An ELISA for glial fibrillary acidic protein.
Glial fibrillary acidic protein (GFAP) is the major intermediate filament protein of the astrocyte, and body fluid levels of GFAP are an important tool for estimating astrogliosis and astrocytic activation in vivo. This paper presents a new sandwich ELISA allowing quantification of GFAP(SMI26) from the cerebrospinal fluid (CSF). The sensitivity of the GFAP(SMI26) ELISA is 5 pg/ml with a recovery of 94% and a mean within- and between-batch precision of 6% and 10%, respectively. The upper reference value for CSF GFAP(SMI26) levels (9 pg/ml) was defined as the 95% cumulative frequency from 315 CSF samples. Based on this cut-off, a significantly higher proportion of patients with subarachnoid hemorrhage (100%), traumatic brain injury (100%), dementia (76%) and normal pressure hydrocephalus (85%) had pathologically elevated CSF GFAP(SMI26) levels compared to patients with peripheral nervous system disorders (0%). In a critical review of the literature, we compare the analytical and clinical sensitivity of previous GFAP ELISA methods with particular reference to patients with dementia.
Petzold
A
A
Department of Neuroimmunology, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK. a.petzold@ion.ucl.ac.uk
Keir
G
G
Green
A J E
AJ
Giovannoni
G
G
Thompson
E J
EJ
D000818:Animals; D000906:Antibodies; D002493:Central Nervous System Diseases / Q000134:cerebrospinal fluid; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005904:Glial Fibrillary Acidic Protein / Q000134:cerebrospinal fluid* / Q000276:immunology; D006801:Humans; D010523:Peripheral Nervous System Diseases / Q000134:cerebrospinal fluid; D012016:Reference Values; D012680:Sensitivity and Specificity
D000906:Antibodies; D005904:Glial Fibrillary Acidic Protein