Jae Ha Lee1, Ji Hoon Jang1, Jin Han Park1, Hang-Jea Jang1, Chan Sun Park2, Sunggun Lee3, Seong-Ho Kim3, Ji Yeon Kim4, Hyun Kuk Kim1. 1. Division of Pulmonology, Department of Internal Medicine, Inje University Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea. 2. Division of Allergy, Department of Internal Medicine, Inje University Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea. 3. Division of Rheumatology, Department of Internal Medicine, Inje University Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea. 4. Division of Pathology, Inje University Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea.
Abstract
BACKGROUND: Interstitial lung diseases (ILDs) are chronic, parenchymal lung diseases with a variable clinical course and a poor prognosis. Within various clinical courses, acute exacerbation (AE) is a devastating condition with significant morbidity and high mortality. The aim of this study was to investigate the role of interleukin-6 (IL-6) to predict AE and prognosis in patients with ILD. METHODS: Eighty-three patients who were diagnosed with ILD from 2016 to 2019 at the Haeundae Paik Hospital, Busan, South Korea, were included and their clinical data were retrospectively analyzed. RESULTS: The median follow-up period was 20 months. The mean age was 68.1 years and 65.1% of the patients were men with 60.2% of patients being ever-smokers. Among ILDs, idiopathic pulmonary fibrosis was the most common disease (68.7%), followed by connective tissue disease-associated ILD (14.5%), cryptogenic organizing pneumonia (9.6%), and nonspecific interstitial pneumonia (6.0%). The serum levels of IL-6 were measured at diagnosis with ILD and sequentially at follow-up visits. During the follow-ups, 15 (18.1%) patients experienced an acute exacerbation (AE) of ILD and among them, four (26.7%) patients died. In the multivariable analysis, high levels of IL-6 (OR 1.014, 95% CI: 1.001-1.027, p = 0.036) along with lower baseline saturations of peripheral oxygen (SpO2) were independent risk factors for AE. In the receiver operating characteristic curve analysis, the area under the curve was 0.815 (p < 0.001) and the optimal cut-off value of serum IL-6 to predict AE was 25.20 pg/mL with a sensitivity of 66.7% and specificity of 80.6%. In the multivariable Cox analysis, a high level of serum IL-6 (HR 1.007, 95% CI: 1.001-1.014, p = 0.018) was only an independent risk factor for mortality in ILD patients. CONCLUSIONS: In our study, a high level of serum IL-6 is a useful biomarker to predict AE and poor prognosis in patients with ILD.
BACKGROUND: Interstitial lung diseases (ILDs) are chronic, parenchymal lung diseases with a variable clinical course and a poor prognosis. Within various clinical courses, acute exacerbation (AE) is a devastating condition with significant morbidity and high mortality. The aim of this study was to investigate the role of interleukin-6 (IL-6) to predict AE and prognosis in patients with ILD. METHODS: Eighty-three patients who were diagnosed with ILD from 2016 to 2019 at the Haeundae Paik Hospital, Busan, South Korea, were included and their clinical data were retrospectively analyzed. RESULTS: The median follow-up period was 20 months. The mean age was 68.1 years and 65.1% of the patients were men with 60.2% of patients being ever-smokers. Among ILDs, idiopathic pulmonary fibrosis was the most common disease (68.7%), followed by connective tissue disease-associated ILD (14.5%), cryptogenic organizing pneumonia (9.6%), and nonspecific interstitial pneumonia (6.0%). The serum levels of IL-6 were measured at diagnosis with ILD and sequentially at follow-up visits. During the follow-ups, 15 (18.1%) patients experienced an acute exacerbation (AE) of ILD and among them, four (26.7%) patientsdied. In the multivariable analysis, high levels of IL-6 (OR 1.014, 95% CI: 1.001-1.027, p = 0.036) along with lower baseline saturations of peripheral oxygen (SpO2) were independent risk factors for AE. In the receiver operating characteristic curve analysis, the area under the curve was 0.815 (p < 0.001) and the optimal cut-off value of serum IL-6 to predict AE was 25.20 pg/mL with a sensitivity of 66.7% and specificity of 80.6%. In the multivariable Cox analysis, a high level of serum IL-6 (HR 1.007, 95% CI: 1.001-1.014, p = 0.018) was only an independent risk factor for mortality in ILDpatients. CONCLUSIONS: In our study, a high level of serum IL-6 is a useful biomarker to predict AE and poor prognosis in patients with ILD.