Correlation between serum levels of interleukin-4 and alexithymia scores in healthy female subjects: preliminary findings.

Some studies suggest that inaccuracy in recognizing and describing emotional states, combined with a highly descriptive mode of expression, as in alexithymia, may influence the immune response. We therefore investigated in healthy women the relationship between alexithymia and circulating levels of IL-1, IL-2 and IL-4. Seventeen mentally and physically healthy women aged between 20 and 25 years completed psychological questionnaires to assess alexithymia (Toronto Alexithymia Scale: TAS) and depressed mood (Hospital Anxiety and Depression Scale: HAD). Serum concentrations of IL-1, IL-2 and IL-4 were measured by ELISA. We found a significant positive correlation between serum levels of IL-4 and TAS score (r=0.55; p=0.021) and between factor 1 of the TAS (difficulty in identifying feelings) and IL-4 (r=0.57; p=0.017) while serum IL-1 and IL-2 were not detected in ten and six patients, respectively. Although there was a significant correlation between age and IL-4 levels, a linear regression with BMI, age, depressed mood and TAS as independent variables showed that only alexithymia could predict significantly increased levels of IL-4. Alexithymia and difficulty in identifying feelings could be associated with increased levels of IL-4 which may result in chronic impairment of pro/anti-inflammatory cytokine balance with psychological and somatic consequences. Nevertheless, these intriguing findings would deserve replication and extension in a larger sample of subjects.