Interleukin-6 and airflow limitation in chemical warfare patients with chronic obstructive pulmonary disease

Abstract

Davood Attaran1, Shahrzad M Lari1, Mohammad Towhidi1, Hassan Ghobadi Marallu2, Hossein Ayatollahi1, Mohammad Khajehdaluee1, Mostafa Ghanei3, Reza Basiri11Lung Disease and Tuberculosis Research Center, Mashhad University of Medical Science, 2Ardabil University of Medical Sciences, 3Research Center of Chemical Injuries, Baqiyatallah University of Medical Sciences, Tehran, IranObjectives: Chronic obstructive pulmonary disease (COPD) is one of the main late complications of sulfur mustard poisoning. The aim of this study was to evaluate serum levels of interleukin (IL)-6 in war veterans with pulmonary complications of sulfur mustard poisoning and their correlation with severity of airways disease.Methods: Fifty consecutive patients with sulfur mustard poisoning and stable COPD, and of mean age 46.3 ± 9.18 years were enrolled in this study. Thirty healthy men were selected as controls and matched to cases by age and body mass index. Spirometry, arterial blood gas, six-minute walk test, BODE (body mass index, obstruction, dyspnea, and exercise capacity), and St George’s Respiratory Questionnaire about quality of life were evaluated. Serum IL-6 was measured in both patient and control groups.Results: Fifty-four percent of patients had moderate COPD. Mean serum IL-6 levels were 15.01 ± standard deviation (SD) 0.61 pg/dL and 4.59 ± 3.40 pg/dL in the case and control groups, respectively (P = 0.03). There was a significant correlation between IL-6 levels and Global Initiative for Chronic Obstructive Lung Disease stage (r = 0.25, P = 0.04) and between IL-6 and BODE index (r = 0.38, P = 0.01). There was also a significant negative correlation between serum IL-6 and forced expiratory volume in one second (FEV1, r = -0.36, P = 0.016).Conclusion: Our findings suggest that serum IL-6 is increased in patients with sulfur mustard poisoning and COPD, and may have a direct association with airflow limitation.Keywords: sulfur mustard, chronic obstructive pulmonary disease, interleukin-6, inflammation, chemical warfare