THE ANTIDEPRESSANT FLUVOXAMINE INCREASES NATURAL-KILLER-CELL COUNTS IN CANCER-PATIENTS

Knowing the negative effect of depression on lymphocyte number and act ivity in humans, we investigated the effect of antidepressant therapy on various lymphocyte subgroups. Cancer patients receiving treatment f or at least 6 months were asked to take the antidepressant, fluvoxamin e, for 28 days. Before and at the end of the study, physical and psych iatric examinations were performed, and the severity of depression was assessed by the Hamilton Scale for Depression (HAM-D). In addition, a sample of blood was withdrawn from the patients to quantify the follo wing parameters: total leukocyte and lymphocyte counts, T4, T8, and Na tural Killer (NK) cells, and lymphocyte response to the mitogens phyto hemagglutinin (PHA) and pokeweed (PWM). Ten adult patients completed t he study. Five of the 10 responded favorably to fluvoxamine treatment. Mean improvement was 50% from the score on day one. There was a signi ficant correlation between the change in the HAM-D score of the ''resp onders'' and the change in NK cell counts (p=0.02). The mean increment in NK cell number was 53%. In 4 of the 5 ''non-responders'', NK cell number dropped by 65% (mean). No correlation between the change in HAM -D score and any other immunological parameters was detected. Fluvoxam ine increases NK cell counts in cancer patients, probably by its antid epressant effect.