Prognosticating Outcomes in Interstitial Lung Disease by Mediastinal Lymph Node Assessment. An Observational Cohort Study with Independent Validation

• Published in: American journal of respiratory and critical care medicine 2019-03, Vol.199 (6), p.747-759
• Main Authors: Adegunsoye, Ayodeji, Oldham, Justin M, Bonham, Catherine, Hrusch, Cara, Nolan, Paul, Klejch, Wesley, Bellam, Shashi, Mehta, Uday, Thakrar, Kiran, Pugashetti, Janelle Vu, Husain, Aliya N, Montner, Steven M, Straus, Christopher M, Vij, Rekha, Sperling, Anne I, Noth, Imre, Strek, Mary E, Chung, Jonathan H
• Format: Article
• Language: English
• Subjects: Age; Aged; Cardiovascular disease; Chemokines; Cohort analysis; Cohort Studies; Cytokines; Epidermal growth factor; Female; Gene expression; Humans; Lung cancer; Lung diseases; Lung Diseases, Interstitial - mortality; Lymph Nodes - diagnostic imaging; Lymphatic system; Male; Mediastinum - diagnostic imaging; Medical imaging; Medical prognosis; Middle Aged; Mortality; Observational studies; Original; Patients; Plasma; Predictive Value of Tests; Pulmonary fibrosis; Sarcoidosis; Systematic review; Tomography, X-Ray Computed - methods; Variables
• ISSN: 1073-449X; 1535-4970; 1535-4970
• DOI: 10.1164/rccm.201804-0761OC

Mediastinal lymph node (MLN) enlargement on chest computed tomography (CT) is prevalent in patients with interstitial lung disease (ILD) and may reflect immunologic activation and subsequent cytokine-mediated immune cell trafficking. We aimed to determine whether MLN enlargement on chest CT predicts clinical outcomes and circulating cytokine levels in ILD. MLN measurements were obtained from chest CT scans of patients with ILD at baseline evaluation over a 10-year period. Patients with sarcoidosis and drug toxicity-related ILD were excluded. MLN diameter and location were assessed. Plasma cytokine levels were analyzed in a subset of patients. The primary outcome was transplant-free survival (TFS). Secondary outcomes included all-cause and respiratory hospitalizations, lung function, and plasma cytokine concentrations. Cox regression was used to assess mortality risk. Outcomes were assessed in three independent ILD cohorts. Chest CT scans were assessed in 1,094 patients (mean age, 64 yr; 52% male). MLN enlargement (≥10 mm) was present in 66% (n = 726) and strongly predicted TFS (hazard ratio [HR], 1.53; 95% confidence interval [CI], 1.12-2.10; P = 0.008) and risk of all-cause and respiratory hospitalizations (internal rate of return [IRR], 1.52; 95% CI, 1.17-1.98; P = 0.002; and IRR, 1.71; 95% CI, 1.15-2.53; P = 0.008, respectively) when compared with subjects with MLN 45 pg/ml predicted mortality (HR, 4.21; 95% CI, 1.21-14.68; P = 0.024). Independent analysis of external datasets confirmed these findings. MLN enlargement predicts TFS and hospitalization risk in ILD and is associated with decreased levels of a key circulating cytokine, soluble CD40L. Incorporating MLN and cytokine findings into current prediction models might improve ILD prognostication.