ИСТИНА

Introduction: Astrocytomas occupy a leading place among brain tumors. In recent years, it has been shown that IDH-1 gene mutation is a more accurate predictor of the astrocytomas development, and the presence of this mutation is directly associated with the lower tumor progression and increased patient survival. Aim: A study of the role of the mutation of the IDH1 gene in oncogenesis by the astrocyte of the brain. Materials and methods: Objects of retrospective study – biopsies of brain G II – III grade astrocytomas. Three groups were formed with the account of tumors variant (n=20 cases in each group): A low proliferative activity (Ki-67 ≤5%); B with medium proliferative activity (Ki-67 - 5% - 10%) and C with high proliferative activity (Ki-67 ≥ 5%). At the second phase, in each group it was identified the percentage of cases with IDH-1 gene mutation, which is detected by determining the product of the mutant gene – atypical 2-hydoxiglutarate. Methods: hematoxylin-eosin, immunohistochemical study – the monoclonal antibodies Ki-67 (Novocastra, UK; 1: 100 dilution; two cuts on glass). Results: Group A.: among astrocytomas with low proliferative activity (Ki-67 ≤ 5%) the number of cases with the IDH-1 mutations was 83±3%. In group B with moderate proliferative activity number of IDH-1 mutations was 57±4%. Group C.: the number of cases with the IDH-1 mutations was 11±2%. Conclusions: The high degree of proliferative activity of astrocytomas atypical cells corresponds to a low frequency of IDH-1 mutations. IDH-1 – a differential diagnostic marker of astrocytomas, and in combination with Ki-67 has an important prognostic value, as it has antioncogen property.