TABLE 2.

GP levels in SF and NP normalized to CSF volume

GP	SF (n = 70)	% Total (SF Mean)	NP (n > 66)	% Total (NP Mean)	NP/SF (% Total)
xPE	1.35 ± 0.1	0.02	10.6 ± 0.7	14.1	705
NAPE	11.9 ± 1.6	0.13	7.8 ± 0.6	10.4	79.6
PE	43.9 ± 3.3	0.5	1.6 ± 0.1	2.1	4.4
PC	9030 ± 398	99.1	52.4 ± 6	69.7	0.7
PS	8.8 ± 0.7	0.1	Low level	ND	ND
PAF_LL	4.9 ± 0.5	0.1	0.08 ± 0.01	0.1	2.0
LPC	12.1 ± 1.3	0.1	2.7 ± 0.2	3.6	27.1
LPC/PC	0.0013		0.0519		39.9

GPs extracted from CSF supernatant fluid or NP were separated using HILIC and detected using MS. Amounts of each GP were quantified using standard curves, and data were expressed as the mean normalized to CSF volume (mean ± SEM, ng/ml). For each fraction, we used the mean values to estimate proportions of each detected GP (% Total) and to calculate the relative enrichment in NP compared with SF (NP/SF). We also calculated the proportion of LPC to PC (LPC/PC). Levels of PS in NP were very low (low level) or not detectable (ND).