Department of Oncology, Section of Pathology, San Giovanni di Dio Hospital, USL Centro Toscana, Florence, Italy.
Department of Laboratory Medicine, Pathology Unit, Santa Chiara Hospital, Trento, Italy.
Pathologica. 2024 Apr;116(2):119-133. doi: 10.32074/1591-951X-985.
The mechanisms underlying the onset and progression of vasculitis remain poorly understood. This condition is characterized by damage to the vascular wall, recruitment of inflammatory cells, and subsequent structural remodeling, which are hallmarks of vasculitis. The histopathological classification of vasculitis relies on the size of the affected vessel and the predominant type of inflammatory cell involved - neutrophils in acute cases, lymphocytes in chronic conditions, and histiocytes in granulomatous forms. Pathological changes progress in every context, and a single vasculitic pattern can be associated with various systemic conditions. Conversely, a single causative agent may lead to multiple distinct clinical and pathological manifestations of vasculitis. Moreover, many cases of vasculitis have no identifiable cause. A foundational understanding of the normal structure of the cutaneous vascular network is crucial. Similarly, identifying the cellular and molecular participants and their roles in forming the "dermal microvascular unit" is propedeutical. This review aims to elucidate the complex mechanisms involved in the initiation and progression of vasculitis, offering a comprehensive overview of its histopathological classification, underlying causes, and the significant role of the cutaneous vascular network and cellular dynamics. By integrating the latest insights from studies on NETosis and the implications of lymphocytic infiltration in autoimmune diseases, we seek to bridge gaps in current knowledge and highlight areas for future research. Our discussion extends to the clinical implications of vasculitis, emphasizing the importance of identifying etiological agents and understanding the diverse histopathological manifestations to improve diagnostic accuracy and treatment outcomes.
血管炎的发病机制和进展仍知之甚少。这种疾病的特征是血管壁损伤、炎症细胞募集和随后的结构重塑，这些都是血管炎的标志。血管炎的组织病理学分类依赖于受影响的血管大小和涉及的主要炎症细胞类型 - 在急性情况下是中性粒细胞，在慢性情况下是淋巴细胞，在肉芽肿形式下是组织细胞。病理变化在每种情况下都在进展，单一的血管炎模式可能与各种系统性疾病有关。相反，单一的致病因素可能导致多种不同的血管炎临床和病理表现。此外，许多血管炎病例没有可识别的原因。对皮肤血管网络的正常结构有一个基本的了解是至关重要的。同样，确定细胞和分子参与者及其在形成“真皮微血管单位”中的作用也是有帮助的。本综述旨在阐明血管炎发病和进展中涉及的复杂机制，全面概述其组织病理学分类、潜在原因以及皮肤血管网络和细胞动力学的重要作用。通过整合 NETosis 研究的最新见解以及淋巴细胞浸润在自身免疫性疾病中的意义，我们试图弥合当前知识的差距，并强调未来研究的领域。我们的讨论扩展到血管炎的临床意义，强调确定病因和理解多种组织病理学表现以提高诊断准确性和治疗结果的重要性。
