Comparison between the macrophage electrophoretic mobility (MEM) and the fixed tanned erythrocyte electrophoretic mobility (FTEEM) tests in the detection of cancer.

When peripheral lymphocytes from patients with a history of cancer are incubated with encephalitogenic factor (EF), in 90% of cases the resulting products reduce the net surface negativity of guinea-pig macrophages, used as detector cells, as revealed in the macrophage electrophoretic mobility (MEM) test. The MEM test is positive in 36% of people with no history of cancer. Formaldehyde-fixed tanned sheep erythrocytes have been used as detector cells in place of guinea-pig macrophages, in a fixed tanned erythrocyte electrophoretic mobility (FTEEM) test, with lymphocyte products identical to those used in MEM tests. In patients with a history of cancer, positive results were obtained in 28/42 cases with the FTEEM test compared with 32/42 in the MEM test. In people with no history of cancer, negative results were obtained in 16/18 cases with the FTEEM test, compared with 12/18 in the MEM test in the present series, and 51/69 in a more extensive series. These differences are not significant. Cases in which discrepancies are revealed between the two tests are discussed in terms of individual case histories.