Accurate and early detection of lung illness has long been a major medical problem. In most circumstances, a single modality cannot provide a clear diagnosis; hence, numerous instruments must be used to provide the most comprehensive and accurate clinical conclusion. Bronchoalveolar lavage fluid is often rich in lower airway cellular and noncellular elements, offering insight into the immunologic and inflammatory condition of the bronchoalveolar region. Despite the simplicity and safety of acquiring bronchoalveolar lavage fluid, the analysis of individual cell populations remains debatable. Lymphocyte subsets such as CD4 T-helper cells and CD8 cytotoxic T cells have been implicated in the immunopathology of a variety of lung illnesses. When used alone, CD4/CD8 ratios have minimal clinical usefulness; however, when combined with other factors, these markers may give significant clinical information that can lead to a more confident diagnosis, particularly when sarcoidosis is the origin of the lung illness. Researchers argued that the skilled physician should not dismiss the potentially beneficial tool entirely.
Reference:journals.lww.com/clinpulm/Abstract/2018/03000/Diagnostic_Utility_of_CD4_CD8_Ratio_in.6.aspx
