Related Experiment Video
Updated: Aug 14, 2026
Bronchoalveolar Lavage (BAL) for Research; Obtaining Adequate Sample Yield
Published on: March 24, 2014
Bronchoalveolar lavage cytological alveolar damage in patients with severe pneumonia
Bogdan Grigoriu1, Frédéric Jacobs, Fabienne Beuzen
1Department of Critical Care, Hôpital Antoine Beclere, Assistance Publique-Hôpitaux de Paris, 157 rue de la porte de Trivaux, 92140 Clamart, Paris, France.
Introduction:
Histological examination of lung specimens from patients with pneumonia shows the presence of desquamated pneumocytes and erythrophages. We hypothesized that these modifications should also be present in bronchoalveolar lavage fluid (BAL) from patients with hospital-acquired pneumonia.
Methods:
We conducted a prospective study in mechanically ventilated patients with clinical suspicion of pneumonia. Patients were classified as having hospital-acquired pneumonia or not, in accordance with the quantitative microbiological cultures of respiratory tract specimens. A group of severe community-acquired pneumonias requiring mechanical ventilation during the same period was used for comparison. A specimen of BAL (20 ml) was taken for cytological analysis. A semiquantitative analysis of the dominant leukocyte population, the presence of erythrophages/siderophages and desquamated type II pneumocytes was performed.
Results:
In patients with confirmed hospital-acquired pneumonia, we found that 13 out of 39 patients (33.3%) had erythrophages/siderophages in BAL, 18 (46.2%) had desquamated pneumocytes and 8 (20.5%) fulfilled both criteria. Among the patients with community-acquired pneumonia, 7 out of 15 (46.7%) had erythrophages/siderophages and 6 (40%) had desquamated pneumocytes on BAL cytology. Only four (26.7%) fulfilled both criteria. No patient without hospital-acquired pneumonia had erythrophages/siderophages and only 3 out of 18 (16.7%) had desquamated pneumocytes on BAL cytology.
Conclusion:
Cytological analysis of BAL from patients with pneumonia (either community-acquired or hospital-acquired) shows elements of cytological alveolar damage as hemorrhage and desquamated type II pneumocytes much more frequently than in BAL from patients without pneumonia. These elements had a high specificity for an infectious cause of pulmonary infiltrates but low specificity. These lesions could serve as an adjunct to diagnosis in patients suspected of having ventilator-associated pneumonia.
Insights
Bronchoalveolar lavage fluid (BAL) analysis in pneumonia patients reveals desquamated pneumocytes and erythrophages. These cytological findings aid in diagnosing hospital-acquired pneumonia and ventilator-associated pneumonia.
Area of Science:
- Pulmonary Medicine
- Critical Care Medicine
- Cytopathology
Background:
- Histological examination of lung tissue in pneumonia cases reveals desquamated pneumocytes and erythrophages.
- These histological findings prompted a hypothesis that similar cellular changes might be detectable in bronchoalveolar lavage (BAL) fluid of hospital-acquired pneumonia (HAP) patients.
Purpose of the Study:
- To investigate the presence of desquamated pneumocytes and erythrophages in BAL fluid of mechanically ventilated patients with suspected pneumonia.
- To determine if these cytological markers can aid in differentiating hospital-acquired pneumonia from other pulmonary conditions.
Main Methods:
- A prospective study was conducted on mechanically ventilated patients with suspected pneumonia.
- BAL fluid was collected for cytological analysis, focusing on leukocyte populations, erythrophages/siderophages, and desquamated type II pneumocytes.
- Patients were classified based on quantitative respiratory tract cultures to confirm HAP, with severe community-acquired pneumonia (CAP) serving as a comparison group.
Main Results:
- Erythrophages/siderophages were found in 33.3% of HAP patients, and desquamated pneumocytes in 46.2%.
- In severe CAP, 46.7% had erythrophages/siderophages and 40% had desquamated pneumocytes.
- Patients without pneumonia showed significantly lower rates of these cytological findings (0% for erythrophages/siderophages, 16.7% for desquamated pneumocytes).
Conclusions:
- Cytological analysis of BAL fluid frequently reveals alveolar damage markers like hemorrhage and desquamated type II pneumocytes in pneumonia patients (both HAP and CAP).
- These cytological elements exhibit high specificity for infectious pulmonary infiltrates but low overall specificity.
- These findings suggest that BAL cytology can serve as an adjunctive diagnostic tool for suspected ventilator-associated pneumonia.
Related Concept Videos
01:29Pneumonia I: Introduction
01:30Pneumonia III: Complications and Assessment