ABSTRACT
A possible association of serum anti-T IgM and IgG antibody levels with Lewis blood-group phenotype was investigated in 168 blood donors and 132 gastric cancer patients using ELISA with synthetic T-disaccharide-polyacrylamide conjugate as antigen. The donors of Le(a-b+) phenotype showed the highest anti-T IgM level irrespective of ABO(H) blood group. A significant decrease in anti-T IgM in serum was observed among cancer patients of Le(a-b+) phenotype: 95% of weak responders versus 17.5% for related groups of donors (p < 10(-6)). In contrast, no significant difference between patients and donors was found for Le(b-) individuals. Thus, a level of natural anti-T antibodies in serum of blood donors and its decrease in patients with gastric cancer are related to Le(a,b) phenotype. This should be taken into account where anti-T antibody level in the serum is used as a tumour marker or for monitoring patients during cancer immunotherapy with mucin-type vaccines.
