Analysis of Clinical Characteristics and Diagnostic Value of Fungal Serology in Patients with Invasive Candidiasis

Objective: To evaluate the diagnostic value of (1 - 3)-β-D glucan and mannan assay for invasive candidiasis. Methods: A retrospective study was conducted on 32 cases in the disease group (18 proven invasive candidiasis and 14 probable invasive candidiasis) and 48 cases in the control group. The subjects were recruited from January 2018 to March 2019 in Clinical Laboratory of Hainan General Hospital. All subjects were detected by (1 - 3)-β-D glucan and mannan assay. Results: The mean concentration of (1 - 3)-β-D glucan in the disease group was 97.45 (43.23, 224.35) pg/ml and it was significantly higher than the mean concentration of the control group which was 49.85(41.91, 56.07) pg/ml (P = 0.005). The mean concentration of mannan in the disease group and the control group were 161.36 (34.96, 224.49) pg/ml and 25.80 (25.00, 29.31) pg/ml, respectively, which were significantly different (P < 0.001). The sensitivity, specificity, positive predictive value and negative predictive value of (1 - 3)-β-D glucan assay were 59.38%, 89.58%, 79.17%, 76.79%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of mannan assay were 65.63%, 95.83%, 91.30%, 80.70%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of combination of two types of assays were 81.25%, 85.42%, 78.79% and 87.23%, respectively. Conclusions: Combination of (1 - 3)-β-D glucan and mannan assay can improve diagnostic specificity and it has essential clinical diagnostic value for invasive candidiasis.

兔肺隐球菌感染模型制作及荚膜多糖胶体金免疫层析法的诊断价值

目的 探讨兔肺隐球菌感染模型制作方法及隐球菌荚膜多糖 （Crag）胶体金免疫层析法 （LFA）对肺隐球菌感染的诊断价值。方法 将36只新西兰大白兔随机分为免疫抑制组20只,免疫正常组10只和对照组6只。采用气管穿刺法对免疫抑制组及免疫正常组进行隐球菌菌种接种,对照组气管内注射生理盐水,免疫抑制组于实验第1-5天每日静脉注射阿糖胞苷,之后隔日1次维持免疫抑制状态;第4日起,每日1次万古霉素、头孢他定静脉注射,隔日1次庆大霉素静脉注射,预防细菌感染。免疫正常组及对照组未注射免疫抑制剂及抗生素。接种1周后抽取静脉血行CragLFA、1-3-β-D-葡聚糖检测 （G试验）、半乳甘露聚糖 （GM试验）,并行胸部CT扫描,之后处死取肺灌洗液行隐球菌荚膜抗原胶体金试验、肺组织进行病原菌培养、肺组织病理检查。结果 胸部CT检查免疫抑制组阳性率75% （15/20）,免疫正常组阳性率20% （2/10）,而且免疫抑制组出现磨玻璃影及斑片影、血管支气管束增粗、结节等多种表现,免疫正常组主要表现为结节影;隐球菌培养免疫抑制组阳性率100% （20/20）,免疫正常组阳性率30% （3/10）;病理检查免疫抑制组阳性率80% （16/20）,免疫正常组阳性率30% （3/10）;空白对照组6只兔子全部检查均阴性。免疫抑制组新型隐球菌组模型建立成功率为80 00% （16/20）,免疫正常组的成功率为30 00% （3/10）,两组差异有统计学意义 （P 〈0.05）;血清CragLFA敏感度为89 47%,特异度为100%;灌洗液CragLFA敏感度为100%,特异度为82 35%。G试验及GM试验均为阴性。结论 免疫功能抑制宿主更容易感染肺隐球菌。血清及肺泡灌洗液CragLFA对诊断肺隐球菌病均有较高的应用价值,特别是两者联合应用时。G试验、GM试验在肺隐球菌感染中多为阴性。