Increased intrathecal TGF-beta1, but not IL-12, IFN-gamma and IL-10 levels in Alzheimer's disease patients.

An inflammatory response has been hypothesised to be involved in the pathogenesis of primary dementias, above all Alzheimer's disease (AD). This study was aimed at evaluating interleukin (IL)-12 and a panel of related cytokine levels in paired CSF and sera of demented patients. IL-12 (p70 heterodimer and total IL-12 p40 chain), interferon (IFN)-gamma, IL-10 and transforming growth factor (TGF)-beta1 levels were measured in 30 patients with probable Alzheimer's disease (PrAD), 57 patients with other dementing disorders, including probable vascular dementia (PrVD), Parkinson's disease (PD) and normal pressure hydrocephalus (NPH), and 25 cognitively normal control subjects. In the presence of unchanged concentrations of IL-12, IFN-gamma and IL-10, the mean CSF level of TGF-beta1 and the correspondent TGF-beta1 index, but not the serum level, were significantly increased in PrAD compared to controls and PrVD, whereas no difference was found vs. NPH and PD. Our results support the pathophysiological role of TGF-beta1 system in AD.