Sams W M
J Invest Dermatol. 1985 Jul;85(1 Suppl):144s-148s. doi: 10.1111/1523-1747.ep12275678.
Human hypersensitivity angiitis is an immune complex disease in which patients present with palpable purpuric lesions of the skin and may often have multiple organ involvement. The antigen may be derived from an infectious organism such as the hepatitis virus, streptococcus, or a drug, and complexes with antibody. Under circumstances of vascular turbulence or vessel wall dilatation this complex may become fixed, activating the complement sequence with elaboration of chemotactic factors for neutrophils. These cells release lysosomal enzymes resulting in vessel wall destruction. Red blood cells leak into the tissue producing purpura and the inflammatory infiltrate accounts for the palpability. Although many patients have skin lesions only, others may have involvement of joints, gastrointestinal tract, kidneys, and even the lungs. The central question in the pathogenesis of this disease is why the immune complex is so selective in its site of deposition. Part of the reason must be related to the lattice formation of a particular complex, while other reasons are related to host factors of altered vascular permeability, integrity of clearance mechanisms or even a genetically determined defect of the phagocytic system.
人类过敏性血管炎是一种免疫复合物疾病，患者表现为皮肤可触及的紫癜性病变，且常可累及多个器官。抗原可能来源于感染性生物体，如肝炎病毒、链球菌或药物，并与抗体形成复合物。在血管湍流或血管壁扩张的情况下，这种复合物可能会固定下来，激活补体序列并产生趋化因子以吸引中性粒细胞。这些细胞释放溶酶体酶，导致血管壁破坏。红细胞渗入组织形成紫癜，炎症浸润导致病变可被触及。虽然许多患者仅出现皮肤病变，但其他患者可能累及关节、胃肠道、肾脏甚至肺部。该疾病发病机制的核心问题是为什么免疫复合物在其沉积部位具有如此的选择性。部分原因必定与特定复合物的晶格形成有关，而其他原因则与血管通透性改变、清除机制完整性甚至吞噬系统的基因决定缺陷等宿主因素有关。
