None of the TNFA or LTA gene variants analysed in the present study resulted correlated with the circulating IL-6, IL-8, IL-16, TNF-α, MCP-1, MMP-9, PARC or VEGF levels in serum of COPD patients (p > 0.05, data not shown). This evidence concerns the gene CXCL8 and chronic obstructive pulmonary disease.