The influence of the immune deregulation on the risk and psychopathology of schizophrenia is increasingly recognized in the literature.

To assess the association between serum IL-1RA on schizophrenia psychopathology.

We recruited 88 schizophrenia patients (38 males and 49 females, mean age 38.12 ± 12.67 years) and 88 healthy adult control subjects (68 males, 20 females, mean age 40.63 ± 7.99 years). Lifetime psychopathology was evaluated using Operational Criteria for Psychotic Illness (OPCRIT) checklist, while current psychopathology was assessed using Positive and Negative Syndrome Scale (PANSS). Serum samples were stored in aliquots at –80 °C. Serum levels of IL1-RA were measured using Immunoassay (ELISA).

There were statistically significant differences between schizophrenia patients and healthy controls (median ± interquartile range: 350,81 ± 227.04 and 888.74 ± 762.63, respectively [pg/ml]) (U Mann–Whitney test, Z = –7.99, P < 0.0001). There were no differences in serum IL1-RA levels between male and female among patients with schizophrenia (U Mann–Whitney test, Z = –0.22, P = 0.82) nor among healthy control subjects (U Mann–Whitney test, Z = –0.17, P = 0.86). Among schizophrenia patients, there was a trend-level association between IL-1RA serum level with negative symptoms (Spearman correlation coefficient, r = –0.23, P = 0.056), positive symptoms (Spearman correlation coefficient r = –0.22, P = 0.066), and on a statistically significant level with general symptoms (Spearman correlation coefficient r = –0.28, P = 0.018).

Serum IL1-RA level is higher in schizophrenia patients in comparison to healthy controls and it is associated with schizophrenia psychopathology.

The authors have not supplied their declaration of competing interest.