Department of Rheumatology, University Hospital Zurich, Zurich, Switzerland.
Department of Rheumatology, South Campus, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Ann Rheum Dis. 2018 Sep;77(9):1326-1332. doi: 10.1136/annrheumdis-2018-213201. Epub 2018 Jun 6.
To identify the predictive clinical characteristics and establish a prediction model for the progression of mild interstitial lung disease (ILD) in patients with systemic sclerosis (SSc).
Patients with SSc from two independent prospective cohorts were included in this observational study. All patients fulfilled the 2013 American College of Rheumatology/European League Against Rheumatism criteria, had mild ILD at baseline diagnosed by High-Resolution Computed Tomography (HRCT), available baseline and ≥1 annual follow-up pulmonary function tests and no concomitant pulmonary hypertension or airflow obstruction. ILD progression was defined as a relative decrease in forced vital capacity (FVC)%≥15%, or FVC%≥10% combined with diffusing capacity for carbon monoxide %≥15% at 1-year follow-up. Candidate predictors for multivariate logistic regression were selected by expert opinion based on clinical significance. A prediction model for ILD progression was established in the derivation cohort and validated in the multinational validation cohort.
A total of 25/98 and 25/117 patients with SSc showed ILD progression in the derivation cohort and the validation cohort, respectively. Lower SpO after 6 min walk test (6MWT) and arthritis ever were identified as independent predictors for ILD progression in both cohorts. The optimal cut-off value of SpO after 6MWT for predicting ILD progression was determined as 94% by receiver operating characteristic curve analysis. The derived SPAR model combining both predictors (SPO and ARthritis) increased the prediction rate from 25.5% to 91.7% with an area under the curve (95% CI) of 0.83 (0.73 to 0.93).
The evidence-based SPAR prediction model developed in our study might be helpful for the risk stratification of patients with mild SSc-ILD in clinical practice and cohort enrichment for future clinical trial design.
确定系统性硬化症（SSc）患者轻度间质性肺病（ILD）进展的预测临床特征，并建立预测模型。
本观察性研究纳入了来自两个独立前瞻性队列的 SSc 患者。所有患者均符合 2013 年美国风湿病学会/欧洲抗风湿病联盟标准，基线时通过高分辨率计算机断层扫描（HRCT）诊断为轻度 ILD，基线时和≥1 年的随访肺功能检查均有记录，且无同时存在的肺动脉高压或气流阻塞。ILD 进展定义为用力肺活量（FVC）%相对下降≥15%，或 FVC%≥10%，同时一氧化碳弥散量（DLCO）%≥15%，在 1 年随访时。根据临床意义，通过专家意见选择多变量逻辑回归的候选预测因子。在推导队列中建立ILD 进展预测模型，并在多国籍验证队列中进行验证。
在推导队列和验证队列中，分别有 25/98 和 25/117 例 SSc 患者出现ILD 进展。6 分钟步行试验（6MWT）后 SpO 较低和关节炎曾发生被确定为两个队列中ILD 进展的独立预测因子。通过受试者工作特征曲线分析，确定 6MWT 后 SpO 的最佳截断值为 94%，用于预测ILD 进展。通过合并两个预测因子（SpO 和关节炎）的推导 SPAR 模型，将预测率从 25.5%提高到 91.7%，曲线下面积（95%可信区间）为 0.83（0.73 至 0.93）。
本研究中开发的基于证据的 SPAR 预测模型可能有助于临床实践中对轻度 SSc-ILD 患者进行风险分层，并为未来临床试验设计进行队列富集。
