Use of Monoclonal Antibodies to Sialylated Lewisx and Sialylated Lewisa for Serological Tests of Cancer

Abstract A new monoclonal antibody, CSLEX1, directed against sialylated Lewis x was tested in parallel with a monoclonal antibody, CSLEA1, directed against sialylated Lewis a antigen. In tests with a solid-phase radioimmune sandwich assay, the sialylated Lewis x monoclonal antibody detected sera from certain cancer patients that were negative with the sialylated Lewis a monoclonal antibody. Some sera from cancer patients showed the reverse reaction. We conclude that the combined use of these two monoclonal antibodies detects a wider range of sera from cancer patients than the use of a single antibody alone. It should be possible in the future to use multiple monoclonal antibodies to increase detection.