Can Chronic Obstructive Pulmonary Disease (COPD) and asthma coexist in one patient?

Asthma and COPD Can Coexist as Asthma-COPD Overlap Syndrome

Yes, COPD and asthma can definitely coexist in the same patient, a condition known as Asthma-COPD Overlap (ACO) which affects approximately 20% of patients with obstructive airway diseases and 2% of the general population. 1

Clinical Features of Asthma-COPD Overlap

ACO is characterized by:

• Incompletely reversible airflow limitation (post-bronchodilator FEV1/FVC <70%) with features of both asthma and COPD 1
• Typically seen in patients over 40 years old with smoking history and previous asthma diagnosis or childhood asthma 1
• Increased morbidity compared to either condition alone, with:
  • Greater health status impairment
  • More frequent acute exacerbations
  • Increased hospitalizations
  • Possibly increased mortality (HR 1.45,95% CI 1.06-1.98) 1

Inflammatory Patterns

ACO demonstrates a heterogeneous pattern of airway inflammation:

• May include eosinophilic patterns (typical in asthma)
• May include neutrophilic or mixed patterns (typical in severe asthma and COPD)
• Systemic inflammation resembling that of COPD 1

Diagnostic Approach

The diagnosis of ACO should be considered when a patient has:

1. Chronic airflow limitation in a smoker or ex-smoker ≥35 years old
2. Features of asthma (history of asthma, significant bronchodilator response)
3. At least one of the following:
   • Very positive bronchodilator test (≥15% and ≥400 mL improvement in FEV1)
   • Blood eosinophilia (≥300 eosinophils/μL) 1

Treatment Implications

The recognition of ACO has important treatment implications:

• When asthma is not recognized in a COPD patient, there is potential for increased adverse events with long-acting β2-agonist (LABA) monotherapy 1, 2
• Guidelines generally recommend a treatment approach dominated by asthma paradigms 1
• Inhaled corticosteroids (ICS) should be included in the treatment regimen due to the asthmatic component 1

Comorbidities

Patients with ACO may have increased comorbidities compared to those with either condition alone:

• Some studies show increased Charlson Comorbidity Index in ACO patients 1
• Specific comorbidities that may be more prevalent include diabetes, stroke, and arthritis 1

Pitfalls and Caveats

1. Diagnostic challenges: Bronchodilator responsiveness alone has not been successful in recognizing different subgroups within ACO 1

2. Treatment risks: LABA monotherapy (without ICS) in patients with asthmatic features carries increased risk of asthma-related deaths (relative risk: 4.37 [95% CI: 1.25,15.34]) 2

3. Clinical trials exclusion: ACO patients are typically excluded from randomized controlled trials, limiting the evidence base for treatment recommendations 1

4. Heterogeneity: ACO represents a diverse group of patients with varying clinical presentations, which complicates standardized treatment approaches 1

The recognition of ACO is clinically important as it helps identify patients who may benefit from specific treatment approaches and closer monitoring due to their increased risk of exacerbations and poorer outcomes compared to either asthma or COPD alone.