ABSTRACT
ObjectiveTo explore the diagnostic value of plasma (1, 3)-β-D-glucan test (G test) in diagnosis of invasive fungal infections (IFI) and the influence of albumin on G test.Methods A prospective observational study was conducted. 267 patients admitted to medical intensive care unit (MICU) of Dalian Municipal Central Hospital from January 21st, 2012 to October 31st, 2014 were enrolled. According to IFI guideline, the patients were divided into without IFI group (n= 35), possible IFI group (n = 70), hypotheticle IFI group (n = 145) and proven IFI group (n = 17). G test was examined routinely using microbiology kinetic rapid reader MB-80.The different threshold values were calculated on G test. The difference among G tests, fungal culture and clinical diagnosis were compared. The results of G test ahead of and post albumin administration in each group were compared, and the value of G test for diagnosis of IFI during albumin infusion was evaluated.Results When the cut-off value was 20 ng/L for IFI diagnosis, higher sensitivity (79.8%), specificity (87.9%), and Youden index (67.7%) were found. The positive rates of G test, fungal culture and clinical diagnosis of IFI were 57.7% (154/267), 60.7% (162/267) and 54.3%(145/267) respectively, without showing significant differences (allP> 0.05). The result of G test (ng/L) was not obviously changed after albumin administration compared with that before in without IFI, possible IFI, hypotheticle IFI, and proven IFI groups (without IFI group: 11.25±2.33 vs. 10.99±1.07,t= -1.723,P= 0.085; possible IFI group: 53.14±5.53 vs. 49.22±8.11,t= -0.395,P= 0.693; hypotheticle IFI group: 90.30±9.38 vs. 85.41±10.11, t= 710.500,P= 0.860; proven IFI group: 100.98±19.24 vs. 103.21±17.66,t= 653.000,P= 0.449). Prior to the administration of albumin, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and Youden index were 79.8%, 87.9%, 45.6%, 96.7%, 67.7%, respectively. However, after the administration of albumin, they were 81.5%, 85.7%, 44.8%, 96.5%, and 67.2%, respectively, without significant difference.Conclusions G test is method for early diagnosis of IFI. The sensitivity and specificity are higher with 20 ng/L as the critical value. The result of G test is not interfered by albumin administration.