IgG4相关性肾病的临床病理特征分析

目的探究本中心中国人群IgG4相关性肾病的发病情况、临床病理特征及预后。 方法回顾性分析2010年1月至2019年1月在东部战区总医院国家肾脏疾病临床医学研究中心行肾穿刺活检患者的临床病理资料，对肾组织中有大量浆细胞浸润的患者，重新测定肾活检时血清IgG4水平及肾组织IgG4阳性浆细胞浸润数目，结合肾外表现，筛选出确诊为IgG4相关性肾病的病例，并分析IgG4相关性肾病的临床特点、病理特征及肾脏预后。 结果44 784例肾活检患者中有22例确诊为IgG4相关性肾病。IgG4相关性肾病最常表现为蛋白尿(86.4%)及肾功能不全(81.8%)，约68.2%患者存在肾外累及。高IgG血症、高IgG4血症、低补体血症的发生率分别为86.4%、84.2%、45.5%。肾脏组织学最常见的病理类型为IgG4相关间质性肾炎(90.9%)，其次为膜性肾病(13.6%)。肾间质席纹状纤维化、鸟眼样改变分别占40.9%、54.5%。22例患者中，21例接受糖皮质激素治疗，2例失访，余20例中位随访时间为12个月，9例肾功能好转，10例肾功能平稳，1例肾功能减退并进展至终末期肾病。 结论IgG4相关性肾病发病率低，好发于中老年男性，最常表现为肾功能不全及蛋白尿。半数以上的患者有肾外表现。高IgG血症、高IgG4血症和低补体血症是其血清学特征。最常见的肾脏病理类型为间质性肾炎；大量IgG4阳性浆细胞浸润、肾间质席纹状纤维化或鸟眼样改变是其典型的病理特征。糖皮质激素仍是IgG4相关性肾病治疗首选的一线药物。

Analysis of clinicopathological features of IgG4-related kidney disease

ObjectiveTo investigate the incidence, clinicopathological characteristics and prognosis of IgG4-related kidney disease (IgG4-RKD) of Chinese patients in our center. MethodsAll of the renal biopsies from January 2010 to January 2019 were reviewed retrospectively by assessing the involvement of extrarenal organs, measuring serum IgG4 concentrations, and carrying out an immunohistochemical analysis to detect IgG4⁺ plasma cells infiltration at the National Clinical Research Center of Kidney Diseases, Jinling Hospital. Analysis was performed of clinical features, pathological features, and renal prognosis in the patients diagnosed as IgG4-RKD. ResultsOf the 44 784 renal biopsy patients, 22 cases were identified as definite IgG4-RKD. The most common manifestations of IgG4-RKD were proteinuria (86.4%) and renal insufficiency (81.8%), with 68.2% of the patients having extrarenal lesions. Of the IgG4-RKD patients, 86.4% had high serum IgG level, 84.2% high serum IgG4 level, and 45.5% hypocomplementemia. About 90.9% of the IgG4-RKD patients presented as tubulointerstitial nephritis, and 3 patients (13.6%) had membranous nephropathy. About 40.9% of the patients showed storiform fibrosis, and 54.5% showed the bird′s eye pattern in renal tissues. 21 patients were treated with corticosteroids, while two patients failed to follow up. The remaining 20 patients had a median 12-month follow-up, of which one patient progressed to end-stage renal disease, 9 patients showed improved renal function, and 10 patients displayed stable renal function. ConclusionsIgG4-RKD was a rare disease, often occurred in the middle-aged and elderly people with a male preponderance. The most common manifestations were renal insufficiency and proteinuria. More than half of the patients had extrarenal manifestations. Most of the IgG4-RKD patients had high serum levels of IgG and IgG4, and half of them had hypocomplementemia. The most common type of renal pathology was interstitial nephritis. IgG4-RKD was characterized by a large number of IgG4⁺ plasma cells infiltration, storiform fibrosis, and the bird′s eye pattern in the renal tissues. Glucocorticoid was still the first line choice for treatment of IgG4-RKD.