Effect of apolipoprotein E (apoE) phenotype on the apoE content of CSF-HDL in children.
BACKGROUND
The majority of the lipoprotein in cerebrospinal fluid (CSF) is apolipoprotein E (apoE)-containing HDL. Since neuronal cells express lipoprotein receptors which recognize apoE, apoE in CSF-HDL is believed to be important for the development of central nervous system (CNS) in children. In adults, the apoE phenotype affects the plasma apoE concentration and the epsilon 4 allele is a risk factor for Alzheimer's disease. Due to the requirement for CNS development, we examined whether the apoE phenotype affects the composition and concentration of CSF-HDL in children.


METHODS
We determined the apoE phenotype in 107 neurologically normal subjects, including 67 children (<20 years), by isoelectronic focusing. We also measured apoE, total cholesterol (TC), and phospholipid (PL) concentrations in the CSF.


RESULTS
The respective frequencies of apoE4/3, E3/3 and E3/2 were 16.4%, 77.6%, and 6.0%. The allele frequencies of epsilon 4, epsilon 3, and epsilon 2 were 0.082, 0.888, and 0.030, respectively. There were no significant differences in the CSF-apoE, TC, or PL concentrations or the apoE/PL ratio among the apoE phenotypes. However, the CSF-apoE/PL ratio was significantly higher in children than in adults.


CONCLUSIONS
The apoE phenotype does not affect the composition or concentration of CSF-HDL in children. We speculate that an apoE4 carrier is prevented in childhood from the impaired development of central nervous system by CSF-HDL enriched with apoE.
Hirayama
Satoshi
S
Division of Endocrinology and Metabolism, Department of Homeostatic Regulation and Developments, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi 1-757, Niigata City, Niigata 951-8510, Japan.
Miida
Takashi
T
Obayashi
Konen
K
Yamazaki
Fusako
F
Yamazaki-Sakurai
Miho
M
Ito
Masayuki
M
Saito
Yuji
Y
Hanyu
Osamu
O
Suzuki
Katsunori
K
Aizawa
Yoshifusa
Y
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000209:etiology; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000134:cerebrospinal fluid* / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D002784:Cholesterol / Q000134:cerebrospinal fluid; D005260:Female; D006801:Humans; D007223:Infant; D008075:Lipoproteins, HDL / Q000134:cerebrospinal fluid*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D010743:Phospholipids / Q000134:cerebrospinal fluid
D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D008075:Lipoproteins, HDL; D010743:Phospholipids; D002784:Cholesterol