Clinical Algorithms for the Diagnosis and Prognosis of Interstitial Lung Disease in Systemic Sclerosis

• Published in: Seminars in arthritis and rheumatism Vol. 47; no. 2; pp. 228 - 234
• Main Authors: Hax, Vanessa, Bredemeier, Markus, Didonet Moro, Ana Laura, Pavan, Thaís Rohde, Vieira, Marcelo Vasconcellos, Pitrez, Eduardo Hennemann, da Silva Chakr, Rafael Mendonça, Xavier, Ricardo Machado
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2017
• Subjects: Adult; Aged; Algorithms; Cohort study; Female; Humans; Interstitial lung disease; Lung - diagnostic imaging; Lung - physiopathology; Lung Diseases, Interstitial - diagnosis; Lung Diseases, Interstitial - epidemiology; Lung Diseases, Interstitial - etiology; Lung Diseases, Interstitial - physiopathology; Male; Middle Aged; Prevalence; Prognosis; Radiography, Thoracic; Respiratory Function Tests; Retrospective Studies; Rheumatology; Scleroderma; Scleroderma, Systemic - complications; Scleroderma, Systemic - physiopathology; Severity of Illness Index; Systemic sclerosis; Algorithms; Scleroderma; Interstitial lung disease; Cohort study; Systemic sclerosis
• ISSN: 0049-0172; 1532-866X
• DOI: 10.1016/j.semarthrit.2017.03.019

Abstract Introduction 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. Objective 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. Methods 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 % 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). Results 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 and Wells (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 to 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. Conclusion 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 and Wells in a developing country.