Blood Test and Sputum Analysis Predict Acute COPD Exacerbation

Chronic obstructive pulmonary disease (COPD) remains a major contributor to global illness, largely driven by cigarette smoking and marked by irreversible lung damage. Acute exacerbations can accelerate lung-function decline, often leading to repeated hospitalizations and worsening symptoms. Predicting which patients are most likely to deteriorate remains a central challenge in clinical care. Now, new research evidence indicates that specific blood-cell patterns and airway bacteria can help clinicians identify high-risk individuals earlier.

A research team from the LKS Faculty of Medicine at The University of Hong Kong (HKUMed) (Hong Kong SAR, China) examined recent advances in COPD research, focusing on risk-stratification tools for exacerbations. Reviewing local data from the past year, the researchers found that blood eosinophil measurements taken at multiple time points—both during stable periods and at the moment of an exacerbation—offer more reliable risk prediction than single-time-point tests recommended by international guidelines.

Image: New insights from a study link blood markers and airway bacteria to COPD exacerbation risk (Photo courtesy of Shutterstock)

They also highlighted the value of sputum analysis, noting that Pseudomonas aeruginosa colonization occurs in roughly 10% of COPD patients and substantially heightens future exacerbation risk. The findings, published in the journal Lung, show that variability in eosinophil levels between stable disease and flare-ups correlates strongly with the likelihood of future exacerbations.

This suggests that longitudinal eosinophil tracking can refine risk stratification and guide more personalized treatment plans. Sputum testing provides another important indicator: the presence of Pseudomonas aeruginosa significantly raises the chance of recurrent exacerbations, reinforcing the need to incorporate airway microbiology into routine COPD assessments.

These insights emerge as the Global Initiative for Chronic Obstructive Lung Disease shifts its risk-classification criteria for 2026, now defining high-risk patients as those with even one moderate exacerbation in the previous year. This change further elevates the clinical importance of recognizing each exacerbation and adapting therapy accordingly. Earlier identification of high-risk individuals is vital for preventive care, treatment selection, and long-term disease management.

The researchers are now expanding their work through a multi-national, multi-center study across eight Asia-Pacific countries and regions aimed at refining COPD phenotyping and tailoring interventions to patient-specific profiles. Their ongoing investigations seek to deepen understanding of exacerbation biology and support more effective preventive strategies.

“Our team is actively pursuing further research into COPD phenotyping and personalized treatment. We are also leading a multi-national multi-center study involving eight countries and regions in the Asia-Pacific to further refine personalized treatment strategies for COPD,” said Dr Herbert Kwok from HKUMed, who led the study. “Through these advancements, we aim to enhance understanding of COPD and its exacerbations, which are both treatable and preventable.”

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