This cross-sectional observational study evaluated serum levels of Leucine-rich repeat and fibronectin type III domain-containing protein 5 (LRFN5) and Olfactomedin-4 (OLFM4) in patients with schizophrenia during acute exacerbation and in healthy controls. The study also assessed associations between these biomarkers and clinical symptom severity, global functioning, and systemic inflammation measured by the Aggregate Index of Systemic Inflammation (AISI). The study aimed to investigate convergent synaptic and immunoinflammatory dysregulation in schizophrenia.