One hundred patients with histologically verified sarcoidosis were studied. They were divided into three groups, based on their clinical presentation and smoking status. Group A consisted of patients whose disease was detected by routine chest x-ray film, without symptoms; group B included those with respiratory and general constitutional symptoms; and group C included patients with erythema nodosum and/or arthralgia and hilar lymphadenopathy. Group A showed an increased CD4/CD8 ratio of 4.7 +/- 1.1; group B, 8.0 +/- 1.2; and group C counted for the highest ratio of 10.7 +/- 1.5. Cigarette smoking modifies the immunologic bronchoalveolar lavage (BAL) fluid sample profile, since alveolitis was less pronounced in smokers. In addition, BAL fluid samples obtained from sarcoidosis patients with hilar lymphadenopathy showed the most characteristic features of alveolitis, suggesting a disseminated instead of a local immune response. Therefore, the clinical presentation of sarcoidosis and the smoking status of a sarcoidosis patient are crucial for interpreting individual lavage analysis results.