The relationship between blood neutrophils, blood eosinophils and exacerbations of COPD – Results from the TIE-study

Background: Increased blood eosinophils (B-Eos) are common in asthma and correlate with asthma attacks. The role of blood eosinophilia in COPD and its relation to acute exacerbations of COPD (AECOPD) have been less studied. Method: Subjects from the TIE-study with spirometry-verified COPD and CRP levels Results: A total of 301 COPD patients (56% females) with a mean ± SD age of 69 ± 8 years and FEV 1 of 55.6 ± 18.3% predicted were recruited. Thirty percent experienced an AECOPD during the preceding year, and these subjects had higher B-Neu (geometric mean (95% CI)) and lower B-Eos than subjects without AECOPD: 4954 (4623-5309) cells/mm 3 vs 4444 (4258-4637), p = 0.007 and 151 (128-178) vs 180 (165-197), p = 0.046. Higher B-Neu related to poorer FEV 1 (% predicted): rho = -0.20, p 1 : rho = 0.12, p = 0.03. Higher B-Neu independently related (p = 0.02) to a history of AECOPD, after adjustments for gender, age and FEV 1 . Conclusions: Increased neutrophils and decreased eosinophils in blood related to poorer FEV 1 and a history of COPD exacerbations. The prospective value of these markers remains to be studied.