Objectives Idiopathic retroperitoneal fibrosis (IRF) is a rare autoimmune-mediated condition characterized by fibro-inflammatory tissue development around the abdominal aorta and iliac arteries. Ureteral entrapment and hydronephrosis are the most common manifestations and acute renal failure or chronic renal insufficiency may occur as the consequence. Glucocorticoids and immunosuppressants may be effective but the therapeutic response and outcome are heterogeneous and hard to predict. This study aimed to investigate the factors associated with early remission in patients with IRF. Methods This retrospective study included 91 IRF patients who visited Peking Union Medical College Hospital between May 2013 and December 2023. Clinical data and outcomes were reviewed and time to remission calculated. Results Over a median follow-up of 2.63 years (IQR, 1.29–3.41), 38 patients achieved remission within six months after treatment initiation. In multivariable analysis, male gender (OR 5.297, 95%CI 1.445–19.420, p = 0.012) and higher baseline complement component 3 (C3) (OR 2.153, 95%CI 1.131–4.097, p = 0.019) levels were significantly associated with early clinical remission (≤6 months). The time to remission was negatively associated with C3 levels (r=-0.243, p = 0.014). Patients with high C3 levels (≥1.144 g/l) tended to achieve remission in a shorter time than their counterparts with low C3 levels(<1.144g/l) (p = 0.028). An effective nomogram model for predicting disease remission was constructed with gender and C3 (AUC= 0.73, 95% CI 0.62–0.84). Conclusion Male gender and higher baseline C3 levels may act as potential predictors for achieving early remission in patients with IRF.

中文翻译：

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特发性腹膜后纤维化患者早期临床缓解的相关因素分析


目的 特发性腹膜后纤维化 （IRF） 是一种罕见的自身免疫介导的疾病，其特征是腹主动脉和髂动脉周围的纤维炎症组织发育。输尿管卡压和肾积水是最常见的表现，因此可能会出现急性肾功能衰竭或慢性肾功能不全。糖皮质激素和免疫抑制剂可能有效，但治疗反应和结果存在异质性且难以预测。本研究旨在探讨与 IRF 患者早期缓解相关的因素。方法 本回顾性研究纳入了 2013年5月至 2023年12月期间就诊的 91 例 IRF 患者。回顾临床数据和结局并计算缓解时间。结果 在中位随访 2.63 年 （IQR， 1.29-3.41） 中，38 例患者在治疗开始后 6 个月内达到缓解。在多变量分析中，男性 （OR 5.297， 95%CI 1.445–19.420， p = 0.012） 和较高的基线补体成分 3 （C3） （OR 2.153， 95%CI 1.131–4.097， p = 0.019） 水平与早期临床缓解 （≤6 个月） 显著相关。缓解时间与 C3 水平呈负相关 （r=-0.243，p = 0.014）。高 C3 水平 （≥1.144 g/l） 的患者往往比低 C3 水平的患者 （<1.144g/l） 在更短的时间内达到缓解 （p = 0.028）。使用性别和 C3 构建预测疾病缓解的有效列线图模型 （AUC= 0.73,95% CI 0.62–0.84）。结论 男性和较高的基线 C3 水平可能是 IRF 患者实现早期缓解的潜在预测因子。