Renal Division, Department of Medicine, Peking University First Hospital, Beijing, P.R. China.
Peking University Institute of Nephrology, Beijing, P.R. China.
Nephrol Dial Transplant. 2018 Jul 1;33(7):1180-1188. doi: 10.1093/ndt/gfx247.
The aim of this study was to explore the etiology, long-term renal outcomes and affecting factors of acute tubulointerstitial nephritis (ATIN).
Patients with biopsy-proven ATIN from 1 January 2005 to 31 December 2013 at Peking University First Hospital were enrolled in the study and received scheduled follow-up for at least 24 months. The causes of ATIN were defined at biopsy and reclassified during follow-up. Factors affecting renal recovery at 6 months post-biopsy and estimated glomerular filtration rate (eGFR) at 12 months post-biopsy and at the end of follow-up were analyzed.
A total of 157 ATIN patients were enrolled, with an average follow-up of 48 months (range 24-108 months). A modified etiology spectrum was identified, with a decreased proportion of drug-induced ATIN (D-ATIN, 64% at biopsy to 50% after follow-up) and an increase in autoimmune-related ATIN (22-41%) with late-onset systemic manifestations in patients who had been classified as D-ATIN or ATIN of unknown cause. Recurrent kidney injury was observed in 51% of the patients with tubulointerstitial nephritis and uveitis syndrome (TINU), 53% of those with an autoimmune disease and 8% of those with D-ATIN, resulting in prolonged immunosuppressive treatment. By 12 months, decreased eGFR (<60 mL/min/1.73 m2) was observed in 47% of the patients with D-ATIN, 74% of those with TINU and 57% of those with other autoimmune diseases. In multivariable analysis, female sex, older age, presence of hypertension and recurrent kidney injury were independent risk factors for worse renal outcomes.
Our data demonstrate that autoimmune-related ATIN may present with systemic manifestations after kidney injury and is, therefore, commonly misdiagnosed. Repeated kidney injury is not uncommon in patients with ATIN. Scheduled follow-up is, therefore, critical for defining the exact etiology and proper management of ATIN.
本研究旨在探讨急性肾小管间质性肾炎（ATIN）的病因、长期肾脏结局和影响因素。
本研究纳入了 2005 年 1 月 1 日至 2013 年 12 月 31 日期间在北京大学第一医院接受经活检证实的 ATIN 患者，并对其进行了至少 24 个月的定期随访。在活检时确定 ATIN 的病因，并在随访期间重新分类。分析了影响活检后 6 个月时肾脏恢复以及活检后 12 个月和随访结束时估算肾小球滤过率（eGFR）的因素。
共纳入 157 例 ATIN 患者，平均随访时间为 48 个月（24-108 个月）。发现了一种改良的病因谱，药物相关性 ATIN（D-ATIN）的比例降低（活检时为 64%，随访时为 50%），而与自身免疫相关的 ATIN（22-41%）比例增加，且具有晚期全身表现的患者最初被归类为 D-ATIN 或原因不明的 ATIN。肾小管间质性肾炎和葡萄膜炎综合征（TINU）患者中有 51%、自身免疫性疾病患者中有 53%和 D-ATIN 患者中有 8%出现复发性肾损伤，导致免疫抑制治疗时间延长。在 12 个月时，D-ATIN 患者中有 47%、TINU 患者中有 74%和其他自身免疫性疾病患者中有 57%的 eGFR 下降（<60mL/min/1.73m2）。多变量分析显示，女性、年龄较大、存在高血压和复发性肾损伤是肾脏结局恶化的独立危险因素。
本研究数据表明，与自身免疫相关的 ATIN 可能在肾损伤后出现全身表现，因此常被误诊。ATIN 患者反复发生肾损伤并不少见。因此，定期随访对于明确 ATIN 的病因和进行适当的管理至关重要。
