Blood eosinophil reference values and determinants in a representative adult population

Area of Science:

• Clinical epidemiology
• Pulmonary medicine
• Allergy and immunology

Background:

• Blood eosinophil count (BEC) is a prognostic biomarker for asthma and COPD.
• Factors like atopy, age, sex, smoking, and comorbidities can complicate BEC interpretation.

Purpose of the Study:

• To establish reference values for BEC in the general adult population.
• To investigate the influence of age, asthma, COPD, and clinical allergy on BEC.

Main Methods:

• Utilized the population-representative West Sweden Asthma Study cohort.
• Included 1145 adults with clinical examinations, skin prick testing, specific IgE, and BEC measurements.

Main Results:

• The upper limit of BEC (95th percentile) ranged from 300-400 cells/μL in healthy adults, varying by age.
• Sex, smoking, atopy, clinical allergy, obesity, asthma, COPD, diabetes, and hypertension were associated with higher BEC.
• Multivariable analysis confirmed asthma, clinical allergy, obesity, and diabetes as significant influencers of BEC.

Conclusions:

• Reference ranges for BEC in healthy adults are age-dependent, generally between 300-400 cells/μL.
• Age, smoking, obesity, asthma, COPD, and clinical allergy are key factors affecting BEC levels.
• Clinical interpretation of BEC requires consideration of these influencing factors for accurate prognostic value.