Title : Immunohistochemical and molecular evaluation of IDH in glioblastomas as prognostic marker in moroccan population

Glioblastomas are the most aggressive primary brain tumors with a median survival of 15 months. This study aims to determine the IDH status by immunohistochemistry or sanger sequencing and their prognostic value. We included confirmed glioblastomas. Ninety-three tissue samples were obtained by neurosurgical intervention. Demographic data, Karnofsky status, clinicopathological factors and the status of IDH1 were reported. The majority of the patients were males (61.3%) with a sex ratio of 1.58. The mean age of patients with glioblastoma at diagnosis was 49.76 years ranged from 6 to 81 years. The expression of IDH was detected in 11 samples (11.8%). There was a highly statistical significant correlations between the mutation status of IDH1 gene and age (𝑝 = 0.003) and between the mutation status of IDH1 and cell density (𝑝 = 0.003). IDH1 R132H immunostaining was detected in patients presenting the R132H mutation which was confirmed by PCR. IHC is an adequate technique to identify IDH mutations in glioblastoma and improve their treatment.