Gliptin-associated bullous pemphigoid shows peculiar features of anti-BP180 and -BP230 humoral response: Results of a multicenter study.

BACKGROUND: Recently, several case-control studies demonstrated an association between gliptins and bullous pemphigoid (BP) occurrence. However, data on the clinical and immunologic features of gliptin-associated bullous pemphigoid (GABP) are controversial. OBJECTIVE: This study aimed to clinically and immunologically characterize a large cohort of GABP patients to get an insight into the pathophysiology of this emerging drug-induced variant of BP. METHODS: Seventy-four GABP patients were prospectively enrolled and characterized from 9 different Italian dermatology units between 2013 and 2020. RESULTS: Our findings demonstrated the following in the GABP patients: (1) a noninflammatory phenotype, which is characterized by low amounts of circulating and skin-infiltrating eosinophils, is frequently found; (2) immunoglobulin (Ig)G, IgE, and IgA humoral responses to BP180 and BP230 antigens are reduced in frequency and titers compared with those in patients with idiopathic BP; (3) IgG reactivity targets multiple BP180 epitopes other than noncollagenous region 16A. LIMITATIONS: A limitation of the study is that the control group did not comprise only type 2 diabetes mellitus patients with BP. CONCLUSION: GABP patients show peculiar features of anti-BP180 and -BP230 humoral responses, laying the foundation for diagnostic improvements and getting novel insights into understanding the mechanism of BP onset.

Germline and somatic mutations in patients with multiple primary melanomas: a next generation sequencing study.

INTRODUCTION: Multiple primary melanomas (MPM) occur up to 8% of patients with cutaneous malignant melanoma (CMM). They are often sporadic harbouring several somatic mutations, but also familial cases harbouring a CDKN2A germline mutation have been describe in Caucasian populations. The aim of this study was to investigate the incidence, the distribution patterns and the impact of known and unknown germline and somatic mutations in patients with MPM from Italy. MATERIALS AND METHODS: One-hundred and two MPM patients were enrolled for germline mutation analysis, and five patients with at least four MPMs were identified for somatic mutation analysis. The demographic, pathologic and clinical features were retrieved from medical records. Molecular analysis for both germline and somatic mutations was performed in genomic DNA from peripheral blood and tissue samples, respectively, through a next generation sequencing approach, using a specific multiple-gene panel constructed by the Italian Melanoma Intergroup for somatic analysis and a commercial cancer hotspot panel for somatic analysis. RESULTS: CDKN2A mutations were detected in 6/16 (37.5%) and 3/86 (3.5%) MPM cases with and without family history for melanoma, respectively. Furthermore, multiple MC1R and, to a lesser extent, ATM variants have been identified. BAP1 variants were found only in MPM patients from southern Italy. The most frequent somatic variants were the pathogenic BRAFV600E and TP53, followed by KIT, PIK3CA, KDR, and NRAS. Single APC, ERBB4, MET, JAK3 and other variants with unknown function were also detected. CONCLUSIONS: CDNK2A mutation is the most relevant susceptibility mutation in Italian patients with MPM, especially those with a family history for CMM. The prevalence of this mutation and other sequence variants identified in this study varies among specific sub-populations. Furthermore, some heterogeneity in driver somatic mutations between sporadic MPMs has been observed, as well as in a number of associated sequence variants the clinical impact of which needs to be further elucidated.

Autoimmune bullous dermatoses in cancer patients treated by immunotherapy: a literature review and Italian multicentric experience.

Cutaneous immune-related adverse events are frequently associated with immune checkpoint inhibitors (ICIs) administration in cancer patients. In fact, these monoclonal antibodies bind the cytotoxic T-lymphocyte antigen-4 and programmed cell death-1/ligand 1 leading to a non-specific activation of the immune system against both tumoral cells and self-antigens. The skin is the most frequently affected organ system appearing involved especially by inflammatory manifestations such as maculopapular, lichenoid, psoriatic, and eczematous eruptions. Although less common, ICI-induced autoimmune blistering diseases have also been reported, with an estimated overall incidence of less than 5%. Bullous pemphigoid-like eruption is the predominant phenotype, while lichen planus pemphigoides, pemphigus vulgaris, and mucous membrane pemphigoid have been described anecdotally. Overall, they have a wide range of clinical presentations and often overlap with each other leading to a delayed diagnosis. Achieving adequate control of skin toxicity in these cases often requires immunosuppressive systemic therapies and/or interruption of ICI treatment, presenting a therapeutic challenge in the context of cancer management. In this study, we present a case series from Italy based on a multicenter, retrospective, observational study, which included 45 patients treated with ICIs who developed ICI-induced bullous pemphigoid. In addition, we performed a comprehensive review to identify the cases reported in the literature on ICI-induced autoimmune bullous diseases. Several theories seeking their underlying pathogenesis have been reported and this work aims to better understand what is known so far on this issue.