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.

Autoimmune bullous diseases during COVID-19 pandemic: 2022 update on rituximab and vaccine.

Autoimmune bullous diseases (AIBDs) are a heterogeneous group of life-threatening disorders associated with subepidermal or intraepidermal blistering. Skin barrier alterations and prolonged immunosuppressive treatments increase the risk of infections in patients with AIBDs, who are considered fragile. COVID-19 pandemic had a heavy impact on these patients. Although advances have been made in terms of prevention and treatment of COVID-19, this topic remains significant as the pandemic and its waves could last several years and, so far, a relevant proportion of the population worldwide is not vaccinated. This review is a 2022 update that summarizes and discusses the pandemic's burden on AIBD patients mainly considering relevant studies in terms of: (i) sample dimension; (ii) quality of control populations; (iii) possible standardization by age, gender and country. The findings show that: (i) the risk of COVID-19 infection and its severe course were comparable in AIBD patients and in the general population, except for rituximab-treated patients that presented a higher risk of infection and severe disease; (ii) the mortality rate in COVID-19-infected bullous pemphigoid patients was higher than in the general population, (iii) 121 cases of AIBD onset and 185 cases of relapse or exacerbation occurred after COVID-19 vaccination and a causal relationship has not been demonstrated so far. Altogether, acquired knowledge on COVID-19 pandemic could also be important in possible, albeit undesirable, future pandemic scenarios.

Pemphigus: trigger and predisposing factors.

Pemphigus is a life-threatening autoimmune blistering disease affecting skin and mucous membranes. Despite its etiopathogenesis remains largely unknown, several trigger and predisposing factors have been reported. Pemphigus is caused by autoantibodies that target desmoglein 1 and desmoglein 3, impacting desmosome function. However, circulating autoantibodies are often the consequence of a precipitating factor that occurs in predisposed individuals. This review aims to describe and discuss almost all trigger and predisposing factors reported as possible or probable cause of the disease. Among the reported trigger factors that may induce or exacerbate pemphigus, we have found of particular interest: drug intake (especially thiol- and phenol-containing compounds), vaccines, infections, as well as some reports about pregnancy, radiations, emotional stress, pesticides and physical trauma. Moreover, we discuss the possible role of food intake in pemphigus onset and particular attention is given to dietary factors containing thiol, phenol and tannin compounds. A trigger factor is "the straw that breaks the camel's back," and often acts together with predisposing factors. Here we discuss how pemphigus onset may be influenced by genetic susceptibility and comorbidities like thyroid diseases, malignancies and other autoimmune disorders. To identify other hitherto unknown trigger and predisposing factors, well designed prospective studies are needed. In this context, future research should explore their connection with the aim to advance our understanding of pemphigus pathogenesis.

Case report: Bullous pemphigoid arising in a patient with scleroderma and multiple sclerosis.

Background: Bullous pemphigoid (BP) is the most common autoimmune-blistering disease, clinically characterized by erythematous urticarial plaques, blisters, and intense pruritus, induced by autoantibodies against two proteins of the dermo-epidermal junction, BP180 and BP230. A large number of autoimmune diseases are reported in the literature as BP comorbidities, such as multiple sclerosis, but only a few cases are in association with scleroderma and none in association with both. Case presentation: We present the case of a 68-year-old woman affected by multiple sclerosis and scleroderma who developed severe bullous pemphigoid with a bullous pemphigoid disease area index of 60 and high titers of anti-BP180 and anti-BP230 autoantibodies by enzyme-linked immunosorbent assays. After 2 months of therapy with both intravenous and oral corticosteroids, the active lesions of bullous pemphigoid were remitted with no relapse. Conclusion: Autoimmune diseases affecting the skin or organs where BP180 and BP230 are present could trigger an immune response to these antigens through an epitope-spreading phenomenon and, over the years, induce bullous pemphigoid onset.