Blood eosinophil count and GOLD stage predict response to maintenance azithromycin treatment in COPD patients with frequent exacerbations.

INTRODUCTION

Maintenance treatment with macrolides are useful in preventing COPD exacerbations. We investigated which characteristics of COPD patients with frequent exacerbations predicted the best response to maintenance treatment with azithromycin.

METHODS

This study was part of the COLUMBUS trial, a prospective randomized, double-blind, placebo-controlled study in 92 COPD patients with frequent exacerbations. During the 1-year treatment period, follow-up data were collected for spirometry, mMRC scores, sputum cultures and blood inflammatory markers.

RESULTS

In the azithromycin group a significant lower number of exacerbations per patient was observed in patients with the following characteristics: baseline blood eosinophil count ≥2.0% (x̄ = 1.26), compared to an eosinophil count < 2.0% (x̄ = 2.50; p = 0.02), GOLD stage 1-2 (x̄ = 1.06), versus GOLD stage 4 (x̄ = 2.62; p = 0.02) and GOLD group C (x̄ = 0.45) compared to group D (x̄ = 2.18; p < 0.01). Moreover, the number of hospitalizations was significantly lower in patients, with a blood eosinophil count ≥2.0% (x̄ = 0.26) compared to an eosinophil count < 2.0% (x̄ = 0.90; p = 0.01) and in GOLD stages 1-2 (x̄ = 1.06) compared to stage 4 (x̄ = 2.62; p = 0.04).

CONCLUSION

In conclusion, azithromycin maintenance treatment appears to be effective in COPD patients with frequent exacerbations, who are either classified in GOLD stage 1-2 or GOLD C and those with a blood eosinophil count of ≥2.0%.