血清1，3-β-D-葡聚糖检测用于造血干细胞移植后患者侵袭性真菌感染诊断的界值初探

Investigation of the cutoff value of a serum 1,3-β-D-glucan assay for early diagnosis of invasive fungal infection in Chinese hematopoietic stem cell transplant recipients

目的评价血清1，3-β-D-葡聚糖（BG）浓度检测对我国造血干细胞移植（HSCT）后患者侵袭性真菌感染（IFI）早期诊断的意义并确定其界值。方法按我国IFI的诊断标准，采用Glucatell试剂盒对HSCT后拟诊IFI的36例患者血清标本（每周采血2次）进行BG浓度的检测（G实验）。根据临床回顾性诊断标准定义阳性和阴性病例，按不同G试验阳性标准计算其灵敏度、特异度，最终确定G试验在我国HSCT后患者IFI诊断的界值。结果按试验中所得的单次结果≥80ng／L或连续两次结果≥60ng／L作为界值，得出G试验的灵敏度、特异度、阳性和阴性预测值，结果分别为81.0％、81．8％、89．5％和69．2％（P=0．002），并以此作为G试验在我国HSCT后IFI诊断的界值。结论G试验在我国HSCT患者IFI诊断的界值与国外基本相同，是一种早期诊断IFI的快速、灵敏的检测方法，值得临床推广。

Objective To evaluate the significance of a serum 1,3-β-D-glucan （BG） assay for early diagnosis of invasive fungal infection （IFI） and determine its cutoff value in Chinese post-hematopoietic stem cell transplant （HSCT） recipients. Methods Serum BG levels were measured twice weekly by Glucatell kit （G-Test） in 36 post-HSCT patients with suspected IFI. The sensitivities and specificities of the assay for clinical proven IFI and non-IFI patients were calculated retrospectively according to different G-Test positive criteria and determined its cutoff. Results The sensitivity, specificity, positive and negative predictive values were 81.0% , 81.8% , 89.5% and 69.2% （ P = 0. 002） respectively, as the cutoff value was set at more than 80 ng/L once or 60 ng/L consecutively twice. Conclusion The cutoff value of G test in Chinese post HSCT patients basically is the same as specified in the instruction of the kit, and it is a quick and reliable method for early diagnosis of IFI.