Inhibition of leucocyte migration by tumour-associated antigens of the colon and rectum.

The test of leucocyte migration inhibition has been used to detect lymphocyte sensitization to tumour-associated antigens of the colon and rectum. The procedure for the isolation of antigens from colorectal adenocarcinomata and normal colonic mucosa is described. The circulating lymphocytes of 22 patients suffering from colorectal adenocarcinomata of various stages have been examined and compared with the results obtained for identical studies performed on the peripheral lymphocytes of 15 control subjects. Sensitization of lymphocytes to tumour antigen was demonstrated in 15 of the 22 patients when culture was performed in homologous AB serum. Of these 15 patients only six showed inhibition of leucocyte migration in the presence of tumour extract when culture was performed in autologous serum. These observations would suggest the presence of factors in the serum of such patients which may prevent the expression of cellular immunity to tumour antigens.