Clinical utility of serum glial fibrillary acidic protein in glial neoplasm.

Abstract

Glial fibrillary acidic protein (GFAP) is a member of the cytoskeletal protein family and is widely expressed in astroglial and neural stem cells, also in glial tumors such as astrocytoma and Glioblastoma (GBM). Increased GFAP expression and disruption of the blood-brain barrier are the characteristic features of GBM. Higher serum GFAP levels can help differentiate GBM from GBM mimics (such as primary central nervous system lymphoma, metastasis, or demyelinating lesions). This prospective study was carried out in a tertiary care center in the department of neurosurgery on newly diagnosed glioma patients who underwent surgery from January 2018 to July 2019, excluded patients with history of the previous surgery for glioma, traumatic brain injury, and ischemic or hemorrhagic stroke. The blood sample was obtained at admission before undergoing invasive procedure. Pathological examination of the tumor biopsy sample was carried out using classical hematoxylin-eosin and immunohistochemical staining. All statistical analyses were performed using SPSS version 24.0. The mean preoperative tumor volume was 40 cm3 (range 17.19-65.57 cm3; standard deviation [SD] = 9.99 cm3) which showed 98.25% mean reduction in volume postsurgery (mean tumor volume = 0.7 cm3; SD = 0.19 cm3). Preoperative serum GFAP measurements show higher levels (spearman's rho coefficient = 0.610 with P = 0.000) with increasing grade of tumor. GFAP levels also demonstrated higher value with increasing preoperative tumor volume. Increasing serum GFAP levels in the preoperative period correlate with higher tumor grade, especially grade III and grade IV tumors. The serum GFAP levels showed relation to tumor volume, both before and after surgery.