Association study on serum protein factors and cognitive function in first-episode schizophrenia characterized by positive and negative symptoms

Abstract

Objective To investigate the relationship between the serum concentration of IL-6, S100β, NT-3 and the cognitive functions in first-episode schizophrenia characterized by positive or negative symptoms. Methods 44 first-episode schizophrenic patients characterized by positive symptoms (positive group), 36 first-episode schizophrenic patients characterized by negative symptoms (negative group) and 50 healthy controls (controls) were collected. The serum levels of IL-6, S100β and NT-3 were measured by enzyme-linked immunosorbent assay (ELISA). The systematic evaluation tool-MCCB was applied to assess cognitive function in patients and controls. Results NT-3 serum levels in positive or negative groups were lower than those in controls and the differences were significant((118.39±37.50) ng/L, (112.55±32.29) ng/L vs (141.18±29.67) ng/L) (P<0.01). IL-6 and S100β serum levels in positive or negative groups were higher than those in controls and the differences were statistically significant((5.74±1.00)ng/L, (5.07±1.17)ng/L vs (4.23±0.91)ng/L), ((132.98±46.71)ng/L, (124.99±43.14)ng/L vs (103.63±31.57)ng/L)(P<0.01). IL-6 serum levels in the positive group ((5.07±1.17)ng/L) were lower than those in the negative group ((5.74±0.99)ng/L) and the difference was statistically significant (P<0.05). In MCCB test, the TMT scores in patients characterize by positive symptoms or patients characterize by negative symptoms were higher than those in healthy control group (P<0.01). BACS SC, HVLT-R WMS-Ⅲ, SS, NAB, BVMT-R, CF in patients characterize by positive symptoms or by negative symptoms were lower than those in healthy control group(P<0.01). There were no statistical difference in the MCCB scores between the patients with positive symptoms and negative symptoms. In positive group, there was a positive correlation between the IL-6 serum concentration and the general symptom scores in PANSS (P<0.05). In positive group, NT-3 serum concentration was positively correlated with the general symptom scores or total scores of PANSS (P<0.05). BVMT-R scores in MCCB were also positively correlated with IL-6 or NT-3 serum concentration in positive group (P<0.05). Conclusion The impairment of part of cognitive functions for schizophrenic patients may be related to the serum protein factors. There may be different in pathophysiology between the first-episode schizophrenic patients characterized by positive symptoms and those characterized by negative symptoms. Key words: First-episode schizophrenia; Positive symptoms; Negative symptoms; Serum protein factor; Cognitive function