Investigation of heme oxygenase-1(HO-1), KELCH-like ECH-associated protein 1 (KEAP1), nuclear factor erythroid-2-associated factor 2 (NRf2), and interleukin-38(IL-38) levels in patients with schizophrenia

Objective: Our aim in this study is to evaluate serum HO-1, KEAP1, NRF2 and IL-38 levels, which we think may be associated with the pathology of the disease, in schizophrenia patients admitted to the outpatient clinic or hospitalized, and to investigate whether there is a difference compared to the healthy control group and to investigate the relationship between these biochemical parameters and the severity of the disease. Materials and Methods: The sample of the study consisted of schizophrenic patients who applied to the Dicle University Psychiatry Outpatient Clinic or were followed up in the clinic between June 2021 and June 2022, and healthy volunteers matched in terms of age, gender, education level and smoking status, and all participants were evaluated by a psychiatrist. People between the ages of 18-65 were included in our study and two groups were formed. Group 1: 93 patients diagnosed with schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Group 2: It consisted of 87 healthy volunteers who did not have any psychiatric diagnosis. After the participants signed the informed consent form, the sociodemographic data form was filled in for the patient and control groups. Positive and Negative Syndrome Scale, Clinical Global Imaging Scale, Sheehan Disability Scale, Calgary Depression in Schizophrenia Scale and Hamilton Anxiety Scale were applied only to the patients in the patient group. Venous blood samples were collected from the participants after at least 12 hours of fasting. HO-1, KEAP1, NRF2 and IL-38 levels were studied in the laboratory by ELISA method. SPSS 24.0 statistical package program was used in the analysis of the data. Findings: In our study, Nrf2, Keap1, Ho1, IL-38 serum levels were found to be significantly lower in patients with schizophrenia compared to the healthy control group. In addition, a significant positive correlation was found between Nrf2, Keap1, Ho1, IL-38. A significant negative correlation was found between PANSS total, PANSS negative findings subscale, PANSS general psychopathology subscale, Clinical global follow-up scale and serum Nrf2 and Keap1 levels. Conclusions: According to our study results, it is valuable that Nrf2, Keap1, Ho1, IL-38 serum levels were found to be significantly lower in patients with schizophrenia compared to the healthy control group, and that there was a positive significant correlation between Nrf2, Keap1, Ho1, IL-38. The low course of Nrf2, Keap1, Ho1, which plays a role in the antioxidant mechanism in schizophrenia patients, suggested that it may have been insufficient in balancing the oxidative stress.In order to fully elucidate the role of these biochemical parameters in the etiopathogenesis of schizophrenia, large-scale studies that can also evaluate their effects on brain pathways are needed.