MicroRNAs and Pro-Inflammatory Cytokines as Candidate Biomarkers for Recent-Onset Psychosis

Abstract

Recent studies on the schizophrenia spectrum and other psychotic disorders showed that alternation of immune system components, particularly microRNAs (miRNAs) and pro-inflammatory compounds, plays a significant role in developing the illness. The current study aimed to evaluate serum expression of the miRNA-26a, miRNA-106a, and miRNA-125b as genetic factors and serum levels of IL-6, IL-1β, and TNF-α as pro-inflammatory factors; then investigated the correlation between these elements in an Iranian Azeri population. Forty patients with recent-onset non-affective psychosis and 40 healthy volunteers as a control group were involved. Expression levels of miRNAs and serum levels of the cytokines were measured using PCR and ELISA, respectively. Our findings showed higher levels of IL-6, IL-1β, TNF-α, miR-26a, and miR-106a in the plasma of the patients' group compared with the control. miRNA-26a showed a statistically significant higher level (p< .0003) compared to the control group, with AUC = 0.8434 (95% CI: 0.7690 to 0.9378, P< .0001) and cut-off point = 0.1726 in comparison to other miRNAs as mentioned above; in this regard, it might be a suggestive biomarker for schizophrenia in the early stage of the illness. Moreover, miRNAs' expression level was not substantially associated with the level of any measured cytokines above. The relationship between other miRNAs and cytokines is not yet well understood; accordingly, there are encouragement and support for continued research in this fascinating field. Funding Statement: This work also was supported by the Faculty of Medicine Tabriz University of Medical Sciences with grant number 65618/D/5. Declaration of Interests: None to declare. Ethics Approval Statement: The regional ethics committee approved the research proposal with the registration code I.R.TBZMED.REC.1397.965 at Tabriz University of Medical Sciences.