1. BRONCHOALVEOLAR LAVAGE

2. Utilities of Analysis:
• Evaluation of immunocompromised
patients for the presence of
opportunistic infections
• Diagnosis of interstitial lung
disease, airway disease, and
alveolar hemorrhage
• Detection of infection and
monitoring antibody therapy

3. Specimen Considerations
1. Specimen collection
• involves infusion of saline through a bronchoscope by
aspiration of bronchial contents for cellular
examination and culture
2. Specimen handling
a. BAL specimens are usually separated into two
samples:
bronchial sample- first aliquot installed and
recovered
aleolar sample- consists of the subsequent 3 to
5 aliquots which are installed
and recovered.
b. Specimens should be analyzed immediately; within 1
hour for cell counts.

4. Microscopic Examination
1. WBC count
• Dilute 1:100 with ammonium oxalate or 1;20 with
glacial acetic acid using unopette systems
• all cells in the 18 squares are counted (both sides
of the hemocytometer) and the average of the two
sides is calculated using the standard Neubauer
formula
2. RBC count
• dilute with isotonic saline
• both sides of the hemocytometer are counted and
the RBC/mmᵌ is calculated
3. Differential count
• slides are prepared by cytocentrifugation
• 500 to 1000 cells are counted and classified

5. Table 29. cells and inclusions seen in BAL specimens
Cells/ inclusions Clinical significance
Macrophages Normal; most frequently seen
Lymphocytes Increased in intertitial lung disease,
drug reactions, pulmonary
lymphoma, and nonbacterial
infections
Neutrophils Elevated in cigarette smokers,
bronchopneumonia, toxin exposure,
and duffuse alveolar damage
Eosinophils Elevated in asthma, drug-induced
lung disease, infections,
hypersensitivity, pneumonitis, and
eosinophilic pneumonia

6. Analysis of body fluids and miscellaneous specimens
Erythrocytes Alveolar hemorrhage
Phagocytized erythrocytes Alveolar hemorrhage
Hemosiderin-laden Alveolar hemorrhage
macrophages
Bronchial epithelial cells Normal; more numerous in bronchial
wash specimens
Sulfur granules Actinomyces infection
Langerhans cells Cigarette smokers, Langerhans cell
histiocytosis
Cytomegalic cells CMV infection
Fat droplets/ lipid-laden Fat embolism
macrophages
Dust particle inclusions Pneumoconioses or asbestos exposure

7. Microbiologic and Serologic Examination
1. Bacterial pathogens
• Mycobacterium tuberculosis,Legionella pneumophila,
Mycoplasma pneumonia
2. Fungal pathogens
• Pneumocystis jiroveci- characteristics amorphous
material is seen microscopically under low power and
organism are visible under high power
• Cryptococcus neoformas- opportunistic pathogen in
patients with AIDS; diagnosed by demonstrating a positive
sryptococcal antigen exhibiting yeast cells
• other: Histoplasma capsulatum, Actinomyses spp.
3. Parasites
• paragonimus westermani, Toxoplasma gondii,
Stronglyloides stercoralis
4. Viruses
• Influenza A and B viruses, respiratory syncytial
virus