What is the normal BAL fluid differential cell count?
In this short video I present the normal differential cell count for bronchoalveolar lavage (BAL) fluid according to the American Thoracic Society (ATS) 2012 clinical practice guideline (in nonsmokers). The BAL fluid differential cell count is very useful in the diagnostic workup of interstitial lung disease (ILD) as it allows to often differentiate between purely fibrotic and inflammatory lung disease. This distinction is important for choosing the initial treatment strategy.
A good quality BAL is however essential for drawing correct conclusions regarding the inflammatory cell distribution (macrophages, lymphocytes, neutrophils, eosinophils). Having a very high percentage of “Other” cells (which are bronchial epithelial cells) means that the fluid constitutes more of a bronchial “wash” rather than a proper, deep lavage.
Despite the bronchoalveolar lavage being considered a rather “simple” bronchoscopy technique, many clinicians actually overlook performing a proper lavage which would yield a low proportion of bronchial epithelial cells.
The video:
The normal BAL fluid differential cell count
Highly recommended to read the full guideline:
Meyer KC, Raghu G, Baughman RP, et al. An official American Thoracic Society clinical practice guideline: the clinical utility of bronchoalveolar lavage cellular analysis in interstitial lung disease. Am J Respir Crit Care Med. 2012;185(9):1004-1014. doi:10.1164/rccm.201202-0320ST
I plan to cover more parts of this extremely useful clinical guideline in future videos and short articles.
If you enjoyed this post, check out the Idiopathic Pulmonary Fibrosis (IPF) tutorial!
