Reduced but not oxidized cerebrospinal fluid glutathione levels are lowered in Lewy body diseases.

Reduced (GSH(R)) but not oxidized glutathione (GSSG) has been shown to be dramatically altered in the substantia nigra (SN) of Lewy body disease (LBD) patients post mortem; but up to now, there is no convincing evidence that these changes can be monitored in vivo. We investigated GSH(R) and GSSG in rapidly processed cerebrospinal fluid (CSF) and plasma samples of 80 LBD and 35 control subjects and detected reduced CSF GSH(R) levels in LBD subjects. The reduction was negatively associated with age but not with disease-associated parameters. Plasma GSH(R), CSF GSSG, and plasma GSSG levels did not significantly differ between the groups. Our findings confirm the results from neuropathologic studies, which demonstrated an alteration of the glutathione system in LBD. We hypothesize that alterations of the glutathione system occur in a very early stage of the disease or may even represent a risk marker for LBD.