Colby Stong
Patients with eosinophilic acute exacerbation of chronic obstructive pulmonary disease (AECOPD) have a lower mortality, shorter hospitalization duration, and a slightly increased rate of readmission compared with those with non-eosinophilic AECOPD, according to study findings published in Respiratory Medicine.
Investigators conducted a systematic review and meta-analysis to evaluate the association between elevated peripheral blood eosinophils (EOS) and clinical outcomes in patients with AECOPD.
The researchers searched PubMed, EMBASE, Cochrane Library, and Web of Science databases from inception to February 28, 2023. Eligible studies included patients aged older than 40 years who met the Global Initiative for Chronic Obstructive Lung Disease classification criteria for COPD and had hospitalizations due to AECOPD. Eligible studies also included the exposure variable of AECOPD with blood EOS (≥2%) and non-EOS (<2%) and used a retrospective comparative design.
A total of 15 studies with 14,433 participants were included in the meta-analysis; of those, 14 were cohort studies and 1 was a case-control study. Participants’ ages ranged from 18 to 100 years, and 55.7% to 88% were male.
Based on 9 studies (n=813) with mortality data available, blood EOS was associated with a reduced risk of death in adult patients with AECOPD (relative risk [RR] 0.65; 95% CI, 0.54-0.77; I2 =0.0%; P <.001).
Hospitalization rates, reported in 3 studies, showed no observed difference between the EOS group and the non-EOS group (weighted mean difference [WMD], 0.14; 95% CI, –0.48 to 0.75; I2 =75.5%; P =.685). Likewise, no difference was seen between groups in the rates of mechanical ventilation.
Readmission rate data, obtained from 7 studies, indicated that the EOS group had a slightly higher rate vs the non-EOS group (RR, 1.07; 95% CI, 1.01-1.13; I2 =80.9%; P =.029).
A total of 9 studies evaluated hospital length of stay, which was significantly shorter in the EOS group by 1.56 days vs the non-EOS group (WMD, –1.56; 95% CI, –2.16 to –0.96; I2 =88.8%; P <.001).
Invasive ventilation data were reported in 5 studies, with no significant difference observed between the 2 groups (RR, 0.61; 95% CI, 0.34-1.10; I2 =80.2%; P =.104).
Study limitations include the potential for information bias and the small number of studies reporting the prevalence of COPD in patients younger than age 40 years.
“The findings suggest that peripheral blood EOS count could serve as a potential biomarker for predicting prognosis and tailoring individualized treatment strategies in AECOPD,” stated the study authors.
References:
Liu H, Xie Y, Huang Y, et al. The association between blood eosinophils and clinical outcome of acute exacerbations of chronic obstructive pulmonary disease: a systematic review and meta-analysis. Respir Med. Published online December 15, 2023. doi:10.1016/j.rmed.2023.107501