Comparison of inflammation biomarkers among chronic obstructive pulmonary disease groups: A cross sectional study

The Global Initiative classification (GOLD) for chronic obstructive pulmonary disease (COPD), which relies on the practical issues of treatment of this complex and heterogeneous disease, may not be reliable in predicting disease severity and prognosis as the term of inflammation is excluded from the definition.

The aim of this study was to determine systemic inflammatory markers in GOLD ABCD groups and to compare these parameters according to clinical and functional features.

The study included 60 COPD patients and 59 healthy subjects. Comparisons were made with the pulmonary function test, transthoracic echocardiography and the six-minute walk test (6MWT). The COPD assessment test (CAT), modified Medical Research Council (mMRC), and index scores of body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) were recorded. The systemic inflammatory state was assessed using C-reactive protein, fibrinogen, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-8 and IL-18.

The levels of all serum inflammatory markers were higher in the COPD group than in the control group. TNF-α and IL-6 were significantly higher in the symptomatic groups (B and D) than in the less symptomatic groups (A and C) (P < 0.05). Spirometric parameters were more severe in Group D, followed by groups C, B and A, respectively. The 6MWT and the BODE scores were worst in Group D, followed by groups B, C and A.

The results suggest that bronchodilator treatment alone might be insufficient in Group B patients, as the systemic inflammatory markers in addition to exercise capacity and mortality predictors were at the worst level in Groups D and B.