Interaction between serum inflammatory cytokines and brain-derived neurotrophic factor in cognitive function among first-episode schizophrenia patients

BACKGROUND The pathogenesis of cognitive impairment in schizophrenia(SCZ)remains unclear.Accumulating studies showed that inflammatory-immune dysregulation and altered brain derived neurotrophic factor(BDNF)levels play a crucial role in the psychopathology of SCZ.However,their association with cognitive dysfunction in first-episode SCZ patients has not been thoroughly investigated.AIM To explore the interaction effects between cognitive function and inflammatory cytokines and BDNF in first-episode SCZ.METHODS The current study is a cross-sectional case-control investigation that recruited 84 patients with first-episode SCZ(SCZ group)and 80 healthy controls(HCs group)at the Huzhou Third Municipal Hospital between August 2021 and September 2023.ELISA was employed to measure the serum levels of interleukin(IL)-1β,IL-4,IL-6,IL-10,and BDNF.The Chinese brief cognitive test(C-BCT)and the positive and negative syndrome scales were measured the severity of cognitive impairment and psychiatric symptoms.RESULTS Compared to the HC group,the SCZ group exhibited elevated IL-1βand IL-6 levels,decreased BDNF levels,and reduced C-BCT scores(all P<0.001).In SCZ,BDNF was negatively correlated with IL-6(r=-0.324,P<0.05).Information processing speed was negatively correlated with IL-6(r=-0.315,P<0.05)and positively with BDNF(r=0.290,P<0.05);attention,working memory,comprehensive ability,and executive function were negatively correlated with IL-1βand IL-6(all P<0.05)and positively with BDNF(all P<0.05).Multiple regression analysis showed IL-6 influenced C-BCT dimensions(β=-0.218 to-0.327,all P<0.05);attention and executive ability were influenced by IL-1β(β=-0.199 to-0.261,all P<0.05);comprehensive executive ability was influenced by BDNF(β=0.209,P<0.05).CONCLUSION Our findings suggested that interrelationships between immune dysfunction and neurotrophic deficiency might underlie the pathological mechanisms of cognitive impairments in first-episode SCZ patients.