This study investigated poor prognostic factors for the relapse of interstitial lung disease (ILD) in patients with microscopic polyangiitis (MPA) after remission induction therapy. We enrolled patients diagnosed with MPA complicated by ILD according to the Chapel Hill Consensus definition from 2001 to 2023 in multiple institutions in the REVEAL cohort. All patients who were treated with immunosuppressive therapy were followed up, and those who relapsed with ILD were extracted in this study. We explored the risk factors for predicting ILD relapse in patients with MPA-ILD by comparing the demographic, clinical, laboratory, and radiological findings and treatments between the relapsed and non-relapsed groups on admission. Of 243 patients with MPA, 134 (55.1%) with MPA-ILD were enrolled. Among them, 28 (20.9%) relapsed during a mean follow-up of 4.2 years. The initial serum Krebs von den Lungen-6 (KL-6) and surfactant protein-D (SP-D) levels and the prevalence of usual interstitial pneumonia (UIP) pattern were significantly higher in the relapsed group. The biomarkers were also risk factors for relapse in multivariate Cox regression analysis. The best cut-off values of KL-6, SP-D for predicting ILD relapse were 430 U/mL and 89.5 ng/mL, respectively. We created prediction models based on the best cut-off values for KL-6, SP-D, and the presence of the UIP pattern (KSU model). The 10-year relapse rate was significantly different among patients with MPA-ILD stratified by the number of risk factors based on the KSU model. A higher relapse rate was associated with higher all-cause mortality. The initial serum high KL-6 and SP-D levels and the prevalence of the UIP pattern were associated with ILD relapse in patients with MPA-ILD. Our multicentre cohort study indicated that the KSU model, which consists of KL-6 ≥ 430 U/mL, SP-D ≥ 89.5 ng/mL, and the presence of the UIP pattern, is a useful predictor of ILD relapse in patients with MPA after immunosuppressive therapy.

中文翻译：

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显微镜下多血管炎间质性肺病复发的不良预后因素：日本多中心 REVEAL 队列研究


本研究调查了显微镜下多血管炎 （MPA） 患者缓解诱导治疗后间质性肺病 （ILD） 复发的不良预后因素。我们根据 2001 年至 2023 年的 Chapel Hill 共识定义在 REVEAL 队列的多个机构中招募了诊断为 MPA 并发 ILD 的患者。对接受免疫抑制治疗的患者进行随访，并提取 ILD 复发患者。我们通过比较入院时复发组和非复发组的人口学、临床、实验室和放射学发现和治疗，探讨了预测 MPA-ILD 患者 ILD 复发的危险因素。在 243 例 MPA 患者中，134 例 （55.1%） 入组了 MPA-ILD 患者。其中，28 例 （20.9%） 在平均 4.2 年的随访中复发。复发组初始血清 Krebs von den Lungen-6 （KL-6） 和表面活性剂蛋白-D （SP-D） 水平以及常见间质性肺炎 （UIP） 模式的患病率显著升高。生物标志物也是多变量 Cox 回归分析中复发的危险因素。KL-6 、 SP-D 预测 ILD 复发的最佳截断值分别为 430 U/mL 和 89.5 ng/mL。我们根据 KL-6 、 SP-D 的最佳临界值和 UIP 模式的存在 （KSU 模型） 创建了预测模型。MPA-ILD 患者的 10 年复发率存在显著差异，根据基于 KSU 模型的危险因素数量分层。较高的复发率与较高的全因死亡率相关。MPA-ILD 患者初始血清高 KL-6 和 SP-D 水平以及 UIP 模式的患病率与 ILD 复发相关。 我们的多中心队列研究表明，由 KL-6 ≥ 430 U/mL、SP-D ≥ 89.5 ng/mL 和 UIP 模式的存在组成的 KSU 模型是免疫抑制治疗后 MPA 患者 ILD 复发的有用预测指标。