Accumulation of CCR4‐expressing CD4+ T cells and high concentration of its ligands (TARC and MDC) in bronchoalveolar lavage fluid of patients with eosinophilic pneumonia

• Published in: Allergy (Copenhagen) Vol. 58; no. 6; pp. 518 - 523
• Main Authors: Katoh, S., Fukushima, K., Matsumoto, N., Matsumoto, K., Abe, K., Onai, N., Matsushima, K., Matsukura, S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Munksgaard International Publishers 01.06.2003; Blackwell
• Subjects: Adult; Allergic diseases; Biological and medical sciences; Blood Cells - metabolism; Blood Cells - pathology; bronchoalveolar lavage fluid; Bronchoalveolar Lavage Fluid - chemistry; Bronchoalveolar Lavage Fluid - cytology; CC chemokine receptor 4; CCR4 protein; CD4 antigen; CD4-Positive T-Lymphocytes - metabolism; CD4-Positive T-Lymphocytes - pathology; Chemokine CCL17; Chemokine CCL22; chemokine MDC; chemokine TARC; Chemokines, CC - metabolism; eosinophilic pneumonia; Female; Humans; Immunopathology; Ligands; macrophage‐derived chemokine; Male; Medical sciences; Middle Aged; Osmolar Concentration; Pulmonary Eosinophilia - metabolism; Pulmonary Eosinophilia - pathology; Receptors, CCR4; Receptors, Chemokine - metabolism; Respiratory and ent allergic diseases; Th2 cells; thymus and activation‐regulated chemokine; Human; Lung disease; Respiratory disease; Pathogenesis; Cell subpopulation; macrophage- derived chemokine; Th2 cells; thymus and activation- regulated chemokine; CCR4 chemokine receptor; bronchoalveolar lavage fluid; CC chemokine receptor 4; eosinophilic pneumonia; Bronchoalveolar lavage; Eosinophilic pneumonia; T-Lymphocyte; Th2 lymphocyte; Molecular biology; ELISA assay
• ISSN: 0105-4538; 1398-9995
• DOI: 10.1034/j.1398-9995.2003.00149.x

Background: Th2 cells are thought to be involved in eosinophilic inflammation of the lung. CC chemokine receptor 4 (CCR4) has been identified as a specific receptor for both thymus and activation‐regulated chemokine (TARC) and macrophage‐derived chemokine (MDC), and is preferentially expressed on Th2 cells. Objective: Our aim was to evaluate the role of Th2 cells in the lung of patients with eosinophilic pneumonia (EP). Methods: The concentrations of TARC, MDC, and interleukin (IL)‐5 were measured in bronchoalveolar lavage fluid (BALF) by ELISA. Proportion of CCR4‐expressing CD4+ T cells (CCR4+ CD4+ T cells) was determined by flow cytometry. Results: TARC and MDC concentrations in BALF were higher in patients with EP than in normal subjects. The proportion of CCR4‐expressing cells among CD4+ T cells was higher in BALF than in peripheral blood of patients with EP. There was a significant correlation between the number of CCR4+ CD4+ T cells and the levels of TARC, MDC, and IL‐5 in BALF of patients with EP. Conclusions: Our data suggest that Th2 cells, which express CCR4 and its ligands (TARC and MDC), contribute to the pathogenesis of EP in the lung.