Fluorescence-polarization changes in mononuclear blood leucocytes after PHA incubation: differences in cells from patients with and without neoplasia.

In 32 healthy blood donors, 20 patients with histologically verified cancer and 18 patients with non-neoplastic diseases, the fluorescence polarization changes of fluorescein samples incorporated in mononuclear leucotyes were measured after incubation with PHA. The leucocytes of healthy persons, and 16/18 persons with non-neoplastic diseases, responded with a decrease in the degree of fluorescence polarization by about 20% from that in non-PHA-stimulated cells. In 19/20 patients with a variety of malignant tumours, the leucotyes did not respond to PHA stimulation with such a decrease. The exceptions among the patients with neoplastic and non-neoplastic diseases are considered, and may not be "false-negative" or "false-positive" respectively, but indicative of a particular situation in that disease. The biophysical mechanisms underlying the observed changes remain to be investigated.