Sarcoidosis is a chronic inflammatory multiorgan disease of unknown origin. Our previous study demonstrated a significant correlation between the relative count of non CD4(+), non CD8(+) lymphocytes in bronchoalveolar lavage of active sarcoidosis patients and proangiogenic activity of BAL homogenates. The aim of the present study was to evaluate in a group of 40 patients with active sarcoidosis the possible relationship between the intensity of alveolitis, particularly the non CD4(+), non CD8(+) lymphocyte subset, and other parameters characterizing the level of pulmonary (lung function tests) and extrapulmonary (spleen longitudinal dimension) disease activity. We found that the relative count of non CD4(+), non CD8(+) lymphocytes in BAL correlated positively with spleen size (r=0.50, P<0.01) and negatively with static compliance (r=0.43, P<0.05). We concluded that the lymphocytes belonging to the non CD4(+)non CD8(+) subset participate in the inflammatory process in sarcoidosis. However, more detailed phenotypic and functional characteristics of this cellular population are needed.