Leukocyte adherence inhibition assay in immunodiagnosis of colon cancers.

35 colon cancer patients and 80 control subjects were submitted to tube leukocyte adherence inhibition test (LAI test), where leukocytes do not adhere to glass in the presence of an antigen to which they are sensitized. The test was performed with the Thomson method; washed leukocytes and 3M KCl tissue extracts were used (as source of antigens colon and unrelated cancer extracts, as control normal colon). Non-adherent cell difference was evaluated by a non adherence index (NAI), indexes higher than 25 were regarded as positive, lower as negative. The test proved to be a high selective test, which can reliably single out the earliest (A and B Dukes' stages) and less differentiated cancers.