Relationship between the ratios of CD4/CD8 T-lymphocytes in the bronchoalveolar lavage fluid and lymph nodes in patients with sarcoidosis.

Background: Evaluating the ratio of CD4/CD8 T-lymphocytes in the bronchoalveolar lavage fluid (BALF) is important for understanding the clinical and pathological conditions of patients with sarcoidosis. However, few studies have thus far demonstrated the usefulness of evaluating the relationship between the ratios of CD4/CD8 T-lymphocytes in the mediastinal lymph nodes and BALF. This study aimed to investigate and identify the relationships between CD4/CD8 T-lymphocyte ratio in the mediastinal lymph nodes and BALF in patients with sarcoidosis.

Methods: Thirty-three consecutive patients with sarcoidosis with enlarged mediastinal and/or hilar lymphadenopathy were enrolled in the study, and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and bronchoalveolar lavage (BAL) were simultaneously performed. The CD4/CD8 T-lymphocyte ratios in the mediastinal lymph nodes and BALF were evaluated using immunohistochemistry and flow cytometry, respectively.

Results: The interobserver variability in the CD4/CD8 ratio in the mediastinal lymph nodes as determined by immunostaining was low, and the pathological and cytological profiles of T-lymphocytes in the mediastinal and/or hilar lymph nodes and BALF were correlated in patients with sarcoidosis. Additionally, the CD4/CD8 T-lymphocyte ratios in BALF were significantly higher than those in the mediastinal lymph nodes. Importantly, non-caseating granulomas were detected at a high rate by using EBUS-TBNA.

Conclusions: Performing EBUS-TBNA in patients with sarcoidosis allows correct diagnosis as well as the estimation of the ratio of CD4/CD8 T-lymphocytes in BALF.