[The clinical significance of tumor-associated glycosylated antigen, sialylated Lewis].

The clinical significance of tumor-associated glycosylated antigen, sialylated Lewisx (SLEX) was demonstrated with reference to pulmonary diseases by fluorescent enzyme immunoassay. In benign lung diseases 5.5% were positive for serum SLEX. Lung cancer, the highest percentage positivity was seen in adenocarcinoma (41.7%), and clinical stage III and IV showed 36.2% and 41.9%, respectively. These results indicate that SLEX might conceivably be useful as a tumor marker, particularly for adenocarcinoma of the lung. Using Sephacryl S-1000 columns the elution profiles of sera and bronchoalveolar lavage in cases of lung cancer, gastric cancer and diffuse panbronchiolitis were also investigated, and it was concluded that the release mechanism of the antigen into blood stream in the malignant diseases is different from that in benign disease and the carrier protein binding to the antigen varies according to the disease.