Isocitrate Dehydrogenase and Alpha Thalassemia/Mental Retardation, X-linked Mutation Status in Human Gliomas at a Tertiary Care Hospital in Southern India: A Cross-sectional Study

Abstract

Introduction: The molecular subtyping of human gliomas in the current World Health Organisation (WHO) 2021 classification highlights the diagnostic and prognostic significance of neoplastic entities. This subsequently contributes to a better understanding of immunohistochemistry markers in various glioma patients. Aim: The study aimed to determine the Isocitrate Dehydrogenase (IDH1) gene mutation and Alpha Thalessemia/Mental retardation X-linked (ATRX) mutation in gliomas through immunohistochemistry and clinically categorise them into various subgroups. Materials and Methods: The present cross-sectional study was conducted in the Department of Pathology and Neurosurgery on 50 glioma samples collected from patients who underwent surgery at ESIC Medical College and Super Speciality Hospital in Hyderabad, Telangana, India from June 2018 to June 2023. Histopathological evaluation and Immunohistochemistry (IHC) study for IDH1 and Alpha Thalessemia/Mental retardation X-linked were performed on all patients. Clinical variables such as age, gender, duration of symptoms, and clinical presentation were collected from medical records and tabulated. Results: Total 50 cases of glioma were studied. The expression of IDH1 wild type was observed in 30 (60%) cases, which was more common than IDH1 mutation observed in 20 (40%) cases. The mean age in the study was 41.9 years, with a majority of male patients 33 (66%). IDH1 mutation was commonly observed in diffuse fibrillary astrocytomas (34%) followed by 12% of cases in anaplastic Astrocytomas. Glioblastoma was the most common histopathological diagnosis in 40% of cases, but the observed IDH mutation was least frequent in glioblastomas. Out of the 20 glioblastoma cases, only one tested positive for IDH mutation. In contrast, ATRX loss was predominantly seen in glioblastomas, with three out of the five positive cases. IDH1 mutation was more common in adults than in children, and a female preponderance (60%) was noted. ATRX mutation was observed in only 10% of cases. Conclusion: The IDH1 and ATRX are reliable prognostic markers, and their analysis through immunohistochemistry provides a practical and dependable method for categorising gliomas compared to molecular analysis, thus assisting clinicians in achieving promising treatment outcomes.

Keywords

• immunohistochemistry
• mutant
• prognostic
• wild type