Prospective evaluation of the leukocyte adherence inhibition (LAI) test in breast cancer using a panel of extracts from known and unknown primary tumors

Leukocyte adherence inhibition in patients with nonmalignant disorders of the colon and colorectal cancer

The tube leukocyte adherence inhibition (LAI) technique was used to investigate the antitumor immunity in two groups of patients generally considered to be at "high risk" of developing colorectal cancer. The first group comprised 21 patients with colorectal polyps and the second 12 patients with various forms of colitis. Also 29 patients with histologically confirmed colorectal cancer were tested. The tube LAI assay was performed using peripheral blood leukocytes from individual patients and crude extracts of colorectal and breast cancers. Positive LAI reactions were observed in 18 out of 29 (62%) patients with colorectal cancer, in 1 out of 21 (5%) patients with colorectal polyps and in 1 out of 12 (8%) patients with colitis. The results indicate that in confirmed cases of malignancies, sensitization to colon tumor-associated antigens could be detected in the tube LAI test, whereas, premalignant sensitization to these antigens in "high risk" groups of patients could not be demonstrated.

Detection of different states of immunity to colon cancer in rats by a leukocyte adherence inhibition (LAI) assay assessing the adherence of T lymphocytes and monocytes selectively

Peripheral blood mononuclear cells (MNC) of rats, which had received a subcutaneous inoculation of either viable or X-irradiated syngeneic DMH-W49 colon carcinoma cells, were investigated sequentially for sensitization against tumor-associated antigens by a new micro-glass-tube leukocyte adherence inhibition (LAI) assay. The number of adherent cells of MNC subpopulations was estimated by a cellular radioimmunoassay (CRIA), which utilizes anti-monocyte (MC) antiserum or anti-T-cell monoclonal antibody (McAb) and 125I-labelled protein A. LAI reactivity was demonstrated in rats sensitized with X-irradiated tumor cells when assessing the adherence of both T lymphocytes and monocytes. It was found that reactivity with the two different types of indicator cells did not usually coincide in time. The same phenomenon was also observed in tumor-bearing rats although with lower levels of LAI reactivity. In both groups the LAI response detected by anti-T-cell reagent mostly appeared earlier after tumor-cell inoculation than the response demonstrated by anti-MC serum. The T-lymphocyte-associated reactivity also disappeared more rapidly. These results suggest that different states of immune reactivity are reflected in LAI responses involving T lymphocytes and monocytes as indicator cells.