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Pyodermatitis-Pyostomatitis Vegetans: The Role of Langerin Deficiency in Disease Pathogenesis
Dan Pan1, Jiongke Wang1, Luyao Cai1
1State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China.
None:
Background/Objectives: Pyodermatitis-pyostomatitis vegetans (PPV) is a rare, chronic inflammatory mucocutaneous disorder. However, the etiology of PPV remains controversial. Methods: A review of online PPV case studies from PubMed, Wanfang database, Web of Science, and books has been performed. Comparative analysis of langerin expression has been conducted to verify the hypothesis summarized from the literature review by Immunohistochemistry (IHC). Results: A total of 63 patients were analyzed across 5 reviews, 44 case reports, and 1 book chapter. Our findings revealed distinct immunological alterations in PPV patients. Innate immunity was upregulated, marked by increased neutrophil and eosinophil counts and enhanced macrophage activity. Adaptive immunity was suppressed, with reduced dendritic cell (DC) numbers and activity and diminished adaptive immune responses. We hypothesize that langerin was a critical factor, contributing to adaptive immune suppression and a compensatory innate immune hyperactivation. Conclusions: We propose the hypothesis that langerin expression on Langerhans cells (LCs) plays a pivotal role in PPV pathogenesis by shifting the immune balance toward innate hyperactivation at the expense of adaptive immunity.
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