IDH1R132H GENE-A DIAGNOSTIC AND PROGNOSTIC MARKER IN GLIOMAS

Aim: To study the frequency of Isocitrate dehydrogenase1 R132H [IDH1R132H] gene mutations in phenotypic lobar gliomas by Immuno histochemistry [IHC] and establish R-132H as a prognostic and diagnostic marker in gliomas. This study was a Material and method: Bidirectional correlative study on the clinical, pathological, and molecular characteristics of adult gliomas, carried out in the Dept of Laboratory sciences at Base Hospital, Delhi Cantt-110010.All consecutive (optd) cases of gliomas from 2015 to 2018 were included Immunohistochemistry was used to detect IDH1-R132H instead of sequencing, aiming to provide a mature and simple tool for clinical practice. In the light of the “ISNHaarlem” consensus, the routine approach to all diffuse astrocytic and oligodendroglial gliomas begins with performing IHC for IDH1-R132H expression. A negative control, in which the primary antibody was excluded was incorpora Results: ted with each batch of staining. Staining intensity was graded as +2 (strong positive staining), +1 (weak positive staining) & 0 (negative/ no staining). In our study only a staining intensity of +2 ie., strong positive staining was considered to label the tumour for the biomarkers studied. The labeling index (LI) for IDH1R132H to be labeled as positive was > 10% and the tumor was considered negative for IDH1R132H if the Labeling index was <10%. It was Conclusion: concluded that the IDH1-R132H is necessary to provide the basic molecular information for the “integrated diagnosis” of gliomas