Reduced TNF-α and increased IGF-I levels in the serum of Alzheimer's disease patients treated with the neurotrophic agent Cerebrolysin

According to current scientific knowledge, excess tumour necrosis factor-alpha (TNF-alpha) and low insulin-like growth factor-I (IGF-I) are pathogenic-risk factors that constitute therapeutic targets for Alzheimer's disease (AD). Changes in serum TNF-alpha, total and dissociable IGF-I levels were determined by ELISA in 207 AD patients completing a 24-wk, double-blind, placebo-controlled trial to evaluate the effects of the neurotrophic compound Cerebrolysin (Cere: 10, 30 or 60 ml for 12 wk). At week 24, Cere reduced TNF-alpha and enhanced dissociable IGF-I with respect to placebo in a dose-related manner. TNF-alpha decreased in parallel with behavioural disturbances. Increases in total IGF-I were induced by 60 ml Cere and correlated significantly with improvements in global function, disabilities and behaviour in late-onset AD patients. These results showing for the first time the opposite influence of one anti-dementia treatment on serum TNF-alpha and IGF-I suggest the contribution of both factors to the clinical effects of Cere, and probably other drugs.