Prognostic value of a 90kD subunit containing glycoprotein tumor-associated antigen specific immune complexes in lung...

An ELISA to detect a glycoprotein TAA-specific immune complexe (IC) has been developed utilizing a murine monoclonal antibody, AD1-40F4, that recognizes a 90kD subunit of the antigen. In this study we determined the applicability of the assay to assess the presence of the glycoprotein TAA-IC in lung cancer patients. The incidence of glycoprotein TAA-IC was 63% (33/89), significantly higher (p < 0.05) than normal controls (3.2%; 8/250). Comparative analyses of pre- and post-operative sera of non-small cell lung cancer patients revealed that in 30% (20/66) of patients, the ELISA value for the marker did not become negative, i.e., decrease below the cut-off level (0.410 ODnm) after surgical resection of the tumor. It is postulated that these patients either had extensive disease or microscopic metastases that were not resectable. Evaluation of post-operative glycoprotein TAA-IC results in relation to disease recurrence revealed a significant association between the presence of the antigen in serum and disease recurrence. There did not appear to be any association between the glycoprotein TAA-IC and the other conventional marker, CEA; however, using more than one marker increases the incidence of detection of the disease.