HLA alleles associated to susceptibility to gliptin-associated bullous pemphigoid in Italian patients.

Bullous pemphigoid (BP), although a rare disease, is the most frequent subepidermal autoimmune disorder. Treatment with gliptins, used for type 2 diabetes, was reported as associated with BP onset. To identify HLA alleles that may reflect a higher susceptibility to BP in the Italian population, we analysed 30 patients affected by idiopathic bullous pemphigoid (IBP) and 86 gliptin-associated BP (GABP) patients. A significant association between HLA-DQB1*03:01 allele and IBP and GABP patients was found. Of note, both IBP and GABP were significantly associated with one of the following haplotypes: DRB1*11:01, DRB3*02:02, DQA1*05:05, DQB1*03:01 or DRB1*11:04, DRB3*02:02, DQA1*05:05 and DQB1*03:01. These data identify, for the first time, potential markers of susceptibility to BP in the Italian population, especially when associated with gliptin intake.

A case report of bullous pemphigoid following secukinumab therapy for a patient with psoriasis.

Aim: Bullous pemphigoid induced by secukinumab in treatment of psoriasis is rare.Methods: We report a 49-year-old man with psoriasis who developed bullous pemphigoid during treatment with secukinumab.Results: Scattered tense vesicles with itching appeared all over the body after the fourth treatment. Bullous pemphigoid was confirmed by pathological examination and direct immunofluorescence. The patient was treated with topical corticosteroids, oral nicotinamide and minocycline hydrochloride. The lesions of bullous pemphigoid improved significantly after 7 days of treatment.Conclusions: Bullous pemphigoid is a rare adverse event following administration of secukinumab.

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.

Two cases of linagliptin-associated bullous pemphigoid resulting in sepsis and endocarditis.

We describe two patients, in their 70s, each presenting to the emergency department, with 6-week histories of progressively developing pruritic bullae. Both individuals had multiple comorbidities, including type 2 diabetes-for which they took linagliptin, chronic kidney disease, hypertension and prosthetic heart valves. Owing to systemic illness and endocarditis secondary to superadded bacterial infections, they both required intensive treatment and prolonged hospital admissions.Despite the beneficial effect of linagliptin on glycaemic control and its reported cardiovascular and renal safety profiles, we add our cases as evidence of the significant risk of developing bullous pemphigoid while taking this medication. Secondary infection of bullous pemphigoid increased the risk of developing endocarditis, particularly among individuals with a medical history of valve replacement surgery. Considering this, we advocate caution when prescribing this medication.

Proteomic changes related to actin cytoskeleton function in the skin of vildagliptin-treated mice.

BACKGROUND: Vildagliptin, a dipeptidyl peptidase-4 inhibitor (DPP-4i) is a widely used type 2 diabetes medication that is associated with an up-to 10-fold increased risk for the development of bullous pemphigoid (BP), an autoimmune skin disease. The mechanism by which vildagliptin promotes the development of BP remains unknown. OBJECTIVE: To elucidate effects of vildagliptin treatment on the mouse cutaneous proteome. METHODS: We analyzed the cutaneous proteome of nondiabetic mice treated for 12 weeks with vildagliptin using label-free shotgun mass spectrometry (MS), two-dimensional difference gel electrophoresis (2D-DIGE), immunohistochemistry, immunoblotting, and quantitative real-time polymerase chain reaction. RESULTS: Although vildagliptin treatment did not cause any clinical signs or histological changes in the skin, separate MS and 2D-DIGE analyses revealed altered cutaneous expression of several proteins, many of which were related to actin cytoskeleton remodeling. Altogether 18 proteins were increased and 40 were decreased in the vildagliptin-treated mouse skin. Both methods revealed increased levels of beta-actin and C->U-editing enzyme APOBEC2 in vildagliptin-treated mice. However, elevated levels of a specific moesin variant in vildagliptin-treated animals were only detected with 2D-DIGE. Immunohistochemical staining showed altered cutaneous expression of DPP-4, moesin, and galectin-1. The changed proteins detected by MS and 2D-DIGE were linked to actin cytoskeleton remodeling, transport, cell movement and organelle assembly. CONCLUSION: Vildagliptin treatment alters the cutaneous proteome of nondiabetic mice even without clinical signs in the skin. Cytoskeletal changes in the presence of other triggering factors may provoke a break of immune tolerance and further promote the development of BP.

A case of anti-laminin γ1 (p200) pemphigoid developed after dipeptidyl peptidase-4 inhibitor administration.

A 73-year-old man with diabetes mellitus was referred to our department for ultraviolet treatment for erythematous skin lesions with itching. On dipeptidyl peptidase-4 inhibitor (DPP-4i) sitagliptin (Januvia®) for diabetes mellitus, the erythematous skin lesions appeared and spread to the whole body. At the initial visit, erythema multiforme-like skin lesions with crusts were observed on the trunk and extremities, and the patient was suspected to have drug eruption. Histopathology demonstrated eosinophilic infiltration in the superficial dermis and inflammatory cell infiltration in the epidermis. Sitagliptin was discontinued, and erythematous lesions improved with oral prednisolone. Thereafter the patient was treated with phototherapy and  betamethasone sodium phosphate infusion for residual prurigo. However, blistering skin lesions appeared 5 months later. Histopathological findings were subepidermal blisters with eosinophilic abscess, and bullous pemphigoid was suspected. CLEIAs for autoantibodies to desmoglein 1 (Dsg1), Dsg3 and BP180 were negative. Direct immunofluorescence showed linear depositions of immunoglobulin G (IgG) and C3 at the epidermal basement membrane zone, and indirect immunofluorescence detected IgG anti-epidermal basement membrane zone antibodies, reacting with the dermal side of 1M NaCl-split normal human skin. IgG antibodies reacted with 200 kDa laminin γ1 (p200) by immunoblotting using dermal extracts. These results indicated that this patient was diagnosed with anti-laminin γ1 (p200) pemphigoid developed after DPP-4i administration. Although reports of DPP-4i-related bullous pemphigoid have accumulated, cases of anti-laminin γ1 (p200) pemphigoid developed after DPP-4i administration are rarely reported.

Lichen planus pemphigoides induced by anti-PD-1 antibody: A case only involved in oral mucosa with excellent topical treatment efficiency.

Lichen planus pemphigoides (LPP) is a rare autoimmune subepidermal disease that can occur in patients receiving immune checkpoint inhibitors. Its clinical manifestations are combined with the characteristics of lichen planus with bullous pemphigoid that can occur on either skin or oral mucosa. It should be noted that oral LPP is very rare. Here, we report a novel case of oral LPP induced by an anti-PD-1 agent. The patient presented with typical clinical features in oral mucosa, and the diagnosis was based on histopathology and immunological studies. Given that the patient was receiving an anti-PD-1 agent, topical therapy was chosen, and a nice therapeutic effect was obtained. No significant recurrence was observed after a 2-year follow-up. A good and stable therapeutic effect achieved by rapid and local symptomatic medication suggests that accurate and sensitive diagnosis is necessary.

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.

From Molecular Insights to Clinical Perspectives in Drug-Associated Bullous Pemphigoid.

Bullous pemphigoid (BP), the most common autoimmune blistering disease, is characterized by the presence of autoantibodies targeting BP180 and BP230 in the basement membrane zone. This leads to the activation of complement-dependent and independent pathways, resulting in proteolytic cleavage at the dermoepidermal junction and an eosinophilic inflammatory response. While numerous drugs have been associated with BP in the literature, causality and pathogenic mechanisms remain elusive in most cases. Dipeptidyl peptidase 4 inhibitors (DPP4i), in particular, are the most frequently reported drugs related to BP and, therefore, have been extensively investigated. They can potentially trigger BP through the impaired proteolytic degradation of BP180, combined with immune dysregulation. DPP4i-associated BP can be categorized into true drug-induced BP and drug-triggered BP, with the latter resembling classic BP. Antineoplastic immunotherapy is increasingly associated with BP, with both B and T cells involved. Other drugs, including biologics, diuretics and cardiovascular and neuropsychiatric agents, present weaker evidence and poorly understood pathogenic mechanisms. Further research is needed due to the growing incidence of BP and the increasing identification of new potential triggers.