Abnormalities of carnitine metabolism in chronic fatigue syndrome.

Carnitine may be involved in the pathogenesis of the chronic fatigue syndrome (CFS). However, no information about the cellular metabolism of carnitine in CFS patients is currently available. Therefore, we aimed to measure the levels of carnitine (total, free and short-chain) in both peripheral blood lymphocytes (PBLs) and sera from patients with CFS. The serum levels of total, free and short-chain were comparable in CFS patients, considered as the whole group, to those in healthy control subjects, even though a trend indicating slightly reduced serum concentrations of free carnitine was observed in male patients with CFS. In contrast, the concentrations of total, free and short-chain carnitine in PBLs from patients with CFS were significantly lower than in cells from healthy controls. Our study indicates that patients with CFS require exogenous carnitine supplementation. The low carnitine concentrations in PBLs from patients with CFS probably reflect the carnitine deficiency occurring in other tissues, including the skeletal muscles. The low cellular concentrations of carnitines may help to explain both the immunological abnormalities and the impaired energy metabolism in skeletal muscles.