Evaluation of Changes in Peripheric Biomarkers Related to Blood Brain Barrier Damage in Patients with Schizophrenia and Their Correlation with Symptoms

OBJECTIVE: The aim of the study was to evaluate the levels of peripheric biomarkers that have been associated with blood brain barrier (BBB) damage in healthy controls and two groups of patients with schizophrenia, those who received typical-atypical antipsychotics and those who received only atypical antipsychotics. Additionally, we sought relationships between these biomarkers and schizophrenia symptoms. METHODS: This study was conducted with the inclusion of 41 healthy volunteers and 75 patients with schizophrenia. The biomarkers measured to evaluate BBB injury were as follows spectrin breakdown product 145 (SBDP145), spectrin breakdown product 150 (SBDP150), ubiquitin carboxy terminal hydrolase L1 (UCHL1), ubiquitin ligase cullin-3 (cullin), occludin and claudin, which were measured via ELISA. Symptoms of patients with schizophrenia were evaluated with the Scale for the Assessment of Positive Symptoms (SAPS), Scale for the Assessment of Negative Symptoms, the Clinical Global Impression Scale (CGI), and the general assessment of functionality (GAF). RESULTS: Compared to controls, SBDP145 (p = 0.022) and cullin (p = 0.046) levels were significantly higher in patients with schizophrenia receiving atypical antipsychotic treatment. SBDP150 levels were lower in the combination treatment group compared to the control group (p = 0.022). Claudin (p = 0.804), occludin (p = 0.058) and UCHL1 (p = 0.715) levels were similar among groups. In recipients of combination treatment, SBDP145 levels were found to be positively correlated with SAPS-total (r = 0.440, p = 0.036) and SAPS-delusions (r = 0.494, p = 0.017) scores. CONCLUSION: The relationships demonstrated in this study indicate that more comprehensive research is needed to understand whether BBB defects contribute to clinical characteristics in patients with schizophrenia.