Response of human lymphocytes to PHA and tumour-associated antigens as detected by fluorescence polarization.

Fluorescence polarization measurement during the progress of fluorochromasia has been used to study the response of human lymphocytes to phytohaemagglutinin (PHA) and to tumour-associated antigens, as a basis for the detection of malignant disease. Polarization (P) values of both stimulated and unstimulated lymphocytes decreased with increasing intracellular fluorescence intensity, and with the duration of the fluorochromatic reaction. When these effects were taken into account, there was no significant difference in the change of P following stimulation of lymphocytes from 50 cancer patients or healthy subjects; the magnitude of the response was related more to the age of the donor and to the extent of granulocyte contamination of the lymphocyte preparation than to the presence of cancer. There were, however, significant differences in the change in leakage of fluorescein out of the lymphocytes and in the change in hydrolysis rate after PHA stimulation between lymphocytes from healthy individuals and from patients with cancer.