Rationale & Objective

Idiopathic retroperitoneal fibrosis (IRF) is a rare disorder of unknown cause. Medical therapy can induce remission, but disease relapses are common. This study sought to characterize long-term outcomes of IRF and the factors associated with disease recurrences.

Study Design

Retrospective cohort study.

Setting & Participants

Retrospective analysis of 50 patients with IRF prospectively followed up for 8.9 (IQR, 4.7-12.7) years at a tertiary-care referral center.

Exposures

Demographic, clinical, treatment, and laboratory parameters, including measures of autoimmunity.

Outcome

Disease relapse.

Analytical Approach

Proportional hazards analysis for the subdistribution of competing risks.

Results

49 patients received medical treatment and 35 underwent interventional procedures. All patients experienced a clinical response (defined as regression of disease-related symptoms and hydronephrosis, and decrease in the maximal transverse diameter of the retroperitoneal mass on computed tomography of >50%), 44 of whom responded within 1 year. The remaining 6 responded over a median of 2.95 years after starting therapy. 40 patients were alive at last observation, 1 receiving maintenance dialysis and 15 with estimated glomerular filtration rate < 60 mL/min/1.73 m². Patient survival at 5, 10, and 15 years was 95%, 84%, and 68%, respectively. 19 (38%) patients had at least 1 relapse (occurring a median of 5.19 years after starting therapy), defined as an increase in serum creatinine level of at least 30% or recurrence/development of hydronephrosis and ≥20% increase in the maximal transverse diameter of the retroperitoneal mass on computed tomography. Cumulative incidences of relapse at 5, 10, and 15 years were 21%, 41%, and 48%, respectively. Baseline antinuclear antibody positivity and male sex were associated with relapse (subdistribution hazard ratios [sHRs] of 5.35 [95% CI, 2.15-13.27] and 4.94 [95% CI, 1.32-18.57], respectively), while higher corticosteroid therapy dosage at 1 year (sHR for relapse per 1-mg/d greater dosage, 0.91 [95% CI, 0.84-0.98]) and treatment with prednisone alone or with tamoxifen (sHR for relapse of 0.25 [95% CI, 0.07-0.85] vs other therapies) were associated with lower rate of relapse.

Limitations

Small sample size and variable approaches to therapy.

Conclusions

IRF relapses were common and were experienced more frequently by male patients. Corticosteroids alone or with tamoxifen were associated with a lower rate of relapse. The strong association of antinuclear antibody positivity with relapse supports the hypothesis of an autoimmune pathogenesis of IRF.

中文翻译：

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特发性腹膜后纤维化：长期风险和复发的预测因素

理由与目标

特发性腹膜后纤维化（IRF）是一种原因不明的罕见疾病。药物治疗可以诱发缓解，但疾病复发很常见。本研究旨在表征IRF的长期预后以及与疾病复发相关的因素。

学习规划

回顾性队列研究。

设置与参与者

在一家三级转诊中心对50例IRF患者进行了回顾性分析，前瞻性随访了8.9年（IQR，4.7-12.7）。

曝光量

人口统计学，临床，治疗和实验室参数，包括自身免疫性指标。

结果

疾病复发。

分析方法

针对竞争风险的子分布的比例风险分析。

结果

49例患者接受了药物治疗，其中35例接受了介入治疗。所有患者均经历了临床反应（定义为疾病相关症状和肾积水的消退，并且在计算机断层扫描上腹膜后肿块的最大横向直径减小> 50％），其中44例在一年内有反应。其余6人在开始治疗后的2.95年中位有效。最后一次观察时有40例患者存活，其中1例接受维持性透析，另外15例患者的肾小球滤过率估计<60 mL / min / 1.73 m ²。5年，10年和15年的患者生存率分别为95％，84％和68％。19名（38％）患者至少复发1次（开始治疗后中位数为5.19年），定义为血清肌酐水平增加至少30％或肾积水的复发/发展，最大程度≥20％体层摄影术中腹膜后肿块的横向直径。在5年，10年和15年时，复发的累积发生率分别为21％，41％和48％。基线抗核抗体阳性和男性与复发相关（亚分布危险比[sHRs]分别为5.35 [95％CI，2.15-13.27]和4.94 [95％CI，1.32-18.57]），而皮质类固醇治疗剂量较高1年（每1 mg / d更大剂量的复发性sHR，0.91 [95％CI，0.84-0。

局限性

小样本量和可变的治疗方法。

结论

IRF复发很常见，男性患者的复发频率更高。单独使用皮质类固醇或与他莫昔芬联合使用可降低复发率。抗核抗体阳性与复发之间的密切联系支持了IRF自身免疫性发病机制的假说。