Quantification of glial fibrillary acidic protein (GFAP) in human body fluids by means of ELISA employing a monoclonal antibody

Abstract

Soluble glial fibrillary acidic protein (GFAP) was quantified in human cerebrospinal fluid (CSF) and amniotic fluid. A normal value in lumbar CSF of 4.3 +/- 0.7 ng GFAP/ml (mean +/- SEM) was obtained from 18 non-neurological patients. Increased GFAP concentrations in CSF were found in patients with intracranial tumours or with normal pressure hydrocephalus, while normal values were found in multiple sclerosis patients and in patients with degenerative dementia. In addition, a concentration gradient between ventricular and lumbar CSF was demonstrated, the GFAP content being significantly higher in ventricular than in lumbar samples. Amniotic fluids from normal pregnancies contained 13 +/- 5.5 ng GFAP/ml (N = 117). Increased GFAP concentrations were observed in amniotic fluid from some but not all pregnancies with fetal anencephaly or encephalocele, but not from pregnancies with fetal spina bifida or any of the other fetal malformations investigated. The quantification method was an enzyme-linked immunosorbent assay employing a monoclonal antibody specific for GFAP.