Significance of lymphocyte fluorescence polarization changes after phytohemagglutinin stimulation in cancer and noncancer conditions.

The double-zone fluorescein fluorescence polarization (FFP) "cancer" test was used to study 540 blood lymphocyte samples from 341 donors, of whom 158 had confirmed cancer: The other donors were noncancer patients, pregnant women, and normal individuals. The FFP response in cancer patients was the reverse of that in normal individuals, but an abnormal response was also obtained in some noncancer conditions, including the chronic inflammatory disorders--rheumatoid arthritis, cholecystitis, and diverticulitis--and in early pregnancy or pregnancy-induced hypertension. Thus the cancer discriminatory value of the test is limited. Examination of its biologic basis suggests that the positive FFP response in cancer and other conditions is due to altered immune status of blood lymphocytes, with associated change in cytoplasmic fluidity affecting the polarization of fluorescence. Incubation of normal blood lymphocytes with cyclic GMP induced an abnormal, cancer-like FFP response.