Agaimy Abbas, Weyand Michael, Strecker Thomas
Institute of Pathology, Friedrich-Alexander-University Erlangen, Germany.
Int J Clin Exp Pathol. 2013 Aug 15;6(9):1713-22. eCollection 2013.
BACKGROUND & AIM: Aortic aneurysms represent one of the major causes of cardiovascular surgery. Their etiology varies greatly based on patient's age and other clinicopathologic determinants. In addition to common atherosclerotic vascular diseases, an inflammatory etiology, in particular IgG4-related disease (IgG4-RD) has increasingly emerged as a cause of dissecting inflammatory aortic aneurysms (IAA).
To assess the frequency and types of IAA, we reviewed all cases of aortic aneurysms resected at our Erlangen Heart Center during 2000-2013.
376 patients underwent resection of aortic aneurysms in the study period. These are further categorized as ascending aortic aneurysms (45%), aortic arch aneurysm (2%), descending aortic aneurysm (3%), type A dissection (46%) and type B dissection (4%). Fifteen cases (4%) showed variable lymphoplasmacytic inflammation thus qualifying as IAA. Affected were 9 females and 6 males (female to male ratio = 1.5:1; age range: 52-80 yrs; mean: 70 yrs; median: 72 yrs). None was known to have IgG4-RD and serum IgG4 and/or IgG levels (known in 6 cases) were normal. Variable sclerosing lymphoplasmacytic inflammation was seen either confined to the adventitia (periaortitis; mainly in males) or extending through all layers (mainly in females). A wide range of IgG4 plasma cells (range: 3-182/HPF; mean: 51/HPF) and IgG4: IgG ratios (range: 0.02 to 0.91; mean: 0.37) were detected. All but one of the cases with at least focally transmural inflammation showed a higher IgG4: IgG ratios in excess of 0.3 (range, 0.32-0.91; median, 0.62). Lymphoid follicle and variable fibrosis were common but obliterative phlebitis was not seen.
IgG4-rich sclerosing lymphoplasmacytic thoracic aortitis is a constant histological feature of thoracic IAA. Normal serum IgG4 in most patients, predilection for women and absence of other features of IgG4-RD all suggest a tissue-specific localized autoimmunological process and argue against a systemic disorder. The relationship (if any) of IgG4-rich lymphoplasmacytic thoracic aortitis in those patients with IAA lacking other organ manifestations or an elevated serum IgG4 level to systemic IgG4-RD remains unclear and merit further studies.
主动脉瘤是心血管外科手术的主要病因之一。其病因因患者年龄和其他临床病理因素的不同而有很大差异。除常见的动脉粥样硬化性血管疾病外，一种炎症性病因，特别是IgG4相关疾病（IgG4-RD）日益成为炎性主动脉夹层动脉瘤（IAA）的病因。
为评估IAA的发生率和类型，我们回顾了2000年至2013年在我们埃尔朗根心脏中心切除的所有主动脉瘤病例。
在研究期间，376例患者接受了主动脉瘤切除术。这些病例进一步分为升主动脉瘤（45%）、主动脉弓瘤（2%）、降主动脉瘤（3%）、A型夹层（46%）和B型夹层（4%）。15例（4%）表现出不同程度的淋巴细胞浆细胞炎症，因此符合IAA的诊断。其中9例为女性，6例为男性（女性与男性比例=1.5:1；年龄范围：52 - 80岁；平均年龄：70岁；中位数：72岁）。所有患者均无IgG4-RD病史，6例患者的血清IgG4和/或IgG水平正常。可见不同程度的硬化性淋巴细胞浆细胞炎症，局限于外膜（主动脉周炎；主要见于男性）或累及所有层（主要见于女性）。检测到广泛的IgG4浆细胞（范围：3 - 182/HPF；平均：51/HPF）和IgG4:IgG比值（范围：0.02至0.91；平均：0.37）。除1例至少有局灶性透壁炎症的病例外，其余病例的IgG4:IgG比值均高于0.3（范围，0.32 - 0.91；中位数，0.62）。淋巴滤泡和不同程度的纤维化常见，但未见闭塞性静脉炎。
富含IgG4的硬化性淋巴细胞浆细胞性胸主动脉炎是胸段IAA恒定的组织学特征。大多数患者血清IgG4正常、女性易患以及缺乏IgG4-RD的其他特征均提示这是一种组织特异性的局部自身免疫过程，而非全身性疾病。在那些无其他器官表现或血清IgG4水平未升高的IAA患者中，富含IgG4的淋巴细胞浆细胞性胸主动脉炎与全身性IgG4-RD的关系（若有）仍不清楚，值得进一步研究。
