Serum tumor necrosis factor (TNF) in Alzheimer's disease and multi-infarct dementia.
Changes in neuroimmune parameters and cytokine production have been reported in patients with Alzheimer's disease, including increased levels of interleukin-1 (IL-1) and histamine in brain tissue, cerebrospinal fluid and serum. Specific neuroimmune reactions may be responsible in part for astrogliosis and neuronal death in particular circumstances. Since IL-1 and tumor necrosis factor (TNF) tend to act synergistically in physiological conditions and in some pathological processes, we have studied the concentration of TNF-alpha in patients with Alzheimer's disease (AD) or multi-infarct dementia (MID) and in age-matched control subjects (CS) in order to evaluate possible changes in the levels of this cytokine with potential influence on the pathogenesis of AD. Serum TNF-alpha levels were significantly lower in AD (2.5 +/- 1.25 pg/ml, p < 0.01) and MID (1.64 +/- 1.17 pg/ml, p < 0.001) than in CS (10.66 +/- 8.92 pg/ml). A negative correlation between serum TNF-alpha levels and age in AD was found (r = -0.645, p < 0.01); however, no significant correlations were detected between serum TNF-alpha levels and mental performance, cerebrovascular risk, heart rate and blood pressure in either AD or MID. In conclusion, there is a marked reduction in the concentration of serum TNF-alpha in both AD and MID which seems to be poorly related to cognitive dysfunction and/or neurovascular damage, probably reflecting an endogenous immune dysregulation and/or an inhibitory reactive process in demented patients.
Cacabelos
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Department of Human Physiology, Complutense University Medical School, Madrid, Spain.
Alvarez
X A
XA
Franco-Maside
A
A
Fernández-Novoa
L
L
Caamaño
J
J
D000328:Adult; D000368:Aged; D000544:Alzheimer Disease / Q000097:blood*; D001794:Blood Pressure; D015161:Dementia, Multi-Infarct / Q000097:blood*; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D014409:Tumor Necrosis Factor-alpha