Peripheral complement C3 and C4 are associated with clinical features of schizophrenia

Area of Science:

• Neuroscience
• Immunology
• Psychiatry

Background:

• Schizophrenia presents with varied outcomes influenced by factors like anxiety, childhood trauma, and duration of untreated psychosis (DUP).
• Immune dysregulation, specifically involving complement components C3 and C4, is implicated in schizophrenia pathophysiology, yet peripheral levels and clinical links are inconsistent.

Purpose of the Study:

• To explore the associations between peripheral complement component levels (C3 and C4) and clinical characteristics in patients with schizophrenia.
• To investigate the relationship between C3, C4, symptom severity, anxiety, cognitive function, childhood trauma, and illness duration in schizophrenia.

Main Methods:

• Thirty-nine schizophrenia patients were assessed using the Childhood Trauma Questionnaire (CTQ), Positive and Negative Syndrome Scale (PANSS), State-Trait Anxiety Inventory (STAI), and Montreal Cognitive Assessment (MoCA).
• Serum concentrations of C3 and C4 were measured at admission.

Main Results:

• Exploratory analyses indicated correlations between baseline C3 and DUP (r=0.407, p=0.010) and hospitalization length (r=0.353, p=0.028).
• Higher C3 and C4 levels were associated with increased symptom severity (PANSS), anxiety (STAI), and childhood trauma (CTQ subscales). C3 also correlated negatively with cognitive performance (MoCA).
• None of these associations remained significant after Benjamini-Hochberg false discovery rate correction (all q>0.05).

Conclusions:

• These exploratory findings suggest potential relationships between peripheral complement markers and clinical variations in schizophrenia.
• Replication in larger, controlled longitudinal studies is necessary to validate these preliminary associations.