Schizophrenia (SZ) is associated with changes in haematological parameters related to low-grade inflammation state and could be amplified via oxidative stress (OS) related mechanisms. Although studies confirm this relationship, the results could be cofounded by patients’ treatment.

The study aimed to assess the connection between venous blood count and OS in drug-naïve first-episode SZ patients.

The study consisted of 24 SZ drug-naïve patients during first episode of psychosis (median age: 22 years), and 31 healthy individuals (HC) as a control group (median age: 28 years). The examination included clinical data, OS parameters (enzymatic and non-enzymatic antioxidants), peripheral blood counts.

We did not find differences between SZ and HC in blood count parameters (p>0.05). In patients group, white blood cells (WBC), neutrophils and neutrophils-to-lymphocyte ratio (NLR) were positively related with the severity of positive symptoms (R=0.59, R=0.53, R=0.50; p<0.05, respectively). WBC was related to superoxide dismutase (SOD-1) levels (HC: R=-0.36, SZ: R=0.70; p<0.05). Neutrophils were positively related to catalase (CAT) (R=0.52; p<0.05) and ferric reducing antioxidant power (FRAP) (R=0.61; p<0.05), but only in the patients’ group. There was a positive relationship between NLR and CAT (R=0.45; p<0.05) in the SZ group.

The results indicate potential connection and interplay between OS and blood count parameters in the onset of psychotic episode. Further studies on a larger group of patients are needed.

No significant relationships.

This meta-analysis on peripheral blood compounds in drug-naïve first-episode patients with either schizophrenia or major depressive disorder (MDD) examined which compounds change following psychopharmacological treatment.

The Embase, PubMed and PsycINFO databases were systematically searched for longitudinal studies reporting measurements of blood compounds in drug-naïve first-episode schizophrenia or MDD.

For this random-effects meta-analysis, we retrieved a total of 31 studies comprising 1818 schizophrenia patients, and 14 studies comprising 469 MDD patients. Brain-derived neurotrophic factor (BDNF) increased following treatment in schizophrenia (Hedges' g (g): 0.55; 95% confidence interval (CI) 0.39–0.70; p < 0.001) and MDD (g: 0.51; CI 0.06–0.96; p = 0.027). Interleukin (IL)-6 levels decreased in schizophrenia (g: −0.48; CI −0.85 to −0.11; p = 0.011), and for MDD a trend of decreased IL-6 levels was observed (g: −0.39; CI −0.87 to 0.09; p = 0.115). Tumor necrosis factor alpha (TNFα) also decreased in schizophrenia (g: −0.34; CI −0.68 to −0.01; p = 0.047) and in MDD (g: −1.02; CI −1.79 to −0.25; p = 0.009). Fasting glucose levels increased only in schizophrenia (g: 0.26; CI 0.07–0.44; p = 0.007), but not in MDD. No changes were found for C-reactive protein, IL-1β, IL-2 and IL-4.

Psychopharmacological treatment has modulating effects on BDNF and TNFα in drug-naïve first-episode patients with either schizophrenia or MDD. These findings support efforts for further research into transdiagnostic preventive strategies and augmentation therapy for those with immune dysfunctions.