Integrin [alpha]^sub E^[beta]^sub 7^ (CD103) expression in bronchoalveolar lymphocytes of patients with hypersensitivity pneumonitis

CD4+/CD8+ ratio in bronchoalveolar lavage fluid (BALF) often retrieves contradictory findings when used for diagnosis of sarcoidosis and hypersensitivity pneumonitis (HP), so CD103+ has been investigated as a possible differential marker. We aimed to compare CD103+ expression in BALF T-lymphocytes between patients with HP, sarcoidosis and other interstitial lung diseases (ILD). An observational study carried out over a 2-year period included consecutive patients with suspected ILD who underwent BALF as part of their initial diagnostic work-up; CD103+ expression on BALF T-lymphocytes was evaluated. After a final diagnosis established according to international criteria, three patient subgroups--HP, ILD (which included idiopathic interstitial pneumonia and connective tissue disease-associated lung disorders) and sarcoidosis--were considered for further analysis. A total of 77 subjects were enrolled, 20 with HP, 16 with other ILD and 41 with sarcoidosis. A significantly higher number of CD4+ CD103+ and CD8+ CD103+ lymphocytes were found in HP patients. Among patients with sarcoidosis, 12 (29.3 %) presented a BALF CD4+/CD8+