[Establishment of a simple fluorescent microscopy method for measurement of the CD4/CD8 ratio in BALF]

The authors established an easy fluorescent microscopy method to measure the ratio of CD4 (helper/inducer T lymphocytes) to CD8 (suppressor/cytotoxic T lymphocytes) (CD4/CD8 ratio) in bronchoalveolar lavage fluid (BALF) in patients with diffuse pulmonary diseases and measles pneumonia. The CD4/CD8 ratio determined by this method strongly correlated with the CD4/CD8 ratio obtained by flow cytometry in both peripheral blood lymphocytes and BALF lymphocytes. When the proportion of lymphocytes in BALF nuclear cells is more than 6%, the CD4/CD8 ratio in BALF was measurable. The CD4/CD8 ratio in peripheral blood was not significantly different among hypersensitive pneumonitis (HP), sarcoidosis (SAR), collagen vascular disease (CVD), idiopathic interstitial pneumonitis (IIP), and measles pneumonia (MP). However, the BALF CD4/CD8 ratio was 0.61 +/- 0.37 in HP, 6.83 +/- 2.73 in SAR, 0.77 +/- 0.40 in CVD, 1.49 +/- 0.29 in IIP. These results were consistent with previously published data. The CD4/CD8 ratio in patients with MP was as low as 0.39 +/- 0.34. In patients with summer type HP, this ratio was low in the acute phase, but became within normal range after moving or reconstructing their homes, accompanied with the improvement of subjective symptoms and the disappearance of inflammation. These data indicate that our method is very simple and useful in the diagnosis and the monitoring of diffuse pulmonary diseases.