Evaluating blood eosinophils and exacerbation history to predict ICS response in COPD

Introduction:

Inhaled corticosteroids (ICS) are used to reduce the rate of COPD exacerbations (EX). Debate continues over use of blood eosinophils (EOS) to predict ICS response, with some suggesting a cut-off of ≥2% (Pascoe S et al. Lancet Respir Med 2015;3:435 – 42). In the WISDOM study (NCT00975195), this response was driven by patients with higher EOS levels (≥4% or ≥300 cells/µL) (Watz H et al. Lancet Respir Med 2016;4:390 – 8]).

Aim:

We analysed WISDOM data stratified by prior EX and EOS levels to determine if the ICS responder group could be better specified.

Methods:

Post hoc analysis of the rate of moderate/severe EX after complete ICS withdrawal using a negative binomial regression model to estimate EX rate according to number of prior EX (< 2 and ≥2, estimated based on the number of courses of antibiotics or steroids in the past year) and EOS subgroups.

Results:

High EOS counts (≥400 cells/µL) were associated with increased EX rate after complete ICS withdrawal only in patients with ≥2 prior EX (Figure).

Conclusions:

Withdrawal of ICS only increased the rate of EX in patients with both raised EOS (≥400 cells/µL) and a history of frequent EX. In patients who do not meet these criteria, ICS may not be as effective as is commonly assumed.

Funding:

Boehringer Ingelheim

Fig. 1: Rate ratios (ICS withdrawal/ICS) for moderate or severe EX by EOS subgroup and EX history

Content already presented at ERS congress 2016