A series of fucosylated glycosphingolipids with the "X" determinant (Gal beta[unreadable]1[unreadable]\\4[Fuc alpha[unreadable]1[unreadable]\\3]GlcNAc) have been shown to accumulate in human colonic and liver adenocarcinoma and are virtually absent in normal colonic mucosa and normal liver tissue. However, small quantities of fucolipids with the "X" determinant (Le[unreadable]x[unreadable]) are distributed in normal tissues, such as gastric epithelia and kidney tubules. Preliminary studies indicated the presence of Le[unreadable]x[unreadable] glycolipids in the circulating immune complexes of breast and colon adenocarcinoma patients, whereas none were detected in normal human or melanoma patients. The aim of this study is to determine whether the Le[unreadable]x[unreadable]-related immune complexes are present specifically in the sera of adenocarcinoma patients. The specific fucolipids will be isolated from the serum of colon, breast, liver, and lung adenocarcinoma patients; characterized by thin layer chromatographic immunostaining, partial methylation, and mass-spectral analysis. Solid phase assays using monoclonal antibodies will be developed to screen quantitatively for the Le[unreadable]x[unreadable] antigens in the circulating immune complexes of adenocarcinoma patients. These immune complexes will be obtained by passing the patient's plasma over protein A linked to an inert support (Prosorba[unreadable]TM[unreadable]). Correlation between the removal of the Le[unreadable]x[unreadable]-related immune complexes by successive protein A treatments to the prognosis of the disease will be established. These studies will determine the usefulness of Le[unreadable]x[unreadable] antigens as a diagnostic and/or prognostic indicator in adenocarcinoma. (5)