Rapid immunoassay for the determination of glial fibrillary acidic protein (GFAP) in serum.
BACKGROUND
This study was aimed to develop a sensitive and rapid assay for the determination of glial fibrillary acidic protein (GFAP) in serum and to evaluate the clinical applicability in serum samples from patients with acute stroke.


METHODS
The two-site chemiluminometric immunoassay, intended to use in a near-patient setting with a single incubation step (20 min), was used to measure serum samples from healthy blood donors and from patients with brain injury and correlated to serum S100B levels.


RESULTS
The GFAP assay covered a concentration range up to 18 microg/L with an analytical sensitivity of 0.014 microg/L. The intra-assay precision was 3.5% at 1.55 microg/L (n=20) and 4.1% at 0.39 microg/L (n=20). The inter-assay precision was 3.8% at 9.1 microg/L (n=10) and 10.3 % at 0.21 microg/L (n=9). Normal controls (n=46) showed non-detectable GFAP with a 99% upper limit of <0.04 microg/L. GFAP values were associated with progression and severity of the illness in acute stroke patients.


CONCLUSIONS
We have developed an improved assay for the measurement of GFAP levels in serum. Serum GFAP is a potential marker for prognosis and outcome in patients with central nervous system disorders.
Vissers
Joost L M
JL
Future Diagnostics, Nieuweweg 172, 6603 BT Wijchen, The Netherlands. vissers.j@future-diagnostics.nl
Mersch
Marsha E C
ME
Rosmalen
Chris F
CF
van Heumen
Marijke J M T
MJ
van Geel
Wieneke J A
WJ
Lamers
Karel J B
KJ
Rosmalen
Frans M A
FM
Swinkels
Leon M J W
LM
Thomsen
Jens
J
Herrmann
Manfred
M
D000208:Acute Disease; D000368:Aged; D001930:Brain Injuries / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000097:blood*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008163:Luminescent Measurements / Q000379:methods; D008297:Male; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000097:blood; D015203:Reproducibility of Results; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000097:blood; D020521:Stroke / Q000097:blood; D013997:Time Factors
D005904:Glial Fibrillary Acidic Protein; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human