Acetyl-L-carnitine administration increases insulin-like growth factor 1 levels in asymptomatic HIV-1 infected subjects and ceramide generation: correlation with its suppressive effect on lymphocytes apoptosis

The aim of this study was to investigate the impact of long-term acetyl-L-carnitine administration on CD4 and CD8 absolute counts, apoptosis, and insulin-like growth factor-1 (IGF-1) serum levels in HIV-1-infected subjects. The generation of cell-associated ceramide and HIV-1 viremia were also investigated. Eleven asymptomatic, HIV-1-infected subjects were treated daily with acetyl-L-carnitine (3 g) for 5 months. Immunologic and virologic measures and safety were monitored at the start of the treatment and then on days 90 and 150. Altogether our findings suggest that acetyl-L-carnitine administration has a substantial impact on the main immunologic abnormality associated with HIV infection, the loss of CD4 cells, by reducing the rate of apoptotic lymphocyte death. The reduction of cel-amide generation and the increase of the serum levels of IGF-1, a major survival factor able to protect cells from apoptosis by different stimuli and conditions, could represent two important mechanisms underlying the observed anti-apoptotic effects of acetyl-L-carnitine.