Decreased cytotoxic lymphocyte counts in alexithymia

Background: Alexithymia is a psychological trait characterized by a difficulty in verbalizing feelings, which has been associated with a number of illnesses, including bronchial asthma and cancer. Methods: In order to understand how psychological variables such as alexithymia affect physical health, we compared the lymphocyte subsets of men (n=97, mean 30.6) rated as high and low alexithymic when measured by the Toronto Alexithymia Scale (TAS). We analyzed our data by considering alexithymia a categorical variable, using TAS scores of 62 and below, and 74 and above, and by considering alexithymia a continuous variable, using the mean TAS score (64.01) separating high from low alexithymia. Results: When alexithymia was considered a categorical variable, highly alexithymic men had significantly lower numbers of the most cytotoxic natural killer (NK) subset, (CD57-CD16+ cells). When alexithymia was considered a continuous variable, in addition to the NK subset, killer effector T cell (CD8+CD11a+cells) count was also significantly lower. These results were obtained after controlling for possible effects of smoking and alcohol intake. Conclusions: These results suggest that the negative modulation of cellular immunity, especially the cytotoxic lymphocytes, may be one mechanism which, combined with other factors that have a negative effect on the immune system such as stress, results in the association between alexithymia and ill health. It is suggested that future studies should, in addition to cell counts, attempt to identify the effects of psychological variables on the cytolytic activity of cytotoxic lymphocytes. Furthermore, follow-up studies should monitor the subjects over the years to demonstrate that alexithymia-mediated negative modulation of the immune system results in clinical pathologies.