Detection of IDH1 mutation in the plasma of patients with glioma

The IDH1(R132H) mutation is both a strong prognostic predictor and a diagnostic hallmark of gliomas and therefore has major clinical relevance. Here, we developed a new technique to detect the IDH1(R132H) mutation in the plasma of patients with glioma. Small-size DNA (150-250 base pairs) was extracted from the plasma of 31 controls and 80 patients with glioma with known IDH1(R132H) status and correlated with MRI data. The IDH1(R132H) mutation was detected by a combination of coamplification at lower denaturation temperature and digital PCR. The small size DNA concentration was 1.2 ng/mL (range 0.1-6.6) in controls vs 1.2 ng/mL (range 0.1-50.3) in patients with glioma (p = not significant) and 0.9 ng/mL (0.0-3.0) in low-grade gliomas vs 1.5 ng/mL in high-grade gliomas (p < 0.01). The small size DNA concentration correlated with enhancing tumor volume (1.6 ng/mL [0.4-24.9] when