APOLIPOPROTEIN-E IN CEREBROSPINAL-FLUID FROM PATIENTS WITH ALZHEIMERS-DISEASE AND OTHER FORMS OF DEMENTIA IS REDUCED BUT WITHOUT ANY CORRELATION TO THE APOE4 ISOFORM

Apolipoprotein E (apoE) has been suggested to play a role in regenerat ive processes in the brain after trauma, and also in the pathogenesis of Alzheimer's disease (AD). We examined cerebrospinal fluid (CSF) apo E in a material consisting of 23 patients with early-onset AD (EAD), 3 1 with late-onset AD CLAD), 16 with frontal-lobe dementia (FLD), 25 wi th vascular dementia (VAD) and 25 controls. CSF-apoE was decreased in all of EAD (1.8 +/- 1.1 mg/l; p < 0.0005), LAD (2.5 +/- 0.9 mg/l; p < 0.0005), VAD (2.3 +/- 1.4 mg/l; p < 0.0005) and FLD (3.0 +/- 1.3 mg/l; p < 0.05) compared to the control group (5.7 +/- 4.0 mg/l). Since apo E4 has been found to bind to beta/A4-amyloid, and AD patients homozygo us for apoE4 to have higher number of senile plaques than apoE3 homozy gotes, we also examined the relation between CSF-apoE and apoE alleles . However, CSF-apoE did not significantly differ between patients with different apoE isoforms. Our findings support that apoE is involved i n the pathogenesis of dementia disorders, both degenerative and vascul ar, but the CSF-apoE level is not influenced by the apoE isoforms. CSF -apoE may be used as an unspecific marker for neurodegenerative disord ers, but not in purpose of differential diagnostics between different dementia disorders.