Bronchoalveolar lavage cell pattern from healthy human lung

Clin Exp Immunol. 2012 Mar;167(3):523-31. doi: 10.1111/j.1365-2249.2011.04529.x.


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.

MeSH terms

  • Adolescent
  • Adult
  • Bronchoalveolar Lavage Fluid / chemistry
  • Bronchoalveolar Lavage Fluid / cytology*
  • Bronchoalveolar Lavage Fluid / immunology
  • CD4-CD8 Ratio
  • Female
  • Forkhead Transcription Factors / blood
  • Forkhead Transcription Factors / metabolism
  • Humans
  • Hypersensitivity, Immediate / immunology
  • Hypersensitivity, Immediate / metabolism
  • Hypersensitivity, Immediate / pathology
  • Leukocyte Count
  • Lung / cytology*
  • Lung Diseases, Interstitial / diagnosis
  • Lung Diseases, Interstitial / immunology
  • Lung Diseases, Interstitial / metabolism
  • Lung Diseases, Interstitial / pathology
  • Lymphocyte Activation
  • Lymphocyte Subsets / cytology
  • Lymphocyte Subsets / immunology
  • Lymphocyte Subsets / metabolism
  • Male
  • Middle Aged
  • Reference Values
  • Smoking / metabolism
  • Smoking / pathology
  • Young Adult


  • FOXP3 protein, human
  • Forkhead Transcription Factors