Growth factor receptor profiles across schizophrenia spectrum disorders: associations with disease stage and clinical course
Schizophrenia is a chronic psychiatric disorder that significantly impairs quality of life. Its causes are complex, involving genetic predisposition, environmental factors, neurodevelopmental issues, chronic inflammation, and neurotransmitter disturbances. As diagnosis is primarily symptom-based, there is growing interest in identifying objective biomarkers related to neural development and synaptic plasticity, such as nerve growth factor receptor (NGFR), epidermal growth factor receptor (EGFR), and integrin β1 (ITGB-1), which may play a role in the disorder’s pathophysiology. To assess serum concentrations of NGFR, EGFR, and ITGB-1 receptors in individuals with deficit schizophrenia (DS), non-deficit schizophrenia (NDS), first-episode psychosis (FEP), and ultra-high risk of psychosis (UHR), compared with healthy controls. The study included 93 patients treated at the Department of Psychiatry, Pomeranian Medical University in Szczecin, categorized into DS ( n = 19), NDS ( n = 37), FEP ( n = 25), and UHR ( n = 12) groups, as well as 34 healthy controls. Serum concentrations of NGFR, EGFR, and ITGB-1 were determined using ELISA. Statistical analyses were performed using RStudio, with p < 0.05 considered statistically significant. Patients in pre-psychotic and early psychosis states (FEP, UHR) had significantly lower NGFR concentrations than controls (FEP: p = 0.025; UHR: p = 0.018). Higher NGFR levels were linked to more disease exacerbations (OR = 3.105; p = 0.011). EGFR concentrations were elevated across all patient groups (DS, NDS, FEP; p < 0.001; UHR; p = 0.003) and increased with exacerbations. Aripiprazole treatment reduced EGFR levels (OR = 0.420; p = 0.002). ITGB-1 levels were higher in all patient groups (DS, NDS, FEP; p < 0.001; UHR; p = 0.014) and were associated with exacerbations, but were lower with aripiprazole treatment. Age-related variability was seen in ITGB-1 concentrations. NGFR may serve as a potential marker for early schizophrenia states and disease activity. While EGFR and ITGB-1 levels do not distinguish between schizophrenia stages, they may indicate illness severity and treatment response. The connections between receptor concentrations, age, exacerbation frequency, and pharmacotherapy underscore the complexity of growth factor-related signaling in schizophrenia disorders. Larger studies are needed to clarify the clinical utility of these biomarkers.