Inhibition of leukocyte migration by tumor-associated antigen and its modification by serum; IgA as a blocking factor.

Based on the investigations of patients the migration inhibition assay proved to be a useful method for the detection of antitumorous cellular immunity. Out of the twenty patients tested 15 gave migratory inhibitory effect against specific tumor antigen. In 8 cases out of the above 15 the blocking activity of sera has been proved. This blocking activity is bound to IgA subclass. The complement played an "unblocking" role. The modifying role of serum factors in cellular immunity against tumors was discussed.