Analysis of Isocitrate Dehydrogenase (IDH) expression in astrocytoma patients: cases of South Sulawesi, Indonesia

Background: Astrocytoma is the most common primary intracerebral tumor in adults and causes high morbidity and mortality. Most patients with astrocytomas, especially diffuse gliomas, have a poor prognosis. Recent genetic and epigenetic studies have shown that mutations in the Isocitrate Dehydrogenase (IDH) gene play an important role in the pathogenesis and prognosis of gliomas, thus facilitating IDH1 mutations in the population to become an important marker, not only to assist in the diagnosis and prognostic factors of these gliomas but also to develop therapeutic targets as currently available. This study aims to see differences in the expression of the IDH in each astrocytoma classification.
Methods: A cross-sectional analytic study was conducted at the Anatomical Pathology Laboratory, Faculty of Medicine, Universitas Hasanuddin, from October 2020 to August 2021. The research sample came from 65 paraffin block preparations for primary brain tumors with the diagnosis of Diffuse Astrocytoma (DA), Anaplastic Astrocytoma (AA) and Glioblastoma (GB). The immunohistochemical staining was performed using the monoclonal antibody IDH1-R132H. The microscopic assessment was carried out using a light microscope. Data were analyzed using SPSS version 20 for Windows.
Results: There was a significant relationship between the expression of IDH1-R132H in each astrocytoma classification (p=0.008). The prevalence of astrocytoma with negative IDH1-R132H expression (IDH-wildtype) is lower by 21 samples (32.3%) compared to astrocytoma with positive IDH1-R132H expression (IDH-mutant), which is 44 samples (67.7%).
Conclusion:There are significant differences in the expression of IDH1-R132H in Diffuse Astrocytoma, Anaplastic Astrocytoma and Glioblastoma, where the proportion of IDH-mutant status is higher than IDH-wildtype and IDH1 mutation status has a significant relationship with tumor grade.