Plasma nerve growth factor (NGF) and inflammatory cytokines (IL-6 and MCP-1) in young and adult subjects with Down syndrome: an interesting pathway

Down's syndrome (DS) is the most frequent chromosomal aberration in men and it is invariably associated with mental retardation. Plasma levels of nerve growth factor (NGF), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) from non demented DS subjects of three different age-cohorts (2-14 years; 20-50 yrs; >60 yrs) and healthy controls were measured. No clinical and sub-clinical inflammation was apparent in DS patients. Plasma levels of NGF were higher in children, adult and old DS subjects than in controls. However, a significant age-related decrease of NGF levels was present in DS subjects. Serum levels of IL-6 and MCP-1 were also increased in DS children and adults, but not in older DS patients. High levels of circulating NGF might protect DS from clinical complications of atherosclerosis. However, the striking decrement of peripheral NGF levels with advancing age may predispose DS to clinical manifestation of dementia after adulthood.