T-cell phenotypes in bronchoalveolar lavage fluid, blood and lymph nodes in pulmonary sarcoidosis - indication for an airborne antigen as the triggering factor in sarcoidosis

• Published in: Journal of internal medicine 2012-11, Vol.272 (5), p.465-471
• Main Authors: Darlington, P., Haugom-Olsen, H., von Sivers, K., Wahlström, J., Runold, M., Svjatoha, V., Porwit, A., Eklund, A., Grunewald, J.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Antigens - genetics; Antigens - immunology; Biological and medical sciences; Bronchoalveolar Lavage Fluid - immunology; Bronchoscopy - methods; Case-Control Studies; CD4-Positive T-Lymphocytes - immunology; endoscopy; Environment. Living conditions; Female; General aspects; Humans; immunology; Immunophenotyping; inflammation; lung disease; Lymph Nodes - immunology; Male; Medical sciences; Middle Aged; Public health. Hygiene; Public health. Hygiene-occupational medicine; Receptors, Antigen, T-Cell - genetics; Receptors, Antigen, T-Cell - immunology; sarcoidosis; Sarcoidosis, Pulmonary - genetics; Sarcoidosis, Pulmonary - immunology; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; Statistics as Topic; T cell
• ISSN: 0954-6820; 1365-2796
• DOI: 10.1111/j.1365-2796.2012.02543.x

.  Darlington P, Haugom‐Olsen H, von Sivers K, Wahlström J, Runold M, Svjatoha V, Porwit A, Eklund A, Grunewald J (Karolinska Institutet, Stockholm, Sweden). T‐cell phenotypes in bronchoalveolar lavage fluid, blood and lymph nodes in pulmonary sarcoidosis – indication for an airborne antigen as the triggering factor in sarcoidosis. J Intern Med 2012; 272: 465–471. Background.  An increased percentage of CD4+ T cells is usually observed in bronchoalveolar lavage fluid (BALF) from patients with sarcoidosis. In HLA‐DRB1*03‐positive patients, such T cells express the T‐cell receptor (TCR) AV2S3+ gene segment. It is not known whether cells found in BALF reflect those in enlarged regional lymph nodes (LNs). Therefore, the aim of this study was to compare T‐cell phenotypes in BALF, blood and mediastinal LNs. Methods.  Fifteen patients underwent clinical investigation including bronchoscopy with bronchoalveolar lavage. Blood samples were drawn, and endoscopic ultrasound‐guided fine‐needle aspiration of enlarged mediastinal LNs was performed via the oesophagus. T cells from all three compartments were analysed by flow cytometry for markers of activity, differentiation and T regulatory function. Results.  The CD4/CD8 ratio was significantly higher in BALF compared with regional LNs and was also significantly higher in LNs than in blood. The CD4+ T cells were recently activated and more differentiated in BALF than in blood and LNs. There was an accumulation of T regulatory cells (FOXP3+) in LNs and a correlation between high levels of FOXP3+ cells in BALF and in LNs. In HLA‐DRB1*03‐positive patients, TCR AV2S3+ CD4+ T cells were predominantly localized within BALF. Conclusions.  The CD4+ T‐cell phenotype in BALF indicates an active ongoing specific immune response primarily localized to the alveolar space.