核酸序列依赖性扩增、Real-time PCR及GM试验诊断侵袭性曲霉菌感染的临床应用评价

The application of nucleic acid sequence-based amplification,real-time PCR and GM test in invasive aspergillosis diagnosis

目的核酸序列依赖性扩增（nucleic acid sequence-based amplification,NASBA）、Real-time PCR及GM试验在侵袭性曲霉菌感染中的诊断价值。方法收集2013年11月~2014年6月临床上曲霉菌感染高危病患的血液标本80例,并根据EORTC/MSG诊断标准分为确诊组8例,拟诊组26例,非感染组46例,分别利用NASBA、real-time PCR及GM试验进行检测,计算3种方法的诊断指标并分析评价。结果 NASBA、real-time PCR及GM试验3种方法的灵敏度分别为76.47%、67.65%、52.94%,特异度分别为80.43%、89.13%、80.43%。联合诊断结果显示,NASBA与real-time PCR串联方案有最好的特异度（100%）及阳性预测值（100%）;NASBA与real-time PCR并联方案则最为灵敏（94.12%）。结论 NASBA用于诊断IA最为敏感,而real-time PCR则最为特异,GM试验的表现差于前两者。联合应用的诊断策略,在特定情况下提高临床早期诊断IA的准确性。

Objective To study the diagnostic performance of nucleic acid sequence-based amplification（ NASBA） assay,realtime PCR and GM test in detecting invasive aspergillosis for clinical diagnosis.Methods Blood samples from 80 patients at a high risk for IA were collected during from November 2013 to June 2014.These patients were categorized as 8 proven IA,26 probable IA,and 46 non-IA according to the 2008 revised definitions of EORTC / MSG. Blood samples were tested by NASBA,real-time PCR and GM test and their diagnostic parameters were calculated,respectively.Result The sensitivity of NASBA,real-time PCR and GM test was 76.47%,67.65% and 52.94%,while their specificity was 80.43%,89.13%,80.43%,respectively.The efficiency of various combinations of tests was also evaluated.Perfect specificity（ 100%） and positive predictive value（ 100%） were achieved by combining NASBA and real-time PCR as a serial testing.A combination of NASBA and real-time PCR as a parallel testing was the most sensitive（ 94.12%）.Conclusion The sensitivity and specificity of NASBA and real-time PCR were superior to GM test.Combination of these assays could be particularly useful in specific clinical situations.