Cerebrospinal fluid apolipoprotein E, calcium and cerebral vasospasm after subarachnoid hemorrhage.
Intracellular calcium (Ca++) regulation of cerebral vessels is impaired after subarachnoid hemorrhage (SAH), making secondary pathways, such as that involving apolipoprotein E, potentially more influential. To evaluate cerebrospinal fluid (CSF) apolipoprotein E and Ca++ levels as biomarkers of cerebral vasospasm, we examined changes in levels over time and apolipoprotein E (APOE) epsilon4 allele presence after SAH in individuals with and without vasospasm. We hypothesized that individuals with low apolipoprotein E levels, increased Ca++ levels and/or at least one copy of the APOE epsilon4 allele would have vasospasm. Daily samples from 50 participants, aged 18-75, with SAH were used to quantify apolipoprotein E and Ca++ levels. Vasospasm was verified using cerebral angiogram and/or elevated transcranial Dopplers in combination with clinical neurologic deterioration. Overall apolipoprotein E levels were higher in individuals with the APOE epsilon4 allele (p = .02) or angiographic vasospasm (p = .01), but there were no differences between individuals with and without symptomatic vasospasm. There were no significant changes in apolipoprotein E levels over time. Individuals with the epsilon4 allele had lower Ca++ levels (p = .02) with trends suggesting a different pattern of change over time (p = .07). CSF Ca++ levels were lower in individuals with symptomatic vasospasm (p < .01). Change in apolipoprotein E and Ca++ levels (p = .006) correlated over time regardless of genotype or vasospasm status. These findings suggest that apolipoprotein E and Ca++ may be interacting after SAH, but this interaction does not appear to influence vasospasm.
Alexander
Sheila A
SA
School of Nursing, University of Pittsburgh, Pennsylvania, USA. salexand@pitt.edu
Kerr
Mary E
ME
Balzer
Jeffrey
J
Horowitz
Michael
M
Kassam
Amin
A
Kim
Yookyung
Y
Hoffman
Leslie
L
Conley
Yvette P
YP
D000328:Adult; D001057:Apolipoproteins E / Q000134:cerebrospinal fluid*; D002118:Calcium / Q000134:cerebrospinal fluid*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013345:Subarachnoid Hemorrhage / Q000134:cerebrospinal fluid / Q000150:complications*; D020301:Vasospasm, Intracranial / Q000134:cerebrospinal fluid / Q000150:complications*
D001057:Apolipoproteins E; D002118:Calcium