[Application of monoclonal antibody to detect the red cell associated antigen LewisX and sialylated LewisX in the serum of cancer patient].

New monoclonal antibodies, CGAD2 and CSLEX1 detected their red cell associated antigens LewisX and sialylated LewisX in serum of cancer patients by reverse passive hemagglutination. With CGAD2, high titers were noted in 56% of the 27 sera from lung adenocarcinoma patients. Of the total 105 sera from cancer patients, 39% showed a positive reaction.

Detection of sialylated LewisX antigen in cancer sera using a sandwich radioimmunoassay.

A monoclonal antibody directed against sialylated LewisX (SLEX) was tested with the serum of 615 cancer patients, 166 patients with non-malignant diseases, and 136 normal persons. The SLEX antibody reacted with the sera of the cancer patients in the following percentages: 29% lung, 19% breast, 12% ovary, 25% colorectal, 13% head and neck, and 13% miscellaneous. SLEX was positive for 22% of stages III and IV (late-stage) cancers as compared with 5% early-stage tumors.