Electrophoretic mobility (EM)-test for childhood cancer diagnosis.

Lymphocyte sensitization to myelin basic protein (encephalitogenic factor, EF) was determined in 193 children by measuring the electrophoretic mobility of indicator particles which had been incubated with the supernatant of the lymphocyte-antigen (EF) mixture. A significant decrease in electrophoretic migration time was found in 77 of 85 children with malignant tumours localized in brain, abdomen and extremities, in 36 of 38 children with acute lymphoblastic leukaemia (all except one in hematological remission), and in all 17 patients with lymphoma, in contrast to only 1 of 10 healthy children and 14 of 48 patients with non-malignant disorders. 10 of these 14 "false positive" patients, however, had auto-immune diseases. Thus, with false negative and false positive rates of less than 10%, this test could be of diagnostic help in patients with suspected malignant or auto-immune disease. Two examples of preoperative application of the EM-test are demonstrated.