Decreased IL-1ra and NCAM-1/CD56 serum levels in unmedicated patients with schizophrenia before and after antipsychotic treatment

Objective Schizophrenia (SZ) has been associated with the inflammatory-related and immunological pathogenesis. This study investigates the aberration of cytokines in patients with SZ. Methods Thirty patients with SZ without antipsychotic treatment for at least two weeks participated. We measured the serum levels of fourteen cytokines at hospital admission and after 8-week antipsychotic treatment. Severity was measured by expanded version of 24-items brief psychiatric rating scale (BPRS-E). Repeated measure analyses of variance were conducted. Results The interleukin-1 receptor antagonist (IL-1ra) was significantly decreased after 8-week antipsychotic treatment than those of before antipsychotic treatment (F=12.15, df=1/30, p=0.002). Neural cell adhesion molecule 1/CD56 (NCAM-1/CD56) was significantly decreased (F=6.61, df=1/30, p=0.016) among those with second-generation antipsychotics but not first-generation antipsychotics treatment. The changes of BPRS-E-manic and BPRS-E-anxiety scores correlated with the baseline IL-1ra (r=-0.393), IL-6 (r=-0.407), and insulin like growth factor binding protein 3 (r=-0.446). Additionally, the changes of BPRS-E and BPRS-E-negative scores correlated with the changes of brain-derived neurotrophic factor (r=0.372) and interferon-gamma (r=0.375). Conclusion Our study supports that IL-1ra and NCAM-1/CD56 may be considered as markers of developing SZ.