Magro Cynthia M, Mo Joshua H, Kerns Mary Jo
Division of Dermatopathology, Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, New York, USA.
Division of Dermatopathology, Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, New York, USA.
Clin Dermatol. 2022 Nov-Dec;40(6):639-650. doi: 10.1016/j.clindermatol.2022.07.011. Epub 2022 Jul 28.
Cutaneous leukocytoclastic vasculitis (LCV) has a distinctive clinical and light microscopic presentation; however, the etiologic basis of LCV is varied. Most cases are attributable to immune complex deposition within a vessel wall and represent an Arthus type III immune complex reaction. The prototypic immunoreactant profile is characterized by granular deposits of components of complement activation in concert with immunoglobulin within the cutaneous vasculature. We encountered nine patients with vasculitic and/or vesiculobullous clinical presentations exhibiting an LCV in association with an immunoreactant profile characterized by homogeneous linear deposits of immunoglobulin along the dermal epidermal junction in a fashion resembling an autoimmune vesiculobullous disease. Among the clinical presentations were palpable purpura, urticarial vasculitis, and vesiculobullous eruptions with supervening purpura. Two patients with Crohn disease presented with classic palpable purpura with biopsy-proven LCV, and direct immunofluorescence (DIF) studies demonstrated linear immunoglobulin G (IgG) with floor localization on the salt-split skin assay. Four patients with systemic lupus erythematosus (SLE) showed purpuric vesiculobullous lesions, with evidence of a neutrophilic interface dermatitis and LCV in three of the four. The remaining patient had urticarial nonbullous lesions showing small-vessel vasculitiswith a neutrophilic interface dermatitis. In all of the patients with SLE, DIF studies showed linear immunoglobulin deposits within the basement membrane zone (BMZ). These constellation of findings clinically, light microscopically, and by immunofluorescence were those of a vasculitic presentation of bullous systemic lupus erythematosus. Two patients had linear IgA disease, which was drug induced in one and paraneoplastic in the other, and the dominant morphology on biopsy in both cases was an LCV. One patient microscopically demonstrated drug-associated and eosinophilic enriched LCV with DIF studies showing striking linear deposits of IgG suggestive of bullous pemphigoid, which was consistent with a vasculitic presentation of drug-induced bullous pemphigoid. In all cases, typical granular vascular immunoglobulin and complement deposition compatible with immune complex mediated vasculitis was observed. It is likely that local immune complexes derived from BMZ antigen bound to antibody are pathogenically relevant. We propose the designation of linear vasculitis for this unique scenario of LCV and linear immunoglobulin epidermal BMZ staining, which in some cases represents a vasculitic presentation of conventional autoimmune vesiculobullous disease.
皮肤白细胞破碎性血管炎（LCV）具有独特的临床和光镜表现；然而，LCV的病因基础多种多样。大多数病例归因于血管壁内免疫复合物沉积，代表ArthusⅢ型免疫复合物反应。典型的免疫反应物谱的特征是皮肤血管内补体激活成分与免疫球蛋白的颗粒状沉积。我们遇到9例具有血管炎和/或水疱大疱性临床表现的患者，其LCV与一种免疫反应物谱相关，该谱的特征是免疫球蛋白沿真皮表皮交界处呈均匀线性沉积，类似于自身免疫性水疱大疱性疾病。临床表现包括可触及的紫癜、荨麻疹性血管炎以及继发紫癜的水疱大疱性皮疹。2例克罗恩病患者表现为典型的可触及紫癜，活检证实为LCV，直接免疫荧光（DIF）研究显示在盐裂皮肤试验中免疫球蛋白G（IgG）呈线状沉积于底层。4例系统性红斑狼疮（SLE）患者出现紫癜性水疱大疱性皮损，4例中有3例有嗜中性粒细胞界面性皮炎和LCV的证据。其余1例患者有荨麻疹性非大疱性皮损，显示小血管血管炎伴嗜中性粒细胞界面性皮炎。在所有SLE患者中，DIF研究显示基底膜带（BMZ）内有线性免疫球蛋白沉积。这些临床、光镜及免疫荧光检查结果构成了大疱性系统性红斑狼疮的血管炎表现。2例患者患有线性IgA病，其中1例由药物诱发，另1例为副肿瘤性，2例活检的主要形态均为LCV。1例患者镜下显示药物相关且富含嗜酸性粒细胞的LCV，DIF研究显示IgG有显著的线性沉积，提示大疱性类天疱疮，这与药物性大疱性类天疱疮的血管炎表现一致。在所有病例中，均观察到与免疫复合物介导的血管炎相符的典型颗粒状血管免疫球蛋白和补体沉积。源自与抗体结合的BMZ抗原的局部免疫复合物可能与发病机制相关。我们建议将这种LCV与线性免疫球蛋白表皮BMZ染色的独特情况命名为线性血管炎，在某些情况下，它代表传统自身免疫性水疱大疱性疾病的血管炎表现。
