Blood eosinophils to direct corticosteroid treatment of exacerbations of chronic obstructive pulmonary disease: a randomized placebo-controlled trial.

Abstract

Exacerbations of chronic obstructive pulmonary disease (COPD) and responses to treatment are heterogeneous. Investigate the usefulness of blood eosinophils to direct corticosteroid therapy during exacerbations. Subjects with COPD exacerbations were entered into a randomized biomarker-directed double-blind corticosteroid versus standard therapy study. Subjects in the standard arm received prednisolone for 2 weeks, whereas in the biomarker-directed arm, prednisolone or matching placebo was given according to the blood eosinophil count biomarker. Both study groups received antibiotics. Blood eosinophils were measured in the biomarker-directed and standard therapy arms to define biomarker-positive and -negative exacerbations (blood eosinophil count > and ≤ 2%, respectively). The primary outcome was to determine noninferiority in health status using the chronic respiratory questionnaire (CRQ) and in the proportion of exacerbations associated with a treatment failure between subjects allocated to the biomarker-directed and standard therapy arms. There were 86 and 80 exacerbations in the biomarker-directed and standard treatment groups, respectively. In the biomarker-directed group, 49% of the exacerbations were not treated with prednisolone. CRQ improvement after treatment in the standard and biomarker-directed therapy groups was similar (0.8 vs. 1.1; mean difference, 0.3; 95% confidence interval, 0.0-0.6; P = 0.05). There was a greater improvement in CRQ in biomarker-negative exacerbations given placebo compared with those given prednisolone (mean difference, 0.45; 95% confidence interval, 0.01-0.90; P = 0.04). In biomarker-negative exacerbations, treatment failures occurred in 15% given prednisolone and 2% of those given placebo (P = 0.04). The peripheral blood eosinophil count is a promising biomarker to direct corticosteroid therapy during COPD exacerbations, but larger studies are required.