IgG4相关性肺疾病一例并文献复习

IgG4-related lung disease： a case report and review of the literature

目的分析1例IgG4相关性肺疾病的临床资料并进行文献复习，探讨该病的诊断及治疗经验。方法分析北京同仁医院呼吸科收治的1例IgG4相关性肺疾病患者的临床表现、实验室检查结果、影像学及组织病理学资料。以“IgG4相关疾病”和“肺”为关键词，自Pubmed共计检索到IgG4相关性肺疾病65例，对呼吸系统症状、肺外器官受累情况、血清IgG4水平、影像学表现及组织标本中IgG4阳性浆细胞数量以及糖皮质激素治疗反应等进行分析。结果患者41岁，男，体检时x线胸片发现肺部阴影，入院后查胸部CT显示以双侧中肺野中内带为主的磨玻璃影，伴有纤维条索影及蜂窝样改变。经胸腔镜肺活检病理显示肺泡间隔及支气管血管束周围大量炎症细胞浸润，主要为淋巴浆细胞，并伴有胶原纤维沉积，肺泡间隔增厚，可见闭塞性静脉炎，免疫组织化学染色可见大量IgG4阳性浆细胞。血清IgG4明显升高（3．07g／L）。诊断IgG4相关性肺疾病，给予泼尼松口服治疗，4个月后复查胸部CT示磨玻璃影基本吸收，仅残余纤维条索影及蜂窝样改变，IgG4水平降至1．99g／L。文献检索到IgG4相关性肺疾病共65例，其中单纯肺部受累者27例，合并肺外表现者38例，其中累及胰腺者21例。36例测定血清IgG4水平，其中34例高于正常。影像学分类显示实性结节型占55．4％（36／65），肺泡间质型占26．2％（17／65），支气管血管束型占13．8％（9／65），圆形磨玻璃影型占4．6％（3／65）。应用糖皮质激素治疗者23例，疗效良好，仅1例治疗失败。结论IgG4相关性肺疾病是一少见疾病，临床易于忽视，可与其他硬化性疾病并发，也可单发，诊断有赖于血清IgG4水平测定及组织病理学检查，糖皮质激素治疗有效，预后良好。

Objective To describe the clinical features of IgG4-related lung disease. Method The clinical symptoms, laboratory tests, radiographic patterns, histopathological features and therapeutic management of a patient with IgG4-related lung disease were described and the literatures were reviewed. Results A 41-year-old male without significant symptoms was admitted to our department because of diffuse opacities on regular X-ray examination. Chest HRCT revealed diffuse ground-glass opacities （GGOs） and reticular opacities in both lungs, predominantly in the middle fields. Thoracoscopic lung biopsy was performed, and pathological examination of the lung tissues found massive lymphoplasma cell infiltration and collagen deposition along the alveolar septa and bronchovascular bundles on HE staining. Obliterative phlebitis and thickening of alveolar septa were observed. IgG4 immunostaining revealed predominant IgG4＋ plasma cells. IgG4- related lung disease was diagnosed combined with elevation of serum IgG4 concentration （3.07 g/L）. The patient received oral prednisone at the dose of 30 mg per day for one month and then the dose was tapered. Four months later a CT scan revealed that the GGOs disappeared and only some reticular opacities and honeycombing changes remained. The serum IgG4 concentration decreased to 1.99 g/L. Twenty-one articles with 65 cases of IgG4-related lung disease were collected through PubMed search engine. Extrapulmonary organs were involved in 38 cases, especially the pancreas. Serum IgG4 concentrations were assessed in 36 cases and elevated in 34. Four radiographic patterns were identified： solid nodule type （55.4%）, alveolar interstitial type （26. 2% ）, bronchovascular type （ 13.8% ） and round-shaped GGO type （4. 6% ）. Glucocorticoids were prescribed to 23 patients with a favorable response except one treatment failure. Conclusion IgG4-related lung disease is a rare disorder and easily overlooked in clinical practice. The lung maybe the only target organ, but extrapulmonary organ involvement is the most common discoveries. The diagnosis of IgG4-related lung disease depends on the elevation of serum IgG4 and characteristic histopathological features. Glucocorticoid therapy is very effective and most patients have a good prognosis.