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Updated: Aug 11, 2026
Bronchoalveolar Lavage (BAL) for Research; Obtaining Adequate Sample Yield
Published on: March 24, 2014
Alveolar lavage fluid (ALF) of normal volunteer subjects: cytologic, immunocytochemical, and biochemical reference
Insights
This study establishes reference values for alveolar lavage fluid (ALF) in healthy volunteers by omitting filtration and washing. These findings provide reliable cytologic, immunocytochemical, and biochemical data for clinical use.
Area of Science:
- Pulmonary Medicine
- Cell Biology
- Biochemistry
Background:
- Bronchoalveolar lavage fluid (BALF) contains both bronchial and alveolar components.
- Standard processing methods like filtration and centrifugation can introduce artifacts.
- Establishing reference values for pure alveolar lavage fluid (ALF) is crucial for accurate clinical interpretation.
Purpose of the Study:
- To determine reference values for alveolar lavage fluid (ALF) in healthy volunteers.
- To evaluate the impact of omitting filtration and centrifugation on cytopreparation.
- To provide reliable cytologic, immunocytochemical, and biochemical data for clinical settings.
Main Methods:
- Healthy volunteers underwent bronchoalveolar lavage.
- The first two aliquots were excluded, and the remaining pooled for analysis.
- Cytologic, immunocytochemical, and biochemical analyses were performed on the ALF without filtration or centrifugation.
Main Results:
- Provided 95% confidence limits for ELF content, total cell counts, and inflammatory cell distribution.
- Detailed lymphocyte subset distributions (CD3+CD2, CD4, CD8) were established.
- Reference ranges for key solutes including total protein, albumin, immunoglobulins, hyaluronic acid, ECP, PCP, and beta 2-microglobulin in ALF were determined.
Conclusions:
- Excluding the bronchial sample and omitting pre-cytopreparation steps yields reliable ALF reference values.
- The established reference values have reasonable 95% confidence limits for clinical application.
- This method provides a more accurate representation of alveolar fluid composition.
Objective:
Pooled bronchoalveolar lavage fluid (BALF), the return of lavage, contains both bronchial and alveolar material which differ from each other. Artifacts may be created by filtering, centrifuging and washing cells before cytopreparation. This study presents reference values of healthy volunteers for the alveolar sample, ALF, cytopreparation being performed without filtration or centrifugation.
Methods:
Eighteen healthy, non-smoking volunteers underwent a standard bronchoalveolar lavage using 10 aliquots of 20 ml of saline. Excluding the return of the first and second aliquots, the rest were pooled and examined cytologically, immunocytochemically and biochemically. The mean, standard deviation, and 95% confidence limits were calculated for the following variables: amount of return, estimated content of epithelial lining fluid (ELF), total and differential cell counts on filter and cytocentrifuge (CCF) preparations, computed cell counts per unit volume of ALF, distribution of lymphocyte subgroups CD3+CD2, CD4, CD8, CD19, CD25 and CD57, and the ratio of CD4 to CD8, the amounts of lymphocytes in the same subgroups per volume of ALF, and the concentrations of total protein, albumin, immunoglobulins A, G and M, hyaluronic acid, eosinophilic cationic protein (ECP), procollagen III aminoterminal propeptide (PCP) and beta 2-microglobulin in ALF and in ELF, as well as the ratios of the concentrations of the solutes in ALF to the same in serum.
Results:
The 95% confidence limits of means for the most important variables were as follows: estimated ELF content 0.42-0.74%; total cells in ALF 76.6-143.0 x 10(6) l-1; distribution of inflammatory cells on filter and CCF slides: macrophages 74.9-83.6 and 81.4-90.1%, lymphocytes 13.1-22.5 and 8.1-16.4%, and neutrophils 1.0-4.1 and 0.7-2.7%, respectively; distribution of lymphocyte subsets: CD3+CD2 85.6-90.6%, CD4 44.3-53.1%, CD8 26.9-35.8%; concentration of solutes in ALF: total protein 44.8-61.3 mg l-1, albumin 15.4-22.2 mg l-1, IgA 1.8-3.4 mg l-1, IgG 3.1-6.1 mg l-1, IgM 0.05-0.26 mg l-1, hyaluronic acid 8.8-11.1 micrograms l-1, ECP 0.19-0.77 micrograms l-1, PCP 0.005-0.58 micrograms l-1, beta 2-microglobulin 62.2-81.5 micrograms l-1.
Conclusions:
Our results show that excluding the bronchial sample from ALF of volunteer subjects and omitting filtering and washing before cytopreparation produces cytologic, immunocytochemical and biochemical reference values with reasonable 95% confidence limits to be used in clinical settings.
