Different serum protein factor levels in first‐episode drug‐naive patients with schizophrenia characterized by positive and negative symptoms

Abstract

Aim The clinical features of schizophrenia can be mainly divided into two symptom domains: positive and negative. Patients in each symptom domain respond differently to treatments, and their prognoses vary accordingly. Serum protein factors, such as nerve growth factor (NGF), neurotrophin‐3 (NT‐3), interleukin‐6 (IL‐6), interleukin‐1 beta (IL‐1β), and the calcium‐binding protein, S100β, have been reported to be involved in the pathogenesis of schizophrenia. However, their roles in the positive and negative symptom domains have not been determined. In this study, we investigated whether the serum levels of these five protein factors differed among first‐episode drug‐naive schizophrenia patients in each symptom domain and in healthy controls. Methods Double‐antibody sandwich ELISA were used to quantify the amounts of the five protein factors in serum. Results Compared with the levels in the controls (n = 60), increased serum levels of IL‐6, IL‐1β, and S100β and decreased serum levels of NGF and NT‐3 were observed in first‐episode drug‐naive schizophrenia patients. Additionally, the serum levels of IL‐6 and IL‐1β were significantly higher in schizophrenia patients characterized by negative symptoms (negative group, n = 37) than in those characterized by positive symptoms (positive group, n = 46). Based on multivariate regression analyses, serum levels of IL‐1β were positively associated with the Negative Symptom subscore of the Positive and Negative Syndrome Scale in the negative group and in all patients with schizophrenia. Conclusion The two subtypes of schizophrenia may have different pathological mechanisms. Patients characterized by negative symptoms probably have more serious disturbances in neuroimmunology.

Cognition in Schizophrenia: Modeling the Interplay between Interleukin-1β C-511T Polymorphism, Metabolic Syndrome, and Sex

“…Specifically, acute exacerbations seem to create an increase in their values [75]. Still, other authors found a significant association between serum levels of IL-1β and negative rather than positive symptoms [76, 77]. On the other hand, an absence of correlation between psychopathology and interleukin levels has also been reported, in accordance with our data [78].…”

Alteration of lipids and amino acids in plasma distinguish schizophrenia patients from controls: A targeted metabolomics study

“…23 Study on serum protein factors indicated that IL-1β expression level was positively associated with the negative symptom score of the Positive and Negative Syndrome Scale (PANSS) in SCZ patients. 24 The plasma levels of dopamine metabolites were significantly correlated with the mismatch negativity of SCZ, but not the serotonin metabolites. 25 In our previous study, we used the GC-MS based metabolomics to find out that the energy metabolism, oxidative stress, and neurotransmitter metabolism were disturbed in the peripheral blood mononuclear cells of SCZ patients.…”

“…In a recent study, researchers found that C‐reactive protein blood level was abnormally increased in non‐remission SCZ and therefore was suggested as a potential biomarker 23 . Study on serum protein factors indicated that IL‐1β expression level was positively associated with the negative symptom score of the Positive and Negative Syndrome Scale (PANSS) in SCZ patients 24 . The plasma levels of dopamine metabolites were significantly correlated with the mismatch negativity of SCZ, but not the serotonin metabolites 25 .…”

Association between CpG island DNA methylation in the promoter region of RELN and positive and negative types of schizophrenia

“…Furthermore, a previous study has also reported that patients with negative symptoms are likely to have more serious neuroimmune disturbances. 29 One limitation of our study was that we did not further investigate the associations between CpG island methylation in the promoter region of RELN and IL-6, IL-1b, or MBP. We will study such associations in the future.…”

“…A previous study has also reported that serum IL-1β and IL-6 levels are higher in patients with schizophrenia characterized by negative symptoms than in those characterized by positive symptoms. 29 This suggests that type II patients (with schizophrenia characterized by negative symptoms) have more severe neuroimmune and nerve damage.…”