibodies and the depth of skin detachment. A blood test can be used to identify circulating autoantibodies.