The value of interleukin 6 as a peripheral diagnostic marker in schizophrenia

Abstract

BackgroundAssociations between a pro-inflammatory state and schizophrenia have been one of the more enduring findings of psychiatry, with various lines of evidence suggesting a compelling role for IL-6 in the underlying pathogenesis of schizophrenia.MethodsIn this study, we examined IL-6 mRNA levels by real-time RT-PCR from fresh extracted peripheral blood mononuclear cells (PBMC) in normal controls and participants with schizophrenia.ResultsWe found that peripheral PBMC IL-6 mRNA levels, in the absence of any other information, reliably discriminated between a diagnosis of schizophrenia and normal controls. Furthermore, in participants with schizophrenia, we also found elevated levels of IL-6 mRNA with earlier ages of illness onset and worse positive symptom presentation, as measured by the Positive and Negative Syndrome Scale.ConclusionsThese findings provide important and continued support for a pathophysiological role of inflammation in patients with schizophrenia. Future utilization of peripheral IL-6 mRNA levels could be clinically useful during an initial diagnosis and help tailor individualized treatment plans for patients with schizophrenia.

Haloperidol affects bones while clozapine alters metabolic parameters - sex specific effects in rats perinatally treated with phencyclidine

“…Dunjić et al [89] have demonstrated higher IL-6 and lower TNF-α level in patients with schizophrenia in both exacerbation and remission phase in comparison to healthy controls and the absence of significant correlation between the levels of cytokines and sex, age, BMI, smoking habits, antipsychotic medication, duration of treatment and duration of illness. Chase et al [90] have found that the levels of IL-6 mRNA in the peripheral blood mononuclear cells, in the absence of any other information, reliably discriminated between a diagnosis of schizophrenia and normal controls suggesting it as a useful and easily clinically accessible biomarker for the diagnosis of schizophrenia. Genome-wide association studies have identified immune system gene loci as among the leading associations with schizophrenia [91–94].…”

Immersion in altered experience: An investigation of the relationship between absorption and psychopathology

“…Recently, more global factors beyond the neuron, such as inflammation, are being examined for their role in the psychogenesis of psychotic breaks (Chase, Cone, Rosen, & Sharma, 2016). One of the primary biological mechanisms linking salience and psychosis is associated with the dopaminergic neurotransmitter system and hypothalamic-pituitary-adrenal (HPA) axis dysregulation (Davis, Kahn, Ko, & Davidson, 1991; Seeman & Kapur, 2000; Seeman, 1987).…”

Serum levels of interleukin 6 in schizophrenic patients during treatment augmentation with sarcosine (results of the PULSAR study)

“…Several previous studies suggest a compelling role for IL-6 in the underlying pathogenesis of schizophrenia: The serum levels of IL-6 and its soluble receptors (sIL-6R) are significantly elevated in patients with schizophrenia (Potvin et al, 2008;Upthegrove, Manzanares-Teson, & Barnes, 2014) and are associated with symptom severity (Kubistova et al, 2012). Some authors even claim that IL-6 mRNA levels from freshly extracted peripheral blood mononuclear cells (PBMC) could be a useful and easily clinically accessible biomarker for a diagnosis of schizophrenia (Chase, Cone, Rosen, & Sharma, 2016) with higher IL-6 levels associated with younger onset of psychosis, longer duration, and worse presentation of the illness.…”