Lazarević Milica, Jovanović Nikola, Cvetković Vladimir J, Tošić Svetlana, Vitorović Jelena, Stamenković Slaviša, Nikolov Vesna, Vidović Nataša, Kostić Perić Jelena, Jovanović Marija, Mitrović Tatjana
Laboratory for Molecular Biology and Biotechnology, Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, 18000 Niš, Serbia.
Faculty of Medicine, Clinic of Neurosurgery, Clinical Centre, University of Niš, 18000 Niš, Serbia.
Diagnostics (Basel). 2023 Jan 18;13(3):360. doi: 10.3390/diagnostics13030360.
Comparative analysis of the conventional methylation-specific PCR (MSP) vs. the quantitative MSP (qMSP) assessment of the O-methylguanine-DNA methyltransferase () promoter methylation status in 34 snap-frozen (SF) glioma samples was performed. The accuracy of the semi-quantitative MSP was compared with the corresponding qMSP semi-quantitative values using two semi-quantitative cut-off values (0-unmethylated and 1-weakly methylated) to discriminate methylated from unmethylated samples. In the case of the cut-off value 0, MSP test showed 80.0% sensitivity and 78.9% specificity compared to the reference qMSP analysis. However, when using the cut-off value 1, the diagnostic accuracy of the MSP test was significantly higher (85.7% sensitivity, 85.2% specificity). Fleiss' Kappa statistical analyses indicated moderate agreement (Fleiss' Kappa Coefficient = 0.509; 70.59% agreement) between MSP and qMSP semi-quantitative measurements of promoter methylation in glioma patients, justifying the conventional MSP use in diagnostics and confirming its high reliability. Further, we aimed to compare the validity of SF and formalin-fixed paraffin-embedded (FFPE) glioma samples for testing. Statistical analyses indicated moderate overall agreement of FFPE glioma samples and SF MSP semi-quantitative measurements (Fleiss' Kappa Coefficient = 0.516/0.509; 70.0% agreement) and emphasized their low reliability in the assessment of highly methylated promoter samples.
对34例速冻（SF）胶质瘤样本中O-甲基鸟嘌呤-DNA甲基转移酶（）启动子甲基化状态进行常规甲基化特异性PCR（MSP）与定量MSP（qMSP）评估的比较分析。使用两个半定量临界值（0-未甲基化和1-弱甲基化）将甲基化样本与未甲基化样本区分开来，将半定量MSP的准确性与相应的qMSP半定量值进行比较。在临界值为0的情况下，与参考qMSP分析相比，MSP检测显示出80.0%的灵敏度和78.9%的特异性。然而，当使用临界值1时，MSP检测的诊断准确性显著更高（灵敏度为85.7%，特异性为85.2%）。Fleiss' Kappa统计分析表明，MSP与qMSP对胶质瘤患者启动子甲基化的半定量测量之间存在中度一致性（Fleiss' Kappa系数 = 0.509；一致性为70.59%），这证明了常规MSP在诊断中的应用合理性，并证实了其高可靠性。此外，我们旨在比较SF和福尔马林固定石蜡包埋（FFPE）胶质瘤样本用于检测的有效性。统计分析表明，FFPE胶质瘤样本与SF MSP半定量测量之间总体一致性适中（Fleiss' Kappa系数 = 0.516/0.509；一致性为70.0%），并强调了它们在评估高度甲基化启动子样本时的低可靠性。
