Department of Internal Medicine, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Division of Rheumatology, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
Division of Rheumatology, Hospital Nossa Senhora da Conceição, Grupo Hospitalar Conceição, Porto Alegre, Brazil.
Semin Arthritis Rheum. 2017 Oct;47(2):228-234. doi: 10.1016/j.semarthrit.2017.03.019. Epub 2017 Apr 1.
Interstitial lung disease (ILD) is currently the primary cause of death in systemic sclerosis (SSc). Thoracic high-resolution computed tomography (HRCT) is considered the gold standard for diagnosis. Recent studies have proposed several clinical algorithms to predict the diagnosis and prognosis of SSc-ILD.
To test the clinical algorithms to predict the presence and prognosis of SSc-ILD and to evaluate the association of extent of ILD with mortality in a cohort of SSc patients.
Retrospective cohort study, including 177 SSc patients assessed by clinical evaluation, laboratory tests, pulmonary function tests, and HRCT. Three clinical algorithms, combining lung auscultation, chest radiography, and percentage predicted forced vital capacity (FVC), were applied for the diagnosis of different extents of ILD on HRCT. Univariate and multivariate Cox proportional models were used to analyze the association of algorithms and the extent of ILD on HRCT with the risk of death using hazard ratios (HR).
The prevalence of ILD on HRCT was 57.1% and 79 patients died (44.6%) in a median follow-up of 11.1 years. For identification of ILD with extent ≥10% and ≥20% on HRCT, all algorithms presented a high sensitivity (>89%) and a very low negative likelihood ratio (<0.16). For prognosis, survival was decreased for all algorithms, especially the algorithm C (HR = 3.47, 95% CI: 1.62-7.42), which identified the presence of ILD based on crackles on lung auscultation, findings on chest X-ray, or FVC <80%. Extensive disease as proposed by Goh et al. (extent of ILD > 20% on HRCT or, in indeterminate cases, FVC < 70%) had a significantly higher risk of death (HR = 3.42, 95% CI: 2.12-5.52). Survival was not different between patients with extent of 10% or 20% of ILD on HRCT, and analysis of 10-year mortality suggested that a threshold of 10% may also have a good predictive value for mortality. However, there is no clear cutoff above which mortality is sharply increased.
Clinical algorithms had a good diagnostic performance for extents of SSc-ILD on HRCT with clinical and prognostic relevance (≥10% and ≥20%), and were also strongly related to mortality. Non-HRCT-based algorithms could be useful when HRCT is not available. This is the first study to replicate the prognostic algorithm proposed by Goh et al. in a developing country.
间质性肺病（ILD）是目前系统性硬化症（SSc）患者死亡的主要原因。胸部高分辨率计算机断层扫描（HRCT）被认为是诊断ILD 的金标准。最近的研究提出了几种临床算法来预测 SSc-ILD 的诊断和预后。
检测预测 SSc-ILD 存在和预后的临床算法，并评估ILD 程度与 SSc 患者死亡率之间的关系。
回顾性队列研究，纳入 177 例接受临床评估、实验室检查、肺功能检查和 HRCT 的 SSc 患者。应用三种临床算法，结合肺部听诊、胸部 X 线和预计用力肺活量（FVC）百分比，对 HRCT 上不同程度的ILD 进行诊断。采用单变量和多变量 Cox 比例模型，使用风险比（HR）分析算法和 HRCT 上ILD 程度与死亡风险的相关性。
HRCT 上ILD 的患病率为 57.1%，中位随访 11.1 年后 79 例患者死亡（44.6%）。对于识别 HRCT 上ILD 程度≥10%和≥20%，所有算法的敏感性均较高（>89%），而阴性似然比均较低（<0.16）。对于预后，所有算法的生存率均下降，尤其是算法 C（HR=3.47，95%CI：1.62-7.42），该算法根据肺部听诊的爆裂声、胸部 X 线检查结果或 FVC<80%来识别ILD 的存在。Goh 等人提出的广泛疾病（HRCT 上ILD 程度>20%或不确定病例 FVC<70%）的死亡风险显著更高（HR=3.42，95%CI：2.12-5.52）。HRCT 上ILD 程度为 10%或 20%的患者之间的生存率无差异，10 年死亡率分析表明，10%的阈值可能对死亡率也有较好的预测价值。但是，没有明确的截止值以上死亡率急剧增加。
临床算法对 HRCT 上 SSc-ILD 程度具有良好的诊断性能，且具有临床和预后相关性（≥10%和≥20%），并且与死亡率密切相关。在无法进行 HRCT 时，基于非 HRCT 的算法可能有用。这是首次在发展中国家复制 Goh 等人提出的预后算法的研究。
