Association between serum cytokine levels and severity of chronic obstructive pulmonary disease in Northern India

The present study was designed to assess the serum cytokines [Interleukin-1β (IL-1β), Interleukin-6 (IL-6), Tumor necrosis factor-α (TNF-α)] levels in chronic obstructive pulmonary disease (COPD) patients and they were correlated with severity of disease by spirometric measurements. Finding of the present study is that among the severity of COPD stages, there was significant (p<0.01) difference in the level of TNF-α, IL-6 and IL-1β. TNF-α, IL-6 and IL-1β levels were also significantly (p<0.05) higher in serum among the very severe COPD than mild, moderate and severe COPD patients. There was direct correlation in cytokines levels of TNF-α, IL-1β and IL-6 in patients with COPD and their severity. The present study signifies that the levels of TNF-α, IL-1β and IL-6 are directly proportional to the post bronchodilator FEV1 percentage. Our results provide population-based evidence that COPD is independently associated with low-grade systemic inflammation, with a different inflammatory pattern than that observed in healthy subjects. Overall, these results identify a novel systemic inflammatory COPD phenotype that may be the target of specific research and treatment.