Ikeda Satoshi, Sekine Akimasa, Baba Tomohisa, Okudela Koji, Iwasawa Tae, Sakai Fumikazu, Notohara Kenji, Ohashi Kenichi, Takemura Tamiko, Ogura Takashi
Department of Respiratory Medicine, Kanagawa Cardiovascular and Respiratory Center, Yokohama, Japan.
Department of Pathology, Yokohama-city Graduate University School of Medicine, Yokohama, Japan.
Histopathology. 2017 Jan;70(2):242-252. doi: 10.1111/his.13053. Epub 2016 Sep 29.
There have been few reports on immunoglobulin-G4 (IgG4)-related interstitial pneumonia (IP), and its clinical features remain unclear. The objective of this study was to assess whether IP with marked IgG4-positive plasma cell infiltration without extrathoracic lesions of IgG4-related disease (RD) should be diagnosed as a subtype of IgG4-RD or a separate entity.
All consecutive patients with surgical lung biopsy-proven idiopathic IP with an IgG4/IgG-positive cell ratio of >40% and >50 IgG4 plasma cells in a high-power field without extrathoracic lesions of IgG4-RD were reviewed retrospectively. Five patients were enrolled into this study. All patients were male with a history of smoking. Four patients met the comprehensive diagnostic criteria for IgG4-RD. The remaining patient lacked data related to the serum IgG4 level. Histologically, a non-specific IP pattern was observed in all patients. The key morphological features of IgG4-RD, such as storiform fibrosis and obliterative phlebitis with lymphoplasmacytic infiltration in a loose background texture, were absent in every patient. In contrast, venule obstruction by densely packed lymphoplasmacytic infiltration was observed in two patients. Marked scarring and remodelling of the lung were also noted, which is not seen typically in IgG4-RD. A favourable response to corticosteroid monotherapy was observed in all patients; however, two patients developed lung cancer during the course of observation.
IP with marked IgG4-positive plasma cell infiltration without extrathoracic lesions of IgG4-RD had different pathological features from those of IgG4-RD, and it is appropriate to regard this as a separate entity.
关于免疫球蛋白G4(IgG4)相关间质性肺炎(IP)的报道较少,其临床特征仍不明确。本研究的目的是评估无IgG4相关疾病(RD)胸外病变但有显著IgG4阳性浆细胞浸润的IP是否应被诊断为IgG4-RD的一种亚型或一个独立的疾病实体。
回顾性分析所有经手术肺活检证实为特发性IP且IgG4/IgG阳性细胞比例>40%、高倍视野下IgG4浆细胞>50个且无IgG4-RD胸外病变的连续患者。本研究纳入了5例患者。所有患者均为男性且有吸烟史。4例患者符合IgG4-RD的综合诊断标准。其余1例患者缺乏血清IgG4水平相关数据。组织学上,所有患者均观察到非特异性IP模式。所有患者均未出现IgG4-RD的关键形态学特征,如席纹状纤维化和在疏松背景质地中有淋巴细胞和浆细胞浸润的闭塞性静脉炎。相反,2例患者观察到密集的淋巴细胞和浆细胞浸润导致的小静脉阻塞。还注意到肺部有明显的瘢痕形成和重塑,这在IgG4-RD中通常未见。所有患者对皮质类固醇单药治疗反应良好;然而,2例患者在观察过程中发生了肺癌。
无IgG4-RD胸外病变但有显著IgG4阳性浆细胞浸润的IP具有与IgG4-RD不同的病理特征,将其视为一个独立的疾病实体是合适的。