Serum High Mobility Group Box Protein-1 Levels in Schizophrenia During Acute Psychotic Episodes and Remission

High mobility group box-1 (HMGB1) is a non-histone protein that plays a role in neuroinflammation by inducing cytokines. We aimed to compare HMGB1 levels in patients with schizophrenia in both acute exacerbation and remission phases and in healthy controls and to determine whether HMGB1 correlates with symptom severity and C-reactive protein (CRP), neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and monocyte/lymphocyte ratio (MLR).

The study included 31 schizophrenia patients in remission and 31 schizophrenia patients hospitalised for acute psychotic exacerbation and 30 healthy controls. Serum HMGB1 levels were measured by enzyme-linked immunosorbent assay (ELISA). Brief Psychiatric Rating Scale (BPRS), Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impression Scale (CGI) were used to assess symptom severity.

Serum HMGB1 levels were found to be significantly higher in both the remission group (140.48±63.52 pg/ml) and the acute exacerbation group (125.92±48.71 pg/ml) compared to healthy controls (57.44±13.04 pg/ml) (p<0.05). There was no statistically significant difference in serum HMGB1 levels between patients in remission and patients in acute psychotic exacerbation. There was no correlation between serum HMGB1 levels and severity of symptoms. No significant correlation was found between serum HMGB1 levels and other inflammatory markers. There was a statistically significant negative correlation between serum HMGB1 levels and chlorpromazine-equivalent antipsychotic doses (rs=-0.316, p=0.047).

Our findings suggest that HMGB1 levels are elevated in individuals with schizophrenia, regardless of phase, which may reflect trait-like characteristics of the disorder. However, further research is needed to confirm this. Increased HMGB1 may contribute to schizophrenia pathogenesis through neuroinflammation.