Differential CSF biomarker levels in APOE-epsilon4-positive and -negative patients with memory impairment.
OBJECTIVE
To investigate the relationships between episodic memory, APOE genotype, CSF markers (total tau, T-tau; phospho-tau, P-tau; beta-amyloid, Abeta42) and longitudinal cognitive decline.


METHODS
124 memory clinic patients were retrospectively divided into 6 groups based on (i) episodic memory function (Rey Auditory Verbal Learning Test, RAVLT): severe, moderate or no impairment (SIM, MIM or NIM), and (ii) APOE genotype (epsilon4+ or epsilon4-). CSF marker levels and cognitive decline were compared across groups.


RESULTS
Episodic memory function, according to RAVLT scores, was significantly correlated with CSF marker levels only among epsilon4+ subjects and not among epsilon4- subjects. When comparing the 6 subgroups, SIM epsilon4+ and MIM epsilon4+ groups showed significantly lower Abeta42 levels than the other groups. T-tau and P-tau levels were significantly increased in SIM epsilon4+ when compared to all the other groups, including the SIM epsilon4- group. However, both SIM epsilon4+ and SIM epsilon4- declined cognitively during the follow-up.


CONCLUSIONS
It remains to be determined whether APOE genotype affects the expression of biomarkers in CSF, or whether the different biomarker patterns reflect different types of disease processes in patients with progressive cognitive dysfunction.
Andersson
Christin
C
Department of Neurobiology, Caring Sciences and Society, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden. christin.andersson@ki.se
Blennow
Kaj
K
Johansson
Sven-Erik
SE
Almkvist
Ove
O
Engfeldt
Peter
P
Lindau
Maria
M
Eriksdotter-Jönhagen
Maria
M
D016564:Amyloid beta-Protein Precursor / Q000134:cerebrospinal fluid*; D053327:Apolipoprotein E4 / Q000235:genetics*; D001057:Apolipoproteins E / Q000235:genetics*; D015415:Biomarkers / Q000134:cerebrospinal fluid; D003072:Cognition Disorders / Q000134:cerebrospinal fluid / Q000175:diagnosis / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000134:cerebrospinal fluid / Q000175:diagnosis / Q000235:genetics; D008875:Middle Aged; D009483:Neuropsychological Tests; D015995:Prevalence; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016875:tau Proteins / Q000134:cerebrospinal fluid*
D016564:Amyloid beta-Protein Precursor; D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D015415:Biomarkers; D016875:tau Proteins