Meng Yanming, Kang Mei, Li Dongdong, Wang Tingting, Kuang Ziwei, Ma Ying
Sichuan University, West China Hospital, Department of Laboratory Medicine, Chengdu, China.
Rev Inst Med Trop Sao Paulo. 2020;62:e25. doi: 10.1590/S1678-9946202062025. Epub 2020 May 11.
Candida is one of the most frequent pathogens of bloodstream infections, which is associated with high morbidity and mortality rates. Rapid immunological detection methods are essential in the early diagnosis of candidemia. Anti-mannan is one of host-derived biomarkers against cell wall components of Candida. We conducted this study to evaluate the diagnostic performance of two anti-mannan assays (IgM, IgG) for candidemia through the analysis of 40 candidemia patients, 48 participants with Candida colonization and 213 participants with neither Candida colonization nor Candida infections (13 patients with other bloodstream infections, 145 hospitalized patients and 55 healthy controls). The performance of the two assays were evaluated by calculating their sensitivity and specificity. The sensitivity ranged from 0.78 to 0.80 for the IgM assay and 0.68 to 0.75 for the IgG assay. The specificity ranged from 0.97 to 0.98 for the IgM assay and 0.91 to 0.94 for the IgG assay. The diagnostic performance of the anti-mannan IgM assay was better than that of IgG, with higher sensitivity and specificity. Combining the two assays (positive results of single or both assays are both considered as positive) could improve the sensitivity up to 0.93 (0.79-0.98) and only slightly reduce the specificity (0.93(0.89-0.95)). The anti-mannan IgM, IgG assays are rapid and cost-effective assays that may be probably useful in the diagnosis of candidemia.
念珠菌是血流感染最常见的病原体之一，与高发病率和死亡率相关。快速免疫检测方法对念珠菌血症的早期诊断至关重要。抗甘露聚糖是一种针对念珠菌细胞壁成分的宿主来源生物标志物。我们通过分析40例念珠菌血症患者、48例念珠菌定植参与者和213例既无念珠菌定植也无念珠菌感染的参与者（13例其他血流感染患者、145例住院患者和55例健康对照），开展本研究以评估两种抗甘露聚糖检测方法（IgM、IgG）对念珠菌血症的诊断性能。通过计算其敏感性和特异性来评估这两种检测方法的性能。IgM检测方法的敏感性范围为0.78至0.80，IgG检测方法为0.68至0.75。IgM检测方法的特异性范围为0.97至0.98，IgG检测方法为0.91至0.94。抗甘露聚糖IgM检测方法的诊断性能优于IgG，具有更高的敏感性和特异性。联合两种检测方法（单项或两项检测结果为阳性均视为阳性）可将敏感性提高至0.93（0.79 - 0.98），且仅略微降低特异性（0.93(0.89 - 0.95)）。抗甘露聚糖IgM、IgG检测方法快速且具有成本效益，可能对念珠菌血症的诊断有用。
