Altered Serum Tumor Necrosis Factor and Interleukin-1β in First-Episode Drug-Naive and Chronic Schizophrenia

Abstract

Objective: Abnormality of the immune system might play a significant role in the pathogenesis of schizophrenia. We want to identity whether the serum TNF-α and IL-1β levels were changed in FEDN patients and CP and to investigate the relationship between both cytokines and psychopathological symptoms.Methods: We recruited 69 FEDN patients, 87 CP and 61 healthy controls. Schizophrenia symptomatology was evaluated with the Positive and Negative Syndrome Scale (PANSS), the Scale for the Assessment of Negative Symptoms (SANS) and Clinical Global Impression Scale (CGI). Serum TNF-α and IL-1β levels were examined using sandwich enzyme-linked immunosorbent assay (ELISA).Results: TNF-α and IL-1β levels in CP were significantly higher compared to healthy controls, but TNF-α and IL-1β levels in FEDN patients were significantly lower than in both CP and healthy controls. A moderate correlation between serum TNF-α or IL-1β levels and PANSS negative subscore was found in CP. But there was no correlation between altered cytokines and clinical symptoms in FEDN patients.Conclusions: Increased TNF-α and IL-1β levels in chronic patients may be associated with the progression, psychotropic drugs or other factors occur during chronic stage. Immune modulating treatments may become a new strategy of therapy for this subgroup of patients.

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

“…Compared to the control subjects, the first-episode drug-naive schizophrenia patients characterized by positive symptoms and those characterized by negative symptoms exhibited increased serum levels of IL-6, IL-1β, and S100β, along with decreased serum levels of NGF and NT-3. These findings confirmed those of previous studies [12][13][14]17,18,30 and may indicate that neurotrophasthenia, increased neuroimmune activation, and damage to glial cells are probably involved in the pathology of schizophrenia. [39][40][41] There is currently no definitive standard for the negative and positive symptom domains.…”

“…54 However, the correlation between the increase in the serum levels of IL-6 or IL-1β and schizophrenia or its negative symptoms have not been observed in some studies. 17 One possible major explanation for the inconsistent findings may be the receipt of treatment. Antipsychotic treatment may normalize immune imbalance and cause alterations of serum levels of IL-6 and IL-1β.…”

“…In recent decades, in addition to the dopamine hypothesis, the pathophysiology of schizophrenia has been demonstrated to involve neurotrophy, neuroimmunology, and neurodegeneration. 10,11 Studies on peripheral blood serum have also reported that some protein factors are associated with the pathophysiology of schizophrenia, as well as with psychotic symptoms, such as central neurotrophic factors (including nerve growth factor [NGF] 12 and neurotrophin-3 [NT-3] 13 ), neural immune-related proteins (including serum interleukin-6 [IL-6] [14][15][16] and interleukin-1 beta [IL-1β] 17 ), and proteins that are related to the damage of glial cells (including the calcium-binding protein, S100β 16,18 ). Levels of NGF have been found to be decreased in the plasma and cerebrospinal fluid of schizophrenia patients.…”

“…29 However, IL-1β exists as a type of pro-inflammatory cytokine in the etiology and pathophysiology of schizophrenia and has been found to be related to the negative symptoms of schizophrenia. 17,30 S100β is related to the damage of glial cells. S100β can regulate the proliferation and differentiation of neurons and glia.…”

Inflammation and Negative Symptoms of Schizophrenia: Implications for Reward Processing and Motivational Deficits

“…Xiu et al found that drug naïve first episode patients had decreased concentrations of IL-10, an antiinflammatory cytokine, relative to matched controls, and IL-10 was inversely correlated with negative symptoms severity on the PANSS (78). Interestingly, recent work from Zhu et al showed elevated TNF-a and IL-1beta in patients with chronic schizophrenia compared to healthy controls, whereas drug naïve first episode patients had lower concentrations compared to both the chronic patients and controls (86). Both TNF and IL-1beta were correlated with PANSS negative subscale scores in chronic patients, but not in the first-episode cohort.…”