Accurate and timely identification of pulmonary disease has long been a great challenge in medicine. In most cases, the clinician cannot arrive at a definitive diagnosis via 1 modality alone; thus, multiple tools must be utilized to arrive at the most complete and accurate clinical conclusion. Bronchoalveolar lavage fluid is typically rich in cellular and noncellular constituents of the lower airways, providing insight into the immunologic and inflammatory state of the bronchoalveolar space. Despite the relative ease and safety of obtaining bronchoalveolar lavage fluid, the analysis of specific cell populations remains controversial. Lymphocyte subsets, including CD4 T-helper cells and CD8 cytotoxic T cells, have known roles in the immunopathology of various lung diseases. CD4/CD8 ratios are of little clinical utility when used alone; however, in combination with other variables, these markers may provide useful clinical information that may contribute to a more confident diagnosis, especially when sarcoidosis is the cause of the lung disorder. We propose that the expert clinician should not completely discard this potentially valuable tool.
Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, Brody School of Medicine, East Carolina University, Greenville, NC
Disclosure: The authors declare that they have no conflicts of interest.
Address correspondence to: Sean A. Marco, MD, Mail Stop 628, Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, Brody School of Medicine, East Carolina University, 3E-149, Greenville, NC 27834. E-mail: email@example.com.