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Updated: May 25, 2026
Bronchoalveolar Lavage of Murine Lungs to Analyze Inflammatory Cell Infiltration
Published on: May 4, 2017
Bronchoalveolar lavage cell pattern from healthy human lung
M Heron1, J C Grutters, K M ten Dam-Molenkamp
1Department of Pulmonology, Center for Interstitial Lung Diseases, St Antonius Hospital, Nieuwegein, the Netherlands.
Insights
Bronchoalveolar lavage (BAL) cell patterns vary by fluid origin. Age-adjusted CD4+/CD8+ ratios in BAL fluid are crucial for diagnosing interstitial lung diseases (ILD).
Area of Science:
- Pulmonology
- Immunology
- Cell Biology
Background:
- Bronchoalveolar lavage (BAL) is essential for diagnosing interstitial lung diseases (ILD).
- Understanding normal BAL fluid cell differentials is key for accurate ILD diagnosis.
- Factors like lavage origin, atopy, smoking, and age may influence BAL cell patterns.
Purpose of the Study:
- Establish reference intervals for BAL fluid differential cell counts in healthy individuals.
- Investigate the influence of lavage origin (bronchial vs. alveolar), atopy, smoking status, and age on BAL cell patterns.
- Evaluate the utility of age-corrected BAL fluid CD4+/CD8+ ratios for ILD diagnosis.
Main Methods:
- Performed bronchoalveolar lavage on 55 healthy subjects (age 18-64, smokers/non-smokers).
- Determined differential cell counts and lymphocyte subsets in BAL fluid and blood.
- Measured regulatory T cell (FoxP3) and activation markers in a subgroup of non-smokers.
Main Results:
- Alveolar lavage cell counts significantly differed from pooled fractions.
- Atopy showed only marginal differences in BAL cell counts.
- The BAL fluid CD4+/CD8+ ratio strongly correlated with age (r² = 0.50, P < 0.0001).
Conclusions:
- Bronchial and alveolar lavage fractions represent distinct compartments.
- Analysis of the alveolar fraction is recommended for ILD diagnostic work-up.
- Age-corrected BAL fluid CD4+/CD8+ ratios should aid in clinical ILD evaluation.
Abstract:
Bronchoalveolar lavage (BAL) is widely accepted as a key diagnostic procedure in interstitial lung diseases (ILD). We performed a study to obtain reference intervals of differential cell patterns in BAL fluid with special attention to the origin of lavage fluid, e.g. bronchial/alveolar, to atopy and smoking status and to age of the healthy people. We performed bronchoalveolar lavage in 55 healthy subjects with known atopy status (age: 18-64 years, non-smokers/smokers: 34/21) and determined differential cell counts and lymphocyte subsets in BAL fluid and blood. Moreover, in a subgroup of non-smoking healthy individuals we measured the expression of the regulatory T cell marker forkhead box protein 3 (FoxP3) on blood and BAL fluid lymphocytes in addition to a comprehensive set of activation markers. Differential cell counts from the alveolar lavage fraction differed significantly from calculated pooled fractions (n = 11). In contrast, marginal differences were found between atopic and non-atopic subjects. Interestingly, the BAL fluid CD4(+) /CD8(+) ratio correlated strongly with age (r(2) = 0·50, P < 0·0001). We consider the bronchial and alveolar fraction to be lavage fluid from fundamentally different compartments and recommend analysis of the alveolar fraction in diagnostic work-up of ILD. In addition, our data suggest that age corrected BAL fluid CD4(+) /CD8(+) ratios should be used in the clinical evaluation of patients with interstitial lung diseases.
