Cerebrospinal fluid interleukin-1 beta (IL-1 beta) in Alzheimer's disease and neurological disorders

Abstract

Recent studies indicate that patients with Alzheimer's disease (AD) exhibit an immune dysfunction at the central and peripheral levels. We have studied the concentration of IL-1 beta in the cerebrospinal fluid (CSF) of patients with AD, multi-infarct dementia (MID), normal pressure hydrocephalus (NPH), and multiple sclerosis (MS). CSF IL-1 beta levels were significantly higher in AD (131 +/- 17.33 pg/ml) than in MID (79.71 +/- 24.37 pg/ml, p less than 0.01), NPH (84.75 +/- 23.17 pg/ml, p less than 0.01), and MS (79.4 +/- 10.23 pg/ml, p less than 0.01). In patients with neurological disorders CSF IL-1 beta levels showed a progressive increase with age (r = +0.49, p less than 0.015). The concentration of IL-1 beta in CSF of demented patients correlated with mental deterioration (r = -0.476). According to these results we postulate that high levels of central IL-1 beta in AD might reflect a reactive neuroimmune response to: (a) abnormal epitopes exposed by lesioned neurons, (b) reactive microglia activated by exogenous and/or endogenous factors and (c) endogenous neurotrophic activation.