Published in:
01-02-2014
Activated CD8+ T Cells and NKT Cells in BAL Fluid Improve Diagnostic Accuracy in Sarcoidosis
Published in: Lung | Issue 1/2014
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Purpose
The clinical diagnosis of pulmonary sarcoidosis is based on the presence of noncaseating granulomas in an appropriate clinical setting with either bilateral hilar adenopathy and/or parenchymal infiltrates. Lymphocytosis with an increased CD4/CD8 T cell ratio in bronchoalveolar lavage fluid is supportive. We evaluated the diagnostic accuracy of a predictive binary logistic regression model in sarcoidosis based on sex, age, and bronchoalveolar lavage fluid cell profile with and without the inclusion of HLA-DR+ CD8+ T cells and natural killer T-cell fractions.
Methods
A retrospective analysis of differential cell counts and lymphocyte phenotypes by flow cytometry in bronchoalveolar lavage was performed in 183 patients investigated for possible diffuse parenchymal lung disease. A logistic regression model with age, sex, lymphocyte fraction, eosinophils, and CD4/CD8 ratio in bronchoalveolar lavage fluid (basic model) was compared with a final model, which also included fractions of HLA-DR+ CD8+ T cells and natural killer T cells. Diagnostic accuracy of the two models was assessed by receiver operating characteristic (ROC) curves.
Results
The area under the ROC curve for the basic and final model was 0.898 [95 % confidence interval (CI) 0.852–0.945] and 0.937 (95 % CI 0.902–0.972), respectively, p = 0.008.
Conclusions
Assessment of HLA-DR+ CD8+ T cell and natural killer T-cell fractions may improve diagnostic accuracy and further strengthen the importance of bronchoalveolar lavage in the diagnostic workup of sarcoidosis.