A sensitive ELISA for glial fibrillary acidic protein: application in CSF of children

Abstract

In the present study we describe a sensitive ELISA for determination of glial fibrillary acidic protein (GFAP). To validate the method combined determinations of GFAP and S-100 protein were performed in cerebrospinal fluid (CSF) of normal children and children with autism. The GFAP ELISA is of sandwich type and uses the biotin-avidin system. Sensitivity was 16 pg/ml. Between-day precision was 0.079 (coeff. of variance). S-100 protein concentrations were measured using a commercially available ELISA kit. Normal CSF from children and young adults were analysed. The CSF levels of GFAP in normal children were low (16-163 pg/ml). Both GFAP and S-100 protein concentrations correlated with age (P < 0.01 and P < 0.05, respectively), but the GFAP increment was more pronounced, probably reflecting the age-dependent expansion of the fibrillary astrocytes in the central nervous system (CNS). GFAP levels in children with infantile autism were higher than those in normal children of the same age range. S-100 protein concentrations were similar in both groups. High levels of GFAP in combination with normal S-100 protein concentrations in CSF indicates reactive astrogliosis in the CNS. In conclusion, the sensitive ELISA described makes it possible to measure low levels of GFAP present in the CSF of children. Combined assays of GFAP and S-100 protein can be used to discriminate between acute and chronic brain disorders in children.

S100 Protein in Serum as a Prognostic Marker for Cerebral Injury in Term Newborn Infants with Hypoxic Ischemic Encephalopathy

“…S100 might be of interest for timing of the event for the brain damage as well as to discriminate between acute and chronic brain disorders, possibly in combination with assessing glial fibrillary acidic protein (GFAP). High levels of GFAP in combination with normal S100 protein concentrations in CSF, indicates reactive astrogliosis in the CNS (44). A combination of a few very early indicators such as, acid base values, the clinical condition of the infant, Apgar score and HIE, early EEG/aEEG and brain specific proteins such as S100 could possibly be of help in identifying the infants with the highest risk of compromise.…”

Glial Fibrillary Acidic Protein in the Cerebrospinal Fluid: A Possible Indicator of Prognosis in Full-Term Asphyxiated Newborn Infants?

“…Very high CSF levels of GFAP have been reported (3)(4)(5) after acute CNS injury, probably as a consequence of disintegration of astroglial cells. Moderately increased levels of GFAP in the CSF have also been found in chronic brain disorders such as Alzheimer's disease, multiinfarct dementia, and recently also in infantile autism (2,3,6). In these disorders, gliosis is the probable cause of the observed increase.…”

“…Using immunochemical techniques, it is frequently used as an astrocyte marker in brain pathology. In the CSF, GFAP is detectable in low concentrations under normal conditions (2,3). Very high CSF levels of GFAP have been reported (3)(4)(5) after acute CNS injury, probably as a consequence of disintegration of astroglial cells.…”

A Novel Rodent Model of Autism: Intraventricular Infusions of Propionic Acid Increase Locomotor Activity and Induce Neuroinflammation and Oxidative Stress in Discrete Regions of Adult Rat Brain

“…The following antibodies were used: 1) anti-glial fibrillary acidic protein (GFAP) (1:500, rabbit polyclonal, DakoCytomation, Glostrup, Denmark) a marker for reactive astrogliosis, found elevated in human autism neuropathology studies [66] and in cerebrospinal fluid from autism patients [67] , 2) anti-rat CD68 antigen (1: 200, monoclonal, Serotec, Oxford, UK), 3) anti-IbA1 ( 1:10, 000, rabbit polyclonal, Wako, Richmond, VA) both markers for activated microglia and found elevated in human autism brain [66] and epilepsy [68] , 4) anti-cleaved caspase 3 (1: 100, rabbit polyclonal, Cell Signaling Technology, Danvers, MA), a marker for apoptotic cytotoxicity [69,70] and; 5) antiNeuN (1:1000, monoclonal, Chemicon USA ), a marker for neurons [71] . Tissue sections were mounted on glass slides (SurgiPath, Canada) and dried overnight at 37°C.…”