GFAP
Pronunciation: G-F-A-P
Also written as: GFAP — glial fibrillary acidic protein
Glial fibrillary acidic protein, an immunohistochemical marker specific for astrocytes and their tumors.
Full Definition
An intermediate filament protein that serves as the primary immunohistochemical marker for identifying astrocytes and astrocytic tumors. GFAP (glial fibrillary acidic protein) staining is essential in neuropathology for distinguishing astrocytic from other glial tumors, identifying reactive gliosis, and confirming astrocytic differentiation. The antibody produces characteristic cytoplasmic staining in astrocytes and astrocytomas but is negative in neurons, oligodendrocytes, and most other brain tumors. GFAP expression levels can also indicate the degree of astrocytic activation or tumor grade.
Usage
Usage note: Always capitalize all letters; distinguish from other glial markers in differential diagnosis.
In Context
- "GFAP immunostaining confirmed the astrocytic nature of the tumor." — pathology report
- "Reactive astrocytes showed increased GFAP expression around the infarct." — research study